August 24, 2023 — Chemicals used in hundreds of products known as phthalates have been linked to emotional and behavioral development issues in 24-month-old-boys who were exposed during the first trimester of pregnancy, according to a new study by Hebrew University of Jerusalem (HU) researchers.

“Our findings, published in NeuroToxicology, underscore the potential impact of maternal exposure to phthalates on children’s emotional and behavioral development, particularly among boys,” says Liron Cohen-Eliraz, a Ph.D. student who conducted the research as part of her dissertation. “Our study adds to the growing body of evidence highlighting the need for greater environmental awareness and action to minimize exposure to harmful chemicals during pregnancy.”

Phthalates are a group of chemicals used to make plastics more durable. Known as the “everywhere plastic,” the ubiquitous chemical is used in vinyl flooring, lubricating oils, and personal-care products (soaps, shampoos, hair sprays) and elsewhere.

Endocrine disrupting chemicals (EDCs) such as phthalates cross the placenta and, when absorbed into the prenatal body, can either mimic or block female hormones, or in males, suppress the hormones involved in male sexual development.

The study involved recruiting pregnant women between 11 and 18 weeks of gestation, and analyzing their spot urine samples for phthalate metabolites (DEHP, DiNP, and MBzBP). The researchers later assessed developmental and behavioral offspring progress at 24 months of age using well-established maternal report measures including CBCL, ASQ-3, and HOME questionnaires.

The results revealed noteworthy gender-specific associations. Specifically, the study found that boys exposed to higher DEHP levels during the first trimester had lower developmental scores in personal social abilities, as measured by the ASQ-3 questionnaire.

Moreover, these toddler aged boys exhibited higher in internalizing, including emotionally reactive, anxiety or depression scores, and somatic complaints, as well as externalizing problems.

Although phthalates were found in 98% of the mother’s urine specimens, no differences were observed in high or low levels of girls’ exposure to varied DEHP levels during pregnancy. Continued research in this field is crucial to further understand the long-term implications of endocrine disrupting chemicals on human health and development.

Cohen-Eliraz’s dissertation was supervised by Hebrew University professors Dr. Tammy Piowsky-Peleg of the Department of Psychology and Ronit Calderon-Margalit of the Braun School of Public Health, Faculty of Medicine. This work was supported by the Israel Science Foundation (grant #RGA 1706/15). The Hebrew University Advanced School of Environmental Studies granted a Ph.D. scholarship to Cohen-Eliraz.