Effects of Lead

Lead exposure in young children can cause:

Developmental delays

Child stringing beads working on fine motor skills

Learning, memory, fine motor skills

Harmful health effects

Child getting an electrocardiogram (ECG)

Reproductive problems, artery, kidney, and heart damage

Learning disabilities

Closeup of a child being examined by a speech therapist

The ability to learn how to
speak and understand words

Evidence shows that even low to moderate levels of lead exposure have a life-long effect on neurological and cognitive development, health and behavior, like aggression and violence, and learning and school performance. These negative outcomes can result in many more adverse health and behavioral consequences described below.

Information on this page has been organized into three categories. Please choose one of the following tabs.

Brain development

Young children are most vulnerable to the effects of lead and other environmental toxins on the brain. The results can be seen as delays in growth, behavior, and learning, which in turn can have an impact on school success.

Information on the structure and growth of the brain, the impact of environmental toxins, how to nurture brain development, and screening to identify delays can be found on these pages.

Illustration of the brain on a blue background

 
Studies
  • As children, those exposed to lead in their early years experience neurological disruptions,1 resulting in lowered IQ,2 hearing loss, and developmental delays in speech and language.3
  • Low-level lead exposure in utero resulted in reduced intellectual development in children six to 10 years later.4
  • When pregnant women are exposed to lead, it can affect future generations. A recent scientific report5 describes how a pregnant woman’s blood lead levels (BLLs) can influence the fetal cells of her children and even her grandchildren. The authors note, “This is the first demonstration that an environmental exposure in pregnant mothers can have an epigenetic effect on the DNA methylation pattern in the grandchildren.”
Guidance and recommendations

Educational Interventions for Children Affected by Lead (PDF) describes how lead impacts a child's ability to learn and offers suggestions for educational interventions.

Low Level Lead Exposure Harms Children: A Renewed Call for Primary Prevention (PDF) details the systematic impact of lead exposure on every body system and irreversible lifelong learning, behavior, and health effects.

In Harm's Way: Toxic Threats to Child Development discusses the fact that 17 percent of children in the United States have been diagnosed with one or more developmental disabilities. These disorders have widespread societal implications, from health and education costs to the repercussions of criminal behavior.

Developmental Surveillance and Screening of Infants and Young Children (PDF) provides recommendations for screening infants and young children and intervening with families to identify developmental delays and disabilities in the primary care setting to ensure access to early intervention services.

References
  1. Brubaker CJ, Schmithorst VJ, Haynes EN, Dietrich, KN, Egelhoff JC, Lindquist DM, Lanphear BP, Cecil, KM. "Altered myelination and axonal integrity in adults with childhood lead exposure: a diffusion tensor imaging study." Neurotoxicology. 2009;30(6):867-875.
  2. Bellinger DC, Stiles KM, Needleman HL., Holland. "Low-level lead exposure, intelligence and academic achievement: a long-term follow-up study." Pediatrics. 1992;90(6):855-61.
  3. Chandramouli K, Steer CD, Ellis M, Emond AM. "Effects of early childhood lead exposure on academic performance and behaviour of school age children." Archives Disabled Child. 2009;94(11):844-8.
  4. Schnaas L, Rothenberg SJ, Flores MF, Martinez S, Hernandez C, Osorio E, Velasco SR, Perroni E. "Reduced intellectual development in children with prenatal lead exposure." Environmental Health Perspectives. 2006;114(5):791-7.
  5. Goodrich JM, Sanchez BN, Dolinoy DC, Zhang Z, Hernandez-Avila M, Hu H, Peterson KE, Tellez-Rojo MM. "Quality Control and statistical modeling for environmental epigenetics: a study on in utero lead exposure and DNA methylation at birth." Epigenetics. 2015:10(1):19-30.

Behavior and health
problems

Lead and behavior and mental health

Deficits in IQ and other formal measures of cognitive attainment are not the only measure of the effects of early exposure to lead. Children who are lead poisoned suffer from neurobehavioral problems, such as impulsivity, aggression, and short attention span. Disturbances in behavior and social conduct are commonly reported among victims of lead poisoning. Parents have reported that following recovery from an episode of acute poisoning, their child’s behavior changed as the child became more restless, impulsive, inattentive, and aggressive. Recent studies of older children and adolescents, as well as young adults, demonstrate the connection between lead and aggressive behavior, juvenile delinquency, and adult crime.

