Fine Air Pollution Particles and Their
Health Effects Lead to Proposed Change in EPA Air Quality Standard
Fine air pollution
particles (PM2.5) are able to travel deep into the lungs:
larger particles do not. Numerous studies have found that people living
in the most PM2.5 polluted cities face an increased death
rate from both lung and heart disease. In fact, a recent study linked an
8% increase in the risk of dying from lung cancer and heart disease for
every 10 microgram increase in PM2.5
.
Therefore, it is not surprising that in light of much scientific
evidence, the U.S. Environmental Protection Agency (EPA) recently
proposed a stronger standard for PM2.5.
Briefly, the Clean Air
Act requires the EPA to set National Ambient Air Quality Standards (NAAQS)
for criteria pollutants, and periodically update those standards if
necessary. The Nation's air quality standards for all size particles
were first established in 1971, significantly revised in 1987 to
regulate particles smaller than, or equal to, 10 micrometers in diameter
(PM10), and further revised in 1997 to set a separate
standard for fine particles (PM2.5) based on their link to
serious health effects. Health effects range from asthma exacerbation
and heart attacks to an increase in death rate from lung and heart
diseases. Finally, in order to further protect public health, on
Wednesday, December 21, 2005, the EPA proposed a stronger standard for
PM2.5.
The proposed revision to
the 1997 standard includes lowering the 24-hour PM 2.5
standard from 65 to 35ug/m3, while retaining the current level of annual
PM 2.5 standard of 15 ug/m3. The EPA is seeking comments on
the proposal.
In an effort to keep the
public informed of the proposed standard and how it would affect them,
the EPC has reviewed the past six years (2000-2005) worth of PM2.5
monitoring data. If the current 24-hour standard is lowered to 35ug/m3,
and EPC applied the proposed level to the past six years worth of PM2.5
data, there would be a total of 12 days that Hillsborough County would
have been above the level. With the current standard set
at 65 ug/m3, Hillsborough County has had no exceedences in 2000-2005.
