Physicians are concerned about dangers of air pollution

There is growing national concern in the medical community that the adverse health impacts of air pollution have been under-appreciated. With our rapid population growth, increasing traffic and proposed port expansions, diesel emissions and other small particulate pollution are of special concern for our area.

We hardly notice diesel exhaust until we get behind a truck or bus in traffic. But most of us don't realize that tiny invisible particles linger in the air for prolonged periods after the soot plume disappears. These particles may bypass the body's natural defense system and penetrate deep into the lungs. Some particles are deposited in the lungs and may cause damage there, but some are so small they may actually pass into the blood stream where they circulate throughout the body.

Similar to the tiny particles from cigarette smoke, diesel particulates contain about 40 toxic chemicals known to cause cancer. Rates of serious asthma attacks in children have been directly correlated to high urban diesel concentrations. Concentrations are likely significantly higher near busy interstate exchanges and ports. Diesel trucks, while moving cargo from port to warehouses and ships during their stay at port, can produce a significant proportion of these emissions in our area.

Small particulate pollution, emissions from various sources that measure less than 2.5 microns, is one of the most widespread and potentially harmful air contaminants threatening public health. While short- and long-term exposures must be studied further before causation can be established, even short-term increases in small particulate pollution have been linked to death from respiratory and cardiovascular causes. Longer-term exposure has been linked to lung diseases, cancers and DNA damage, as well as to death from cardiovascular disease and stroke.

A recent New England Medical Journal article showed that even within cities, particulate concentration can vary enough to cause significant differences in risks of heart disease for people living at different sites within the same city.

For two years in a row, Charleston has received a grade of F for particulate pollution from the American Lung Association. Although DHEC has monitors set up to comply with federal standards for regional monitoring, site specific monitoring to identify high-risk sites within our community has not been done.

Most industries such as paper mills and coal-powered power plants are monitored for their emissions. They receive permits to release known quantities. But this is not true of the growing amounts of emissions from our mobile sources. South Carolina agencies do not monitor or control particulates from cars, ships, trucks or port facilities, although other places around the country do.

All of these concerns recently prompted the South Carolina Medical Association to pass the following resolution at their annual meeting last month:

"Resolved, That the South Carolina Medical Association support: 1) The maximum feasible reduction of all forms of harmful air pollution, especially new and existing sources of toxic fine particle pollution; 2) Appropriate funding for epidemiological studies targeted toward communities at high risk from emissions, to look at adverse health impact of air emissions in the communities directly affected, and be it further Resolved,

That the South Carolina Medical Association ask the South Carolina Department of Health and Environmental Control, the South Carolina General Assembly, and appropriate elected officials to oversee a detailed site specific air monitoring program in the Charleston area prior to the commencement of operations of a new port facility. Appropriate air monitoring would establish a baseline of air quality at targeted sites within the urban area; would identify any areas within the community at high risk for poor air quality; and would establish a means for continued follow-up monitoring at sites of high risk, such as around major port terminals."

Proper monitoring will define the problem and help us design strategies for minimizing the health risks to our growing population.

M. Edward Wilson, M.D., is president of the Charleston County Medical Society.