Interactions between environmental lead exposure and sociodemographic factors on cognitive development.
A total of 375 children who lived in Port Pirie, South Australia, and surrounding towns were followed from birth to ages 11-13 y. Possible interactions between lifetime average blood lead concentration and sociodemographic factors (including gender, parents' occupational prestige [as a surrogate of socioeconomic status], quality of home environment, and maternal intelligence quotient) on children's intelligence quotients were examined. Although no statistically significant interaction between blood lead concentration and any of these covariates was found, the results suggested that-after adjustment for a wide range of covariates--children from socially disadvantaged backgrounds (adjusted regression coefficient = -9.6 intelligence quotient points per log unit of blood lead concentration; 95% confidence interval = -2.5, -17.7) were more sensitive to the effects of lead than those of a higher socioeconomic status (adjusted regression coefficient = -2.9; 95% confidence interval = 3.8, -9.6). In addition, girls (adjusted regression coefficient = -7.4; 95% confidence interval = -1.7, -13.1) were more sensitive to the effects of lead than boys (adjusted regression coefficient = -2.6; 95% confidence interval = 2.9, -8.0). These results were basically consistent with our findings observed at ages 2 y, 4 y, and 7 y.
Tong
S
S
Centre for Public Health Research, School of Public Health, Queensland University of Technology, Kelvin Grove, Australia.
McMichael
A J
AJ
Baghurst
P A
PA
D000293:Adolescent; D017677:Age Distribution; D001315:Australia / Q000453:epidemiology; D002648:Child; D002657:Child Development / Q000187:drug effects*; D002675:Child, Preschool; D003072:Cognition Disorders / Q000139:chemically induced* / Q000453:epidemiology*; D015331:Cohort Studies; D016001:Confidence Intervals; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006801:Humans; D015994:Incidence; D007360:Intelligence / Q000187:drug effects*; D007854:Lead / Q000009:adverse effects* / Q000097:blood; D008297:Male; D011159:Population Surveillance; D012016:Reference Values; D012044:Regression Analysis; D012307:Risk Factors; D017678:Sex Distribution; D012959:Socioeconomic Factors
D007854:Lead