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    Persistent Organic Pollutants


From: (NACEC) North American Commission for Environmental Cooperation
Español Français - Note: NACEC also has the study and a summary in .pdf (big)

Jan. 29, 2001 Dioxin linked to cancer despite protests from several business segments
April 12, 2001 Dioxin Report By EPA On Hold

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http://www.cec.org/news/announce/Data.cfm?varlan=english&vardate=60&unique_no=291

 

A study conducted for the North American Commission for Environmental Cooperation (NACEC) has, for the first time, linked dioxin pollution in Canada's Arctic to specific sources in Canada, Mexico and the United States.

Using a sophisticated air transport model developed by the US National Oceanographic and Atmospheric Administration (NOAA), a research team headed by renowned scientist Dr. Barry Commoner, of Queens College, New York, identified facilities in the south causing dioxin pollution at eight locations in Nunavut, the Canadian territory covering the eastern Arctic north of the 60th parallel to the pole. US waste incinerators (municipal and medical), together with cement kilns burning hazardous waste as fuel and metal processing facilities were the main sources of dioxin reaching the far North, the research found. The report is based on data from a 1996-97 inventory of sources, some of which may have reduced or eliminated dioxin emissions since.

It is the first-ever continent-wide study of dioxin that traces source-to-receptor relationships.

NACEC is a Montreal-based organization established under the environmental side accord to the North American Free Trade Agreement. The research was done by the Center for the Biology of Natural Systems, Queens College, City University of New York. In addition to Dr. Commoner, the research team included Paul Woods Bartlett, Holger Eisl and Kimberly Couchot.

Dioxins are a public health and environmental concern because some types have known carcinogenic and toxic properties that can produce a range of health problems. These include adverse effects upon reproduction and development, suppression of the immune system, chloracne (a severe acne-like disease that sometimes persists for many years), and cancer.

Dioxins are produced by a number of chemical processes, including some metal refining methods, the chlorinated bleaching of pulp and paper, and, most importantly, as a byproduct of the combustion of certain materials.

Combining North American pollution data with meteorological records and other information, the study identifies the main sources of dioxin pollution at each of eight Nunavut areas over the period 1 July 1996 to 30 June 1997, the most recent year for which comparable Canadian and US data were available. Mexican data were derived through the preparation of a first dioxin emissions inventory for that country.

Nunavut provides an ideal test ground for the study of long-range transport of the pollutant because there are no significant sources of dioxin in the territory nor within 500 km (300 miles) of its boundaries. The contribution of Nunavut sources to the dioxin in the territory was estimated at 0.2 percent.

US facilities were found to have contributed between 70 and 82 percent of dioxin deposited at the eight locations in Nunavut. Canadian facilities contributed 11 to 25 percent (depending on the northern location in question), while Mexican emissions, largely caused by backyard trash burning, contributed 5 to 11 percent.

The relatively small contribution of Mexican sources to dioxin deposition in Nunavut compared to their larger share of the total North American dioxin emission inventory (30 percent) is in part a reflection of their greater distances from the receptor areas compared to US and Canadian sources.

An estimated 2 to 20 percent of dioxin pollution in Nunavut areas originates outside North America—chiefly in Japan, France, Belgium and the U.K., the study says.

"It is clear that what we do anywhere on this continent can have serious effects somewhere else, even very far away, and the study shows us these connections," says NACEC Executive Director Janine Ferretti. "This model provides us with a tool that can help us tackle the problem at source and provides communities across North America with a means of identifying the origins of all kinds of pollutants-not just dioxins-entering their environments."

"Our results show that the exposure of Nunavut to airborne dioxin is almost entirely due to sources in the rest of North America, " says Dr. Commoner. "Sharply reducing or eliminating dioxin emissions from less than one percent of these 44,000 sources could appreciably reduce this serious health hazard."

Some remedial measures already in place

Since the period covered in this study, a number of the major sources and source types have come under new requirements to reduce their dioxin emissions.

In the United States, the US EPA has promulgated regulations that should reduce dioxin emissions by 99 percent from municipal waste incinerators and by about 95 percent from medical waste incinerators. The US EPA has also promulgated regulations to reduce dioxin from some hazardous waste incinerators, including cement kilns.

In Canada, environment ministers in June 2000 accepted a Canada-wide Standard for Dioxins and Furans that may be endorsed at the next meeting of the federal and provincial environment ministers in November 2000. Six sectors, including waste incineration, burning salt-laden wood, residential wood combustion, and electric arc furnace steel manufacturing, have been identified for early action. The municipal waste incinerator in Quebec has undergone modifications to virtually eliminate its dioxin emissions.

