Relationships between Asthma and Air Pollution
Professor’s comment: This student’s research paper synthesizes the results of a well-selected group of articles that explore relationships between asthma and air pollution. That laboratory science is at base a social enterprise is nicely exemplified by the focus of the studies she reviews. In drawing from the articles she reviews and in organizing her paper, the student maintains a good balance between discussing air-borne pollutants themselves and their physical effects, between analysis and implication. The result is a readable and interesting explanation of current work on this increasingly important subject.
While air pollution is currently controlled nationwide under the Clean Air Act and mandated by the Environmental Protection Agency (EPA), air pollution levels that do not exceed those set by the EPA have been shown to be associated with an increased incidence of respiratory diseases, such as asthma. One indication that air pollution has affected acute asthma is the increase in hospital admissions above the normal annual trend that occurred in 1991 and 1994, an increase that coincided with increased air pollution and heavy haze due to forest fires and volcano eruptions near the study’s location (Chew et al., 1999). Further analysis conducted by Chew et al. (1999) suggests that these air pollutants also have influenced acute asthma beyond the episodes of increased air pollution. This finding has important implications for the growing number of asthma sufferers who are continually being exposed to rising concentrations of air pollutants.
Because most of the population is exposed to air pollution and because there are ways to reduce pollutant levels, the role of air pollution in the history of asthma has become a great concern for public health (Baldi et al., 1999). In order to reset EPA air-quality standards and to determine which therapeutic actions can be applied to patients to prevent deterioration of their asthma conditions (Neukirch et al., 1998), researchers have found it increasingly necessary to discover the relationships between asthma symptoms and episodes of air pollution and to identify the pollutants that are responsible for the rise in the number of people seeking respiratory medical treatment.
Pollutants of Concern
Epidemiologic studies have determined that the following are the major air pollutants contributing to respiratory diseases: sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and particulate matter (PM) less than 10 mm and less than 2. 5 mm in diameter (PM10 and PM2.5, respectively) (Baldi et al., 1999; Chew et al., 1999; McConnell et al., 1999; McDonnell et al., 1999; Neukirch et al., 1998; Ostro et al., 1998; Sheppard et al., 1999; Taggart et al., 1996). Particulate matter is the product of solid and liquid particles being directly emitted into the air from such things as diesel engine soot, road and agricultural...