Collaborative ECHO research led by Jennifer Ames, PhD of the Kaiser Permanente Northern California Division of Research and Ghassan Hamra, PhD of Johns Hopkins Bloomberg School of Public Health, investigates whether exposures to per- and polyfluoroalkyl substances (PFAS) during pregnancy were associated with the development of autism-related traits in children. The researchers looked at data from 1,224 mother-child pairs and found that prenatal exposure to one specific PFAS chemical, perfluorononanoic acid (PFNA), may be associated with an increase in autism-related traits in children. Prenatal exposure to the mixture of all PFAS chemicals combined was not associated with increased autism-related traits in children. This research, titled “Prenatal exposure to per- and polyfluoroalkyl substances and childhood autism-related outcomes,” is published in Epidemiology.
PFAS are widely used, long lasting chemicals, the components of which break down very slowly over time. Previous studies that have investigated the association between prenatal PFAS exposure and childhood autism spectrum disorder (ASD) have been inconsistent and mostly involved small sample sizes. This study leveraged the large, diverse ECHO-wide cohort to evaluate how prenatal PFAS exposure affects the development autism-related traits, even when a child does not receive a clinical ASD diagnosis.
This study included children born between 2011 and 2018 from 10 racially and ethnically diverse ECHO cohorts across the United States, including one cohort that enrolls children from families with an increased likelihood of ASD. The researchers measured the levels of eight different PFAS in blood samples collected from mothers during pregnancy. Later, when their children were aged 2.5 years or older, researchers asked caregivers to report on their child’s autism-related traits using a questionnaire called the Social Responsiveness Scale (SRS). The research team tracked the associations between these data to examine child SRS scores in relation to each individual PFAS as well as the combination of the PFAS.
“In the U.S. population, exposures to perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have dropped substantially since the industry voluntarily phased out these chemicals in the early 2000s,” said Dr. Ames. “However, other PFAS exposures have increased over time, including thousands with unknown toxicity. These so-called ‘forever chemicals’ continue to pose risks to health even after they are phased out because they persist in the environment and inside people’s bodies and don’t break down easily.”
These results underscore the need for more research on whether PFAS chemicals might have more significant effects on child neurodevelopment, and whether factors such as genetics, underlying health conditions, or nutritional status may change the effect of PFAS exposure on brain development.