Exposure during pregnancy's first trimester to mixtures of suspected endocrine disrupting chemicals found in consumer products is related to lower IQ in children after age 7, according to a study by researchers at Icahn School of Medicine at Mount Sinai and Karlstad University, Sweden, published Environment International in October. This study is among the first to look at suspected suspected hormone disrupting chemical mixtures in advance.
Researchers measured 26 chemicals in blood and urine from 718 mothers during the first trimester of their pregnancies in the study of Swedish mothers and children, known as SELMA. These chemicals included bisphenol A (BPA), which is found in plastic food and beverage containers, as well as pesticides, phthalates and other chemicals found in consumer products. Some of the 26 are known to interfere with endocrine (hormone) activity in humans; others have been shown to do so only in animals, or are suspected of endocrine disruption because they share chemical properties with known disruptors.
Researchers later followed up with the children at age seven and found that those whose mothers had higher levels of chemicals in their system during pregnancy had lower IQ scores -1; especially boys, whose scores were lower by two points. Within the mix, bisphenol F (BPF), a BPA replacement compound, made the highest contribution to lowering children's IQ, suggesting that BPF is no safer for children than BPA.
The study found that other chemicals of concern in the mixture were the pesticide chlorpyrifos; polyfluoroalkyl substances, which are found in cleaning products; triclosan, a chemical found in antibacterial soaps; and phthalates, which are found in soft polyvinyl chloride plastic and cosmetics. Many of the chemicals only stay in the body for a short period of time, which means even short-term exposure can be harmful, so researchers believe this indicates that preventing exposure to pregnant women or women trying to get pregnant is crucial to preventing neurological damage to children. .
- This study is important because most studies evaluate one chemical at a time. But people are exposed to many chemicals at once, and multiple exposures can be harmful even if each individual chemical is at a low level." said Eva Tanner, Ph.D., MPH, postdoctoral fellow in the Department of Environmental Medicine and Public Health at the Icahn School of Medicine at Mount Sinai.
Carl-Gustaf Bornehag, PhD student, professor at Karlstad University, says that it shows that exposure to mixtures of chemicals in ordinary consumer products can affect the development of the brain's brain and that some chemicals that are believed to be safer, such as BPF, may not be something safer for children.
The chemicals affect hormone activity, even at low levels. Previous studies link many suspected endocrine disorders, including phthalates and BPA, to neurodevelopmental disorders in children.
Some of these chemicals cross the placenta during pregnancy, expose the fetus and may cause irreversible developmental damage. While termination of exposure to a short-lived pollutant can eliminate adverse effects in adults, exposure during critical periods of fetal development can be permanent, with subtle endocrine changes potentially affecting health outcomes in adulthood, Dr. Tanner.
Dr. Tanner says that this study only assessed exposure at a single point in early pregnancy, so more research needs to be done to understand how exposures during later pregnancy and childhood can affect outcomes. The researchers note that several of the chemicals studied only remain in the body for a short time, so the mothers in the study may have had additional exposures before or after their blood and urine tests were taken.
Researchers note the study was observational, and further studies are needed to confirm these results.
Karlstad University, Örebro University, Lund University and the National Institute for Health and Welfare in Helsinki, Finland, made significant contributions to this research.
This research was partially funded by the National Institute of Environmental Health Sciences (R01ES028811-01) and the European Union (EDC-MixRisk 634880).
Articel in Environment International
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