What is particulate matter (PM) and how is it harmful to our health?
A. Suspended particulate matter (PM) is an air pollutant derived from the combustion of fossil fuels in the form of dust, soot, or smoke. Diesel engines account for about one quarter of the particulate air pollution from all on-road sources. More than 98 percent of the particles emitted from diesel engines are fine particles, less than 1 micron in diameter, which can bypass respiratory defense mechanisms and penetrate deep into the lungs. Numerous studies have found that fine particles impair lung function, aggravate respiratory illnesses such as bronchitis and emphysema, and are associated with premature deaths. Also, dozens of studies link airborne fine-particle concentrations to increased hospital admissions for respiratory diseases, chronic obstructive lung disease, pneumonia, and heart disease, including an increased risk of acute myocardial infarction (heart attack).