Few sources cause a large proportion of pollution

Among the study's main findings: relatively few types of sources and individual facilities are responsible for the majority of dioxin deposited in Nunavut, which makes remedial action more manageable.

For example, 35 percent of the dioxin present at one Arctic location, Coral Harbour, is attributed to only 19 sources in the south.

The study shows the amount of dioxin deposited in Nunavut was a function of several factors such as weather, distance, and the rate of emission from a facility.

As well, dioxin deposition varied over the year, with high deposition occurring when the weather patterns favored efficient transport from areas in North America with high emissions. For example, in one Arctic community, Ikaluktutiak, over half of the annual dioxin burden from June 1996 to July 1997 was deposited in two months, September and October.

Top dioxin source categories in North America

While governments have made efforts to reduce dioxin emissions from some of the largest source types, the study shows other major sources of deposition in Nunavut that are not currently subject to controls. These include certain metal processing facilities as well as facilities burning less than 250 tons per day of municipal solid waste.

Of the 23 categories of dioxin sources throughout North America, the biggest are:

  • municipal waste incinerators (25 percent),
  • backyard trash burning (22 percent),
  • cement kilns burning hazardous waste (18 percent),
  • medical waste incinerators (11 percent),
  • secondary copper smelters (8 percent), and
  • iron sintering plants (7 percent).

Together, these six categories contributed more than 90 percent of total North American emissions in 1996-97.

Of the 44,091 individual sources of dioxin on the continent, 22,439 (51 percent) were found to be in the US, 16,729 (38 percent) were in Canada and 4,923 (11 percent) were in Mexico. When ranked according to the amount of dioxin emitted, the United States accounted for 62 percent, Canada 8 percent and Mexico 30 percent.

Creation of Mexico's first draft dioxin inventory

Among several firsts associated with the study was the preparation of a draft inventory of Mexico's dioxin pollution, prepared in cooperation with the Mexican Environment Ministry (Instituto Nacional de Ecología). The study estimates that Mexicans recycle six percent of 31 million metric tonnes of municipal solid waste generated annually. Of the remaining 29 million tonnes, roughly half is sent to landfills and half is burned in community dumps and backyard fires, producing dioxin.

Mexico's dioxin inventory, combined with US EPA and Environment Canada data on sources in those countries, allowed researchers to create an unprecedented, comprehensive North American overview of dioxin pollution.

Dioxin and human health

Dioxins are widely distributed in the environment at low concentrations and are not easily broken down by natural processes. As a result, most people have detectable dioxin levels in their tissues that have bioaccumulated over their lifetime, generally through dietary intake.

Human exposure to dioxin is almost entirely (95 percent) through consumption of animal fats. In temperate climates, dioxin enters the food chain through animal food crops and appears in milk and beef. In the Arctic, dioxin enters the food chain through lichen, mosses and shrubs eaten by caribou, and through algae eaten by fish on which seals and walruses feed. The traditional indigenous diet in Nunavut includes caribou, fish and marine mammals.

Earlier studies have found that dioxin concentrations in Inuit mothers' milk are twice the levels observed in southern Quebec.

The report does not analyze the health effects of dioxin on the people in the Arctic. However, the US EPA has recently published a major draft report on dioxin, which found it has the potential to produce a broad spectrum of adverse effects.

Dioxins can alter the fundamental growth and development of cells, which can lead to:

  • adverse effects on reproduction and development,
  • suppression of the immune system,
  • chloracne ( a severe acne-like condition), and
  • cancer.

Because of their rapid growth and development, fetuses, infants and children may be more sensitive to dioxin exposure than other groups.

The EPA's draft dioxin reassessment has revised the cancer risk from dioxin from earlier reports. The increased lifetime risk of cancer of the general US population from exposure to dioxin could be in the range from 1 in 1000 to 1 in 100, in comparison with the "acceptable" level of 1 in a million generally adopted by US EPA.

Body burdens of dioxin in the US general population appear to be declining from the late 1980s.

The North American Commission for Environmental Cooperation

NACEC was established to build cooperation among the NAFTA partners-Canada, Mexico and the United States-in protecting their shared environments, with a particular focus on the opportunities and challenges presented by continent-wide free trade.




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Dioxin linked to cancer despite protests from several business segments



By Susanna Duff
WASTE NEWS
January 29, 2001


WASHINGTON -- The U.S. Department of Health and Human Services´ National Toxicology Program last week reclassified dioxin as a "known human carcinogen," moving the chemical from the category of "reasonably anticipated to be a human carcinogen."