Studies
  • Among more than 1,300 preschool children in China, even low blood lead levels were associated with increased risk of behavioral and emotional problems,1 such as being anxious, depressed, or aggressive.
  • Researchers found higher exposure to lead in childhood is linked to major behavioral problems in later childhood and young adulthood, such as attention-deficit/hyperactivity disorder, teen pregnancy, and aggressive and criminal behavior.2
  • Children exposed to lead early in life show a greater likelihood of cognitive problems, and disorders such as hyperactivity and impulsivity.3
  • Adults lead poisoned as children are more likely to develop depression and panic attacks.4
  • Early research showed that lead-poisoned children were more likely to exhibit aggressive classroom behavior.5
  • Research demonstrates how lead affects the progression of violent behavior from birth to adulthood.6
  • Research delineated international criminal trends due to lead exposure.7
  • Adults poisoned as young children are more likely to be arrested for a violent crime, adults are 50% more likely to be arrested for every 5 micrograms per deciliter (mcg/dL) of lead in blood.8

Lead and lifelong health

Recent studies have suggested that the adverse health effects of elevated childhood blood lead levels (including those below 10 mcg/dL) extend beyond cognitive function to include cardiovascular, immunological, endocrine, neurocognitive and muscular-skeletal effects.

Studies
  • Teens lead poisoned as young children were more likely to have poor upright balance, coordination, and motor skills, increasing their long-term injury risk.9/sup>
  • Teens and adults lead poisoned as young children were also more likely to develop kidney disease.10
  • Adults lead poisoned in childhood also were more likely to experience hypertension,11 and increased risk of early death from heart attack and stroke.12, 13
  • Adults poisoned as young children were more likely to experience cognitive deficits, such as memory loss.14

Lead and reproductive health

Lead has long been recognized as a reproductive toxicant in both men and women. A history of maternal lead exposure, prenatal, postpartum lead exposures, and childhood elevated blood-lead levels can be a concern for the developing child. These studies raise questions about all possible pathways of lead exposure and their impacts on reproductive health, prenatal exposure, and breastfeeding benefits.

Studies
  • Research found that lead was linked to delayed puberty in girls aged 8 to 18 years old.15
  • Reproductive disorders occur in both men and women who were lead poisoned; men can suffer from testicular dysfunction16 and women can develop hypertension during pregnancy.17
  • Adverse birth outcomes may occur, including increased risk of spontaneous abortion,18 preterm delivery,19 and low birth weight.20
Guidance and recommendations

The Centers for Disease Control and Prevention (CDC) Guidelines for the Identification and Management of Lead Exposure in Pregnant and Lactating Women (PDF) provides recommendations based on scientific data and practical considerations regarding preventing lead exposure during pregnancy, assessment and blood-lead testing during pregnancy, medical and environmental management to reduce fetal exposure, breastfeeding, and follow-up of infants and children exposed to lead in utero.

Useful resources

Wisconsin local health departments can assist in establishing prenatal care and newborn services to women.

Wisconsin Women, Infant, and Children Nutrition Program clinic locations provide education and support for adequate prenatal nutrition and breastfeeding to pregnant women and new mothers who are income-eligible.

References

[1] Liu J, Liu X, Wang W, McCauley L, Pinto-Martin J, Wang Y, Li L, Yan C, Rogan WJ. 2014. "Blood lead levels and children’s behavioral and emotional problems: a cohort study." Journal of American Medical Association of Pediatricians. 2014;168(8):737-45.

[2] Wolpaw Reyes J. "Lead exposure and behavior: effects on antisocial and risky behavior among children and adolescents." Economic Inquiry. 2015;53(3):1580-1605.

[3] Nigg JT, Nikolas M, Mark Knottnerus G, Cavanagh K, Friderici K. "Confirmation and extension of association of blood lead with attention-deficit/hyperactivity disorder (ADHD) and ADHD symptom domains at population-typical exposure levels." Journal of Child Psychology and Psychiatry. 2010;51(1):58-65.

[4] Bouchard MF, Bellinger DC, Weuve J, Matthews-Bellinger J, Gilman SE, Wright RO, Schwartz J, Weisskopf MG. "Blood lead levels and major depressive disorder, panic disorder, and generalized anxiety disorder in US young adults." Archives of General Psychiatry. 2009:66(12):131-9.

