World Library  
Flag as Inappropriate
Email this Article

Lead poisoning

Lead poisoning
An X ray demonstrating the characteristic finding of lead poisoning in humans—dense metaphyseal lines.
Classification and external resources
Specialty Toxicology
ICD-10 T56.0
ICD-9-CM 984.9
DiseasesDB 7307
MedlinePlus 002473
eMedicine article/815399
MeSH D007855

Lead poisoning, also known as plumbism, colica pictorum, saturnism, heart, bones, intestines, kidneys, and reproductive and nervous systems. It interferes with the development of the nervous system and is therefore particularly toxic to children, causing potentially permanent learning and behavior disorders. Symptoms include abdominal pain, confusion, headache, anemia, irritability, and in severe cases seizures, coma, and death. Routes of exposure to lead include contaminated air, water, soil, food, and consumer products. Occupational exposure is a common cause of lead poisoning in adults. According to estimates made by the National Institute of Occupational Safety and Health (NIOSH), more than 3 million workers in the United States are potentially exposed to lead in the workplace.[1] One of the largest threats to children is lead paint that exists in many homes, especially older ones; thus children in older housing with chipping paint or lead dust from moveable window frames with lead paint are at greater risk. Prevention of lead exposure can range from individual efforts (e.g., removing lead-containing items such as piping or blinds from the home) to nationwide policies (e.g., laws that ban lead in products, reduce allowable levels in water or soil, or provide for cleanup and mitigation of contaminated soil, etc.) Elevated lead in the body can be detected by the presence of changes in blood cells visible with a microscope and dense lines in the bones of children seen on X-ray, but the main tool for diagnosis is measurement of the blood lead level by means of a "heavy metals screen." When blood lead levels are recorded, the results indicate how much lead is circulating within the blood stream, not the amount stored in the body.[2] There are two units for reporting blood lead level, either micrograms per deciliter (µg/dl), or micrograms per 100 grams (µg/100 g) of whole blood, which are numerically equivalent. The Centers for Disease Control (US) has set the standard elevated blood lead level for adults to be 10 µg/dl of the whole blood. For children the number is set much lower at 5 µg/dl of blood as of 2012[3] down from a previous 10 µg/dl.[4] Children are especially prone to the health effects of lead. As a result, blood lead levels must be set lower and closely monitored if contamination is possible.[2] The major treatments are removal of the source of lead and chelation therapy, which consists of administration of agents that bind lead so it can be excreted from the body. Humans have been mining and using this heavy metal for thousands of years, poisoning themselves in the process. Although lead poisoning is one of the oldest known work and environmental hazards, the modern understanding of the small amount of lead necessary to cause harm did not come about until the latter half of the 20th century. No safe threshold for lead exposure has been discovered—that is, there is no known sufficiently small amount of lead that will not cause harm to the body.


  • Classification 1
  • Signs and symptoms 2
    • Acute poisoning 2.1
    • Chronic poisoning 2.2
    • Effects on children 2.3
    • Complications 2.4
      • Kidneys 2.4.1
      • Cardiovascular system 2.4.2
      • Reproductive system 2.4.3
      • Nervous system 2.4.4
  • Exposure routes 3
    • Occupational exposure 3.1
    • Paint 3.2
    • Soil 3.3
    • Water 3.4
    • Lead-containing products 3.5
    • Hunting 3.6
  • Pathophysiology 4
    • Enzymes 4.1
    • Neurons 4.2
  • Diagnosis 5
    • Reference levels 5.1
  • Prevention 6
  • Treatment 7
  • Epidemiology 8
  • Prognosis 9
    • Reversibility 9.1
    • Encephalopathy 9.2
    • Long-term 9.3
  • History 10
  • Notable cases 11
  • Other species 12
    • Wildlife 12.1
  • Notes 13
  • External links 14


Classically, "lead poisoning" or "lead intoxication" has been defined as exposure to high levels of lead typically associated with severe health effects.[5] Poisoning is a pattern of symptoms that occur with toxic effects from mid to high levels of exposure; toxicity is a wider spectrum of effects, including subclinical ones (those that do not cause symptoms).[6] However, professionals often use "lead poisoning" and "lead toxicity" interchangeably, and official sources do not always restrict the use of "lead poisoning" to refer only to symptomatic effects of lead.[6]

The amount of lead in the blood and tissues, as well as the time course of exposure, determine toxicity.[7] Lead poisoning may be acute (from intense exposure of short duration) or chronic (from repeat low-level exposure over a prolonged period), but the latter is much more common.[8] Diagnosis and treatment of lead exposure are based on blood lead level (the amount of lead in the blood), measured in micrograms of lead per deciliter of blood (μg/dL). Urine lead levels may be used as well, though less commonly. In cases of chronic exposure lead often sequesters in the highest concentrations first in the bones, then in the kidneys. If a provider is performing a provocative excretion test, or "chelation challenge", a measurement obtained from urine rather than blood is likely to provide a more accurate representation of total lead burden to a skilled interpreter.[9]

The US central nervous system predominantly.[14]

Signs and symptoms

Symptoms of lead poisoning.

Lead poisoning can cause a variety of insomnia, delirium, cognitive deficits, tremor, hallucinations, and convulsions.[14] Symptoms may be different in adults and children; the main symptoms in adults are headache, abdominal pain, memory loss, kidney failure, male reproductive problems, and weakness, pain, or tingling in the extremities.[20]

Early symptoms of lead poisoning in adults are commonly nonspecific and include depression, loss of appetite, intermittent abdominal pain, nausea, diarrhea, constipation, and muscle pain.[21] Other early signs in adults include malaise, fatigue, decreased libido, and problems with sleep.[15] An unusual taste in the mouth and personality changes are also early signs.[22]

In adults, symptoms can occur at levels above 40 μg/dL, but are more likely to occur only above 50–60 μg/dL.[15] Symptoms begin to appear in children generally at around 60 μg/dL.[23] However, the lead levels at which symptoms appear vary widely depending on unknown characteristics of each individual.[24] At blood lead levels between 25 and 60 μg/dL, neuropsychiatric effects such as delayed reaction times, irritability, and difficulty concentrating, as well as slowed motor nerve conduction and headache can occur.[25] Anemia may appear at blood lead levels higher than 50 μg/dL.[21] In adults, abdominal colic, involving paroxysms of pain, may appear at blood lead levels greater than 80 μg/dL.[16] Signs that occur in adults at blood lead levels exceeding 100 μg/dL include wrist drop and foot drop, and signs of encephalopathy (a condition characterized by brain swelling), such as those that accompany increased pressure within the skull, delirium, coma, seizures, and headache.[26] In children, signs of encephalopathy such as bizarre behavior, discoordination, and apathy occur at lead levels exceeding 70 μg/dL.[26] For both adults and children, it is rare to be asymptomatic if blood lead levels exceed 100 μg/dL.[16]

Acute poisoning

In acute poisoning, typical neurological signs are pain, muscle weakness, paraesthesia, and, rarely, symptoms associated with encephalitis.[20] Abdominal pain, nausea, vomiting, diarrhea, and constipation are other acute symptoms.[27] Lead's effects on the mouth include astringency and a metallic taste.[27] Gastrointestinal problems, such as constipation, diarrhea, poor appetite, or weight loss, are common in acute poisoning. Absorption of large amounts of lead over a short time can cause shock (insufficient fluid in the circulatory system) due to loss of water from the gastrointestinal tract.[27] Hemolysis (the rupture of red blood cells) due to acute poisoning can cause anemia and hemoglobin in the urine.[27] Damage to kidneys can cause changes in urination such as decreased urine output.[27] People who survive acute poisoning often go on to display symptoms of chronic poisoning.[27]

Chronic poisoning

Chronic poisoning usually presents with symptoms affecting multiple systems,[14] but is associated with three main types of symptoms: gastrointestinal, neuromuscular, and neurological.[20] Central nervous system and neuromuscular symptoms usually result from intense exposure, while gastrointestinal symptoms usually result from exposure over longer periods.[27] Signs of chronic exposure include loss of short-term memory or concentration, depression, nausea, abdominal pain, loss of coordination, and numbness and tingling in the extremities.[22] Fatigue, problems with sleep, headaches, stupor, slurred speech, and anemia are also found in chronic lead poisoning.[20] A "lead hue" of the skin with pallor and/or lividity is another feature.[28][29] A blue line along the gum with bluish black edging to the teeth, known as a Burton line, is another indication of chronic lead poisoning.[30] Children with chronic poisoning may refuse to play or may have hyperkinetic or aggressive behavior disorders.[20] Visual disturbance may present with gradually progressing blurred vision as a result of central scotoma, caused by toxic optic neuritis.[31]

Effects on children

A fetus developing in the womb of a woman who has elevated blood lead level is susceptible to lead poisoning by intrauterine exposure, and is at greater risk of being born prematurely or with a low birth weight.[32]

Children are more at risk for lead poisoning because their smaller bodies are in a continuous state of growth and development.[33] Lead is absorbed at a faster rate compared to adults, which causes more physical harm than to older people. Furthermore, children, especially as they are learning to crawl and walk, are constantly on the floor and therefore more prone to ingesting and inhaling dust that is contaminated with lead.[34]

The classic signs and symptoms in children are loss of appetite, abdominal pain, vomiting, weight loss, constipation, anemia, kidney failure, irritability, lethargy, learning disabilities, and behavioral problems.[33] Slow development of normal childhood behaviors, such as talking and use of words, and permanent intellectual disability are both commonly seen.[32] Although less common, it is possible for fingernails to develop leukonychia striata if exposed to abnormally high lead concentrations.[35]


Lead affects every one of the body's organ systems, especially the nervous system, but also the bones and teeth, the kidneys, and the cardiovascular, immune, and reproductive systems.[36] Hearing loss and tooth decay have been linked to lead exposure,[37] as have cataracts.[38] Intrauterine and neonatal lead exposure promote tooth decay.[39][40][41][42][43][44][45] Aside from the developmental effects unique to young children, the health effects experienced by adults are similar to those in children, although the thresholds are generally higher.[46]


Kidney damage occurs with exposure to high levels of lead, and evidence suggests that lower levels can damage kidneys as well.[47] The toxic effect of lead causes nephropathy and may cause Fanconi syndrome, in which the proximal tubular function of the kidney is impaired.[48] Long-term exposure at levels lower than those that cause lead nephropathy have also been reported as nephrotoxic in patients from developed countries that had chronic kidney disease or were at risk because of hypertension or diabetes mellitus.[49] Lead poisoning inhibits excretion of the waste product urate and causes a predisposition for gout, in which urate builds up.[50][51][52] This condition is known as saturnine gout.

