The ABCs of PBTs

It’s a mouthful: Persistent Bioaccumulative Toxic substances., also known as PBTs. Persistent means they don’t break down and they last for a long time in the environment. Bioaccumulative means that they build up in the tissues of living organisms, including people. Toxic means that they can cause a variety of health effects.

PBTs contaminate air, water, soil and living organisms—they are found in almost everything we eat, drink and breathe. From the mercury in your tuna fish sandwich to the pesticides in water to the pollutant benzo(a) pyrene in wood or charcoal smoke, you may have trouble escaping exposure to PBTs.

The U.S. Environmental Protection Agency (EPA) has identified a dozen “priority PBTs”---the so-called “dirty dozen.” The names of these substances appear on the background of this page. The Washington State Department of Ecology has included a number of additional substances for evaluation on its PBT Working List. It is likely that, as we learn more, additional PBTs will be defined.