APONAL can help: Whatever that number is...why not change the number to PM 2.5 so we can remember it! LOL RE:
From Raging Bull
ragingbull.com
Fuel Cells will help...
The Air You Breathe Can Kill You
ATLANTA, Georgia, August 16, 1999 (ENS) - Healthy adults are facing
previously unsuspected threats from air pollution. Tiny particles can zoom
through human lungs up to two times faster and penetrate more deeply
than assumed before, a University of Delaware scientist says. Children
and the elderly are at even greater risk.
"Smog kills perhaps partly because pollutant particles are so deeply
deposited in our airways," says Anthony Wexler, a professor of
mechanical engineering at the University of Delaware.
A Georgia Institute of Technology researcher
measures wind speed and direction at an
Atlanta air quality testing facility (Photo courtesy
Georgia Institute of Technology)
Scientists from around the world have gathered
in Atlanta this month to determine the best
ways to measure this fine particulate matter
that is polluting the nation's air, particularly in
large urban areas. Atlanta's air pollution
problems have halted several new highway
construction projects that officials feared would
increase already dangerous city smog levels.
Particulate matter, which is federally regulated,
is created by the burning of coal and oil.
Numerous studies link it to serious health
problems.
Fine particulate matter, called PM 2.5 because it is less than 2.5 microns
in diameter - about 30 times smaller than the diameter of a human hair,
includes soot, dust, aerosols, metals and sulfates. These particles
emitted by vehicles, factories and industrial facilities contribute to the
smog so common in American cities.
In the first of two studies initiated by the U.S. Environmental Protection
Agency (EPA), about 60 scientists have converged at an Atlanta air
quality research facility owned by Georgia Power. Scientists began
measuring PM 2.5 around the clock at 7:00 am August 3 and will continue
through 7:00 am September 1.
"We are trying to determine how to measure the concentration and
composition of fine particulate matter in the atmosphere and the types of
instruments best suited to do that," said Dr. William Chameides, a
professor in the Georgia Institute of Technology's School of Earth and
Atmospheric Sciences and head of the study. "We need to do this to
understand the health effects and the sources, and to monitor
compliance with EPA standards."
Smog causes problems in cities across the U.S., sometimes in hard to
predict locales. In the nation's smog capital, Los Angeles residents are
now enjoying one of their least polluted summers ever. The Los Angeles
region has made it to mid-August without suffering a single full scale
smog alert - the first time that has happened since officials began
tracking air quality.
Texas is promoting car
pools to help combat air
pollution (Photo courtesy North
Central Texas Council of
Governments)
But in east Texas and along
the Eastern Seaboard,
residents are coping with some of the worst smog seasons on record.
Texas City, near Galveston, Texas, has recorded the highest one-hour
concentration of urban ozone so far this summer. On August 6, the town
had 0.206 parts per million of particulate matter, the equivalent of a
Stage 1 smog alert. Today, the Dallas/Fort Worth area declared an
Ozone Alert Action Day, warning of dangerous levels of air pollutants.
Air pollution may be even more dangerous than experts have suspected.
A study by Wexler and Ramesh Sarangapani, expected to appear in the
next "Journal of Aerosol Science," reveals how PM 2.5 particles penetrate
buildings and people's airways more quickly and deeply than previously
known.
"As people breathe," Wexler explains, "a clump of fine particles called a
bolus will rapidly disperse throughout the lungs. At the terminal alveoli -
little sacks at the end of each respiratory branch, where oxygen and
carbon dioxide trade places with blood - these particles take up water
and expand, much like a sponge, because of hydroscopic effects."
Mathematical models of these physical events - dispersion and
hydroscopic expansion - suggest that "the smallest particles can
sometimes penetrate almost two times farther into airways than we had
suspected," Wexler says.
That happens because air in the center of a lung tube flows faster than
the surrounding stream, Wexler explains. Particle laden air mixes with
clean air at each intersection of the respiratory branches. All that
secondary mixing "dramatically speeds the movement of these fine
particles through the respiratory system," Wexler reports.
The next step, Sarangapani says, is to further investigate why fine
particles can be toxic in the lungs. "With the current amount of
knowledge available to us," he says, "I think that the EPA's current
standards are a reasonable response. But, additional research is needed
to identify the precise mechanisms involved in particulate toxicity."
Professor Anthony Wexler calls air pollution a
fast and invisible threat (Photo courtesy University
of Delaware)
In 1997, the EPA set a new, tighter standard for
PM 2.5, in response to studies associating
exposure to air pollution with serious health
problems. But trucking associations and other
industry groups have challenged the new
standards in federal court, preventing them
from being implemented.
Earlier this year, two judges of a three judge
panel ruled that the new PM 2.5 standard was
unconstitutional. The panel did not challenge the science on which the
new standard is based and in fact, said there was ample scientific
support for the new standard. The Department of Justice is appealing the
ruling.
Health effects of smog include increased hospital admissions and
emergency room visits, increased respiratory disease, decreased lung
function, and changes in respiratory tract defense mechanisms.
"Tens of thousands of elderly people die prematurely each year from
exposure to ambient levels of fine particles," according to the EPA.
Because children breathe 50 percent more air per pound of body weight,
compared to adults, they are more susceptible, especially if they suffer
from asthma. Even adults can die from air pollution exposure, because of
the way the particles act in the lungs.
© Environment News Service (ENS) 1999. All Rights Reserved.
We have the power to change this...
mannyt
...
Chucka |