The change had been expected for some time but was delayed due to a legal challenge from several businesses that claimed the National Toxicology Program had not followed its own criteria for revising scientific data before making its decision. In September, a federal court ruled in favor of the toxicology program, stating that its approach was reasonable. anticipated to be a human carcinogen."

The businesses appealed the ruling, asking the U.S. Court of Appeals for the District of Columbia to grant an injunction to halt publication of the revised dioxin listing. Their request was denied, but the case not yet been heard. anticipated to be a human carcinogen."

The reclassification does not sit well with the paper industry, said Barry Polsky, a spokesman for the American Forest & Paper Association. anticipated to be a human carcinogen."

The paper industry has spent $1 billion since it began a voluntary reduction of dioxin in 1988, Polsky said. By changing bleaching products and mechanical practices, it has reduced dioxin in effluents by 90 percent, he said. anticipated to be a human carcinogen."

But Polsky said he disagreed with the methods used to reclassify dioxin. "It´s not based on conclusive evidence for humans," he said. anticipated to be a human carcinogen."

Still, the reclassification change will have little impact on the sources listed last spring by the U.S. Environmental Protection Agency as high dioxin generators. "The reality is the agency was acting as if it already was proven to be a problem," said Alice Jacobsohn, who oversees the National Solid Wastes Management Association´s Medical Waste Institute. anticipated to be a human carcinogen."

But the reclassification likely will be used by groups that oppose the burning of medical waste, she said. anticipated to be a human carcinogen."

Indeed, the reclassification is documentation for community activists and elected officials, said Monica Rohde, dioxin campaign coordinator for the Center for Health, Environment and Justice. anticipated to be a human carcinogen."

Rohde said she recognizes that several industries have reduced their dioxin emissions. Waste-to-energy facilities, for example, have reduced dioxin emissions to less than 0.5 percent under federal regulations, said Maria Zannes, president of the Integrated Waste Services Association. anticipated to be a human carcinogen."

But Rohde said reduction is not enough. "It has to be eliminated. It is affecting our health," she said. anticipated to be a human carcinogen."

Rich Kogler, chief operating officer at Stericycle Inc., the nation´s largest medical waste management firm, disputed that point. The industry is changing with the times, Kogler said. But while Stericycle and other firms move toward non-burning technologies, some types of medical waste, such as devices used in pathology and chemotherapy, have to be incinerated, he said. anticipated to be a human carcinogen."





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Dioxin Report By EPA On Hold
Industries Oppose Finding of Cancer Link, Urge Delay



by Eric Pianin
Washington Post Staff Writer
April 12, 2001; Page A01

The chemical, beef and poultry industries are waging an intense campaign to delay further an Environmental Protection Agency study showing that consumption of animal fat and dairy products containing traces of dioxin can cause cancer in humans.

EPA scientists and officials say they are confident of the report's findings, which they began circulating last June, and are urging EPA Administrator Christine Todd Whitman to issue it in final form this summer. But the study, more than a decade in the works, has drawn such intense opposition from industry groups and congressional Republicans that it could be held up for several more years.

By any measure, the economic stakes in the dioxin controversy are high: The EPA's issuance of a final report could result in federal and state regulations costly to chemical manufacturers. It also could provide more adverse publicity for the beef industry at a time of heightened consumer concern about the outbreak of foot-and-mouth disease in Europe.

Industry groups including the American Chemistry Council, the Chlorine Chemistry Council, the Chemical Manufacturers Association, the American Meat Institute and the National Cattlemen's and Beef Association contend the EPA's study is seriously flawed and exaggerates the health risk dioxin poses.

"We are alarmed at any study that reaches conclusions not based on science," said Gary Weber, executive director of regulatory affairs for the cattlemen's association.

Environmentalists who have closely followed the issue for years charge that industry groups and their political allies in government are working to keep the study bottled up indefinitely for political reasons, not scientific ones.

"What we're saying is the chemical industry has had a big influence over the way the EPA makes its decisions," said Stephen Lester of the Center for Health, Environment and Justice, which monitors hazardous waste. "They've affected the way the science policy and business of the agency is done."

The Bush administration has challenged several Clinton-era environmental and public health rules and initiatives -- including a tough new standard for arsenic in drinking water -- on the grounds they weren't scientifically sound and would cause economic hardship to industry and local governments.

The politically active chemical, livestock and meatpacking industries contributed $1,171,000 to Bush's campaign last year, according to the Center for Responsive Politics. Industry officials are lobbying the administration to postpone indefinitely release of the study until other agencies, such as the Department of Agriculture and the Food and Drug Administration, can conduct lengthy studies.

