Intellectual Impairment in Children with Blood Lead Concentrations below 10 µg per Deciliter
Richard L. Canfield, Ph.D., Charles R. Henderson, Jr., M.A., Deborah A. Cory-Slechta, Ph.D., Christopher Cox, Ph.D., Todd A. Jusko, B.S., and Bruce P. Lanphear, M.D., M.P.H.
Background Despite dramatic declines in children's blood leadconcentrations and a lowering of the Centers for Disease Controland Prevention's level of concern to 10 µg per deciliter(0.483 µmol per liter), little is known about children'sneurobehavioral functioning at lead concentrations below thislevel.
Methods We measured blood lead concentrations in 172 childrenat 6, 12, 18, 24, 36, 48, and 60 months of age and administeredthe StanfordBinet Intelligence Scale at the ages of 3and 5 years. The relation between IQ and blood lead concentrationwas estimated with the use of linear and nonlinear mixed models,with adjustment for maternal IQ, quality of the home environment,and other potential confounders.
Conclusions Blood lead concentrations, even those below 10 µgper deciliter, are inversely associated with children's IQ scoresat three and five years of age, and associated declines in IQare greater at these concentrations than at higher concentrations.These findings suggest that more U.S. children may be adverselyaffected by environmental lead than previously estimated.
Source Information
From the Division of Nutritional Sciences (R.L.C.) and the Department of Human Development (C.R.H.), College of Human Ecology, Cornell University, Ithaca, N.Y.; the Departments of Environmental Medicine (D.A.C.-S.) and Biostatistics and Computational Biology (C.C.), University of Rochester School of Medicine, Rochester, N.Y.; the Division of Epidemiology, Statistics, and Prevention, National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, Md. (C.C.); the Department of Epidemiology, School of Public Health and Community Medicine, University of Washington, Seattle (T.A.J.); and Cincinnati Children's Environmental Health Center, Children's Hospital Medical Center, Cincinnati (B.P.L.).
Address reprint requests to Dr. Canfield at the Division of Nutritional Sciences, College of Human Ecology, Cornell University, Ithaca, NY 14853, or at rlc5{at}cornell.edu.
Chandramouli, K, Steer, C D, Ellis, M, Emond, A M
(2009). Effects of early childhood lead exposure on academic performance and behaviour of school age children. Arch. Dis. Child.
94: 844-848
[Abstract][Full Text]
Narag, R. E., Pizarro, J., Gibbs, C.
(2009). Lead Exposure and Its Implications for Criminological Theory. Criminal Justice and Behavior
36: 954-973
[Abstract]
Muennig, P.
(2009). The Social Costs of Childhood Lead Exposure in the Post-Lead Regulation Era. Arch Pediatr Adolesc Med
163: 844-849
[Abstract][Full Text]
Fan, G., Feng, C., Li, Y., Wang, C., Yan, J., Li, W., Feng, J., Shi, X., Bi, Y.
(2009). Selection of Nutrients for Prevention or Amelioration of Lead-Induced Learning and Memory Impairment in Rats. ANN OCCUP HYG
53: 341-351
[Abstract][Full Text]
Liu, J., McCauley, L. A, Zhao, Y., Zhang, H., Pinto-Martin, J., Jintan Cohort Study Group,
(2009). Cohort profile: The China Jintan Child Cohort Study. Int J Epidemiol
0: dyp205v2-dyp205
[Full Text]
Jones, R. L., Homa, D. M., Meyer, P. A., Brody, D. J., Caldwell, K. L., Pirkle, J. L., Brown, M. J.
(2009). Trends in Blood Lead Levels and Blood Lead Testing Among US Children Aged 1 to 5 Years, 1988-2004. Pediatrics
123: e376-e385
[Abstract][Full Text]
Winickoff, J. P., Friebely, J., Tanski, S. E., Sherrod, C., Matt, G. E., Hovell, M. F., McMillen, R. C.