Cardiovascular system

Evidence suggests lead exposure is associated with high blood pressure, and studies have also found connections between lead exposure and coronary heart disease, heart rate variability, and death from stroke, but this evidence is more limited.[53] People who have been exposed to higher concentrations of lead may be at a higher risk for cardiac autonomic dysfunction on days when ozone and fine particles are higher.[54]

Reproductive system

Lead affects both the male and female reproductive systems. In men, when blood lead levels exceed 40 μg/dL, sperm count is reduced and changes occur in volume of sperm, their motility, and their morphology.[55] A pregnant woman's elevated blood lead level can lead to miscarriage, prematurity, low birth weight, and problems with development during childhood.[56] Lead is able to pass through the placenta and into breast milk, and blood lead levels in mothers and infants are usually similar.[18] A fetus may be poisoned in utero if lead from the mother's bones is subsequently mobilized by the changes in metabolism due to pregnancy; increased calcium intake in pregnancy may help mitigate this phenomenon.[57]

Nervous system

Eight MRI views of a brain in black and white, with yellow, orange, and red areas overlaid in spots mainly toward the front.
The brains of adults who were exposed to lead as children show decreased volume, especially in the prefrontal cortex, on MRI. Areas of volume loss are shown in color over a template of a normal brain.[58]

Lead affects the

  • Binns, H.J.; Ricks, O.B. "Helping Parents Prevent Lead Poisoning". ERIC Digest. 
  • Agency for Toxic Substances and Disease Registry (August 20, 2007). "Lead Toxicity". Environmental Health and Medicine Education. U.S.  
  • National Pollutant Inventory. "Lead and compounds: Health effects". Fact Sheets. Canberra, Australia: Department of Sustainability, Environment, Water, Population and Communities. 
  • National Institute for Occupational Safety and Health. "Lead". NIOSH Workplace Safety & Health Topics. Centers for Disease Control and Prevention. 
  • Katz, N.L. (June 26, 2007). "City payout to Brooklyn family largest ever in lead poisoning". NY Daily News. 
  • Karalus, Daniel E (2010). "Review: The Great Lead Water Pipe Disaster". Electronic Green Journal 1 (29). 
  • Health and Safety Executive UK. "Lead". Working safely with lead. HSE. 

External links

  • Brunton, L.L.; Goodman, L.S.; Blumenthal, D.; Buxton, I.; Parker, K.L., ed. (2007). "Principles of toxicology". Goodman and Gilman's Manual of Pharmacology and Therapeutics. McGraw-Hill Professional.  
  • Casarett, LJ; Klaassen, CD; Doull, J, ed. (2007). "Toxic effects of metals". Casarett and Doull's Toxicology: The Basic Science of Poisons (7th ed.). McGraw-Hill Professional.  
  • Chisolm, J.J. (2004). "Lead poisoning". In Crocetti, M.; Barone, M.A.; Oski, F.A. Oski's Essential Pediatrics (2nd ed.). Lippincott Williams & Wilkins.  
  • Dart, R.C.; Hurlbut, K.M.; Boyer-Hassen, L.V. (2004). "Lead". In Dart, RC. Medical Toxicology (3rd ed.). Lippincott Williams & Wilkins.  
  • Grant, L.D. (2009). "Lead and compounds". In Lippmann, M. Environmental Toxicants: Human Exposures and Their Health Effects (3rd ed.). Wiley-Interscience.  
  • Henretig F.M. (2006). "Lead". In Goldfrank, LR. Goldfrank's Toxicologic Emergencies (8th ed.). McGraw-Hill Professional.  
  • Hodge, A. Trevor (1992). Roman Aqueducts & Water Supply. London: Duckworth.  
  • Kosnett M.J. (2005). "Lead". In Brent, J. Critical Care Toxicology: Diagnosis and Management of the Critically Poisoned Patient. Gulf Professional Publishing.  
  • Kosnett, M.J. (2007). "Heavy metal intoxication and chelators". In Katzung, B.G. Basic and Clinical Pharmacology. McGraw-Hill Professional.  
  • Kosnett, M.J. "Lead". In Olson, K.R. Poisoning and Drug Overdose (5th ed.). McGraw-Hill Professional. p. 2006.  
  • Menkes, J.H. (2006). "Toxic and nutritional disorders". In Menkes, J.H.; Sarnat, H.B.; Maria, B.L. Child Neurology (7th ed.). Lippincott Williams & Wilkins. p. 706.  
  • Merrill, J.C.; Morton, J.J.P.; Soileau, S.D. (2007). "Metals". In Hayes, A.W. Principles and Methods of Toxicology (5th ed.). CRC Press.  
  • Mycyk, M.; Hryhorczuk, D.; Amitai, Y. (2005). "Lead". In Erickson, TB; Ahrens, WR; Aks, S; Ling, L. Pediatric Toxicology: Diagnosis and Management of the Poisoned Child. McGraw-Hill Professional.  
  • Olson, K.R. (2007). "Poisoning". In McPhee, S.J.; Tierney, L.M.; Papadakis, M.A. Current Medical Diagnosis and Treatment (46th ed.). McGraw-Hill Professional.  
  • Pearson H.A.; Schonfeld, D.J. (2003). "Lead". In Rudolph, C.D. Rudolph's Pediatrics (21st ed.). McGraw-Hill Professional.  
  • Rambousek, A.J., ed. (2008). "The symptoms and treatment of industrial poisoning". Industrial Poisoning from Fumes, Gases, and Poisons of Manufacturing Processes. READ BOOKS.  
  • Rubin, R.; Strayer, D.S., ed. (2008). "Environmental and nutritional pathology". Rubin's Pathology: Clinicopathologic Foundations of Medicine (5th ed.). Lippincott Williams & Wilkins.  
  • Salvato, J.A.; Nemerow, N.L.; Agardy, F.J., ed. (2003). "Noninfectious and noncommunicable diseases and conditions associated with the environment, including air, water, and food". Environmental Engineering (5th ed.). John Wiley and Sons.  
  • Trevor, A.J.; Katzung, B.G.; Masters, S.B., ed. (2007). "Heavy metals". Katzung & Trevor's Pharmacology: Examination & Board Review (8th ed.). McGraw-Hill Professional.  
  • Yu, M.H. (2005). "Soil and water pollution: Environmental metals and metalloids". Environmental Toxicology: Biological and Health Effects of Pollutants. CRC Press.  