EPA officials and spokesmen for the chemical and meat industries dispute environmentalists' charges of a "conspiracy" to block the study's release. They describe the controversy as a dispute over the interpretation of mountains of studies on the health effects of dioxin. Moreover, some scientists were skeptical of the EPA's latest report and predicted it would not withstand scrutiny.

Whitman declined last week to speculate on the fate of the agency draft report, saying only, "We're still looking at that."

Some industry officials concede their primary goal is simply to keep the study of dioxin -- begun during the Reagan administration -- going for as long as possible. David Fischer, managing counsel for the Chlorine Chemistry Council, said his group is pressing the administration to take "an interagency approach" that would allow the FDA, the Agriculture Department and other agencies with jurisdiction over food safety to weigh in.

Fischer said any attempt by Whitman and the EPA to conclude unilaterally that dioxin causes cancer "is a plan doomed for failure."

Dioxin is the airborne byproduct of burning plastics and medical waste containing chlorine. These pollutant compounds infiltrate the food chain through grass and feed, then settle into the fat of livestock and poultry.

The most toxic form of the chemical is known by the acronym TCDD and was more commonly recognized as the contaminant found in Agent Orange, a defoliant used during the Vietnam War. The Air Force has found a "significant and potentially meaningful" relationship between diabetes and bloodstream levels of chemical dioxin in its ongoing study of people who worked with Agent Orange.

Although there is some research of people who were accidentally exposed to the chemical, most data about the potential health effects of dioxin have come from laboratory experiments on animals.

The prevalence of this toxic chemical in the environment has declined by nearly 80 percent since the 1970s because of changing practices in the chemical industry and in waste disposal operations, but the latest EPA study concludes that people who consume even small amounts of dioxin in fatty foods and dairy products face a cancer risk of 1 in 100. They may also develop other problems, such as attention disorder, learning disabilities, susceptibility to infections and liver disorders.

In 1985, the EPA released its first dioxin health assessment, but the agency's findings that the chemical posed one of the most serious threats of cancer in humans of any chemical studied drew strong protests from the chemical industry, which prompted the agency to do a reassessment.

That study, completed in 1994, spurred yet another reassessment. That one culminated in the EPA's issuance last June of its latest findings, showing that the risk of getting cancer from dioxin exposure was 10 times greater than previously thought, ranging from 1 in 1,000 to 1 in 100.

But now there are more hurdles. A subcommittee of an EPA scientific advisory panel composed of outside experts publicly convened in November for two days to review the agency's findings and to make recommendations.

About a third of the 21 panel members were scientists and scholars who have worked as paid consultants to the chemical industry. They included John D. Graham -- long a critic of the notion that dioxin and cancer are linked and founder of the industry-backed Harvard Center for Risk Analysis -- who was recently appointed to a key regulatory review post in the Office of Management and Budget, and Dennis Paustenbach, vice president of Exponent Inc., an engineering and scientific consulting firm. Paustenbach's firm has advised Chemical Land Holdings Inc. and Occidental Chemical Corp. on ways of challenging the EPA's dioxin findings.

An EPA official involved in the preparation of the latest dioxin reassessment said when the advisory panel had completed its meetings, he and other agency officials were under the strong impression that "they had accepted our assumption the data was sufficient to characterize the best studied of the dioxins as a human carcinogen."

Yet on March 13 the panel, headed by Morton Lippmann of the New York University School of Medicine, issued an executive summary of its deliberations that cast serious doubt on many of the EPA's findings -- including the risk assessment of contracting cancer -- and recommended wholesale revisions and rethinking of the study. The industry experts contend that the EPA has overstated the risks posed by normal levels of dioxin in food and questioned the research models used.

Moreover, Lippmann and panel member Genevieve Matanoski had raised strong concerns that EPA scientists had excluded contrary data from two important dioxin studies in reaching their conclusions, according to Gary Kayajanian, an independent consultant who closely monitored the November meetings.

The Center for Health, Environment and Justice protested that some panel members who assisted in preparing the March 13 report had misrepresented the views of the majority of the advisory panel members. But some panel members and their industry supporters say environmental protesters who attended the November sessions may have intimidated some experts and prompted them to withhold their views until they wrote their report.

"I think a lot of us -- me included -- believe the data in the current analysis is fairly weak that risks of cancer [from normal doses of dioxin] are equal to 1 in 1,000," Paustenbach said. "When there's a number of vocal [protesters] who clearly have strong views, there may be a tendency [by panel members] to be cautious and to not antagonize the crowd, if you will."



© 2001 The Washington Post Company



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