Hair lead content, intelligence tests, school achievement, and motor impairment assessments were obtained from 149 public school children aged 5 to 16. Hair lead concentration significantly discriminated between groups and significantly predicted IQ scores, independent of group classifications. Regression analyses showed a significant negative correlation between lead and intellectual functioning, even in the normal to gifted IQ range. These results demonstrate a continuous inverse relationship between intelligence and relatively low levels of body lead in which the higher levels of cognitive function are affected before any signs of gross motor impairment are seen.
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References
1.
Brown, S., Dragann, N., & Vogel, W.Effects of lead acetate on learning and memory in the rat. Archives of Environmental Health, 1971, 22, 370–382.
2.
Burchfiel, J.L., Duffy, F.H., Bartels, P.H., & Needleman, H.L.The combined discriminating power of quantitative electroencephalography and neuropsychologic measures in evaluating central nervous system effects of lead at low levels. In H.L. Needleman (Ed.), Low Level Lead Exposure: The Clinical Implications of Current Research. Raven Press, N.Y.: 1980, p. 75.
3.
Campbell, B., Brodie, M., Thompson, G., Meredith, P.A., Moore, M.R., & Goldberg, A.Alterations in the activity of enzymes of haem biosynthesis in lead poisoning and acute hepatic porphyria. Clinical Science and Molecular Medicine, 1977, 53, 335–340.
4.
Carmer, S.G., & Swanson, M.R.An evaluation of ten pairwise multiple comparison procedures by Monte Carlo methods. Journal of the American Statistical Assocation, 1973, 68, 66–74.
5.
Cohen, H.Statistical Power Analysis for the Behavioral Sciences. New York: Academic Press, 1977.
6.
Cohen, J., & Cohen, P.Applied Multiple Regression/Correlation Analysis for the Behavioral Sciences. Hillsdale, N.J.: Lawrence Erlbaum Assoc., 1975.
7.
David, O.Association between lower-level lead concentrations and hyperactivity in children. Environmental Health Perspective, 1974, 7, 17–24.
Dixon, W., & Brown, M.Biomedical Computer Programs P-Series. Los Angeles; University of California Press, 1979.
10.
Goldberg, A.Meredith, P., Miller, S., Moore, M., & Thompson, G.Hepatic drug metabolism and haem biosynthesis in lead poisoned rats. British Journal of Pharmacology, 1978, 62, 529–536.
Govoni, S., Memo, M., Spano, P.F., & Trabucchi, M.Chronic lead treatment differentially affects dopamine synthesis in various rat brain areas. Toxicology, 1979, 12, 343–352.
13.
Hollingshead, B.Four Factor of Social Status. New Haven: Yale Station Press, 1975.
Landrigan, P., Whitworth, R., Baloh, R., Staehling, N., Barthel, N., & Rosenblum, B.Neurophysiological dysfunction in children with chronic low-level lead absorption. Lancet, 1975, 708, 236–239.
16.
LaPorte, R.E., & Talbott, E.E.Effects of low levels of lead exposure on cognitive function—A review. Archives of Environmental Health. 1980, 33, 236–248.
17.
Maxwell, J., & Meyer, U.Effect of lead on hepatic aminolaevulinic acid synthetase activity in the rat: A model for drug sensitivity in intermittent acute porphyria. Europ. J. Clin. Invest., 1972, 6, 373–379.
18.
Moore, M.Meredith, P., & Goldberg, A.Lead and heme biosynthesis. In R. Sighal & J. Thomas (Eds.), Lead Toxicity. Baltimore: Urban and Schwartz, 1980, p. 79.
19.
National Research Council, Lead: Airborne Lead in Perspective. Washington D.C.: National Academy of Sciences, 1972.
20.
Needleman, H.L., Davidson, I., Sewell, E., & Shapiro, I.Subclinical lead exposure in Philadelphia school children: Identification by dentine lead analysis. New England Journal of Medicine, 1974, 290, 245–250.
21.
Needleman, H.L. In R. Sighal & J. Thomas, (Eds.), Lead Toxicity. Baltimore: Urban and Schwartz, 1980, p. 1.
22.
Perino, J., & Ernhart, C.The relation of subclinical lead level to cognitive and sensorimotor impairment in black preschoolers. Journal of Learning Disabilities, 1974, 7, 26–36.
23.
Pihl, R.O., & Parkes, M.Hair element content in learning disabled children. Science, 1978, 198, 204–207.
24.
Settle, D.M., & Patterson, C.C.Lead in albacore: Guide to lead pollution in Americans. Science, 1980, 207, 1167–1179.
25.
Stott, F., Moyers, G., & Henderson, R.Test of Motor Impairment. Ontario, Canada: Brook Educational Publishing Ltd., 1972.
26.
Tiffin, J.Purdue Pegboard Examiner. Chicago: Science Research Associates, Inc., 1968.
27.
U.S. Environmental Protection Agency, Air Quality Criteria for Lead. Washington, D.C.: Office of Research and DevelopmentDecember 1977 (EPA-600/8-77-017).
28.
Vaughan, H.C., McVay, R.S., & Nelson, W. (Eds.). Textbook of Pediatrics. Philadelphia: W.B. Saunders, 1973, p. 1786.
29.
Waldron, H.A.The blood lead threshold. Archives of Environmental Health, 1974, 29, 271–278.
30.
Wechsler, D.Wechsler Intelligence Scale for Children–Revised. New York: The Psychological Corporation, 1974.
31.
Wechsler, D.Wechsler Preschool and Primary Scale of Intelligence. New York: The Psychological Corporation, 1976.
32.
Weir, P.A., & Hine, C.H.Effects of various metals in behavior of conditioned goldfish. Archives of Environmental Health, 1970, 20, 45–53.