  1. ^ Staudinger KC, Roth VS (1998). "Occupational lead poisoning". Am Fam Physician 57 (4): 719–26, 731–2.  
  2. ^ a b Blood Lead Level Testing, Department of Ecology State of Washington. 2011
  3. ^ a b "Advisory Committee On Childhood Lead Poisoning Prevention (ACCLPP)". CDC. May 2012. Retrieved 18 May 2012. 
  4. ^ a b "Low Level Lead Exposure Harms Children: A Renewed Call for Primary Prevention" (PDF). Centers for Disease Control and Prevention. Retrieved 5 January 2012. 
  5. ^ Grant (2009) p. 785
  6. ^ a b c d e f g Guidotti, TL; Ragain, L (2007). "Protecting children from toxic exposure: three strategies". Pediatric clinics of North America 54 (2): 227–35, vii.  
  7. ^ a b c d e Pearson, Schonfeld (2003) p.369
  8. ^ Trevor, Katzung, Masters (2007) p. 479
  10. ^ a b c d e f g h i j k Rossi, E (2008). "Low Level Environmental Lead Exposure – A Continuing Challenge". The Clinical biochemist. Reviews / Australian Association of Clinical Biochemists 29 (2): 63–70.  
  11. ^ a b c d e Barbosa Jr, F; Tanus-Santos, JE; Gerlach, RF; Parsons, PJ (2005). "A Critical Review of Biomarkers Used for Monitoring Human Exposure to Lead: Advantages, Limitations, and Future Needs". Environmental health perspectives 113 (12): 1669–74.  
  12. ^ a b c Ragan, P; Turner, T (2009). "Working to prevent lead poisoning in children: getting the lead out". JAAPA 22 (7): 40–5.  
  13. ^ Grant (2009) p. 761
  14. ^ a b c d e f g h i j k Kosnett (2007) p. 948
  15. ^ a b c d e f g h Karri, SK; Saper, RB; Kales, SN (2008). "Lead Encephalopathy Due to Traditional Medicines". Current drug safety 3 (1): 54–9.  
  16. ^ a b c d e Kosnett (2005) p. 825
  17. ^ a b c d e Mycyk, Hryhorczuk, Amitai (2005) p. 463
  18. ^ a b c d e f g h i Dart, Hurlbut, Boyer-Hassen (2004) p. 1426
  19. ^ Timbrell, J.A., ed. (2008). "Biochemical mechanisms of toxicity: Specific examples". Principles of Biochemical Toxicology (4th ed.). Informa Health Care.  
  20. ^ a b c d e f g h i Pearce, JM (2007). "Burton's line in lead poisoning". European neurology 57 (2): 118–9.  
  21. ^ a b c d Merrill, Morton, Soileau (2007) p. 860
  22. ^ a b c d e f g h i j k l m n o p Patrick, L (2006). "Lead toxicity, a review of the literature. Part 1: Exposure, evaluation, and treatment". Alternative medicine review : a journal of clinical therapeutic 11 (1): 2–22.  
  23. ^ a b c d e f g h i j k Needleman, H (2004). "Lead poisoning". Annual review of medicine 55: 209–22.  
  24. ^ a b c d e f g Bellinger, DC (2004). "Lead". Pediatrics 113 (4 Suppl): 1016–22.  
  25. ^ a b c Kosnett (2006) p.240
  26. ^ a b Henretig (2006) p. 1314
  27. ^ a b c d e f g h i j k l Brunton (2007) p. 1131
  28. ^ James, William; Berger, Timothy; Elston, Dirk (2005). Andrews' Diseases of the Skin: Clinical Dermatology. (10th ed.). Saunders. ISBN 0-7216-2921-0. :859
  29. ^ El Safoury, OmarSoliman; Abd El Fatah, DinaSabry; Ibrahim, Magdy (2009). "Treatment of periocular hyperpigmentation due to lead of kohl (surma) by penicillamine: A single group non-randomized clinical trial". Indian Journal of Dermatology 54 (4): 361.  
  30. ^ Rambousek (2008) p.177
  31. ^ Review of Ophthalmology® > Wills Eye Resident Case Series. Retrieved on 2015-04-23.
  32. ^ a b J. Chisolm, H. Harrison. (1956-12-01) "The Exposure of Children to Lead," Journal of the American Academy of Pediatrics.Vol. 18. pp. 943 -958
  33. ^ a b Landrigan, PJ; Schechter, CB; Lipton, JM; Fahs, MC; Schwartz, J (2002). "Environmental pollutants and disease in American children". Environmental health perspectives 110 (7): 721–8.  
  34. ^ Woolf, AD; Goldman, R; Bellinger, DC (2007). "Update on the clinical management of childhood lead poisoning". Pediatric clinics of North America 54 (2): 271–94, viii.  
  35. ^ Baran, Robert et al. (2012) Baran and Dawber’s Diseases of the Nails and Their Management. John Wiley & Sons. ISBN 1118286707. p. 417.
  36. ^ a b White, LD; Cory-Slechta, DA; Gilbert, ME; Tiffany-Castiglioni, E; Zawia, NH; Virgolini, M; Rossi-George, A; Lasley, SM; et al. (2007). "New and evolving concepts in the neurotoxicology of lead". Toxicology and applied pharmacology 225 (1): 1–27.  
  37. ^ a b c Lanphear, BP; Hornung, R; Khoury, J; Yolton, K; Baghurst, P; Bellinger, DC; Canfield, RL; Dietrich, KN; et al. (2005). "Low-Level Environmental Lead Exposure and Children's Intellectual Function: An International Pooled Analysis". Environmental health perspectives 113 (7): 894–9.  
  38. ^ a b c d e f g h i Pokras, MA; Kneeland, MR (2008). "Lead poisoning: using transdisciplinary approaches to solve an ancient problem". EcoHealth 5 (3): 379–85.  
  39. ^ Brudevold F, Steadman LT (1956). "The distribution of lead in human enamel" (PDF). J Dent Res 35 (3): 430–437.  
  40. ^ Brudevold F, Aasenden R, Srinivasian BN, Bakhos Y (1977). "Lead in enamel and saliva, dental caries, and the use of enamel biopsies for mesuring past exposure to lead" (PDF). J Dent Res 56 (10): 1165–1171.  
  41. ^ Goyer RA (1990). "Transplacental transport of lead". Environ Health Perspect (Environmental Health Perspectives, Vol. 89) 89: 101–105.  
  42. ^ Moss ME, Lamphear BP, Auinger P (1999). "Association of dental caries and blood lead levels". JAMA 281 (24): 2294–2298.  
  43. ^ Campbell JR, Moss ME, Raubertas RF (2000). "The association between caries and childhood lead exposure". Environ Health Perspect (Environmental Health Perspectives, Vol. 108, No. 11) 108 (11): 1099–1102.  
  44. ^ Gemmel A, Tavares M, Alperin S, Soncini J, Daniel D, Dunn J,Crawford S, Braveman N, Clarkson TW, McKinlay S, Bellinger DC (2002). "Blood lead level and dental caries in school-age children". Environ Health Perspect 110 (10): A625–A630.  
  45. ^ Billings RJ, Berkowitz RJ, Watson G (2004). "Teeth" (PDF). Pediatrics 113 (4): 1120–1127.  
  46. ^ Agency for Toxic Substances and Disease Registry (August 20, 2007). "Lead Toxicity: Who Is at Risk of Lead Exposure?". Environmental Health and Medicine Education. U.S. Department of Health and Human Services. Course: WB 1105. 
  47. ^ a b Grant (2009) p. 789
  48. ^ a b c Rubin, Strayer (2008) p. 267
  49. ^ Ekong, EB; Jaar, BG; Weaver, VM (2006). "Lead-related nephrotoxicity: a review of the epidemiologic evidence". Kidney international 70 (12): 2074–84.  
  50. ^ Wright, LF; Saylor, RP; Cecere, FA (1984). "Occult lead intoxication in patients with gout and kidney disease". The Journal of rheumatology 11 (4): 517–20.  
  51. ^ Lin JL, Huang PT (1994). "Body lead stores and urate excretion in men with chronic renal disease". J. Rheumatol. 21 (4): 705–9.  
  52. ^ Shadick NA, Kim R, Weiss S, Liang MH, Sparrow D, Hu H (2000). "Effect of low level lead exposure on hyperuricemia and gout among middle aged and elderly men: the normative aging study". J. Rheumatol. 27 (7): 1708–12.  
  53. ^ Navas-Acien, A; Guallar, E; Silbergeld, EK; Rothenberg, SJ (2007). "Lead Exposure and Cardiovascular Disease—A Systematic Review". Environmental health perspectives 115 (3): 472–82.  
  54. ^ Park, SK; O'Neill, MS; Vokonas, PS; Sparrow, D; Wright, RO; Coull, B; Nie, H; Hu, H; et al. (2008). "Air Pollution and Heart Rate Variability: Effect Modification by Chronic Lead Exposure". Epidemiology (Cambridge, Mass.) 19 (1): 111–20.  
  55. ^ Grant (2009) p. 792
  56. ^ a b c d e Cleveland, LM; Minter, ML; Cobb, KA; Scott, AA; German, VF (2008). "Lead hazards for pregnant women and children: part 1: immigrants and the poor shoulder most of the burden of lead exposure in this country. Part 1 of a two-part article details how exposure happens, whom it affects, and the harm it can do". The American journal of nursing 108 (10): 40–9; quiz 50.  
  57. ^ Bellinger, DC (2005). "Teratogen update: lead and pregnancy". Birth defects research. Part A, Clinical and molecular teratology 73 (6): 409–20.  
  58. ^ a b Cecil, KM; Brubaker, CJ; Adler, CM; Dietrich, KN; Altaye, M; Egelhoff, JC; Wessel, S; Elangovan, I; et al. (2008). Balmes, John, ed. "Decreased Brain Volume in Adults with Childhood Lead Exposure". PLoS medicine 5 (5): e112.  
  59. ^ a b c Meyer, PA; McGeehin, MA; Falk, H (2003). "A global approach to childhood lead poisoning prevention". International journal of hygiene and environmental health 206 (4–5): 363–9.  
  60. ^ a b Bellinger, DC (2008). "Very low lead exposures and children's neurodevelopment". Current Opinion in Pediatrics 20 (2): 172–7.  
  61. ^ Needleman, HL; Schell, A; Bellinger, D; Leviton, A; Allred, EN (1990). "The long-term effects of exposure to low doses of lead in childhood. An 11-year follow-up report". The New England Journal of Medicine 322 (2): 83–8.  
  62. ^ a b Merrill, Morton, Soileau (2007) p. 861
  63. ^ Casarett, Klaassen, Doull (2007) p. 944
  64. ^ Shih, RA; Hu, H; Weisskopf, MG; Schwartz, BS (2007). "Cumulative Lead Dose and Cognitive Function in Adults: A Review of Studies That Measured Both Blood Lead and Bone Lead". Environmental health perspectives 115 (3): 483–92.  
  65. ^ a b c Kosnett, MJ; Wedeen, RP; Rothenberg, SJ; Hipkins, KL; Materna, BL; Schwartz, BS; Hu, H; Woolf, A (2007). "Recommendations for Medical Management of Adult Lead Exposure". Environmental health perspectives 115 (3): 463–71.  
  66. ^ "Research Links Lead Exposure to Changes in Violent Crime Rates Throughout the 20th century" (PDF). ICF International. 
  67. ^ Nevin, R (2000). "How lead exposure relates to temporal changes in IQ, violent crime, and unwed pregnancy". Environmental research 83 (1): 1–22.  
  68. ^ Nevin, R (2007). "Understanding international crime trends: the legacy of preschool lead exposure". Environmental research 104 (3): 315–36.  
  69. ^ a b Vedantam, Shankar (July 8, 2007). "Research links lead exposure, criminal activity". Washington Post. Retrieved September 24, 2009. 
  70. ^ a b Mañay, N; Cousillas, AZ; Alvarez, C; Heller, T (2008). "Lead contamination in Uruguay: the "La Teja" neighborhood case". Reviews of environmental contamination and toxicology. Reviews of Environmental Contamination and Toxicology 195: 93–115.  
  71. ^ a b c d Sanborn, MD; Abelsohn, A; Campbell, M; Weir, E (2002). "Identifying and managing adverse environmental health effects: 3. Lead exposure". Canadian Medical Association Journal 166 (10): 1287–92.  
  72. ^ Watts, J (2009). "Lead poisoning cases spark riots in China". Lancet 374 (9693): 868.  
  73. ^ Jack Lewis (May 1985). "Lead Poisoning: A Historical Perspective". EPA. 
  74. ^ Deborah Blum (January 5, 2013). "Looney Gas and Lead Poisoning: A Short, Sad History". Wired. 
  75. ^ Kevin Drum (January 2013). "America's Real Criminal Element: Lead". Mother Jones. 
  76. ^ Dominic Casciani (April 20, 2014). "Did removing lead from petrol spark a decline in crime?". BBC. 
  77. ^ a b c d e f g Brodkin, E; Copes, R; Mattman, A; Kennedy, J; Kling, R; Yassi, A (2007). "Lead and mercury exposures: interpretation and action". Canadian Medical Association Journal 176 (1): 59–63.  
  78. ^ a b Dart, Hurlbut, Boyer-Hassen (2004) p. 1424
  79. ^ a b c d e f g Henretig (2006) p. 1310
  80. ^ a b c d e Gilbert, SG; Weiss, B (2006). "A rationale for lowering the blood lead action level from 10 to 2 μg/dL". Neurotoxicology 27 (5): 693–701.  
  81. ^ a b Jacobs, David E.; Clickner, Robert P.; Zhou, Joey Y.; Viet, Susan M.; Marker, David A.; Rogers, John W.; Zeldin, Darryl C.; Broene, Pamela; et al. (2002). "The prevalence of lead-based paint hazards in U.S. housing". Environmental Health Perspectives 110 (10): A599–606.  
  82. ^ a b c Dart, Hurlbut, Boyer-Hassen (2004) p. 1423
  83. ^ a b Kosnett (2006) p.241
  84. ^ a b c d Chisolm (2004) pp. 221–22
  85. ^ a b Salvato (2003) p.116
  86. ^
  87. ^ Barltrop D, Strehlow CD, Thornton I, Webb JS (November 1975). "Absorption of lead from dust and soil". Postgrad Med J 51 (601): 801–4.  
  88. ^ a b Woolf, AD; Goldman, R; Bellinger, DC (2007). "Update on the clinical management of childhood lead poisoning". Pediatric clinics of North America 54 (2): 271–94, viii.  
  89. ^ Murphy, K. (May 13, 2009). "For urban gardeners, lead is a concern". New York Times. Retrieved September 18, 2009. 
  90. ^ a b Yu (2005) p.188
  91. ^ Yu (2005) p.187
  92. ^ Menkes (2006) p.703
  93. ^ a b Maas, RP; Patch, SC; Morgan, DM; Pandolfo, TJ (2005). "Reducing lead exposure from drinking water: recent history and current status". Public Health Reports 120 (3): 316–21.  
  94. ^ "Alum Wins Investigative Reporting Award with Post Team".  
  95. ^ "HONORS". The Washington Post. February 23, 2005. 
  96. ^ "Mattel CEO: 'Rigorous standards' after massive toy recall". CNN. November 15, 2007. Retrieved September 26, 2009. 
  97. ^ Schep, LJ; Fountain, JS; Cox, WM; Pesola, GR (2006). "Lead shot in the appendix". The New England Journal of Medicine 354 (16): 1757; author reply 1757.  
  98. ^ Madsen, HH; Skjdt, T; Jrgensen, PJ; Grandjean, P (1988). "Blood lead levels in patients with lead shot retained in the appendix". Acta radiologica (Stockholm, Sweden : 1987) 29 (6): 745–6.  
  99. ^ Durlach, V; Lisovoski, F; Gross, A; Ostermann, G; Leutenegger, M (1986). "Appendicectomy in an unusual case of lead poisoning". Lancet 1 (8482): 687–8.  
  100. ^ Centers for Disease Control and Prevention (CDC) (2006). "Death of a child after ingestion of a metallic charm—Minnesota, 2006". MMWR. Morbidity and mortality weekly report 55 (12): 340–1.  
  101. ^ a b Salvato (2003) p.117
  102. ^ The Best Way To Solder Nitinol. (2011-02-28). Retrieved on 2011-12-03.
  103. ^ a b Hunt, WG; Watson, RT; Oaks, JL; Parish, CN; Burnham, KK; Tucker, RL; Belthoff, JR; Hart, G (2009). Zhang, Baohong, ed. "Lead Bullet Fragments in Venison from Rifle-Killed Deer: Potential for Human Dietary Exposure".  
