Science Trumps Denialism: International Cancer Research Body Declares Soot Pollution to Be Known Human Carcinogen

A new report from the World Health Organization’s (WHO) cancer research agency announced the classification of outdoor air pollution and particulate matter as known human carcinogens. The International Agency for Research on Cancer (IARC) independently reviewed over 1,000 of the latest scientific studies on air pollution across five continents to conclude there is sufficient evidence to show that with increased levels of air pollution and particulate matter (commonly known as soot pollution), cancer risks increase too. As my colleague Dr. Jennifer Sass noted, “[t]he link is strongest for lung cancer, but bladder cancer was also flagged as a risk.”

This places particulate matter and outdoor air pollution in the company of asbestos, plutonium, silica dust, ultraviolet radiation and tobacco smoke. The IARC lists all of these as “Group 1” carcinogens (the highest classification) that are known to be carcinogenic to humans.

Beyond causing cancer, the report confirms that “[a]ir pollution is already known to increase risks for a wide range of diseases, such as respiratory and heart diseases.” These findings have been confirmed by numerous peer-reviewed studies and the 2010 Global Burden of Disease report, which estimated that particulate matter worldwide caused “over 2.1 million premature deaths and 52 million years of healthy life lost in 2010 due to ambient fine particle air pollution.”

Despite this overwhelming scientific consensus that “[t]he air we breathe has become polluted with a mixture of cancer-causing substances”, Republicans in Congress have repeatedly attacked the extensive science on this pollution in an effort to undermine health-protective EPA standards that limit soot pollution.

In 2011, Congressman Joe Barton (R-TX) asserted at a congressional hearing on EPA clean air standards that even though he is not a “medical doctor” there is no “medical negative” to particulate pollution. In response to this astonishing statement, the American Lung Association, American Public Health Association and American Academy of Pediatrics wrote the Congressman expressing “shock[] at such statements.” These doctors stated that they “see in the patients we treat what [] the scientific literature lets us know to expect: that air pollution makes people sick and cuts lives short.”

But the political attacks did not stop there. For a June 2012 hearing attacking clean air safeguards and particulate matter science, House Republicans on the Energy and Environment Subcommittee declined to invite respected scientists from the National Academy of Sciences, Health Effects Institute, American Heart Association or U.S. Environmental Protection Agency, all of which have found a causal relationship between particulate matter and mortality. Instead, House Republicans chose to invite a Texas state official who presented outlier testimony that “[s]ome studies even suggest PM [particulate matter] makes you live longer.”

Most recently, Congressman Lamar Smith (R-TX) of the House Science Committee subpoenaed EPA to seize confidential patient data underlying one study showing the linkage between particle pollution and premature death. I’ve outlined the problems with this outrageous witch hunt here.

While House Republicans waste time attacking well-established science that clearly shows the devastating health impacts from air pollution, the IARC’s report tells us that “[t]here 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.” Denial by politicians won’t reduce this deadly pollution. Only health-protective standards will.

The IARC report underscores the urgency of cleaning up the sources of dangerous particulate matter―such as dirty diesel fuels and dirty coal plants, both in the U.S. and globally―to limit the outdoor air pollution that we know leads to heart attacks, asthma attacks, premature death and now, cancer.