Neurobehavioural and cognitive effects of prenatal exposure to organochlorine compounds in three year old children

BackgroundWe report data of a Belgian observational prospective cohort study regarding cognitive and behavioural development until the age of 36months in relation to internal exposure to organochlorine pollutants [sum of polychlorinated biphenyls (sum PCB), dioxin-like activity, PCB118, PCB170, hexachlorobenzene (HCB) and p,p'-dichlorodiphenyldichloroethylene (DDE)] measured in cord blood.MethodsParticipants were recruited as part of an Flemish Environmental Health Survey (2002-2006). Two hundred and six mother-child pairs were recruited. Hundred twenty five toddlers [Reynell Taal Ontwikkelings Schalen (language development, RTOS), Snijders-Oomen Niet-verbale intelligentietest (non-verbal intelligence, SON), Bayley Scales, milestones, Infant Behaviour Questionnaire (IBQ), gender specific play behaviour, Neurobehavioral Evaluation System (NES)-attentional task] and their mothers [Home Observation Measurement of the Environment (HOME), Wechsler Abbreviated Scale of Intelligence (WASI), State-Trait Anxiety Inventory (STAI), general questionnaires] were tested. Statistical analysis was performed with the SPSS program. Much attention was paid to confounding factors.ResultsIn the first years of development, higher organochlorine pollutants were associated with less active children (delayed crawling: sum PCB*HCB (p<0.05), sumPCB*DDE (p<0.1); delayed first steps alone: sum PCB (p<0.5), PCB118 (p<0.01), PCB170 (p<0.01), HCB (p<0.01); less switching between toys: sum PCB (p<0.01); less switching between toys in boys: PCB118 (p<0.01), sum PCB(p<0.01)). At 12months children with higher dioxin-like activity tended to show less fear responses(p<0.1) (IBQ 12months). At 36months, a slower development of language comprehension (RTOS) was related to all organochlorine exposure parameters(p<0.1 or p<0.05) except DDE. Lower nonverbal IQ scores (SON) were related to PCB118 in boys only(p<0.05 or p<0.01). Less masculine and more non-gender specific play behaviour was associated with ...