[5] Needleman HJ, Gunnoe C, Leviton A, Reed R, Peresie H, Maher C, Barrett P. "Deficits in psychologic and classroom performance of children with elevated dentine lead levels." New England Journal of Medicine. 1979;300(13):689-95.

[6] Denno DW. "Biology and violence: from birth to adulthood." Contemporary Sociology. 1992;21(5).

[7] Nevin R. "Understanding international crime trends: the legacy of preschool lead exposure." Environmental Research. 2007;104(3):315-36.

[8] Wright JP, Dietrich KN, Ris MD, Hornung RW, Wessel SD, Lanphear BP, Ho M, Rae MN. "Association of prenatal and childhood blood lead concentrations with criminal arrests in early adulthood." PLoS Medicine. 2008;27(5):e101.

[9] Kincl LD, Dietrich, KN, Bhattacharya A. "Injury trends for adolescents with early childhood lead exposure." Journal of Adolescent Health. 2006;39(4):604-6.

[10] Fadrowski JJ, Navas-Acien A, Tellez-Plaza M, Guallar E, Weaver VM, Furth SL. "Blood lead level and kidney function in US adolescents: the Third National Health and Nutrition Examination Survey." Archives of Internal Medicine. 201;170(1):75-82.

[11] Navas-Acien A, Guallar E, Silbergeld EK, Rothenberg SJ. "Lead exposure and cardiovascular disease—a systematic review." Environmental Health Perspectives. 2007;116(3):472-82.

[12] Tsong-Hai L, Mei-Chun T, Chi-Jen C, Ja-Liang L. "Association of high body lead store with severe intracranial carotid atherosclerosis." NeuroToxicology. 2009;30(6):876-80.

[13] Lanphear BP, Rauch S, Auinger P, Allen RW, Hornung RW. "Low-level lead exposure and mortality in US adults: a population-based cohort study." Lancet Journal of Public Health. 2018;3(4):e177-e184.

[14] Shi RA, Glass TA, Bandeen-Roche K, Carlson MC, Bolla KI, Toss AC, Schwartz BS. "Environmental lead exposure and cognitive function in community-dwelling adults." Neurology. 2006;67(9):1556-62.

[15] Wu T, Buck GM, Mendola P. "Blood lead levels and sexual maturation in US girls: the Third National Health and Nutrition Examination Study." Environmental Health Perspectives. 2003;111(5):737-41.

[16] Rodamilans M, Osaba MJ, To-Fugueras J, Rivera Fillat F, Marques JM, Pérez P, Corbella. "Lead toxicity on endocrine testicular dysfunction in an occupationally exposed population." Human Toxicology. 1998;7(2):125-8.

[17] Yazbeck C, Thiebaugeorges O, Moreau T, Goua V, Debotte G, Sahuquillo J, Forhan A, Foliguet B, Magnin G, Slama R, Charles MA, Huel G. "Maternal blood lead levels and risk of pregnancy-induced hypertension: the EDEN cohort study." Environmental Health Perspectives. 2009;117(10):1526-30.

[18] Borja-Aburto VH, Hertz-Picciotto I, Rojas Lopez M, Farias P, Rios C, Blanco. "Blood lead levels measured prospectively and risk of spontaneous abortion." American Journal of Epidemiology. 1999;150(6):590-7.

[19] Jeliffe-Pawlowski LL, Miles SQ. Courtney JG, Materna B, Charlton V. "Effect of magnitude and timing of maternal pregnancy blood lead (Pb) levels on birth outcomes." Journal of Perinatology. 2006;26(3):154-62.

[20] Zhu M, Fitzgerald EF, Gelberg KH, Lin S, Druschel CM. "Maternal low-level lead exposure and fetal growth." Environmental Health Perspectives. 201;118(10):1471-5.

Learning and school
performance

Children with blood lead levels at or above 5 mcg/dL are at greater risk for developmental delays and behavioral issues that can result in academic failure and diminished life success than children who do not have a history of lead exposure. It is important that all children with lead exposure be screened for adverse neurocognitive effects using neuropsychological evaluation tools that provide a complete assessment to identify the complex subsystems in the brain that work differently when affected by lead. This assessment is critical for determining a child’s specific detriments and to identify the most appropriate early childhood interventions or elementary school interventions that are necessary.

