Once hailed as an “industrial miracle,” manmade polychlorinated biphenyls, or PCBs, were used to make all kinds of things.
Invented in 1929, scientists later found PCBs were carcinogens and they were widely banned from commercial use in 1979. But for decades they were ubiquitous, used to make children’s fingerpaints. Trash bags. Containers you kept leftovers in. Baby bottles. Magazines. Fluorescent bulbs.
Yet, even with a ban, PCBs still haunt us as they linger in the environment.
Now, a team of Japanese researchers say that enzymes produced by the body unevenly metabolize those lingering PCBs. Some end up with more chlorine atoms, even though all PCBs are chemically identical. The Japanese study on that process is expected to boost scientists’ understanding about potential toxicity in humans and other mammals.
PCBs don’t break down easily and can cycle repeatedly from air to water to soil. We ingest them when we eat salmon or catfish, and they find their way into our body fat, where they stay for months or even years.
Understanding which parts of PCBs are reduced by metabolism and which remain entrenched in the body will allow scientists to better estimate the toxicity of those high-chlorine PCBs.
Some 1.5 billion pounds of PCBs were made before 1979. In the 1960s, as scientists began to understand the compound’s persistence, traces of PCBs in people and animals were found around the globe, from population centers like New York City to the remote Arctic.
States and cities across the U.S. have filed lawsuits against the manufacturer of most PCBs.
One age’s industrial miracle has become another’s environmental mess —and a legal one.