Chris Gennings, Ph.D.
Icahn School of Medicine at Mount Sinai
Exposure to a mixture of suspected endocrine-disrupting chemicals (EDCs) early in pregnancy may reduce IQ in children, according to a new NIEHS-funded study. EDCs are chemicals that can interfere with hormone action, even at low levels. This is the first study to investigate prenatal exposure to suspected EDC mixtures in relation to child neurodevelopment.
The researchers analyzed blood and urine samples from 718 mothers participating in the Swedish Environmental Longitudinal, Mother and Child, Asthma and Allergy (SELMA) study. Samples were taken during the women’s first prenatal visit to the clinic. The team assessed the relationship between 26 EDCs in the mother’s blood and urine and her child’s IQ, measured at age 7 years. They adjusted their models for the child’s sex, gestational age, and the mother’s education, IQ, weight, and smoking status.
They found that early prenatal exposure to the EDC mixture was associated with lower IQ in children, and that the EDC mixture disproportionately affected boys. The researchers estimated that boys in the highest quarter of exposure levels had IQ scores that were approximately 2 points lower than boys in the lowest quarter of exposure levels. Within the mixture, the team identified specific chemicals that most highly contributed to a lower IQ. Bisphenol F (BPF), a bisphenol A (BPA)−replacement compound, made the largest contribution, followed by a pyrethroid pesticide, an organophosphate pesticide, two phthalates, three per- and polyfluoroalkyl substances, triclosan, and BPA.
According to the authors, identification of BPF as the primary chemical of concern suggests that the BPA replacement may not be safer for children.
Citation: Tanner EM, Hallerback MU, Wistrom S, Lindh C, Kiviranta H, Gennings C, Bornehag CG. 2019. Early prenatal exposure to suspected endocrine disruptor mixtures is associated with lower IQ at age seven. Environ Int 19:105185.