  104. ^ Spitz, M; Lucato, LT; Haddad, MS; Barbosa, ER (2008). "Choreoathetosis secondary to lead toxicity". Arquivos de neuro-psiquiatria 66 (3A): 575–7.  
  105. ^ Dimaio, VJ; Dimaio, SM; Garriott, JC; Simpson, P (1983). "A fatal case of lead poisoning due to a retained bullet". The American journal of forensic medicine and pathology : official publication of the National Association of Medical Examiners 4 (2): 165–9.  
  106. ^ Fiorica, V; Brinker, JE (1989). "Increased lead absorption and lead poisoning from a retained bullet". The Journal of the Oklahoma State Medical Association 82 (2): 63–7.  
  107. ^ "Doubts over MSG and Lead Content in Maggi Instant Noodles". 19 May 2015. 
  108. ^ "Beware! Eating 2 -Minute Maggi Noodles can ruin your Nervous System". 18 May 2015. Retrieved 18 May 2015. 
  109. ^ "Maggi Noodles Packets Recalled Across Uttar Pradesh, Say Food Inspectors: Report".  
  110. ^ Sushmi Dey (16 May 2015). "‘Maggi’ under regulatory scanner for lead, MSG beyond permissible limit".  
  111. ^ "Delhi govt bans sales of Maggi from its stores: Report".  
  112. ^ IANS (June 4, 2015). "Gujarat bans Maggi noodles for 30 days".  
  113. ^ "Future Group bans Maggi too: The two-minute death of a India's favourite noodle brand".  
  114. ^ Iqbal, Shahed; Blumenthal W, Kennedy C, Yip FY, Pickard S, Flanders WD, Loringer K, Kruger K, Caldwell KL, Jean Brown M. (2009). "Hunting with lead: association between blood lead levels and wild game consumption". Environ Res 109 (8): 952–959.  
  115. ^ "No Danger of Lead Poisoning from Meat Obtained by Hunting". [2] ( 
  116. ^ a b Iqbal, Shahed. "Epi-AID Trip Report: Assessment of human health risk from consumption of wild game meat with possible lead contamination among the residents of the State of North Dakota" (PDF). Epi-AID Trip Report. National Center for Environmental Health, Centers for Disease Control and Prevention: Atlanta, Georgia, USA. Retrieved March 2, 2011. 
  117. ^ "Blood lead levels—United States, 1999–2002". MMWR Morb. Mortal. Wkly. Rep. 54 (20): 513–6. May 2005.  
  118. ^ "Lead Exposure in Wisconsin Birds" (PDF). Wisconsin department of natural resources. 3 September 2008. Retrieved 10 December 2012. 
  119. ^ Grant (2009) p. 767
  120. ^ Rubin, Strayer (2008) p. 266
  121. ^ a b c d e Hu, H; Shih, R; Rothenberg, S; Schwartz, BS (2007). "The Epidemiology of Lead Toxicity in Adults: Measuring Dose and Consideration of Other Methodologic Issues". Environmental health perspectives 115 (3): 455–62.  
  122. ^ a b Kosnett (2006) p.238
  123. ^ a b c Flora, SJ; Mittal, M; Mehta, A (2008). "Heavy metal induced oxidative stress & its possible reversal by chelation therapy". The Indian journal of medical research 128 (4): 501–23.  
  124. ^ Yu (2005) p.193
  125. ^ a b c Casarett, Klaassen, Doull (2007) p. 946
  126. ^ Fujita H, Nishitani C, Ogawa K (2002). "Lead, chemical porphyria, and heme as a biological mediator". Tohoku J. Exp. Med. 196 (2): 53–64.  
  127. ^ a b Mycyk, Hryhorczuk, Amitai (2005) p. 462
  128. ^ a b Kosnett (2005) p. 822
  129. ^ a b Xu, J; Yan, HC; Yang, B; Tong, LS; Zou, YX; Tian, Y (2009). "Effects of lead exposure on hippocampal metabotropic glutamate receptor subtype 3 and 7 in developmental rats". Journal of negative results in biomedicine 8: 5.  
  130. ^ Lidsky, Theodore; et al. (2003). "Lead neurotoxicity in children: basic mechanisms and clinical correlates". Brain 126 (Pt 1): 5–19.  
  131. ^ Sanders, T; Liu, Y; Buchner, V; Tchounwou, PB (2009). "Neurotoxic Effects and Biomarkers of Lead Exposure: A Review". Reviews on environmental health 24 (1): 15–45.  
  132. ^ "How Lead Changes the Brain to Impair Learning and Memory, How Lead Changes the Brain to Impair Learning and Memory". Johns Hopkins Bloomberg School of Public Health. Retrieved 2007-08-14. 
  133. ^ a b Henretig (2006) p. 1316
  134. ^ Fred HL, van Dijk HA. "Images of Memorable Cases: Case 81". Connexions. Retrieved August 25, 2009. 
  135. ^ Fischer C (2007). Kaplan Medical USMLE Steps 2 and 3 Notes: Internal Medicine, Hematology. pp. 176–177. 
  136. ^ Grant (2009) p. 784
  137. ^ Vaziri, ND (2008). "Mechanisms of lead-induced hypertension and cardiovascular disease". American journal of physiology. Heart and circulatory physiology 295 (2): H454–65.  
  138. ^ a b c Mycyk, Hryhorczuk, Amitai (2005) p. 464
  139. ^ Gwiazda, R; Campbell, C; Smith, D (2005). "A Noninvasive Isotopic Approach to Estimate the Bone Lead Contribution to Blood in Children: Implications for Assessing the Efficacy of Lead Abatement". Environmental health perspectives 113 (1): 104–10.  
  140. ^ Wu, A. (2006) Tietz Clinical Guide to Laboratory Tests, 4th ed., Saunders Elsevier, St. Louis, MO, pp. 658–659.
  141. ^ "NIOSH Adult Blood Lead Epidemiology & Surveillance (ABLES) program description. Cincinnati, OH: US Department of Health and Human Services, CDC, National Institute for Occupational Safety and Health".  
  142. ^ "Fourth National Report on Human Exposure to Environmental Chemicals. Updated Tables" (PDF). US Department of Health and Human Services. Atlanta, GA: September 2012. 
  143. ^ Baselt, Randall Clint (2008). Disposition of Toxic Drugs and Chemicals in Man (8th ed.). Biomedical Publications. pp. 823–6.  
  144. ^ a b c d e f g h Payne, M (2008). "Lead in drinking water". Canadian Medical Association Journal 179 (3): 253–4.  
  145. ^ National Environmental Public Health Tracking Network, 2010.
  146. ^ Yeoh, B; Woolfenden, S; Lanphear, B; Ridley, GF; Livingstone, N (15 December 2014). "Household interventions for preventing domestic lead exposure in children.". The Cochrane database of systematic reviews 12: CD006047.  
  147. ^ Chisamera, D (October 19, 2008). "EPA Sets Tightest Lead Air Emission Standard". eFluxMedia. 
  148. ^ "Polluted Kansas Town Seeks Federal Buyout".  
  149. ^ Treece Journal: Welcome to Our Town. Wish We Weren't Here. Saulny, S. New York Times, September 13, 2009
  150. ^ Kosnett (2006) p.242
  151. ^ Henretig (2006) p. 1321
  152. ^ Mycyk, Hryhorczuk, Amitai (2005) p. 465
  153. ^ a b Olson (2007) p.1658
  154. ^ Kosnett (2005) p. 832
  155. ^ Kosnett (2007) p. 949
  156. ^ Trevor, Katzung, Masters (2007) p. 480
  157. ^ a b c d e Lightfoot, TL; Yeager, JM (2008). "Pet bird toxicity and related environmental concerns". The veterinary clinics of North America. Exotic animal practice 11 (2): 229–59, vi.  
  158. ^ Menkes (2006) p.706
  159. ^ a b Meyer, PA; Brown, MJ; Falk, H (2008). "Global approach to reducing lead exposure and poisoning". Mutation research 659 (1–2): 166–75.  
  160. ^ a b Flora, SJ; Pachauri, V (Jul 2010). "Chelation in metal intoxication.". International journal of environmental research and public health 7 (7): 2745–88.  
  161. ^ a b Gracia RC, Snodgrass WR (January 2007). "Lead toxicity and chelation therapy". Am J Health Syst Pharm 64 (1): 45–53.  
  162. ^ Bradberry, S; Vale, A (2009). "A comparison of sodium calcium edetate (edetate calcium disodium) and succimer (DMSA) in the treatment of inorganic lead poisoning". Clinical toxicology (Philadelphia, Pa.) 47 (9): 841–58.  
  163. ^ Pearson, Schonfeld (2003) p.370
  164. ^ Lee, BK; Schwartz, BS; Stewart, W; Ahn, KD (1995). "Provocative chelation with DMSA and EDTA: evidence for differential access to lead storage sites". Occupational and Environmental Medicine 52 (1): 13–9.  
  165. ^ Herbert L. Needleman (June 28, 1999). "The Removal of Lead from Gasoline" (PDF). University of North Carolina. 
  166. ^ Global health risks : mortality and burden of disease attributable to selected major risks. (PDF). Geneva, Switzerland: World Health Organization. 2009. p. 24.  
  167. ^ Konradsen F, van der Hoek W, Cole DC, et al. (November 2003). "Reducing acute poisoning in developing countries—options for restricting the availability of pesticides". Toxicology 192 (2–3): 249–61.  
  168. ^ Jones, RL; Homa, DM; Meyer, PA; Brody, DJ; Caldwell, KL; Pirkle, JL; Brown, MJ (2009). "Trends in blood lead levels and blood lead testing among US children aged 1 to 5 years, 1988–2004". Pediatrics 123 (3): e376–85.  
  169. ^ Murata, K; Iwata, T; Dakeishi, M; Karita, K (2009). "Lead toxicity: does the critical level of lead resulting in adverse effects differ between adults and children?". Journal of occupational health 51 (1): 1–12.  
  170. ^ Chisolm (2004) p. 223
  171. ^ Merrill, Morton, Soileau (2007) p. 862
  172. ^ Needleman, H (2009). "Low level lead exposure: history and discovery". Annals of epidemiology 19 (4): 235–8.  
  173. ^ Prioreschi, P (1998). A History of Medicine, Volume 3 Of Roman Medicine. Horatius Press. p. 279.  
  174. ^ Couper RTL.; Fernandez, P. L.; Alonso, P. L. (2006). "The Severe Gout of Emperor Charles V". N Engl J Med 355 (18): 1935–36.  
  175. ^ Hodge 1992, p. 308
  176. ^ Delile, H.; Blichert-Toft, J.; Goiran, J. -P.; Keay, S.; Albarede, F. (2014). "Lead in ancient Rome's city waters". Proceedings of the National Academy of Sciences 111 (18): 6594.  
  177. ^ Ancient Rome's tap water heavily contaminated with lead, researchers say – The Guardian
  178. ^ Lead in Ancient Rome’s Water Was 100 Times Natural Levels – Discover
  179. ^ Director: Chris Warren (2004). Tales of the Living Dead: Poisoned Roman Babies (television). Brighton TV for National Geographic. 
  180. ^ Nriagu JO (1983). "Saturnine gout among Roman aristocrats. Did lead poisoning contribute to the fall of the Empire?".  
  181. ^ Scarborough, John (1984). The Myth of Lead Poisoning Among the Romans: An Essay Review
  182. ^ a b Hernberg, S (2000). "Lead poisoning in a historical perspective". American journal of industrial medicine 38 (3): 244–54.  
  183. ^ a b c d Eisinger, J (1982). "Lead and wine. Eberhard Gockel and the colica Pictonum". Medical history 26 (3): 279–302.  
  184. ^ Gochfeld, M (2005). "Chronologic history of occupational medicine". Journal of occupational and environmental medicine / American College of Occupational and Environmental Medicine 47 (2): 96–114.  
  185. ^ The mystery of Caravaggio's death solved at last – painting killed him, Tom Kington, The Guardian, Wednesday, 16 June 2010.
  186. ^ Varney, Tamara L, Murphy, A. Reginald et al. (October 2012). "A Preliminary Investigation of Lead Poisoning in a Napoleonic Era Naval Cemetery in Antigua, W.I." (PDF). Caribbean Connection 2. 
  187. ^ Curtin, Philip D. (November 1989). Death by Migration: Europe's Encounter with the Tropical World in the Nineteenth Century. pp. 78–79.  
  188. ^  
  189. ^ The Franklin Institute (2010). "Benjamin Franklin's Lead Letter," History's Lead Story
  190. ^ a b Mai, FM (2006). "Beethoven's terminal illness and death". The journal of the Royal College of Physicians of Edinburgh 36 (3): 258–63.  
  191. ^ Weiss, Rick Study Concludes Beethoven Died From Lead Poisoning, The Washington Post, December 6, 2005
  192. ^ Grant (2009) p. 757
  193. ^ Mycyk, Hryhorczuk, Amitai (2005) p. 467
  194. ^ Chiras, DD (2009). Environmental Science (8th ed.). Jones & Bartlett. p. 394.  
  195. ^ Grant (2009) p. 758
  196. ^ Agency for Toxic Substances and Disease Registry (August 20, 2007). "Lead Toxicity Cover Page". Environmental Health and Medicine Education. U.S. Department of Health and Human Services. Course: WB 1105. 
  197. ^ Kennedy, Donald (1997). Academic Duty. Harvard University Press. p. 237.  
  198. ^  
  199. ^ "Lead Poisoning Prevention Panel Influenced by Industry". The Center for Science and Democracy. Union of Concerned Scientists. 8 February 2004. Retrieved 8 October 2002. 
  200. ^ Markey, Edward J. (8 October 2002). "Turning Lead Into Gold: How the Bush Administration is Poisoning the Lead Advisory Committee at the CDC" (PDF). US House of Representatives. Archived from the original (PDF) on 24 October 2002. Retrieved 28 August 2014. 
  201. ^ Kleinberg, James (7 January 2014). "Judge Kleinberg's Order, final statement of decision, Case Number 1-00-CV-788657" (PDF). Santa Clara County Superior Court's Electronic Filing System. Retrieved 26 August 2014. 
  202. ^ Kleinberg, James (26 March 2014). "Judge Kleinberg's Order, Final Amended Judgment March 26, 2014, Case Number 1-00-CV-788657" (PDF). Santa Clara County Superior Court's Electronic Filing System. Retrieved 26 August 2014. 
  203. ^ "China to relocate 15,000 from lead-poisoned area". AFP. 2009-10-16. Archived from the original on 2009-10-19. Retrieved 2009-10-20. 
  204. ^ "China to move residents from lead smelter base-report". Reuters. 2009-10-18. Retrieved 2009-10-20. 
  205. ^ "Aid groups say lead poisoning has killed 400 children in Nigeria". Associated Press. 2010-10-05. Retrieved 2010-10-05. 
  206. ^ Redig, PT; Arent, LR (2008). "Raptor toxicology". The veterinary clinics of North America. Exotic animal practice 11 (2): 261–82, vi.  
  207. ^ Grant (2009) pp. 768, 771, 774
  208. ^ Neathery, MW; Miller, WJ (1975). "Metabolism and toxicity of cadmium, mercury, and lead in animals: a review".  
  209. ^ Ferreyra, H; Romano, M; Uhart, M (2009). "Recent and chronic exposure of wild ducks to lead in human-modified wetlands in Santa Fe Province, Argentina". Journal of wildlife diseases 45 (3): 823–7.  
  210. ^ Federal Cartridge Company Waterfowl and Steel Shot Guide. Volume I; 1988.
  211. ^ a b Degernes, LA (2008). "Waterfowl toxicology: a review". The veterinary clinics of North America. Exotic animal practice 11 (2): 283–300, vi.  
  212. ^ a b c Green, RE; Hunt, WG; Parish, CN; Newton, I; Pizzari, Tom (2008). Pizzari, Tom, ed. "Effectiveness of Action to Reduce Exposure of Free-Ranging California Condors in Arizona and Utah to Lead from Spent Ammunition". PLoS ONE 3 (12): e4022.  
  213. ^ "Get the Lead Out (Protecting the Condor)". California Department of Fish and Game. Retrieved 2009-07-28. 