(2009). Beliefs About the Health Effects of "Thirdhand" Smoke and Home Smoking Bans. Pediatrics
123: e74-e79
[Abstract][Full Text]
Fergusson, D M, Boden, J M, Horwood, L J
(2008). Dentine lead levels in childhood and criminal behaviour in late adolescence and early adulthood. J. Epidemiol. Community Health
62: 1045-1050
[Abstract][Full Text]
Zailina, H., Junidah, R., Josephine, Y., Jamal, H.
(2008). The Influence of Low Blood Lead Concentrations on the Cognitive and Physical Development of Primary School Children in Malaysia. Asia Pac J Public Health
20: 317-326
[Abstract]
Nduka, J., Orisakwe, O., Maduawguna, C.
(2008). Lead levels in paint flakes from buildings in Nigeria: a preliminary study. Toxicol Ind Health
24: 539-542
[Abstract]
Rabin, R.
(2008). The Lead Industry and Lead Water Pipes "A MODEST CAMPAIGN". AJPH
98: 1584-1592
[Abstract][Full Text]
Payne, M. MSc
(2008). Lead in drinking water. CMAJ
179: 253-254
[Full Text]
Eisenberg, K., van Wijngaarden, E.
(2008). LEAD POISONING IN IMMIGRANT CHILDREN IN THE UNITED STATES. AJPH
98: 1156-1157
[Full Text]
Tehranifar, P., Leighton, J., Auchincloss, A. H., Faciano, A., Alper, H., Paykin, A., Wu, S.
(2008). Immigration and Risk of Childhood Lead Poisoning: Findings From a Case-Control Study of New York City Children. AJPH
98: 92-97
[Abstract][Full Text]
Kordas, K., Lonnerdal, B., Stoltzfus, R. J.
(2007). Interactions between Nutrition and Environmental Exposures: Effects on Health Outcomes in Women and Children. J. Nutr.
137: 2794-2797
[Abstract][Full Text]
Binns, H. J., Campbell, C., Brown, M. J., for the Advisory Committee on Childhood Lead Poiso,
(2007). Interpreting and Managing Blood Lead Levels of Less Than 10 {micro}g/dL in Children and Reducing Childhood Exposure to Lead: Recommendations of the Centers for Disease Control and Prevention Advisory Committee on Childhood Lead Poisoning Prevention. Pediatrics
120: e1285-e1298
[Abstract][Full Text]
Brody, J. G., Morello-Frosch, R., Brown, P., Rudel, R. A., Altman, R. G., Frye, M., Osimo, C. A., Perez, C., Seryak, L. M.
(2007). Improving Disclosure and Consent: "Is It Safe?": New Ethics for Reporting Personal Exposures to Environmental Chemicals. AJPH
97: 1547-1554
[Abstract][Full Text]
Lee, D.-H., Jacobs, D. R, Porta, M.
(2007). Association of serum concentrations of persistent organic pollutants with the prevalence of learning disability and attention deficit disorder. J. Epidemiol. Community Health
61: 591-596
[Abstract][Full Text]
Chen, A., Cai, B., Dietrich, K. N., Radcliffe, J., Rogan, W. J.
(2007). Lead Exposure, IQ, and Behavior in Urban 5- to 7-Year-Olds: Does Lead Affect Behavior Only by Lowering IQ?. Pediatrics
119: e650-e658
[Abstract][Full Text]
Glorennec, P., Declercq, C.
(2007). Performance of several decision support tools for determining the need for systematic screening of childhood lead poisoning around industrial sites. Eur J Public Health
17: 47-52
[Abstract][Full Text]
Suratt, P. M., Barth, J. T., Diamond, R., D'Andrea, L., Nikova, M., Perriello, V. A. Jr, Carskadon, M. A., Rembold, C.
(2007). Reduced Time in Bed and Obstructive Sleep-Disordered Breathing in Children Are Associated With Cognitive Impairment. Pediatrics
119: 320-329
[Abstract][Full Text]
Brodkin, E., Copes, R., Mattman, A., Kennedy, J., Kling, R., Yassi, A.
(2007). Lead and mercury exposures: interpretation and action. CMAJ
176: 59-63
[Abstract][Full Text]
Gracia, R. C., Snodgrass, W. R.
