Thank you for the opportunity to respond to the EPA’s proposed particulate matter (PM) standards. These standards are critically important to public health, particularly for the most vulnerable members of our society—the sick, the aged, and the young.

The public health and scientific community is united in support of stricter fine and course particulate matter standards than the EPA proposes. The EPA’s proposal is contrary to hundreds of peer-reviewed studies and EPA staff research on the health impacts of particulate pollution, as well as to the legal requirements and spirit of the Clean Air Act. 

Public Health Impacts

• Fine Particulate Pollution

Many epidemiological studies have linked fine particulate matter with a variety of serious illnesses.  Fine particles are linked to hospitalizations for respiratory and cardiovascular illnesses, as well as to premature death. The EPA has utilized these studies in its recent rulemaking for nonroad diesel equipment, and estimates that the public health benefits of particulate matter control exceed costs by 40 to one. EPA estimates annual health benefits of PM control from non-road engines to be $80 billion by 2030.

In adults, concentrations below the current fine particle standards have been associated with premature death from heart and lung disease. Studies show increased risk down to the lowest levels investigated.

• Course Particle Pollution

There is increasing evidence that course particles also contribute to increased hospitalizations for heart and lung disease, decreased lung function, and increased respiratory symptoms. Course PM may have as strong short-term effects as fine PM on pulmonary disease, asthma and respiratory admissions. 

• Children’s Heightened Sensitivity to Air Pollution 

Compared with adults, children may have higher sensitivity to air pollution due to physiological differences, higher activity levels, and greater exposure to outdoor air pollution. Their developing bodies do not have the full range of defense mechanisms that can protect against harmful exposures. Children breathe more rapidly than adults, taking in more air—and pollution—per unit of body weight. 

Recent studies have linked long-term exposure to fine particles with deficits in lung growth, asthma exacerbations and hospitalizations, and even the possible development of asthma in healthy children.  Even in areas that meet the current annual fine particle standard, researchers have found children experience increased cough, higher cases of bronchitis, and decreased lung function.

Clean Air Act Requirements are Clear

By law, the EPA administrator must establish health-based standards without regard to costs or political pressures. By proposing weak daily particulate matter standards and maintaining the annual standard as is, the Agency is rejecting the scientific recommendations of its own clean air science advisors, as well as the American Academy of Pediatrics, the American College of Cardiology, the American Thoracic Society, and hundreds of other medical professionals and organizations.

There is no scientific justification for limiting the course particulate standard to urban areas or to exempt agriculture and mining. The Clean Air Act clearly specifies that public health and sound science should shape national air quality standards, not powerful lobbying interests.

Recommended Standards

We support an annual daily PM2.5 standard at California’s current level, 12 micrograms per cubic meter and a daily standard no higher than 25 micrograms per cubic meter. In addition, the course particulate standard should apply to urban and rural areas alike, without blanket exemptions for high-polluting sources.

Thank you for the opportunity to deliver these comments.