The critically endangered California condor has also been affected by lead poisoning. As scavengers, condors eat carcasses of game that have been shot but not retrieved, and with them the fragments from lead bullets; this increases their lead levels.[212] Among condors around the Grand Canyon, lead poisoning due to eating lead shot is the most frequently diagnosed cause of death.[212] In an effort to protect this species, in areas designated as the California condor's range the use of projectiles containing lead has been banned to hunt deer, feral pigs, elk, pronghorn antelope, coyotes, ground squirrels, and other non-game wildlife.[213] Also, conservation programs exist which routinely capture condors, check their blood lead levels, and treat cases of poisoning.[212]

Lead, one of the leading causes of toxicity in waterfowl, has been known to cause die-offs of wild bird populations.[157] When hunters use lead shot, waterfowl such as ducks can ingest the spent pellets later and be poisoned; predators that eat these birds are also at risk.[209] Lead shot-related waterfowl poisonings were first documented in the US in the 1880s.[38] By 1919, the spent lead pellets from waterfowl hunting was positively identified as the source of waterfowl deaths.[210] Lead shot has been banned for hunting waterfowl in several countries,[38] including the US in 1991 and Canada in 1997.[211] Other threats to wildlife include lead paint, sediment from lead mines and smelters, and lead weights from fishing lines.[211] Lead in some fishing gear has been banned in several countries.[38]

A large tan bird of prey with dark brown neck feathers and a bare red head sits on a dead cow in a desert with dead grass and scrub
Turkey vultures, Cathartes aura (shown), and California condors can be poisoned when they eat carcasses of animals shot with lead pellets.


Farm animals such as cows and horses[208] as well as pet animals are also susceptible to the effects of lead toxicity.[157] Sources of lead exposure in pets can be the same as those that present health threats to humans sharing the environment, such as paint and blinds, and there is sometimes lead in toys made for pets.[157] Lead poisoning in a pet dog may indicate that children in the same household are at increased risk for elevated lead levels.[38]

Humans are not alone in suffering from lead's effects; plants and animals are also affected by lead toxicity to varying degrees depending on species.[90] Animals experience many of the same effects of lead exposure as humans do, such as abdominal pain, peripheral neuropathy, and behavioral changes such as increased aggression.[38] Much of what is known about human lead toxicity and its effects is derived from animal studies.[24] Animals are used to test the effects of treatments, such as chelating agents,[206] and to provide information on the pathophysiology of lead, such as how it is absorbed and distributed in the body.[207]

Other species

The Zamfara State lead poisoning epidemic occurred in Nigeria in 2010. As of October 5, 2010 at least 400 children have died from the effects of lead poisoning.[205]

15,000 people are being relocated from Jiyuan in central Henan province to other locations after 1000 children living around China's largest smelter plant (owned and operated by Yuguang Gold and Lead) were found to have excess lead in their blood. The total cost of this project is estimated to around 1 billion yuan ($150 million). 70% of the cost will be paid by local government and the smelter company, while the rest will be paid by the residents themselves. The government has suspended production at 32 of 35 lead plants.[203] The affected area includes people from 10 different villages.[204]

Notable cases

In 2014 a case by the state of California against a number of companies decided against Sherwin-Williams NL Industries and ConAgra and required them to pay $1.15 billion.[201][202]

In 2002 Tommy Thompson, secretary of Health and Human Services appointed at least two persons with conflicts of interest to the CDC's Lead Advisory Committee.[199][200]

In the 1980s Herbert Needleman was falsely accused of scientific misconduct by the Lead Industry Associates.[197][198]

The levels found today in most people are orders of magnitude greater than those of pre-industrial society.[22][62] Due to reductions of lead in products and the workplace, acute lead poisoning is rare in most countries today, but low level lead exposure is still common.[194] It was not until the second half of the 20th century that subclinical lead exposure became understood to be a problem.[182] During the end of the 20th century, the blood lead levels deemed acceptable steadily declined.[195] Blood lead levels once considered safe are now considered hazardous, with no known safe threshold.[71][196]

The 20th century saw an increase in worldwide lead exposure levels due to the increased widespread use of the metal.[192] Beginning in the 1920s, lead was added to gasoline to improve its combustion; lead from this exhaust persists today in soil and dust in buildings.[10] Blood lead levels worldwide have been declining sharply since the 1980s, when leaded gasoline began to be phased out.[10] In those countries that have banned lead in solder for food and drink cans and have banned leaded gasoline additives, blood lead levels have fallen sharply since the mid-1980s.[193]

In the 18th century lead poisoning was fairly frequent on account of the widespread drinking of rum, which was made in stills with a lead component (the "worm"). It was a significant cause of mortality amongst slaves and sailors in the colonial West Indies.[186][187] Lead poisoning from rum was also noted in Boston.[188] Benjamin Franklin suspected lead to be a risk in 1786.[189] Also in the 18th century, "Devonshire colic" was the name given to the symptoms suffered by people of Devon who drank cider made in presses that were lined with lead.[20] Lead was added to cheap wine illegally in the 18th and early 19th centuries as a sweetener.[190] The composer Beethoven, a heavy wine drinker, suffered elevated lead levels (as later detected in his hair) possibly due to this; the cause of his death is controversial, but lead poisoning is a contender as a factor.[190][191] With the Industrial Revolution in the 19th century, lead poisoning became common in the work setting.[79] The introduction of lead paint for residential use in the 19th century increased childhood exposure to lead; for millennia before this, most lead exposure had been occupational.[24] An important step in the understanding of childhood lead poisoning occurred when toxicity in children from lead paint was recognized in Australia in 1897.[79] France, Belgium, and Austria banned white lead interior paints in 1909; the League of Nations followed suit in 1922.[80] However, in the United States, laws banning lead house paint were not passed until 1971, and it was phased out and not fully banned until 1978.[80]

In 17th-century Germany, the physician Eberhard Gockel discovered lead-contaminated wine to be the cause of an epidemic of colic.[183] He had noticed that monks who did not drink wine were healthy, while wine drinkers developed colic,[20] and traced the cause to sugar of lead, made by simmering litharge with vinegar.[183] As a result, Eberhard Ludwig, Duke of Württemberg issued an edict in 1696 banning the adulteration of wines with litharge.[183]

The painter Caravaggio might have died of lead poisoning. Bones with high lead levels were recently found in a grave thought likely to be his.[185] Paints used at the time contained high amounts of lead salts. Caravaggio is known to have exhibited violent behavior, as caused by lead poisoning.

