Cognitive development and low-level lead exposure in poly-drug exposed children.
The impact of early postnatal lead exposure measured at age 4 on children's IQ and academic achievement at and 11 years of age was examined. The sample consisted of 278 inner-city, primarily African American children who were polydrug exposed prenatally. Regression analyses indicated a linear effect of lead exposure on outcomes and no moderating effects of polydrug exposure. An IQ loss of about 4.1-5.4 Full Scale IQ points was estimated for each 10 microg/dL increase in blood lead level at ages 4, 9, and 11 years as a function of blood lead level at age 4. Decrements in scores on tests of non-verbal reasoning were consistently associated with higher lead levels at age 4, while verbal decrements became apparent only at age 11. Lower reading summary scores at 9 and 11 years were consistently associated with higher lead exposure, while decrements in mathematics were not apparent until 11 years. Subgroup analyses on children with blood lead levels <10 microg/dL showed detrimental lead effects even at the 5 microg/dL level, providing additional evidence of adverse effects occurring at blood lead levels below the current 10 microg/dL public health blood lead action level.
Case Western Reserve University School of Medicine, Department of Pediatrics, Cleveland, OH 44106-7164, USA. meeyoung.min@case.edu
Meeyoung O
MO
Min
Lynn T
LT
Singer
H Lester
HL
Kirchner
Sonia
S
Minnes
Elizabeth
E
Short
Zehra
Z
Hussain
Suchitra
S
Nelson
D001741:Black or African American / Q000706:statistics & numerical data; D017677:Age Distribution; D002675:Child, Preschool; D003071:Cognition / Q000187:drug effects; D003072:Cognition Disorders / Q000139:chemically induced* / Q000175:diagnosis / Q000503:physiopathology; D002658:Developmental Disabilities / Q000139:chemically induced* / Q000175:diagnosis / Q000503:physiopathology; D004347:Drug Interactions / Q000502:physiology; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006801:Humans; D013287:Illicit Drugs / Q000009:adverse effects; D008607:Intellectual Disability / Q000139:chemically induced / Q000175:diagnosis / Q000503:physiopathology; D007360:Intelligence / Q000187:drug effects / Q000502:physiology; D007805:Language Development Disorders / Q000139:chemically induced / Q000175:diagnosis / Q000503:physiopathology; D007854:Lead / Q000009:adverse effects* / Q000097:blood; D020264:Lead Poisoning, Nervous System, Childhood / Q000150:complications* / Q000503:physiopathology; D008137:Longitudinal Studies; D008297:Male; D009483:Neuropsychological Tests; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D014505:Urban Population / Q000706:statistics & numerical data
D013287:Illicit Drugs; D007854:Lead