Biomaterial Database

Lifetime exposure to environmental lead and children's intelligence at 11-13 years: the Port Pirie cohort study. 1996

S Tong, and P Baghurst, and A McMichael, and M Sawyer, and J Mudge

Division of Human Nutrition, Commonwealth Scientific Industrial Research Organisation, Adelaide, Australia.

OBJECTIVE To examine the association between environmental exposure to lead and children's intelligence at age 11-13 years, and to assess the implications of exposure in the first seven years of life for later childhood development. METHODS Prospective cohort study. METHODS 375 children born in or around the lead smelting town of Port Pirie, Australia, between 1979 and 1982. METHODS Children's intelligence quotient (IQ) measured at 11-13 years of age. RESULTS IQ was inversely associated with both antenatal and postnatal blood lead concentrations. Verbal, performance, and full scale IQ were inversely related to blood lead concentration with no apparent threshold. Multivariate analyses indicated that after adjustment for a wide range of confounders, the postnatal blood lead concentrations (particularly within the age range 15 months to 7 years) exhibited inverse associations with IQ. Strong associations with IQ were observed for lifetime average blood lead concentrations at various ages. The expected mean full scale IQ declined by 3.0 points (95% confidence interval 0.07 to 5.93) for an increase in lifetime average blood lead concentration from 0.48 to 0.96 mumol/l (10 to 20 micrograms/dl). CONCLUSIONS Exposure to environmental lead during the first seven years of life is associated with cognitive deficits that seem to persist into later childhood.

UI	MeSH Term	Description	Entries
D007360	Intelligence	The ability to learn and to deal with new situations and to deal effectively with tasks involving abstractions.
D007361	Intelligence Tests	Standardized tests that measure the present general ability or aptitude for intellectual performance.	Mental Tests,Raven Test,Raven's Progressive Matrices,Intelligence Test,Mental Test,Raven Progressive Matrices,Ravens Progressive Matrices,Test, Intelligence,Test, Mental,Test, Raven
D007854	Lead	A soft, grayish metal with poisonous salts; atomic number 82, atomic weight 207.2, symbol Pb.
D008297	Male		Males
D011446	Prospective Studies	Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.	Prospective Study,Studies, Prospective,Study, Prospective
D012044	Regression Analysis	Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.	Regression Diagnostics,Statistical Regression,Analysis, Regression,Analyses, Regression,Diagnostics, Regression,Regression Analyses,Regression, Statistical,Regressions, Statistical,Statistical Regressions
D002648	Child	A person 6 to 12 years of age. An individual 2 to 5 years old is CHILD, PRESCHOOL.	Children
D002657	Child Development	The continuous sequential physiological and psychological maturing of an individual from birth up to but not including ADOLESCENCE.	Infant Development,Development, Child,Development, Infant
D004787	Environmental Pollution	Contamination of the air, bodies of water, or land with substances that are harmful to human health and the environment.	Pollution, Environmental,Soil Pollution,Pollution, Soil
D005260	Female		Females