The consumption of sapa as having a role in the fall of the Roman Empire was used in a theory proposed by geochemist Jerome Nriagu[180] to state that "lead poisoning contributed to the decline of the Roman Empire". John Scarborough, a pharmacologist and classicist, criticized the conclusions drawn by Nriagu's book as "so full of false evidence, miscitations, typographical errors, and a blatant flippancy regarding primary sources that the reader cannot trust the basic arguments."[181] After antiquity, mention of lead poisoning was absent from medical literature until the end of the Middle Ages.[182] In 1656 the German physician Samuel Stockhausen recognized dust and fumes containing lead compounds as the cause of disease, called since ancient Roman times morbi metallici, that were known to afflict miners, smelter workers, potters, and others whose work exposed them to the metal.[183][184]

Romans also consumed lead through the consumption of defrutum, carenum, and sapa, musts made by boiling down fruit in lead cookware. Defrutum and its relatives were used in Ancient Roman cuisine and cosmetics, including as a food preservative.[179] The use of leaden cookware, though popular, was not the general standard and copper cookware was used far more generally. There is also no indication how often sapa was added or in what quantity.

Thirty years ago, Jerome Nriagu argued in a milestone paper that Roman civilization collapsed as a result of lead poisoning. Clair Patterson, the scientist who convinced governments to ban lead from gasoline, enthusiastically endorsed this idea, which nevertheless triggered a volley of publications aimed at refuting it. Although today lead is no longer seen as the prime culprit of Rome’s demise, its status in the system of water distribution by lead pipes (fistulæ) still stands as a major public health issue. By measuring Pb isotope compositions of sediments from the Tiber River and the Trajanic Harbor, the present work shows that “tap water” from ancient Rome had 100 times more lead than local spring waters.[176][177][178]

However, recent research supports the idea that the lead found in the water came from the supply pipes, rather than another source of contamination. It was not unknown for locals to punch holes in the pipes to draw water off, increasing the number of people exposed to the lead.

The great disadvantage of lead has always been that it is poisonous. This was fully recognised by the ancients, and Vitruvius specifically warns against its use. Because it was nevertheless used in profusion for carrying drinking water, the conclusion has often been drawn that the Romans must therefore have suffered from lead poisoning; sometimes conclusions are carried even further and it is inferred that this caused infertility and other unwelcome conditions, and that lead plumbing was largely responsible for the decline and fall of Rome. Two things make this otherwise attractive hypothesis impossible. First, the calcium carbonate deposit that formed so thickly inside the aqueduct channels also formed inside the pipes, effectively insulating the water from the lead, so that the two never touched. Second, because the Romans had so few taps and the water was constantly running, it was never inside the pipes for more than a few minutes, and certainly not long enough to become contaminated.[175]

Lead poisoning was among the first known and most widely studied work and environmental hazards.[123] One of the first metals to be smelted and used,[79] lead is thought to have been discovered and first mined in Anatolia around 6500 BCE.[80] Its density, workability, and corrosion-resistance were among the metal's attractions.[123] In the 2nd century BCE the Greek botanist Nicander described the colic and paralysis seen in lead-poisoned people.[20][23] Dioscorides, a Greek physician who lived in the 1st century CE, wrote that lead makes the mind "give way".[79][172] Lead was used extensively in Roman aqueducts from about 500 BCE to 300 CE[80] Julius Caesar's engineer, Vitruvius, reported, "water is much more wholesome from earthenware pipes than from lead pipes. For it seems to be made injurious by lead, because white lead is produced by it, and this is said to be harmful to the human body."[173] Gout, prevalent in affluent Rome, is thought to be the result of lead, or leaded eating and drinking vessels. Sugar of lead (lead(II) acetate) was used to sweeten wine, and the gout that resulted from this was known as "saturnine" gout.[174] It is even hypothesized that lead poisoning may have contributed to the decline of the Roman Empire,[23][79] a hypothesis thoroughly disputed:

a block with two dull, dark gray metal spouts coming from the top. The spouts are chipped and very old-looking.
Roman lead water pipes with taps

an ancient Greek black-and-white woodcut print of a middle aged bearded man. His left hand rests on a book and in his right he holds a plant.
Dioscorides noted lead's effect on the mind in the first century A.D.


Exposure to lead may also decrease lifespan and have health effects in the long term.[23] Death rates from a variety of causes have been found to be higher in people with elevated blood lead levels; these include cancer, stroke, and heart disease, and general death rates from all causes.[10] Lead is considered a possible human carcinogen based on evidence from animal studies.[171] Evidence also suggests that age-related mental decline and psychiatric symptoms are correlated with lead exposure.[121] Cumulative exposure over a prolonged period may have a more important effect on some aspects of health than recent exposure.[121] Some health effects, such as high blood pressure, are only significant risks when lead exposure is prolonged (over about one year).[65]


Lead encephalopathy is a medical emergency and causes permanent brain damage in 70–80% of children affected by it, even those that receive the best treatment.[17] The mortality rate for people who develop cerebral involvement is about 25%, and of those who survive who had lead encephalopathy symptoms by the time chelation therapy was begun, about 40% have permanent neurological problems such as cerebral palsy.[27]


Outcome is related to the extent and duration of lead exposure.[170] Effects of lead on the physiology of the kidneys and blood are generally reversible; its effects on the central nervous system are not.[48] While peripheral effects in adults often go away when lead exposure ceases, evidence suggests that most of lead's effects on a child's central nervous system are irreversible.[24] Children with lead poisoning may thus have adverse health, cognitive, and behavioral effects that follow them into adulthood.[88]



[82] In many countries including the US, household paint and dust are the major route of exposure in children.[7] Blood levels usually peak at about 18–24 months old.[24] Children ages one to three tend to have the highest blood lead levels, possibly because at that age they begin to walk and explore their environment, and they use their mouths in their exploration.[82] Children may also have a higher intake of lead than adults; they breathe faster and may be more likely to have contact with and ingest soil.[169] Children are more sensitive to elevated blood lead levels than adults are.[10] In adults of all ages, men have higher blood lead levels than women do.[10] In adults, blood lead levels steadily increase with increasing age.[24] Differences in vulnerability to lead-induced neurological damage between males and females have also been found, but some studies have found males to be at greater risk, while others have found females to be.[65] Lead is one of the largest [165] Atmospheric lead pollution increased dramatically beginning in the 1950s as a result of the widespread use of leaded gasoline.[121][15] Environmental lead is ubiquitous, and everyone has some measurable blood lead level.[144] Since lead has been used widely for centuries, the effects of exposure are worldwide.


People receiving dimercaprol need to be assessed for peanut allergies since the commercial formulation contains peanut oil. Calcium EDTA is also effective if administered four hours after the administration of dimercaprol. Administering dimercaprol, DMSA (Succimer), or DMPS prior to calcium EDTA is necessary to prevent the redistribution of lead into the central nervous system.[160] Dimercaprol used alone may also redistribute lead to the brain and testes.[160] An adverse side effect of calcium EDTA is renal toxicity. Succimer (DMSA) is the preferred agent in mild to moderate lead poisoning cases. This may be the case in instances where children have a blood lead level >25μg/dL. The most reported adverse side effect for succimer is gastrointestinal disturbances.[161] It is also important to note that chelation therapy only lowers blood lead levels and may not prevent the lead-induced cognitive problems associated with lower lead levels in tissue. This may be because of the inability of these agents to remove sufficient amounts of lead from tissue or inability to reverse preexisting damage.[161] Chelating agents can have adverse effects;[77] for example, chelation therapy can lower the body's levels of necessary nutrients like zinc.[157][162] Chelating agents taken orally can increase the body's absorption of lead through the intestine.[163] Chelation challenge, also known as provocation testing, is used to indicate an elevated and mobilizable body burden of heavy metals including lead.[77] This testing involves collecting urine before and after administering a one-off dose of chelating agent to mobilize heavy metals into the urine.[77] Then urine is analyzed by a laboratory for levels of heavy metals; from this analysis overall body burden is inferred.[164] Chelation challenge mainly measures the burden of lead in soft tissues, though whether it accurately reflects long-term exposure or the amount of lead stored in bone remains controversial.[9][14] Although the technique has been used to determine whether chelation therapy is indicated and to diagnose heavy metal exposure, some evidence does not support these uses as blood levels after chelation are not comparable to the reference range typically used to diagnose heavy metal poisoning.[77] The single chelation dose could also redistribute the heavy metals to more sensitive areas such as central nervous system tissue.[77]

A chelating agent is a molecule with at least two negatively charged groups that allow it to form complexes with metal ions with multiple positive charges, such as lead.[156] The chelate that is thus formed is nontoxic[157] and can be excreted in the urine, initially at up to 50 times the normal rate.[128] The chelating agents used for treatment of lead poisoning are edetate disodium calcium (CaNa2EDTA), dimercaprol (BAL), which are injected, and succimer and d-penicillamine, which are administered orally.[158] Chelation therapy is used in cases of acute lead poisoning,[22] severe poisoning, and encephalopathy,[153] and is considered for people with blood lead levels above 25 µg/dL.[27] While the use of chelation for people with symptoms of lead poisoning is widely supported, use in asymptomatic people with high blood lead levels is more controversial.[14] Chelation therapy is of limited value for cases of chronic exposure to low levels of lead.[159] Chelation therapy is usually stopped when symptoms resolve or when blood lead levels return to premorbid levels.[14] When lead exposure has taken place over a long period, blood lead levels may rise after chelation is stopped because lead is leached into blood from stores in the bone;[14] thus repeated treatments are often necessary.[23]

a chemical diagram of [CH2N(CH2CO2-)2]2 (shown in black) with the four O- tails binding a metal ion (shown in red).
EDTA, a chelating agent, binds a heavy metal, sequestering it.

