The League joined coalition partners in urging the Environmental Protection Agency to stay true to science and set a primary National Ambient Air Quality Standard for ozone of 60 ppb.

July 9, 2015

Administrator Gina McCarthy
United States Environmental Protection Agency
1200 Pennsylvania Avenue NW
Washington, DC 20460

RE: Docket No. EPA-HQ-OAR-2008-0699

Dear Administrator McCarthy:

On behalf of our millions of members and supporters, our organizations urge the Environmental Protection Agency (EPA) to stay true to the science and set a primary National Ambient Air Quality Standard for ozone at the more protective end of the range recommended by the Clean Air Scientific Advisory Committee (CASAC): 60 parts per billion (ppb).

After extensive review, on June 26, 2014, CASAC advised the Administrator “to set the level of the standard lower than 70 ppb within a range down to 60 ppb,” after finding that “there is substantial scientific evidence of adverse effects” at 70 ppb. CASAC also concluded that 70 ppb “may not meet the statutory requirement to protect public health with an adequate margin of safety.” CASAC cautioned further that “a level of 70 ppb provides little margin of safety for the protection of public health, particularly for sensitive subpopulations.”

Since the last review in 2008, the body of scientific literature has become even more compelling that a standard of 60 ppb is needed to protect our children and communities from smog pollution. CASAC affirms that a standard of 60 ppb “would provide an adequate margin of safety” to protect Americans, a definitive judgment CASAC did not offer about 65 ppb and certainly not 70 ppb. A strong, science-based standard of 60 ppb is important for the health and well-being of all Americans, but is particularly important for vulnerable and sensitive populations. These include children and young adults, pregnant women, asthmatics and sufferers of other breathing ailments and lung diseases, seniors, communities of color, low income individuals and families, outdoor workers, athletes and outdoor recreationalists.

Poorer communities and communities of color in particular bear an outsized share of the burden from air pollution. These populations are more likely to live adjacent to stationary sources of pollution and major roadways, have lower access to adequate healthcare and die prematurely from asthma-related complications. In order to protect our must vulnerable communities, EPA must be mindful of these disproportionate impacts and historical environmental injustices when updating the standard.

All Americans, no matter their income or where they live, have a right to clean air. Americans also have a right to know whether or not the air outside is safe for themselves and their loved ones to breathe. It is well-established that the current standard of 75 ppb is outdated and not protective of public health.

We applaud your recognition of this reality in the ozone proposal. Tens of millions of Americans are breathing dirty air today and they are frequently doing so unknowingly, due to an outdated and unprotective health standard. The existing method by which our government informs Americans of unsafe levels of air pollution – the Air Quality Index – is tethered to the existing standard, thereby giving the public an inaccurate description of air quality. This is a critically dangerous shortcoming that demands correction by the establishment of a science-based standard of 60 ppb.

The Clean Air Act has been one of the nation’s most successful laws. In its relatively short lifespan it has prevented hundreds of thousands of premature deaths, saved taxpayers billions of dollars in avoided healthcare costs, and driven technological innovations that created good jobs for American workers. The law is flexibly written and allows local governments ample time to craft cost-effective cleanup plans. We are confident that existing technologies, coupled with ingenuity and reductions from other anticipated air safeguards, give states the tools and resources necessary to cut pollution and meet a strong, truly health-protective standard. Americans deserve nothing less.

Thank you for considering our views.


Center for Biological Diversity
Clean Water Action
Environment America
Environmental Defense Fund
Environmental Law & Policy Center
Friends of the Earth
Interfaith Power & Light
League of Conservation Voters
League of Women Voters
Moms Clean Air Force
National Audubon Society
Natural Resources Defense Council
Physicians for Social Responsibility
Sierra Club
Tribal Environmental Policy Center
WE ACT for Environmental Justice