PCBs Impact Cognitive Abilities of the Elderly Decades Later

Polychlorinated biphenyls, known as PCBs, have been banned in the United States since 1979. These chemicals can cause a host environmental issues, impacting wildlife as they filter into water sources and move up the food chain. Now, though, researchers have found that even though PCBs have been banned, they're still impacting our health. It turns out that higher levels of the toxin have been found in seniors and is being associated with lower cognitive performance.

"While most studies have looked at the impact of PCBs on infant development, our research shows that this toxin might affect us throughout our lives," said Maryse Bouchard, one of the researchers, in a news release.

The use and production of PCBs have been phased out for over 40 years. However, these substances are highly persistent and can be found in the blood of most individuals, especially older people. PCBs can accumulate in the lipid tissues of animal and marine life forms, which means that they can enter the food chain and biomagnify.

In order to test the effects of PCBs, the scientists examined 708 Americans. They researchers collected blood samples to determine the levels of toxins in the volunteer's bodies and then had the participants complete a memory and motor-skill task to determine their cognitive performance.

In the end, the researchers found that the PCB levels were representative of those in the general U.S. population. In addition, they discovered that there was a significant association between PCB levels and cognitive abilities among individuals aged 70 to 84 years. There was also a correlation detected to a lesser extent among people aged 60 to 69 years. In addition, the association differed by sex; women in the older age group had the largest diminution in cognition in relation to exposure.

"Aging persons could be at particular risk because of higher cumulative exposure built up across a lifetime, susceptibility due to underlying medical conditions, such as vascular disorders, and diminished cognitive reserve capacity," said Bouchard, one of the researchers, in a news release. "Our present findings suggest that PCBs, even at levels generally considered to pose low or no risk, may contribute to cognitive deficits."

The findings reveal that PCBs are continuing to impact the environment and even human populations. This, in turn, reveals the importance of fully testing chemicals before using them in products.

The findings are published in the journal Environmental Health Perspectives.