[155] The mainstays of treatment are removal from the source of lead and, for people who have significantly high blood lead levels or who have symptoms of poisoning,

CDC management guidelines for children with elevated blood levels[150]
Blood lead
level (μg/dL)
10–14 Education,
repeat screening
15–19 Repeat screening, case
management to abate sources
20–44 Medical evaluation,
case management
45–69 Medical evaluation,
chelation, case management
>69 Hospitalization, immediate
chelation, case management


Prevention measures also exist on national and municipal levels. Recommendations by health professionals for lowering childhood exposures include banning the use of lead where it is not essential and strengthening regulations that limit the amount of lead in soil, water, air, household dust, and products.[37] Regulations exist to limit the amount of lead in paint; for example, a 1978 law in the US restricted the lead in paint for residences, furniture, and toys to 0.06% or less.[79] In October 2008, the US Environmental Protection Agency reduced the allowable lead level by a factor of ten to 0.15 micrograms per cubic meter of air, giving states five years to comply with the standards.[147] The European Union's Restriction of Hazardous Substances Directive limits amounts of lead and other toxic substances in electronics and electrical equipment. In some places, remediation programs exist to reduce the presence of lead when it is found to be high, for example in drinking water.[144] As a more radical solution, entire towns located near former lead mines have been "closed" by the government, and the population resettled elsewhere, as was the case with Picher, Oklahoma in 2009.[148][149]

Screening is an important method in preventive medicine strategies.[6] Screening programs exist to test the blood of children at high risk for lead exposure, such as those who live near lead-related industries.[17]

Recommended steps by individuals to reduce the blood lead levels of children include increasing their frequency of hand washing and their intake of calcium and iron, discouraging them from putting their hands to their mouths, vacuuming frequently, and eliminating the presence of lead-containing objects such as blinds and jewellery in the house.[144] In houses with lead pipes or plumbing solder, these can be replaced.[144] Less permanent but cheaper methods include running water in the morning to flush out the most contaminated water, or adjusting the water's chemistry to prevent corrosion of pipes.[144] Lead testing kits are commercially available for detecting the presence of lead in the household.[101] As hot water is more likely than cold water to contain higher amounts of lead, use only cold water from the tap for drinking, cooking, and for making baby formula. Since most of the lead in household water usually comes from plumbing in the house and not from the local water supply, using cold water can avoid lead exposure.[145] Measures such as dust control and household education do not appear to be effective in changing children's blood levels.[146]

In most cases, lead poisoning is preventable[71] by avoiding exposure to lead.[10] Prevention strategies can be divided into individual (measures taken by a family), preventive medicine (identifying and intervening with high-risk individuals), and public health (reducing risk on a population level).[6]

A box of cigarette-like white cylinders on the left, in the middle a white cylinder with a pink tip, on the right a paper with four circles, two blank and two pink
Testing kits are commercially available for detecting lead. These swabs, when wiped on a surface, turn red in the presence of lead.


Blood lead concentrations in poisoning victims have ranged from 30->80 µg/dL in children exposed to lead paint in older houses, 77–104 µg/dL in persons working with pottery glazes, 90–137 µg/dL in individuals consuming contaminated herbal medicines, 109–139 µg/dL in indoor shooting range instructors and as high as 330 µg/dL in those drinking fruit juices from glazed earthenware containers.[143]

The National Institute for Occupational Safety and Health (CDC/NIOSH) reference blood lead level in adults is 10 μg/dL[141] The U.S. national BLL geometric mean among adults was 1.2 μg/dL in 2009–2010.[142]

The current reference range for acceptable blood lead concentrations in healthy persons without excessive exposure to environmental sources of lead is less than 5 µg/dL for children.[3] It was less than 25 µg/dL for adults.[140] Previous to 2012 the value for children was 10 (µg/dl).[4] The current biological exposure index (a level that should not be exceeded) for lead-exposed workers in the U.S. is 30 µg/dL in a random blood specimen.

Reference levels

Exposure to lead also can be evaluated by measuring erythrocyte protoporphyrin (EP) in blood samples.[22] EP is a part of red blood cells known to increase when the amount of lead in the blood is high, with a delay of a few weeks.[16] Thus EP levels in conjunction with blood lead levels can suggest the time period of exposure; if blood lead levels are high but EP is still normal, this finding suggests exposure was recent.[16][25] However, the EP level alone is not sensitive enough to identify elevated blood lead levels below about 35 μg/dL.[22] Due to this higher threshold for detection and the fact that EP levels also increase in iron deficiency, use of this method for detecting lead exposure has decreased.[136] Blood lead levels are an indicator mainly of recent or current lead exposure, not of total body burden.[137] Lead in bones can be measured noninvasively by X-ray fluorescence; this may be the best measure of cumulative exposure and total body burden.[25] However this method is not widely available and is mainly used for research rather than routine diagnosis.[77] Another radiographic sign of elevated lead levels is the presence of radiodense lines called lead lines at the metaphysis in the long bones of growing children, especially around the knees.[138] These lead lines, caused by increased calcification due to disrupted metabolism in the growing bones, become wider as the duration of lead exposure increases.[138] X-rays may also reveal lead-containing foreign materials such as paint chips in the gastrointestinal tract.[14][138] Fecal lead content that is measured over the course of a few days may also be an accurate way to estimate the overall amount of childhood lead intake. This form of measurement may serve as a useful way to see the extent of oral lead exposure from all the diet and environmental sources of lead.[139] Lead poisoning shares symptoms with other conditions and may be easily missed.[27] Conditions that present similarly and must be ruled out in diagnosing lead poisoning include carpal tunnel syndrome, Guillain-Barré syndrome, renal colic, appendicitis, encephalitis in adults, and viral gastroenteritis in children.[133] Other differential diagnoses in children include constipation, abdominal colic, iron deficiency, subdural hematoma, neoplasms of the central nervous system, emotional and behavior disorders, and intellectual disability.[17]

Blood film examination may reveal basophilic stippling of red blood cells (dots in red blood cells visible through a microscope), as well as the changes normally associated with iron-deficiency anemia (microcytosis and hypochromasia).[22][48] However, basophilic stippling is also seen in unrelated conditions, such as megaloblastic anemia caused by vitamin B12 (colbalamin) and folate deficiencies.[135]

dozens of pink circular bodies with white centers on a white background. Arrows point to three of the cells; two are speckled with dark purple dots, and the third has an irregular outer border
Basophilic stippling (arrows) of red blood cells in a 53-year-old who had elevated blood lead levels due to drinking repeatedly from glasses decorated with lead paint.[134]

Diagnosis includes determining the clinical signs and the medical history, with inquiry into possible routes of exposure.[133] Clinical toxicologists, medical specialists in the area of poisoning, may be involved in diagnosis and treatment. The main tool in diagnosing and assessing the severity of lead poisoning is laboratory analysis of the blood lead level (BLL).[17]


The brain is the organ most sensitive to lead exposure.[58] Lead is able to pass through the endothelial cells at the ion channels.[127] It causes loss of neurons' myelin sheaths, reduces numbers of neurons, interferes with neurotransmission, and decreases neuronal growth.[7] Lead interferes with the release of neurotransmitters, chemicals used by neurons to send signals to other cells.[18][23] It interferes with the release of glutamate, a neurotransmitter important in many functions including learning, by blocking NMDA receptors. The targeting of NMDA receptors is thought to be one of the main causes for lead's toxicity to neurons.[129] A Johns Hopkins University report found that in addition to inhibiting the NMDA receptor, lead exposure decreased the level of expression of the gene for the receptor in part of the brain.[132] In addition, lead has been found in animal studies to cause programmed cell death in brain cells.[23]

Two black-and-white photos; one shows dark, fairly regular rings on a lighter background, and the other shows irregular, smaller, and not as dark clusters.
Lead exposure damages cells in the hippocampus, a part of the brain involved in memory. Hippocampi of lead-exposed rats (bottom) show structural damage such as irregular nuclei (IN) and denaturation of myelin (DNS) compared to controls (top).[129]


The primary cause of lead's toxicity is its interference with a variety of enzymes because it binds to sulfhydryl groups found on many enzymes.[7] Part of lead's toxicity results from its ability to mimic other metals that take part in biological processes, which act as cofactors in many enzymatic reactions, displacing them at the enzymes on which they act.[18] Lead is able to bind to and interact with many of the same enzymes as these metals but, due to its differing chemistry, does not properly function as a cofactor, thus interfering with the enzyme's ability to catalyze its normal reaction or reactions. Among the essential metals with which lead interacts are calcium, iron, and zinc.[122] One of the main causes for the pathology of lead is that it interferes with the activity of an essential enzyme called delta-aminolevulinic acid dehydratase, or ALAD, which is important in the biosynthesis of heme, the cofactor found in hemoglobin.[22] Lead also inhibits the enzyme ferrochelatase, another enzyme involved in the formation of heme.[11][22][126] Ferrochelatase catalyzes the joining of protoporphyrin and Fe2+ to form heme.[11][18][22] Lead's interference with heme synthesis results in production of zinc protoporphyrin and the development of anemia.[127] Another effect of lead's interference with heme synthesis is the buildup of heme precursors, such as aminolevulinic acid, which may be directly or indirectly harmful to neurons.[128]


[84] and causes it to build up within them.calcium in cells Lead also interferes with the normal metabolism of [125].polymorphonuclear leukocytes Lead exposure has also been associated with a decrease in activity of immune cells such as [125] in children.asthma proteins; this mechanism may mean that lead exposure is a risk factor for inflammatory, causing production of excessive immune system Lead may also be harmful to the developing [23] synthesis.collagen and alters the permeability of blood vessels and [125] Lead interferes with metabolism of bones and teeth[124] become more fragile as the result of damage to their blood cells Anemia may result when the cell membranes of [18].cell membrane, and enzymes that maintain the integrity of the vitamin D that help in the synthesis of enzymes, DNA transcription Lead also interferes with [123].cell membranes and DNA which damage cell structures including radicals and its harmful effects are myriad. Lead and other heavy metals create reactive [70][36] Lead has no known physiologically relevant role in the body,[122] Smaller amounts of lead are also eliminated through the feces, and very small amounts in hair, nails, and sweat.[7] It is removed from the body very slowly, mainly through urine.[18] Many other tissues store lead, but those with the highest concentrations (other than blood, bone, and teeth) are the brain, spleen, kidneys, liver, and lungs.[121] Also, if lead exposure takes place over years, clearance is much slower, partly due to the re-release of lead from bone.[11], which allows the lead to be continuously re-introduced into the bloodstream.remodeling The half-life of lead in the blood in men is about 40 days, but it may be longer in children and pregnant women, whose bones are undergoing [22] The estimated half-life of lead in bone is 20 to 30 years, and bone can introduce lead into the bloodstream long after the initial exposure is gone.[11] In adults, 94% of absorbed lead is deposited in the bones and teeth, but children only store 70% in this manner, a fact which may partially account for the more serious health effects on children.[120] Lead in the bones, teeth, hair, and nails is bound tightly and not available to other tissues, and is generally thought not to be harmful.[15] The main body compartments that store lead are the blood, soft tissues, and bone; the half-life of lead in these tissues is measured in weeks for blood, months for soft tissues, and years for bone.[119] Children and infants may absorb about 50% of ingested lead, but little is known about absorption rates in children.[15] Exposure occurs through

Two chemical diagrams of tetra-ethyl lead, or (CH3CH2)4Pb. On the left one, carbon and hydrogen are labeled, on the right they are shown as lines only.
Tetraethyllead, still used as an additive in some fuels, can be absorbed through the skin.[22]


Lead birdshot is banned in some areas, but this is primarily for the benefit of wildfowl and their predators, rather than humans.[118] Non-lead alternatives include steel, tungsten-nickel-iron, bismuth-tin, and tungsten-polymer.