(2007). Lead toxicity and chelation therapy. Am J Health Syst Pharm
64: 45-53
[Abstract][Full Text]
Struzynska, L., Dabrowska-Bouta, B., Koza, K., Sulkowski, G.
(2007). Inflammation-Like Glial Response in Lead-Exposed Immature Rat Brain. Toxicol Sci
95: 156-162
[Abstract][Full Text]
Adebamowo, E. O., Agbede, O. A., Sridhar, M. K. C., Adebamowo, C. A.
(2006). An Evaluation of Lead Levels in Paints for Residential Use Sold in the Nigerian Market. Indoor and Built Environment
15: 551-554
[Abstract]
Shih, R. A., Glass, T. A., Bandeen-Roche, K., Carlson, M. C., Bolla, K. I., Todd, A. C., Schwartz, B. S.
(2006). Environmental lead exposure and cognitive function in community-dwelling older adults. Neurology
67: 1556-1562
[Abstract][Full Text]
Gawarammana, I B, Dargan, P I, Woodcock, S, Sculley, M, House, I M, Wood, D M, Jones, A L
(2006). Should all patients with unexplained anaemia be screened for chronic lead poisoning?. Hum Exp Toxicol
25: 645-649
[Abstract]
Suratt, P. M., Peruggia, M., D'Andrea, L., Diamond, R., Barth, J. T., Nikova, M., Perriello, V. A. Jr, Johnson, M. L.
(2006). Cognitive Function and Behavior of Children With Adenotonsillar Hypertrophy Suspected of Having Obstructive Sleep-Disordered Breathing. Pediatrics
118: e771-e781
[Abstract][Full Text]
Vasterling, J. J., Proctor, S. P., Amoroso, P., Kane, R., Heeren, T., White, R. F.
(2006). Neuropsychological outcomes of army personnel following deployment to the Iraq war.. JAMA
296: 519-529
[Abstract][Full Text]
Tellez-Rojo, M. M., Bellinger, D. C., Arroyo-Quiroz, C., Lamadrid-Figueroa, H., Mercado-Garcia, A., Schnaas-Arrieta, L., Wright, R. O., Hernandez-Avila, M., Hu, H.
(2006). Longitudinal Associations Between Blood Lead Concentrations Lower Than 10 {micro}g/dL and Neurobehavioral Development in Environmentally Exposed Children in Mexico City. Pediatrics
118: e323-e330
[Abstract][Full Text]
Zimmermann, M. B., Muthayya, S., Moretti, D., Kurpad, A., Hurrell, R. F.
(2006). Iron fortification reduces blood lead levels in children in Bangalore, India.. Pediatrics
117: 2014-2021
[Abstract][Full Text]
Morley, R.
(2006). The Cost of Being Poor: Poverty, Lead Poisoning, and Policy Implementation. JAMA
295: 1711-1712
[Full Text]
Rico, J. A., Kordas, K., Lopez, P., Rosado, J. L., Vargas, G. G., Ronquillo, D., Stoltzfus, R. J.
(2006). Efficacy of Iron and/or Zinc Supplementation on Cognitive Performance of Lead-Exposed Mexican Schoolchildren: A Randomized, Placebo-Controlled Trial. Pediatrics
117: e518-e527
[Abstract][Full Text]
Robbins, B.
(2006). Lead Levels Declining in Adults. AAP Grand Rounds
15: 16-17
[Full Text]
Pickrell, J A, Oehme, F W
(2006). Examining the risks and benefits of considering both the traditional dose-response and hormesis in arriving at an acceptable exposure level. Hum Exp Toxicol
25: 23-27
[Abstract]
Brown, M. J., McLaine, P., Dixon, S., Simon, P.
(2006). A Randomized, Community-Based Trial of Home Visiting to Reduce Blood Lead Levels in Children. Pediatrics
117: 147-153
[Abstract][Full Text]
Laraque, D., Trasande, L.
(2005). Lead Poisoning: Successes and 21st Century Challenges. Pediatr. Rev.
26: 435-443
[Full Text]
Committee on Environmental Health,
(2005). Lead Exposure in Children: Prevention, Detection, and Management. Pediatrics
116: 1036-1046
[Abstract][Full Text]
Woolf, A. D., Woolf, N. T.
