Why and How to Avoid Polychlorinated Biphenyls (PCBs)

January 31, 2023

When you’re busily learning about environmental health concerns and their potential to harm your kids, sometimes you come across confusing stuff. Like why do parents need to know anything about a class of chemicals used mainly electronics that hasn’t been manufactured in the U.S. since 1977?

Here’s why: Yes, the manufacture of PCBs was halted in the 70s because of evidence that they build up in the environment and can cause harmful health effects. The EPA deems PCBs “probably carcinogenic.” The issue is that during the time they were being manufactured and used in electrical equipment as well as things like transformers, and capacitors (they don’t burn easily and are good insulators), they entered the air, water, and soil. PCBs remain there today. And even though they’re no longer being manufactured, they are still being released into the environment via hazardous waste sites, and via leaks, improper disposal, and incineration.

Still don’t understand how this can harm your kids or you? Follow the chain a little bit downstream. PCBs build up in sediment in rivers, lakes, and coastal areas. Then they accumulate in fish and marine mammals in levels higher than found in the water. Then you and your family sit down to a lovely seafood dinner and—you guessed it—you eat the PCBs. Farmed seafood isn’t the way to avoid PCBs found in wild fish; its feed usually includes ground-up wild fish containing PCBs. Because of this farmed fish can actually have higher concentrations of PCBs than wild fish.

This is of concern because PCBs have been linked to low birth weight, slowed growth, and interfering with brain—and intellectual—development. Beyond its status as a probable human carcinogen, other studies suggest it can also be toxic to the reproductive system, the immune system, and the thyroid.

Beyond seafood, people are typically exposed to PCBs via meat (it accumulates in all fatty flesh), breast milk (when mom eats PCBs, she passes them on), and even via old light fixtures. The EPA maintains guidelines online for how to determine if your school has the kind of fixtures that could release PCBs into a classroom. It’s well worth checking with your school administration about these.

To lower your family’s PCB intake, minimize the amount of animal fat you eat and make all seafood choices carefully. Thankfully there are many seafood databases online as well as apps for smartphones that list safer fish by contaminants (PCBs and mercury) as well as sustainability. Certain common fish notoriously high in good nutrients are also high in PCBs, including Atlantic as well as farmed salmon. In 2023 the FDA reinforced that isn’t a good idea to remove seafood from your diet entirely, suggesting kids and pregnant moms consume more, not less seafood. Rely on the online databases to find out how many meals of any given fish are safe to eat per month. Cooking fish and meat so the fat drips away from the flesh is another way to reduce the PCBs in your finished meal.