Copper-jacketed, lead-based bullets are more economical to produce and use than any material. Alternative materials are available such as steel, copper, and tungsten, but alternatives are universally less effective and/or more expensive. However, the biggest impediment to using the vast majority of alternatives relates to current laws in the United States pertaining to armor-piercing rounds. Laws and regulations relating to armor-piercing ammunition expressly prohibit the use of brass, bronze, steel, tungsten, and nearly every metallic alternative in any bullet that can be shot by a handgun, which at this time is nearly every caliber smaller than 50BMG (including the popular .223 Remington, .308 Winchester and .30-06 to name just a few). Some lead-based bullets are resistant to fragmentation, offering hunters the ability to clean game animals with negligible risk of including lead fragments in prepared meat. Other bullets are prone to fragmentation and exacerbate the risk of lead ingestion from prepared meat. In practice, use of a non-fragmenting bullet and proper cleaning of the game animal's wound can eliminate the risk of lead ingestion from eating game;[103] however, isolating such practice to experimentally determine its association with blood lead levels in study is difficult. Bismuth is an element used as a lead-replacement for shotgun pellets used in waterfowl hunting although shotshells made from bismuth are nearly ten times the cost of lead.

While this study suggests that consumption of wild game meat can adversely affect PbB, no participant had PbB higher than the CDC recommended threshold of 10μg/dl—the level at which CDC recommends case management; and the geometric mean PbB among this study population (1.17μg/dl) was lower than the overall population geometric mean PbB in the United States (1.60 μg/dl).[117] The clinical significance of low PbB in this sample population and the small quantitative increase of 0.30μg/dl in PbB associated with wild game consumption should be interpreted in the context of naturally occurring PbB.[116]

This study has been cited by popular media as simple evidence that hunting increases exposure to lead poisoning, prompting the University of Illinois Extension to release a statement that there is no such risk.[115] Concerning the CDC report, the authors' conclusion in a related Epi-AID Trip Report[116] notes the small increase associated with game consumption in the study, and urges interpretation with respect to environmental context:

Because game animals can be shot using lead bullets, the potential for lead ingestion from game meat consumption has been studied clinically and epidemiologically. In a recent study conducted by the CDC,[114] a cohort from North Dakota was enrolled and asked to self-report historical consumption of game meat, and participation in other activities that could cause lead exposure. The study found that participants' age, sex, housing age, current hobbies with potential for lead exposure, and game consumption were all associated with blood lead level (PbB).


In May 2015, Indian food safety regulators in the state of Uttar Pradesh found that samples of Maggi 2 Minute Noodles contained lead up to 17 times beyond permissible limits.[107][108][109][110] On 3 June 2015, New Delhi Government banned the sale of Maggi noodles in New Delhi stores for 15 days because it was found to contain lead beyond the permissible limit.[111] The Gujarat FDA on June 4, 2015 banned the noodles for 30 days after 27 out of 39 samples were detected with objectionable levels of metallic lead, among other things.[112] Some India's biggest retailers like Future Group, Big Bazaar, Easyday and Nilgiris have imposed a nationwide ban on Maggi noodles.[113] Many other states too have banned Maggi noodles.

Lead can be found in products such as kohl, an ancient cosmetic from the Middle East, South Asia, and parts of Africa that has many names; and from some toys.[6] In 2007, millions of toys made in China were recalled from multiple countries owing to safety hazards including lead paint.[96] Vinyl mini-blinds, found especially in older housing, may contain lead.[12] Lead is commonly incorporated into herbal remedies such as Indian Ayurvedic preparations and remedies of Chinese origin.[10][15][22] There are also risks of elevated blood lead levels caused by folk remedies like azarcon and greta, which each contain about 95% lead.[15] Ingestion of metallic lead, such as small lead fishing lures, increases blood lead levels and can be fatal.[97][98][99][100] Ingestion of lead-contaminated food is also a threat. Ceramic glaze often contains lead, and dishes that have been improperly fired can leach the metal into food, potentially causing severe poisoning.[101] In some places, the solder in cans used for food contains lead.[22] When manufacturing medical instruments and hardware, solder containing lead may be present.[102] People who eat animals hunted with lead bullets may be at risk for lead exposure.[103] Bullets lodged in the body rarely cause significant levels of lead,[104][105] but bullets lodged in the joints are the exception, as they deteriorate and release lead into the body over time.[106]

Lead-containing products

In Australia, collecting rainwater from roof runoff used as potable water may contain lead if there are lead contaminants on the roof or in the storage tank.[10] The Australian Drinking Water Guidelines allow a maximum of .01 mg/L lead in water.[10]

Lead from the atmosphere or soil can end up in groundwater and surface water.[91] It is also potentially in drinking water, e.g. from plumbing and fixtures that are either made of lead or have lead solder.[84][92] Since acidic water breaks down lead in plumbing more readily, chemicals can be added to municipal water to increase the pH and thus reduce the corrosivity of the public water supply.[84] Chloramines, which were adopted as a substitute for chlorine disinfectants due to fewer health concerns, increase corrositivity.[93] In the US, 14–20% of total lead exposure is attributed to drinking water.[93] In 2004, a team of seven reporters from The Washington Post discovered high levels of lead in the drinking water in Washington, D.C. and won an award for investigative reporting for a series of articles about this contamination.[94][95]


Residual lead in soil contributes to lead exposure in urban areas.[6] It has been thought that the more polluted an area is with various contaminants, the more likely it is to contain lead. However, this is not always the case, as there are several other reasons for lead contamination in soil.[87] Lead content in soil may be caused by broken-down lead paint, residues from lead-containing gasoline, used engine oil, or pesticides used in the past, contaminated landfills, or from nearby industries such as foundries or smelters.[88] Although leaded soil is less of a problem in countries that no longer have leaded gasoline, it remains prevalent, raising concerns about the safety of urban agriculture;[89] eating food grown in contaminated soil can present a lead hazard.[90]

a closeup of a red gasoline pump with a warning label that reads,
A lead warning on a fuel pump. Tetraethyllead, which used to be added to automotive gasoline (and still is added to some aviation gasolines), contributed to soil contamination.


Some lead compounds are colorful and are used widely in paints,[79] and lead paint is a major route of lead exposure in children.[80] A study conducted in 1998–2000 found that 38 million housing units in the US had lead-based paint, down from a 1990 estimate of 64 million.[81] Deteriorating lead paint can produce dangerous lead levels in household dust and soil.[82] Deteriorating lead paint and lead-containing household dust are the main causes of chronic lead poisoning.[20] The lead breaks down into the dust and since children are more prone to crawling on the floor, it is easily ingested.[81] Many young children display pica, eating things that are not food. Even a small amount of a lead-containing product such as a paint chip or a sip of glaze can contain tens or hundreds of milligrams of lead.[83] Eating chips of lead paint presents a particular hazard to children, generally producing more severe poisoning than occurs from dust.[84] Because removing lead paint from dwellings, e.g. by sanding or torching creates lead-containing dust and fumes, it is generally safer to seal the lead paint under new paint (excepting moveable windows and doors, which create paint dust when operated).[85] Alternately, special precautions must be taken if the lead paint is to be removed.[85] In oil painting it was once common for colours such as yellow or white to be made with lead carbonate. Lead white oil colour was the main white of oil painters until superseded by compounds containing zinc or titanium in the mid-20th century. It is speculated that the painter Caravaggio and possibly Goya had lead poisoning due to overexposure or carelessness when handling this colour.[86]


In adults, occupational exposure is the main cause of lead poisoning.[23] People can be exposed when working in facilities that produce a variety of lead-containing products; these include radiation shields, ammunition, certain surgical equipment, developing dental x-ray films prior to digital x-rays (each film packet had a lead liner to prevent the radiation from going through), fetal monitors, plumbing, circuit boards, jet engines, and ceramic glazes.[22] In addition, lead miners and smelters, plumbers and fitters, auto mechanics, glass manufacturers, construction workers, battery manufacturers and recyclers, firing range instructors, and plastic manufacturers are at risk for lead exposure.[71] Other occupations that present lead exposure risks include welding, manufacture of rubber, printing, zinc and copper smelting, processing of ore, combustion of solid waste, and production of paints and pigments.[78] Parents who are exposed to lead in the workplace can bring lead dust home on clothes or skin and expose their children.[78]

A man in a hard hat with a clear face plate leans over a conveyor belt with a metal instrument. He is in a factory setting with heavy machinery in the background.
Battery recycling workers are at risk for lead exposure.[77] This worker ladles molten lead into billets in a lead-acid battery recovery facility.

Occupational exposure

Lead is a common environmental pollutant.[12] Causes of environmental contamination include industrial use of lead, such as is found in facilities that process lead-acid batteries or produce lead wire or pipes, and metal recycling and foundries.[70] Children living near facilities that process lead, such as lead smelters, have been found to have unusually high blood lead levels.[71] In August 2009, parents rioted in China after lead poisoning was found in nearly 2000 children living near zinc and manganese smelters.[72] Lead exposure can occur from contact with lead in air, household dust, soil, water, and commercial products.[10] Leaded gasoline has also been linked to increases in lead pollution.[73][74] Some research has suggested a link between leaded gasoline and crime rates.[75][76]

Exposure routes

[69] It is believed that the U.S. ban on lead paint in buildings in the late 1970s, as well as the phaseout of leaded gasoline in the 1970s and 1980s, partially helped contribute to the decline of violent crime in the United States since the early 1990s.[69][68] A 2007 paper by the same author claims to show a strong association between preschool blood lead and subsequent crime rate trends over several decades across nine countries.[67][66] theorizes that lead exposure explains 65% to 90% of the variation in violent crime rates in the US.Rick Nevin A May 2000 study by economic consultant [23] Countries with the highest air lead levels have also been found to have the highest murder rates, after adjusting for confounding factors.[56] A correlation has also been found between prenatal and early childhood lead exposure and violent crime in adulthood.[23] Elevated lead levels in children are correlated with higher scores on aggression and delinquency measures.[60].anti-social behaviour and attention deficit hyperactivity disorder Lead exposure in children is also correlated with neuropsychiatric disorders such as [47] Increases in blood lead levels from about 50 to about 100 μg/dL in adults have been found to be associated with persistent, and possibly permanent, impairment of central nervous system function.[65]

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.