PCBs May Increase Risk of Autism, Researchers Say

Exposure to polychlorinated biphenyl, most commonly known as PCBs, could increase a child’s risk of developing an autism spectrum disorder, according to new research. 

In a study published in the journal Environmental Health Perspectives, researchers from the University of California – Davis and Washington State University found that PCBs promote neural irregularities that could be the deciding factor of whether children with a genetic propensity towards autism actually manifest the disorder.

The researchers found that PCBs cause a chain of events in the brain that results in overproduction of dentrites, which are strands of material that help signals in the brain transmit between neurons. If these dentrites grow out of control it can impair neural connectivity, which is a condition related to disorders on the autism spectrum.

While researchers say that their studies do not indicate that PCBs cause children to develop autism, they could be the final push for children who have the genetic tendency already.

The study involved the use of baby rats who were breastfed by mother rats who had been exposed to PCBs. The chemicals appeared to trigger increased calcium levels in neurons, resulting in dentrite growth.

PCBs were used for decades in dielectric and coolant fluids in electrical motors, transformers, and capacitors. It was eventually determined to be toxic and PCB spills, clean-up sites and the landfills created to dispose of the chemicals were a crucial part of the birth of the environmentalist movement in the United States.

Production of PCBs was banned in the U.S. in 1979 and later worldwide in the Stockholm Convention on Persistent Organic Pollutants in 2001.