|Particulate Monitoring||Creating the Context: Further Research|
Results of Study
Results of Study
Can we identify sources of particulates measured at our site? We need additional information on the amount of particles, the color of particles, the direction and speed or the wind to suggest possible sources.
Can we determine the effects of particulate concentrations on human health? Comparing concentration measurements with information from the school nurse and/or a local hospital on asthma or other respiratory problems experiences by students or residents in the area. (See the guided research area.)
Can we determine the effects of particulate concentrations on vegetation? Comparing concentration measurements with information obtained from the other air pollutant KanCRN programs dealing with vegetation would be useful.
Work needs to be done to determine trends in particulate concentrations and their relationship with other KanCRN measured pollutants.
PM10 is particulate matter (particles like soot or dust) whose aerodynamic size is less than or equal to 10 microns.
Three counties had a monitor with a very high 24-hour PM10 second maximum concentration. The highest was recorded in Howell County, Missouri at a
monitor adjacent to a charcoal kiln facility. The next highest was a monitor in Imperial
County, California at a site just 1/4 mile from the border with Mexico. The third highest
second maximum concentration was recorded at the Franklin Smelter in Philadelphia. In 1996, approximately 5 million
people lived in 11 counties where the second highest maximum 24-hour PM10 concentration
was above the level of the 24-hour PM10 NAAQS.
When both the annual and 24-hour standards are considered, there were 7 million people
living in 15 counties with PM10 concentrations above the PM10 NAAQS in 1996.
Additional scientific studies need to strengthen the link between particulate matter, PM10 (alone, or combined with other pollutants in the air) and a series of significant health effects. These health effects include premature death, increased hospital admissions and emergency room visits, increased respiratory symptoms and disease, decreased lung function, and alterations in lung tissue and structure and in respiratory tract defense mechanisms. Sensitive groups that appear to be at greatest risk to such effects include the elderly, individuals with cardiopulmonary disease such as asthma, and children.
In addition to health problems, several other aspects of particulates need to be explored; particulate matter is the major cause of reduced visibility in many parts of the United States, airborne particles also can cause soiling and damage to materials, emissions of PM10 come from a variety of sources including windblown dust and grinding operations and how these particulates travel are all open questions for exploration
Ambient PM10 concentrations decreased 25 percent between 1988 and 1996 and decreased 4 percent between 1995 and 1996. PM10 estimated emissions (excluding fugitive emissions and emissions from natural sources) decreased 12 percent between 1988 and 1996 and remained unchanged between 1995 and 1996.
On July 18, 1997 EPA revised the national ambient air quality standards for particulate matter. After a lengthy scientific review, EPA determined that the annual PM10 standard set at 50 micrograms per cubic meter (ug/m3) should not change but that the form of the PM10 24-hour standard (which remains at a level of 150 ug/m3) should be revised. Further, these studies indicated serious health risk associated with exposure to particles in the smaller part of that range. Therefore, EPA added an indicator for PM2.5 (those whose aerodynamic size is less than or equal to 2.5 micrometers). The combination of the PM10 and PM2.5 indicators will provide protection against a wide array of particles. The annual PM2.5 standard is set at 15 ug/m3 and the 24-hour PM2.5 standard set at 65 ug/m3. The secondary (welfare-based) standards were also revised by making them identical to the primary (health-based) standards. In conjunction with the Regional Haze Program, the secondary standards will protect against major PM welfare effects, such as visibility impairment, soiling, and materials damage. In July, 1997, EPA proposed a rule to address regional haze, and EPA plans to finalize this rule in July, 1998.
As the implementation of these revised standards begins and a national air quality monitoring network for PM2.5 is established, additional work will need to be done to track trends in concentrations of PM2.5.
|1999, KanCRN Collaborative Research Network|