Persistence is a great trait if you're job hunting, learning to play the piano or potty training your child. But when it comes to toxic chemicals, persistence is a characteristic that spells trouble for people, animals and the environment.
Congress, as it sets about updating and reforming the outmoded laws governing chemicals in commerce, can make the job easier and straightforward by restricting all non-essential uses for persistent toxic chemicals that build up in living beings and the environment. It's simply common sense, given what we know about the hazards of substances identified as persistent, bioaccumalative toxics or PBTs.
While PBTs aren't the only kinds of chemicals associated with toxic effects, they warrant special attention in the rewriting of our toxics laws because of the challenges they pose. Namely, they do not break down readily (or sometimes at all) in the environment. They hang around, or bioaccumulate, in the bodies of humans and animals for years and years. And they biomagnify, or increase in concentration, as they move up the food chain. As a result, humans and wildlife at the top of the food chain have the highest concentrations of PBTs.
Unfortunately, PBTs are associated with a wide range of serious and long-term human health problems, including early onset of puberty, infertility, endocrine disruption, learning disabilities, behavioral disorders, and certain cancers. (Note to First Lady Michelle Obama: recent animal research suggests low dose developmental exposures may be somehow programming bodies for obesity later in life.)
And despite the industrial-sounding name, PBTs hit close to home. In fact, they're in your home. One example is a family of toxic chemicals used in making any number of items we take for granted: non-stick cookware surfaces; carpets and carpet treatments; floor waxes; water- and stain-resistant clothing,; linens, and grease-resistant food wrappings (think microwave popcorn bags and pizza boxes).
Studies show these substances, known as perfluorinated chemicals (PFCs), have dirtied the planet and everyone on it over the course of the past half-century.
Biomonitoring studies have detected PFCs in human blood samples in the United States, Japan, Canada, Colombia, Brazil, Italy, Poland, Germany, Belgium, Sweden, India, Malaysia, Korea, China and Australia.
Researchers have looked for -- and found -- PFCs in breast milk, seminal plasma and umbilical cord blood. That means PFCs cross the placenta, exposing fetuses during sensitive times of development that could cause health problems that may not emerge until much later in life.
Wildlife is tainted by PFCs, too - from mink to field mice, from bottle-nosed dolphins to ringed seals, from Brandt's cormorant to polar bears.
In the environment, there is simply nowhere on earth you can escape PFCs. The Arctic is polluted, so are the coastal waters of South China, Japan and Korea. They are in drinking water sources near production plants in West Virginia and Germany.
They mix with the air we breathe and the dust in our homes.
Indeed, the Environmental Protection Agency is concerned that children who crawl and play on floors are particularly susceptible to exposure from inhaling PFCs off-gassing from carpet and carpet treatments. "The significantly high levels of PFC found in carpet and carpet protectants pose an exposure concern for children through this pathway," stated an EPA action plan on PFCs released in December 2009.
Because of their long human half-life (measured in years), the EPA concludes "it can reasonably be anticipated that continued exposure (to PFCs) could increase body burdens to levels that would result in adverse outcomes."
Sadly, the story of PFCs is one of recent history repeating itself. Because our toxics laws have failed to adequately restrict the uses of persistent bioaccumulative chemicals, our situation with PFCs is strikingly similar to a dilemma faced by our parents and grandparents.
A generation ago, the PBTs at issue were the pesticide DDT and the industrial insulators known as PCBs. These persistent, bioaccumulative substances - both banned more than 30 years ago -- were used widely for years before their perils were truly understood. Today, they are known as "legacy" chemicals because of their continued presence in the environment and in people. Because of gross inadequacies in U.S. toxics laws, PFCs are destined to become the legacy substances of tomorrow - measurable in people, animals and the environment for decades to come.
We can stop this destructive cycle now by writing a new law that phases out all non-essential uses of PBT chemicals already on the market, and specifically bans the introduction of new chemicals with those characteristics.
Tell your lawmakers that ridding the marketplace of persistent, bioaccumulative toxic chemicals is important to you and your family.
And in this case, please be persistent.
This post first appeared on the Healthy Families Safer Chemicals blog.
Investigative journalist Nena Baker is the author of The Body Toxic: How the Hazardous Chemistry of Everyday Things Threatens Our Health and Well-being (North Point Press).