Persistent, bioaccumulative toxics, commonly known as PBTs, are a group of toxic chemicals that are joined together by some common features. Common PBTs in our lives include mercury, DDT, cadmium, lead, and several groups of chemicals including PCBs, toxic flame retardants (PBDEs) and dioxins. While these chemicals have many different uses in our lives, and different effects on our health, they are joined together by the following facts:
- PBTs are persistent. These chemicals are often used in manufacturing because of the exact features that cause great, great trouble in our environment: they don't break down, and they stay in the environment for a very long time. PCBs, for instance, are man-made mixtures of chlorinated compounds that are used in manufacturing because they are non-flammable, have a high boiling point, and are insoluble in water: all features that make them very difficult to dispose of.
- PBTs are bioaccumulative. Once these chemicals are ingested by living creatures, they build up in fatty tissue, and move up the food chain as they are consumed by bigger creatures, eventually making their way into our diets.
- PBTs are toxic. These chemicals have been associated with all manner of health effects: mercury affects the nervous system of developing fetuses, chronic exposure to DDT affects the liver and kidneys among other parts of the body, cadmium has been labeled by the Environmental Protection Agency (EPA) as a probable carcinogen, lead exposure in adults results in neurological effects like seizures, PCBs pose a cancer risk, PBDEs have been found to be endocrine disruptors, and dioxins cause reproductive and developmental problems.
Perhaps as important as the above features, PBTs know no borders. DDT and PCBs have not been used widely in the United States for over thirty years, yet they persist in our water and in our animals all over the world, and thus in the bodies of many human beings.
"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."
- Nena Baker, author of "The Body Toxic".
These chemicals are the worst of the worst (see chart below for a complete description of the chemicals), and for that reason, they are receiving special attention from environmental advocates in many states. While the federal government is still determining how to handle PBT contamination on a national level, many states are taking the lead in eliminating these dangerous chemicals.
Tackling PBTs in Washington State
Much of Washington State surrounds water. Between the Puget Sound (which has 2,000 miles of coastline), and the many rivers and lakes, much of the state's economy depends on healthy water.
As a result of increasing populations in the Puget Sound area in the second half of the 20th century, many toxic chemicals are found in the Sound, including PCBs, dioxins and PBDEs. Harbor seals have been found to have levels of PCBs that were three times higher than harbor seals in other common areas1 and orcas have high levels of PBDEs.
"The decline in some marine mammal populations is linked to the prevalence of flame retardant chemicals and other persistent organic pollutants"
- Jean-Michel Cousteau, Ocean Futures Society
Additionally, studies have found high levels of perfluorinated chemicals (PFCs) in osprey eggs in the Columbia River2 in concentrations which were higher than the surrounding environment – proving the bioaccumulative effect of these chemicals. It is suspected that the high levels got to the osprey eggs by way of the fish that compose their diet. The Department of Ecology has also found high levels of PBDEs in the fish of the Spokane River, and are searching for a source of the chemical which is not immediately clear.3
Due to the extreme effect of PBTs on Washington State, the state plays a leadership role in going after PBTs and developing strategies to handle these dangerous chemicals:
- In 2000, Washington State became the first state in the nation to have a mandated, long-term PBT strategy. The legislature allocated $800,000 to identify the worst-of-the-worst PBTs.
- In 2003, the state legislature banned the use of mercury in most consumer applications.
- In 2007, Washington banned PBDEs from mattresses, televisions, computers and residential upholstered furniture.
"Washington is blazing a trail that other states and the international community can watch and learn from."
- Center for International Environmental Law.
Alaskan indigenous people show high PBT exposure
Due to its location, Alaska is a hemispheric sink for PBT chemicals. Few of the chemicals are manufactured in Alaska, rather "Alaska is on the receiving end of toxic chemicals that arrive in the north via wind and ocean currents," says Pam Miller, the executive director of Alaska Community Action on Toxics. Once the contaminants arrive in the Arctic, they are trapped by the cold climate – a process known as global distillation.
"Indigenous Arctic peoples are among the most highly exposed people on earth to toxic chemicals, because these chemicals—DDT, PCBs, brominated flame retardants, and perflourinated compounds, to name a few—are persistent, and drift hundreds and thousands of miles north on wind and ocean currents from where they are manufactured from more southern latitudes. These chemicals contaminate our traditional foods and affect our health and the health of our children,"
- Vi Waghiyi (Yupik Eskimo) Tribal Member.4
Alaska's wildlife tests high for contamination—there are high levels of DDT in bald eagles, sea otters and Steller sea lions, and some orcas have tested at levels which show them to be among the most contaminated mammals on earth.5
In Alaska, more than other places, PBTs make their way into the bodies of its citizens—namely the Alaskan tribal communities – via food. Alaskan tribal communities are closely dependent on traditional foods that include fish and marine mammals. "This is a physical, spiritual, and cultural dependence on the land and ocean," says Miller. Native peoples are eating foods at the top of the food chain that are oil and fat based, where the toxic chemicals are the most highly concentrated.
