Fine Particulate Matter


EPA Health Sheet - Heath and Environmental Effects of Particulate Matter


Hundreds of scientific studies have linked fine particulates, a major component of which is sulfur dioxide, alone or in combination with other pollutants, with a series of health problems, including:

  • Premature Death

  • Respiratory related hospital admissions and emergency room visits

  • Aggravated asthma

  • Acute respiratory symptoms; including aggravated coughing and difficult or painful breathing, chronic bronchitis, decreased lung function that can be experiences as shortness of breath, and work and school absences.

Most risk to:

  • Elderly

  • Those with respiratory problems

  • Children

Children breathe 50% more air than adults per pound of body weight. Because children's respiratory symptoms are still developing, they are more susceptible to environmental threats. Exposure to fine particles is associated with increased frequency of childhood illnesses, which is of concern both in the short run, and for the future development of their lungs.

Fine particles are also associated with increased respiratory symptoms and reduced lung function in children, including symptoms such as aggravate coughing and difficulty or pain in breathing. These can result in school absences and limitations in normal childhood activities.

Childhood asthma incidence has increased 50% in ten years, 6% AMERICAN children are affected, asthma is the most common cause of absenteeism from school.

The EPA paper concludes: In the years since the last particulate standard was enacted, hundreds of significant new scientific studies have been published. Recent health effects studies suggest the health effects mentioned above are associated with exposure to particle levels well below those allowed by the current standard.

Several particle studies involving researchers from the Harvard school of public health found:

  • Fine particles cause such harm because they penetrate the lung more deeply

  • Small changes in lung function can easily be tolerated by health lungs or even mildly diseased ones but may lead to a need for acute hospitalization for people with weaker lungs.

  • These particles are so small they penetrate homes easily, as a result there is almost no difference between the level of fine particles inside as outside 

  • Day to day changes in airborne particle concentrations are consistently associated with increased death in all of the cities studied (including Boston), and even low levels were associated with mortality independent of smoking, occupational exposure, body mass index, age, sex and education.

  • Fine particles have been found to have no threshold effect.

There is no level that is "Safe".

SO2 emitted from power plants feeds the fine particle problem by causing sulfates and SO4. SO2 that leaves the stack as a gas undergoes a chemical reaction as it gets higher in the sky to form fine sulfate particles, called "secondary" particles and compound our problem with fine particles.

Tiny Soot Particles Can Shorten Lives


American Lung Association:

EPA Air Standards Are "Fully Validated"

U.S. Newswire

July 26

WASHINGTON - An independent scientific panel has "vindicated" the U.S. Environmental Protection Agency (EPA) and confirmed that tiny soot particles can shorten lives, the American Lung Association said today. The Health Effects Institute panel reanalyzed two long-term epidemiological studies that the EPA relied upon in setting air quality standards for fine particles in 1997, and concluded that they were well conducted and accurate.

The original studies, known as the Harvard Six Cities Study and the American Cancer Society Study, reported that air pollution shortens lives. Industry groups launched an extensive campaign to undermine the EPA standards by attacking the validity of the studies, calling them "junk science." They claimed the researchers used sloppy data gathering and inappropriate methodology to obtain a "predetermined" result.

The original investigators agreed to make their data available to the industry- and EPA-funded Health Effects Institute for reanalysis. "The reanalysis confirms that these were excellent studies by top scientists," said John M. Coruthers Jr., president of the American Lung Association. "It shows once again that air pollution shortens lives, and that strong EPA standards are needed to protect public health."

The Health Effects Institute confirmed the original studies through an extensive three part reanalysis. First, they undertook a quality control audit and found the original data was accurately collected and recorded. Second, they replicated the results of the original investigators using the original analytical methods. Third, they performed a detailed sensitivity analysis to assess whether additional variables and different statistical techniques would change the original findings. They did not. "This independent reanalysis vindicates EPA and shows that we can improve and lengthen people's lives by reducing air pollution. The longer we wait to take action, the more unnecessary deaths will occur," said Corothers.

Last spring, in response to an industry lawsuit, a federal appeals court set aside the EPA standards for reasons unrelated to the science. The appeals court decision is now undergoing review by the U.S. Supreme Court. EPA is currently reviewing the latest scientific evidence on particle pollution as part of its periodic five-year review.