(2005). Childhood Lead Poisoning in 2 Families Associated With Spices Used in Food Preparation. Pediatrics
116: e314-e318
[Abstract][Full Text]
Lasky, R. E., Luck, M. L., Parikh, N. A., Laughlin, N. K.
(2005). The Effects of Early Lead Exposure on the Brains of Adult Rhesus Monkeys: A Volumetric MRI Study. Toxicol Sci
85: 963-975
[Abstract][Full Text]
Lanphear, B P, Bearer, C F
(2005). Biomarkers in paediatric research and practice. Arch. Dis. Child.
90: 594-600
[Abstract][Full Text]
Lanphear, B. P., Wright, R. O., Dietrich, K. N.
(2005). Environmental Neurotoxins. Pediatr. Rev.
26: 191-198
[Full Text]
Kemper, A. R., Cohn, L. M., Fant, K. E., Dombkowski, K. J., Hudson, S. R.
(2005). Follow-up Testing Among Children With Elevated Screening Blood Lead Levels. JAMA
293: 2232-2237
[Abstract][Full Text]
Lanphear, B. P.
(2005). Childhood Lead Poisoning Prevention: Too Little, Too Late. JAMA
293: 2274-2276
[Full Text]
Pickrell, J. A, Oehme, F. W
(2005). Examining the risks and benefits of replacing traditional dose-response with hormesis. Hum Exp Toxicol
24: 259-264
[Abstract]
Trepka, M. J.
(2005). Using Surveillance Data to Develop and Disseminate Local Childhood Lead Poisoning Screening Recommendations: Miami--Dade County's Experience. AJPH
95: 556-558
[Abstract][Full Text]
Tavakoli-Nezhad, M., Pitts, D. K.
(2005). Postnatal Inorganic Lead Exposure Reduces Midbrain Dopaminergic Impulse Flow and Decreases Dopamine D1 Receptor Sensitivity in Nucleus Accumbens Neurons. J. Pharmacol. Exp. Ther.
312: 1280-1288
[Abstract][Full Text]
Wright, N J, Thacher, T D, Pfitzner, M A, Fischer, P R, Pettifor, J M
(2005). Causes of lead toxicity in a Nigerian city. Arch. Dis. Child.
90: 262-266
[Abstract][Full Text]
Harris, P.
(2005). Getting the Lead Out. NEJM
352: 841-843
[Full Text]
Lee, M.-G., Chun, O. K., Song, W. O.
(2005). Determinants of the Blood Lead Level of US Women of Reproductive Age. J. Am. Coll. Nutr.
24: 1-9
[Abstract][Full Text]
Samuels, M. A.
(2005). Update in Neurology. ANN INTERN MED
142: 28-36
[Full Text]
Saper, R. B., Kales, S. N., Paquin, J., Burns, M. J., Eisenberg, D. M., Davis, R. B., Phillips, R. S.
(2004). Heavy Metal Content of Ayurvedic Herbal Medicine Products. JAMA
292: 2868-2873
[Abstract][Full Text]
Weisskopf, M. G., Wright, R. O., Schwartz, J., Spiro, A. III, Sparrow, D., Aro, A., Hu, H.
(2004). Cumulative Lead Exposure and Prospective Change in Cognition among Elderly Men: The VA Normative Aging Study. Am J Epidemiol
160: 1184-1193
[Abstract][Full Text]
Hipkins, K. L., Materna, B. L., Payne, S. F., Kirsch, L. C.
(2004). Family Lead Poisoning Associated with Occupational Exposure. CLIN PEDIATR
43: 845-849
VanArsdale, J. L., Leiker, R. D., Kohn, M., Merritt, T. A., Horowitz, B. Z.
(2004). Lead Poisoning From a Toy Necklace. Pediatrics
114: 1096-1099
[Abstract][Full Text]
ozden, T. A., Issever, H., Gokcay, G., Saner, G.
(2004). Longitudinal Analyses of Blood-Lead Levels and Risk Factors for Lead Poisoning in Healthy Children under Two Years of Age. Indoor and Built Environment
13: 303-308
[Abstract]
Lewis, M. W., Pitts, D. K.