Though Alaska is a perfect argument for the need for federal legislation—its citizens are receiving many more chemicals than they are manufacturing – the state is still tackling toxic chemical legislation on the state level.
Environmental advocates this year introduced a State Senate bill which would phase out the sale of PBDE chemicals from consumer products in order to protect Alaskans from developmental effects, thyroid disruption, and adverse reproductive effects.
Even in far-afield Alaska, some of the well-known dissidents of flame retardant bans have been showing up at hearings for this bill. Under the guise of protecting people from fires, representatives from the Citizens for Fire Safety – an industry group with a goal of protecting the $4 billion-a-year global market for flame retardants6—show up at nearly all hearings regarding flame retardants. This front group takes their playbook from the tobacco industry who worked to fight all Clean Indoor acts and other anti-smoking legislative initiatives.7
The truth is the phase-out of toxic PBDEs is supported by many citizens, physicians and even firefighter groups. Those who fight fires are among the people who are in the most danger from high PBDE exposure.
The Great Lakes' Toxic Legacy: Great Lakes Areas of Concern. Click image to view larger.
Credit: Safer Chemicals, Healthy Families.
The Great Lakes: A melting pot for PBTs
The Great Lakes cover over 10,000 miles of coast line, and are the largest surface area of freshwater in the world. They are bordered by two countries and eight U.S. states, and they provide drinking water for 40 million people. Unfortunately, they also have a history of pollution and contamination.8
The EPA has identified 43 Areas of Concern around the Great Lakes (26 in the United States). – areas that have undergone a significant change in its chemical, physical, or biological integrity. These changes can include things like changes in algae growth, tainted fish, or a problem with drinking water.
Due to the fact that the Great Lakes are also bordered by Canada, a special agreement was entered into between the U.S. and Canada in 1972. The Great Lakes Water Quality Agreement9 shows the intention of both countries to "restore and maintain the chemical, physical and biological integrity of the waters of the Great Lakes Basin Ecosystem." The agreement has served to reduce many of the pollutants in the lakes; however they do not address the contaminants that the federal Toxic Substances Control Act (TSCA) does not recognize.
Therefore, many PBTs are still found in the lakes. For instance, in Lake Superior the levels of PBDEs doubled every 3-4 years between 1980 and 2000, Lake Erie has extremely high levels of mercury, lead and PCBs, and there have been over 1500 advisories against eating fish in the Great Lakes due to the presence of many PBT chemicals.10
Environmental advocates in the states around the Great Lakes have been doing what they can to protect the lakes via state legislation:
- In 2008, the Great Lakes-St. Lawrence River Basin Water Resources Compact was signed by the legislatures of Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania and Wisconsin and the President of the United States. It is a binding interstate compact that provides a framework to enact protective laws, including environmental protection standards.
- The state of Michigan tried to pass a PBDE ban last year that is similar to the bans in Vermont, Oregon, Washington and Maine.
- New York, which borders Lake Ontario, has several pieces of PBT legislation this session, including a ban on cadmium in consumer products, a limit on lead in jewelry, a limit on PBDE flame retardants, and a comprehensive bill which would establish a list of chemicals of concern, presumably including many PBT toxins.
- Last year, the state of Illinois became the third state in the nation to restrict cadmium in children's jewelry. Illinois joins another Great Lake state—Minnesota—in this groundbreaking ban.
The Safe Chemicals Act: taking PBT cues from the states
This month, the Safe Chemicals Act of 2011 was introduced into the U.S. Senate, sponsored by Senators Lautenberg (NJ), Boxer (CA), Klobuchar (MN), and Schumer (NY). This law will overhaul the antiquated Toxic Substances Control Act (TSCA), which has not been updated since first passed in the 1970's, and is so weak, it makes true regulation of toxic chemicals in this country nearly impossible.
If there's one thing we know about PBT chemicals, it's that they don't respect state borders – which is why it is critical that the federal government's policies work hand-in-hand with state legislation to keep Americans safe from these harmful toxins which risk the health of our families.
"We need a fix at the federal level so that we don't have to do this in the states," said Ted Sturdevant, Director of the Washington State Department of Ecology. "States have limited resources and lack the tools of federal agencies to drive a national program. However, until we have a national solution, we will continue to act on chemical safety concerns in our states."
