EPA's agency-wide multimedia Persistent, Bioaccumulative, and Toxic Pollutants Initiative

1999 Accomplishments Report, first annual edition

by US Environmental Protection Agency


n continuing its mission of protecting human health and the environment, the US Environmental Protection Agency (EPA) launched the Persistent, Bioaccumulative, and Toxic (PBT) Pollutants Initiative in November 1998. The PBT Initiative is an integrated approach for addressing widespread problems associated with toxic chemicals that persist and bioaccumulate in the environment.

Pollutants such as mercury, polychlorinated biphenyls (PCBs), and some pesticides have persistent, bioaccumulative, and toxic characteristics and pose significant health and environmental concerns. Challenges in controlling pollutants with these characteristics result from their ability to transfer rather easily to air, water, and land, and to travel long distances. Once ingested by fish, birds, or mammals, many of these substances bioaccumulate, leading to body burdens far in excess of levels found in the environment.

With frequent exposure over time, the amount present in organisms' tissues can build up and cause toxic effects. In humans, effects include nervous system abnormalities, reproductive and developmental problems, cancer and genetic impacts. Young children and developing fetuses are especially at high risk.

Over the years, a substantial amount of work has been done by federal and state regulatory agencies, industry, environmental and public health groups, and the scientific community to reduce the risk associated with these pollutants. However, the following examples illustrate the current imperative to continue to take action. Studies have been conducted worldwide to understand more fully the impacts of PBTs on human health and the environment. We have chosen to summarize some of these major findings in two large geographic areas.

Most PBT pollutant releases occur between the Arctic Circle and the Tropic of Cancer, where the majority of industrialized nations are located. In this area, known as the North Temperate Zone, the general population has detectable levels of dioxin in their bodies as a result of eating contaminated meat, fish, eggs, and dairy products. EPA's draft dioxin reassessment (1994) estimated cancer risk to the US population from this exposure to be in the 1:10,000 to 1:1,000 range. Dioxin exposure is approaching levels associated with adverse non-cancer effects (NHANES). Also, about 25 percent of children and nine percent of the general US population are exposed to a level of methylmercury that exceeds the current EPA Reference Dose. Those who rely on fish as a main source of food have even higher PBT body burden levels. US tribes tell the EPA that contamination of subsistence foods is their main concern.

In the Arctic Zone, located north of the Arctic Circle and centered on the North Pole, PBTs are present due to long-range transport from industrialized nations and exposure of migrating species. PBT levels are substantial in the Arctic Zone and PBTs persist longer there because of the low temperatures. Levels of PBTs are expected to rise in the Arctic due to increased local and southeast Asian industrialization. Global distillation alone means decades more of PBT pollutants entering this area (Bard 1999).

For many Arctic tribes, PBT contamination of subsistence foods is linked to their long term survival. PBT exposures are aggravated by the fact that high-food-chain meats are their major source of protein. Extensive recent Canadian research suggests Alaskan wildlife has high PBT levels. If confirmed, most animal protein sources are in question. Often, for many of these populations, there is no alternative but to eat contaminated food. (Alaskan and Arctic Fish and Wildlife database, 1998 AMAP)

Some marine mammal and bird populations are experiencing disease, reproductive problems, and population declines, probably in whole or in part due to contamination from PBT pollutants. A review on harbor porpoises indicates that levels of organochlorines, especially PCBs, are high enough to cause concern about maintaining the population (Aguilar and Bornell 1995). Free-ranging orca whales along the Pacific Northwest coast have PCB levels four to five times higher than highly-PCB-polluted St. Lawrence beluga whales, who themselves have serious health problems. Canadian Arctic whales are providing the first statistical inference that PBT (specifically, PCB) levels in Arctic species relate to subtle health effects. (Lockhart 1995, AMAP 1998). A 1998 study by the International Whaling Commission determined levels of contamination among some marine mammals are so high that the animals would be classified as hazardous waste sites if they were on land.


Integrating PBT efforts at EPA: action, policy and science

Like other environmental departments around the world, the US Environmental Protection Agency (EPA) has learned, little by little over time, that the impacts of PBT contamination have not been, and could not have been, entirely addressed by single-medium approaches or by a singularly domestic approach. Addressing PBT contamination requires a perspective that cuts across environmental media and geographic boundaries. Therefore, EPA continues to stay the course announced in its November 1998 draft PBT Strategy: that of taking an increasingly holistic and integrated approach to addressing PBT contamination.

EPA's PBT effort will be accomplished by using all of the tools available to the Agency - regulatory, compliance, enforcement, research, voluntary actions, and international negotiations. The effort also stresses an approach, but recognizes that, in some situations, treatment and remediation will also be required.

EPA's commitment to addressing PBT contamination implies a dual obligation: (1) to account for the many significant areas of Agency activity that are being integrated or need to be integrated, and (2) to clarify how this process of increasing integration produces better results. In numerous instances, EPA began integrating certain PBT activities several years ago. The increasingly larger scale on which this is being attempted presents a constant challenge to the Agency.

Being the first year of the Initiative, many of the activities in this Report are new and/or ongoing and so have not produced formal, quantifiable results. However, these planning, integration, and development efforts have been included in order to recognize their value to the Initiative in 1999 and beyond. Future editions of the Report will undoubtedly have a greater emphasis on outcomes. It is also important to note that this Report does not attempt to capture each and every accomplishment made by the Agency and its Regions with regard to PBT pollutants. Rather, it is our hope that the following accomplishments demonstrate that the PBT Initiative is making great strides in further integrating the Agency's efforts a new way of doing business.

For additional sections of the report: Actions, Policy and Science, see: www.epa.gov/pbt/accomp99.htm.