Because more and more research was showing the impact of lead on school performance, the CDC published guidance for clinical and public health professionals, parents, advocates, and educators1 to help ensure that children affected by lead receive intervention services to increase their likelihood of academic success.

Studies

A study published by UW-Madison researchers on Milwaukee children showed that students who were lead poisoned before age 3 were at a considerable educational disadvantage compared to their unexposed peers seven to eight years later.2 Lead-exposed students in the fourth grade scored below fourth-grade ability, an outcome with serious negative consequences for both the student and the school.

A second study of Milwaukee students showed that children with moderate lead exposure before the age of 3 were nearly three times more likely to be suspended in fourth grade compared to their peers who had little or no exposure to lead.3 This study showed that 23 percent of the "discipline gap" between African American and white children was explained by early childhood lead exposure.

Third grade Chicago students who had been exposed to lead earlier in life scored lower on math and reading tests4 as compared to their nonexposed peers.

Children attending a public kindergarten in Rhode Island were enrolled in a study of reading readiness at kindergarten entry. Reading readiness is an early measure of a child's capacity to integrate cognitive ability and skills learned from educational and enrichment experiences. Children with lead exposure of 5mcg/dL or greater showed a decrease in readiness scores compared to children with lead exposure levels below 5mcg/dL, scoring 4.5 to 10 points lower.5

Three studies, conducted in North Carolina and Connecticut, demonstrated that children with previous lead exposure were more likely to score lower on end-of-grade tests,6 less likely to be placed into advanced and intellectually gifted programs and more likely to be classified as learning disabled,7 and to have decreased achievement on math and reading tests than children not previously exposed to lead.8

Test scores of New York students in third grade who were exposed to lead earlier in life predicted lower test performance in eighth grade.9 After adjusting the analysis for poverty, lead accounted for 8 to 16 percent of the variability of reading and math scores.

Detroit students who were lead exposed early in life, and tested in third, fifth and eighth grades, were 1.4 to 2.5 times more likely to be less proficient in math, science and reading.10

References

[1] Educational Services for Children Affected by Lead by Lead Expert Panel. "Educational interventions for children affected by lead." Atlanta: U.S. Department of Health and Human Services; 2015.

[2] Amato MS, Moore CF, Magzamen S, Imm P, Havlena JA, Anderson HA, Kanarek MS. "Lead exposure and educational proficiency: moderate lead exposure and educational proficiency on end-of-grade examinations." Annuals of Epidemiology. 2012;22(10):738-43.

[3] Amato MS, Magzamen S, Imm P, Havlena JA, Anderson HA, Kanarek MS, Moore CF. "Early lead exposure (<3 years old) prospectively predicts fourth grade school suspension in Milwaukee, Wisconsin (USA)." Environmental Research. 2013;126:60-5.

[4] Evens A, Hryhorczuk D, Laphear B, Rankin D, Lewis D, Forst L, Rosenberg D. "The effect of childhood lead exposure on School performance in Chicago public schools: A population-based retrospective cohort study." Environmental Health. 2015;7;14-21.

[5] McLaine P, Navas-Acien A, Lee R, Simon P, Diener-West M, Agnew J. "Elevated blood lead levels and reading readiness at the start of kindergarten." Pediatrics. 2013;131:1081-9.

[6] Miranda ML, Kim D, Reiter J, Overstreet Galeano MA, Maxson P. "Environmental contributors the achievement gap." Neurotoxicology. 2009;30(6):1019-24.

[7] Miranda ML, Dohyeong K, Osgood C, Hasting D. "The impact of early childhood lead exposure on educational test performance among Connecticut schoolchildren, Phase 1 report." Children's Environmental Health Initiative, Duke University, 2011.

[8] Stefanak M, Diorio J, Frisch L. "Cost of child lead poisoning to taxpayers in Mahoning County, Ohio." Public Health Reports. Washington, D.C.:1974.

[9] Strayhorn JC, Strayhorn JM Jr. "Lead exposure and the 2010 achievement test scores of children in New York counties." Child Adolescent Psychiatry and Mental Health. 201;6(4):4.

[10] Zhang N, Baker HW, Tufts M, Raymond RE, Salihu H, Elliott MR. "Early childhood lead exposure and academic achievement: evidence from Detroit public schools." American Journal of Public Health. 2013;113:e72-7.

Last Revised: December 20, 2018