Outdoor Air Pollution Declared a Human Carcinogen

Florida traffic
A crowded Florida highway (Photo credit unknown)


LYON, France, October 17, 2013 (ENS) – Outdoor air pollution “causes lung cancer” and increases the risk of bladder cancer, the specialized cancer agency of the World Health Organization said for the first time today.

The International Agency for Research on Cancer, IARC, placed outdoor air pollution in Group 1, a category used only when “there is sufficient evidence of carcinogenicity in humans.”

air pollution
Industry by the River Tees near Middlesbrough, England (Photo by Ian Britton courtesy Freefoto.com)

Particulate matter, a major component of outdoor air pollution, was evaluated separately and was also classified as carcinogenic to humans.

The world’s top experts convened by the IARC Monographs Programme concluded that there is an increasing risk of lung cancer with increasing levels of exposure to particulate matter and air pollution after independently reviewing more than 1,000 scientific papers from studies on five continents.

The reviewed studies analyze the carcinogenicity of pollutants present in outdoor air pollution, especially particulate matter and transportation-related pollution. IARC says the evaluation is driven by findings from large epidemiologic studies that included millions of people living in Europe, North and South America, and Asia.

“The air we breathe has become polluted with a mixture of cancer-causing substances,” said Dr. Kurt Straif, who heads the IARC Monographs Section. “We now know that outdoor air pollution is not only a major risk to health in general, but also a leading environmental cause of cancer deaths.”

Although the composition of air pollution and levels of exposure can vary widely between locations, these conclusions apply to all regions of the world.

In the past, the IARC Monographs Programme has evaluated many individual chemicals and specific mixtures that occur in outdoor air pollution such as diesel engine exhaust, solvents, metals, and dusts. But this is the first time that experts have classified outdoor air pollution as a cause of cancer.

IARC said the most recent data indicate that worldwide in 2010, at least 223,000 deaths from lung cancer resulted from air pollution.

Nanning City
Air pollution blankets Nanning City, China, October 2012 (Photo by Andrew Tseng)

The IARC Monographs Programme, known as the “encyclopaedia of carcinogens,” provides an authoritative source of scientific evidence on cancer-causing substances and exposures.

Air pollution is known to increase risks for a wide range of respiratory and heart diseases. Studies indicate that in recent years exposure levels have shot up in some parts of the world, including rapidly industrializing countries with large populations.

“Our task was to evaluate the air everyone breathes rather than focus on specific air pollutants,” explains Dr. Dana Loomis, deputy head of the Monographs Section. “The results from the reviewed studies point in the same direction – the risk of developing lung cancer is significantly increased in people exposed to air pollution.”

The summary evaluation will be published by the journal “The Lancet Oncology” online on October 24.

The predominant sources of outdoor air pollution are transportation, stationary power generation, industrial and agricultural emissions, and residential heating and cooking. Some air pollutants have natural sources, as well.

“Classifying outdoor air pollution as carcinogenic to humans is an important step,” emphasizes IARC Director Dr. Christopher Wild. “There are effective ways to reduce air pollution and, given the scale of the exposure affecting people worldwide, this report should send a strong signal to the international community to take action without further delay.”

U.S. Senator Barbara Boxer, a California Democrat who chairs the Environment and Public Works Committee, said that in response to this new information she will hold a committee hearing to explore how the Clean Air Act can reduce the risk of outdoor air pollution.

Florida traffic
A crowded Florida highway (Photo credit unknown)

“Top scientists have confirmed that outdoor air pollution is a leading environmental cause of cancer deaths,” said Boxer. “This comprehensive World Health Organization report finds that the air we breathe has become polluted with a mixture of cancer-causing substances like toxic soot. I plan to hold a hearing at the earliest opportunity on the critical role played by the Clean Air Act in reducing the health threat posed to our children and families by toxins found in outdoor air pollution.”

The nonprofit American Lung Association welcomes the IARC conclusion and hopes that it “will end the debate about the need to clean up air pollution.”

“Thanks to the Clean Air Act, the air quality in the United States has improved significantly over the past 40 years. However, too many people remain exposed to dangerous levels of cancer-causing air pollution and particulate matter,” said the Lung Association in a statement today. “As a nation, we owe protection from lung cancer to our families, our children and our neighbors.”

“Big polluters and their allies on Capitol Hill have tried time and again to dispute the science, even though these published studies have stood multiple, thorough, independent reviews. This IARC review is only the latest and most comprehensive,” said the the Lung Association.

The IARC classification comes just two days after the European Environment Agency issued a report showing that that more than 90 percent of city dwellers in the European Union are exposed to what the World Health Organization considers dangerous levels of two air pollutants – fine particles (PM2.5) and ozone.

“This new report has shown that fine particles which penetrate deep into the lungs, causing health problems and premature deaths, are ubiquitous in cities,” commented Louise Duprez, senior policy officer on air quality with Europe’s largest association of environmental groups, the European Environmental Bureau, EEB.

“Air pollution alone cost Europe over 400,000 deaths each year and hundreds of billions of Euros in health care costs that could have been avoided,” said Duprez.

“Those sky-high numbers are even more alarming considering recent scientific findings which indicate that damaging effects can occur at levels lower than the current WHO Guidelines.” she said.

Responding to the new information, the EEB is calling for a revision of the National Emissions Ceilings Directive to reduce overall levels of air pollution and set new ambition levels for 2020 and beyond, making it possible for cities to meet local air quality standards.

This law is intended to reduce trans-boundary air pollution across Europe. This is critically important as the European Environment Agency report shows that half of the observed fine particles concentrations come from outside national borders.

In addition to damaging health, air pollution is one of the main drivers behind ecosystem degradation, said Duprez, most crucially through acidification and eutrophication of ecosystems, but also by damaging vegetation and crops due to high ozone levels.

Duprez points to evidence that two-thirds of the protected sites in the EU Natura 2000 network are currently under severe threat from air pollution.

Copyright Environment News Service (ENS) 2013. All rights reserved.

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