(2004). Inorganic Lead Exposure in the Rat Activates Striatal cFOS Expression at Lower Blood Levels and Inhibits Amphetamine-Induced cFOS Expression at Higher Blood Levels. J. Pharmacol. Exp. Ther.
310: 815-820
[Abstract][Full Text]
Dietrich, K. N., Ware, J. H., Salganik, M., Radcliffe, J., Rogan, W. J., Rhoads, G. G., Fay, M. E., Davoli, C. T., Denckla, M. B., Bornschein, R. L., Schwarz, D., Dockery, D. W., Adubato, S., Jones, R. L., for the Treatment of Lead-Exposed Children Clinica,
(2004). Effect of Chelation Therapy on the Neuropsychological and Behavioral Development of Lead-Exposed Children After School Entry. Pediatrics
114: 19-26
[Abstract][Full Text]
Geltman, P. L., Meyers, A. F., Mehta, S. D., Brugnara, C., Villon, I., Wu, Y. A., Bauchner, H.
(2004). Daily Multivitamins With Iron to Prevent Anemia in High-Risk Infants: A Randomized Clinical Trial. Pediatrics
114: 86-93
[Abstract][Full Text]
Eden, A. N.
(2004). Iron Deficiency and Blood Lead Levels. Pediatrics
114: 329-329
[Full Text]
Mycyk, M. B, Leikin, J. B
(2004). Combined Exchange Transfusion and Chelation Therapy for Neonatal Lead Poisoning. The Annals of Pharmacotherapy
38: 821-824
[Abstract][Full Text]
Ozden, T. A., Kilic, A., Toparlak, D., Gokcay, G., Saner, G.
(2004). Blood Lead Levels in School Children. Indoor and Built Environment
13: 149-154
[Abstract]
Lavoie, P. M., Bailey, B.
(2004). Lead poisoning from "lead-free" paint. CMAJ
170: 956-956
[Full Text]
Grigg, J
(2004). Environmental toxins; their impact on children's health. Arch. Dis. Child.
89: 244-250
[Abstract][Full Text]
Cheong, J. H., Bannon, D., Olivi, L., Kim, Y., Bressler, J.
(2004). Different Mechanisms Mediate Uptake of Lead in a Rat Astroglial Cell Line. Toxicol Sci
77: 334-340
[Abstract][Full Text]
Needleman, H. L., Landrigan, P. J.
(2004). WHAT LEVEL OF LEAD IN BLOOD IS TOXIC FOR A CHILD?. AJPH
94: 8-8
[Full Text]
Brown, M. J., Meehan, P. J.
(2004). HEALTH EFFECTS OF BLOOD LEAD LEVELS LOWER THAN 10 MG/DL IN CHILDREN. AJPH
94: 8-9
[Full Text]
Markowitz, M. E., Sinnett, M., Rosen, J. F.
(2004). A Randomized Trial of Calcium Supplementation for Childhood Lead Poisoning. Pediatrics
113: e34-39
[Abstract][Full Text]
(2003). Even Very Low Blood Lead Levels May Affect Intelligence. JWatch Neurology
2003: 3-3
[Full Text]
Shannon, M. W.
(2003). Study raises questions about definition of lead poisoning. AAP News
23: 63-64
[Full Text]
Bellinger, D. C., Needleman, H. L., Eden, A. N., Donohoe, M. T., Canfield, R. L., Henderson, C. R. Jr., Lanphear, B. P.
(2003). Intellectual Impairment and Blood Lead Levels. NEJM
349: 500-502
[Full Text]
Neuspiel, D. R.
(2003). Lead Levels Under 10 Micrograms per Deciliter Are Hazardous. AAP Grand Rounds
10: 1-2
[Full Text]
(2003). Even Low Blood Lead Levels Can Have Bad Consequences. JWatch Psychiatry
2003: 1-1
[Full Text]
(2003). Lead: Devastating Impact Even at Low Levels. JWatch Pediatrics
2003: 1-1
[Full Text]
(2003). Lead: Devastating Effects, Even at Low Levels of Exposure. JWatch General
2003: 4-4
[Full Text]