The 2011 Safe Chemicals Act gives special priority to PBT chemicals, classifying them as particularly harmful and will hopefully give the EPA the support it needs to move swiftly against the use of PBTs when safer alternatives are available. The states have begun the hard process of eliminating PBTs, and in the case of the Great Lakes Water Resources Compact, they've even banded together to create regional regulations. But without the backup of the federal government, future generations will still be dealing with the consequences of ubiquitous PBT use.
"I'm pleased that the 2011 version of the Safe Chemicals Act directly targets persistent, bioaccumulative and toxic (PBT) chemicals and requires actions to quickly achieve the 'greatest practicable reductions in exposure' to them. Some state legislatures have also identified PBTs as chemicals of high concern and are acting as best they can to restrict their use, but it's time for the federal government to ensure all Americans are protected. These chemicals know no borders, and a national approach is essential."
- Dr. Richard Denison, Senior Scientist, Environmental Defense Fund.
You can read more about the Safe Chemicals Act, and keep abreast of its progress at Safer Chemicals, Healthy Families.
Worst-of-the-Worst PBT Chemicals
|Mercury||Mercury is a naturally found element, and is the only metal that is liquid at room temperature. It is used in dental fillings, some batteries, and in compact fluorescent bulbs and has even been found in tested toys.|
|DDT*||Dichlorodiphenyltrichloroethane (DDT) is a synthetic insecticide that was used in the United States in the 1940's and 1950s. Its use was outlawed by the federal government in 1972 for many purposes after its effect on people and wildlife was determined. DDT has not been used widely in first-world countries in over 30 years, yet it is still found in the fat of marine mammals.|
|PCBs*||Polychlorinated biphenyls (PCBs), are man-made mixtures of chlorinated compounds that have been used in electrical equipment, synthetic rubber, plasticizers and even products like asphalt. They are non-flammable, have a high boiling point, are insoluble in water, and have insulating properties – exact features that make them difficult to get rid of in the environment.|
|Dioxins*||Dioxins are chemical compounds that are formed as a result of industrial processes like bleaching of paper pulp, waste incineration and manufacture of some chemicals. Exposure to dioxins usually comes from food. It accumulates in fatty tissue (of humans, and the meat we eat), and stays there.|
|PFCs||Perfluorinated chemicals (PFCs) are used are used to make non-stick and stain-resistant chemicals like Teflon, Scotchguard and Stainmaster. They are commonly found in non-stick cookware, food packaging like pizza boxes and microwave popcorn, and stain-resistant material for clothing, furniture and carpeting. They "off-gas" from many of those products and mix with air and dust in our homes. PFCs are detected in human blood samples worldwide.|
|PBDEs||Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in our everyday lives. They are found on furniture, in electronics casings, in household dust, in children's clothing and products. High levels have also been found in farmed fish – presumably from water contamination and feed.|
|Cadmium||Cadmium is an extremely toxic metal that is used in batteries, industrial paints, metal coatings and as a stabilizer for plastics. It is mainly produced as a byproduct of smelting and refining of zinc concentrates. Cadmium is of increasing concern to parents as it's been found recently in many instances of inexpensive, metal children's jewelry.|
|Lead||Lead is a naturally-occurring metal that is resistant to corrosion and is used in paints, pigments and dyes. It was outlawed from use in paint in 1978, and from children's consumer products in 2009. However, it is still found in old homes, in some plastic PVC products, and in drinking water (when the lead leaches from metal pipes).|
PBTs that are marked with an asterisk (*) are considered to be persistent organic pollutants (POPs) by the Stockholm Convention, a treaty that has been signed by over 100 countries (but not the United States) to eliminate the most harmful contaminants that are persistent in the environment and cross borders.
1U.S. States and the Global POPs Treaty. Center for International Environmental Law, May 2005.
2Study affirms state's aim to reduce perfluorinated compounds. State of Washington, Department of Ecology, 08/10/2010.
3Toxic flame retardants may be decreasing in Spokane River fish. State of Washington, Department of Ecology, 03/22/11.
4Chemical Reform Urgent for People of Color and Low Income Communities. Native American Times, 04/11/11
5Contaminants in Alaska: is America's Arctic at Risk? An Interagency Collaborative Paper (US Department of Interior, US Environmental Protection Agency, National Oceanic and Atmospheric Administration, et al.link, 2000.
6ACC announces the North American Flame Retardant Alliance.American Chemistry Council, 03/31/11.
7Citizens for Fire Safety Exposed: A chemical industry front group for manufacturers of toxic flame retardants (PBDEs). Environmental Health Fund.
8Great Lakes Basin Facts. National Oceanic and Atmospheric Administration.
9Great Lakes Water Quality Agreement. Environmental Protection Agency.
10Toxic Substances Control Act: Failing the Great Lakes. Safer Chemicals, Healthy Families.