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Protecting Lives, Lungs from Soot

Deadly fine particulate matter, also known as soot, is caused by pollution from tailpipes, smokestacks and industrial power plants.

Deadly fine particulate matter, also known as soot, is caused by pollution from tailpipes, smokestacks and industrial power plants. Breathing soot can cause premature death, heart disease and lung damage.

Chris Jordan-Bloch / Earthjustice

What’s at Stake

Soot pollution is deadly—leading to tens of thousands of premature deaths every year. After years of delay by the EPA, Earthjustice is seeking to defend stronger pollution limits on this major threat to public health.


In December 2006, Earthjustice challenged the Environmental Protection Agency’s refusal to strengthen national standards for airborne particulates, despite a nearly unanimous recommendation from its own Clean Air Science Advisory Committee to do so. Particulate matter (PM) is one of the most dangerous forms of air pollution as small particles of soot, smoke, metals and other chemical compounds can travel deep into lungs, triggering an array of adverse health problems.

According to various experts and studies, the tightening of annual standards for particulate matter from 15 micrograms per cubic meter (µg/m3) to 14 micrograms per cubic meter would prevent thousands of premature deaths every year. The EPA’s own Clean Air Science Advisory Committee recommended limiting emissions to as low as 13 µg/m3 per year; however, under intense pressure from industry, the EPA rejected the views of its own panel of experts and kept the annual standard at 15 µg/m3. Additionally, the EPA’s 2006 regulations left rural Americans unprotected because they exempt the mining and agribusiness industries from complying with the PM standards. The adopted standards failed to provide an adequate margin of safety for the public and would have allowed thousands of needless deaths, asthma attacks and hospital visits.

In 2009, following an Earthjustice lawsuit, a federal court of appeals ruled that the clean air standards approved under the Bush Administration were deficient and they were sent back to the EPA for corrective action. The court ruled that the standards failed to protect public health with an adequate margin of safety and failed to address adverse visibility impacts. The court considered the 2006 approval arbitrary as the agency disregarded recommendations from various experts and medical associations to tighten the standards.

In 2011, Earthjustice filed another lawsuit as the EPA failed to take any action on revised particulate matter standards. The additional lawsuit was a deadline enforcement action under the Clean Air Act to pressure the EPA to act on new particulate standards.

In December of 2012, the EPA responded by strengthening the soot standard to a more protective level. EPA’s adoption of a more health protective annual standard is overwhelmingly supported by extensive evidence of health effects evidence and will result in significant national health benefits, including the prevention of thousands of premature deaths each year. The new standards are expected to save 15,000 lives and prevent hundreds of thousands of cases of asthma exacerbation.

Industry challenged the stronger standard, and Earthjustice intervened in court to defend the EPA’s standard. Oral arguments were heard in February 2014, and in May 2014 a federal appeals court denied industry’s attempt to overturn soot protections. The court also found that EPA’s decision to require the placement of air monitors near heavily trafficked roadways in major urban areas to capture the elevated levels of PM2.5 to which people are being exposed was well supported by the record, comports with the Clean Air Act and is justified to adequately protect people living and spending time near roads.

Case Updates

October 2, 2014 | Article

California: A Terrible Place To Breathe

The Golden State claimed all five of the top slots for the highest air pollution in the American Lung Association's 2014 State of the Air Report.

January 9, 2013 | In the News: Bloomberg News

Court mandates EPA to create tighter restrictions on soot pollution

A federal court ruled that the Environmental Protection Agency incorrectly enforced soot control requirements in the Clean Air Act. The decision requires the EPA to develop more specific guidelines. Communities will have five years to comply with the new requirements before being mandated to meet tougher standards.