Washington, D.C. – The Centers for Disease Control announced that autism rates are once again rising among children. The new data says 1 in 44 children in the U.S. is on the autism spectrum, or 2.3% of children. The CDC made the announcement Thursday.

In a commentary published this week in Pediatrics, a group of epidemiologists, toxicologists, and physicians with decades of expertise in research, public health, and clinical practice says the interaction of toxic chemicals with genetic susceptibilities is a major contributor to autism spectrum disorder (ASD). The experts, members of Project TENDR, urge a national shift in research, funding, and regulation toward protecting children’s developing brains from harmful exposures.

Heather Volk, PhD, associate professor at the Johns Hopkins Bloomberg School of Public Health and lead author says: “Mounting evidence tells us the key to understanding autism is to examine toxic chemicals and pollutants in combination with genetics. Typically, researchers look at genetics separately from environmental factors. But the greatest risks for autism and its related impairments may result from gene-environment interactions.”

Deborah Hirtz, MD, pediatric neurologist and professor at University of Vermont Medical Center and co-author notes, “My practice sees children who are on the spectrum and their parents. To make a real difference moving forward, we need to focus our efforts where the science is clearly pointing – toward preventing toxic exposures that may do lasting harm to children’s brains.”

The commentary outlines three starting points for action based on growing scientific evidence:

• Air pollution exposures during pregnancy and early infancy, resulting from fossil fuel combustion and at levels typically found in large cities, have been associated with ASD in multiple studies.
• Children exposed prenatally to certain pesticides (“organophosphates”) appear more likely to develop ASD.
• Emerging evidence indicates prenatal exposures to phthalates– ubiquitous endocrine-disrupting chemicals used in plastics, food processing and packaging, and personal care products – are associated with ASD.

Likewise, some environmental factors can reduce the probability of ASD.  Folic acid around the time of conception may protect the developing brain from toxic chemicals. Exposures to air pollutants, pesticides, and phthalates appear to be more strongly related to ASD in children of women who did not take folic acid or needed higher levels of folate during pregnancy.

Irva Hertz-Picciotto, PhD, professor at UC Davis and co-author, states, “We need far more research studying how environmental exposures are altering brain development, and identifying those that are more potent in combination with underlying susceptibilities.”

“From what we’ve already learned, we know what is necessary to protect pregnant women and children: regulation to prevent exposures to neurotoxic pesticides and phthalates, and to quickly achieve further reductions in air pollution from fossil fuels, starting with communities most highly impacted.”

Project TENDR is a collaboration of leading scientists, health professionals, and advocates working to protect children’s brains from toxic chemicals and pollutants. Project TENDR is a program of The Arc, the largest national organization advocating for and with people with intellectual and developmental disabilities, and serving them and their families.

Heather Volk, PhD, is an associate professor, Dept. of Mental Health, and Dept. of Environmental Health and Engineering at Johns Hopkins University Bloomberg School of Public Health. Dr. Volk is Associate Director of Johns Hopkins’ Wendy Klag Center for Autism and Developmental Disabilities and co-Director of the Intellectual and Developmental Disabilities Research Center (IDDRC) at the Kennedy Krieger Institute. Her research seeks to identify factors that relate to the risk and progression of neurodevelopmental disorders. Dr. Volk has particular expertise in how air pollution exposures combined with other factors, including genetics, impact autism risk.

Deborah Hirtz, MD, is a pediatric neurologist and attending physician at the University of Vermont Children’s Hospital, and a professor of neurology and pediatrics at the University of Vermont College of Medicine. Prior to her tenure at U. of Vermont, Dr. Hirtz was a director of clinical trials for the Office of Clinical Research at the National Institute of Neurological Disorders and Strokes (NINDS) of the National Institutes of Health (NIH). Her work as a clinician and scientist has had a profound impact on child neurology, neuroscience, and children’s health and welfare.

Irva Hertz-Picciotto, MPH, PhD, is Professor of the Department of Public Health Sciences and Director of the NIH-funded Environmental Health Sciences Center at UC Davis, representing over a dozen disciplines. A renowned epidemiologist, her 300+ publications have examined environmental chemicals, social factors, and gene-environment interaction associated with pregnancy and child development, and most recently, health effects of climate change. For the last 17 years, Dr. Hertz-Picciotto has directed a research program on Environmental Epidemiology of Autism and Neurodevelopment, which has shaped the field by generating seminal results linking autism to an array of risk and protective factors.