Prenatal exposure to trichlorinated biphenyls (PCB 18 and 28) is associated with child hyperactivity 8 years later

Abstract

Background: Polychlorinated biphenyl (PCB) exposure may be associated with neurodevelopmental problems, particularly hyperactivity and attention deficit/hyperactivity disorder (ADHD). In animal studies, exposure to PCBs increased hyperactivity, decreased dopamine in key brain regions, and PCB 28, 47, and 52 were found in those regions. Dopamine has also been implicated in the etiology of ADHD in humans. Most epidemiologic studies have relied on maternal blood rather than newborn blood to quantify prenatal PCB exposure, and neonatal levels might better reflect fetal exposure. Methods: Whole-blood concentrations of PCB congeners #8, 15, 18, 28, 52, 70, 95, 101, 138, and 153 were measured in the Upstate KIDS study, a population-based longitudinal study of children born in New York State between 2008-2010, using newborn dried blood spots (n=2610). PCBs were quantified (ng/mL) using gas chromatography-DFS high resolution mass spectrometry. Individual blood spots provided insufficient volume for assays, so pools of 5 were used, and individual values were derived from pools. Child hyperactivity symptoms (Mean=4.82, SD=5.13) were assessed by maternal report on the Vanderbilt ADHD Parent Rating Scale when children were 8 years of age. Models were adjusted for child age, sex, and plurality, and maternal age, education, race/ethnicity, insurance status, marital status, pre-pregnancy body mass index, gestational weight gain, parity, and pregnancy smoking. Results: Each 1 ng/mL increase in PCB 18 and PCB 28 was associated with 3.63 (95%CI=0.42-6.84) and 4.08 (95%CI=0.61-7.55) more points in hyperactive behavioral ratings, respectively. Except for PCB 15, other PCBs also had positive but imprecise relations with hyperactivity. Conclusions: Levels of PCBs in newborn blood spots were associated with less than 1 standard deviation higher hyperactivity 8 years later. Even low-level prenatal exposure may have long-term behavioral consequences.