You
may or may not notice haze or smog, but the pollutants in the
air you breathe pose a sinister hazard that is painfully obvious
to persons with asthma.
Asthma is the leading chronic illness affecting American children,
and the prevalence of the disease has been increasing among both
children and adults over the past 25 years. Usually because of
some trigger in the environment, a person with asthma experiences
inflammation and constriction of the airways, leading to wheezing,
coughing, tightness in the chest and shortness of breath.
More than 152 million Americans live in areas with unhealthy levels
of pollutants in the air, according to Air: 2005, an American
Lung Association report. Hazards include exhaust fumes from motor
vehicles, smoke from power plants and factories and soot from
indoor or outdoor wood burning. Under such conditions, asthma
patients are at risk of attacks–often serious enough to
require emergency medical attention.
If someone in your home has asthma, you undoubtedly pay attention
to reports of the air quality index (AQI) on your local news media.
Five major pollutants are measured each day, and the AQI is calculated
based on a formula developed by the Environmental Protection Agency.
An AQI under 100 is considered “satisfactory” and
anything over that number is “unhealthy.” Levels somewhat
higher than 100 can be dangerous to everyone, and a person with
asthma may be affected even by readings considered satisfactory.
Know
Your Enemy
The five pollutants are:
Ground-level ozone, which is formed when exhaust
fumes from cars, power plants and industrial boilers are exposed
to heat and sunlight, typically during a summer afternoon. While
the ozone layer of clouds in the stratosphere protects us from
excessive exposure to ultraviolet radiation, ground-level ozone
is not so good, damaging the lining of lungs even when it causes
no symptoms.
Particle pollution refers to particles emitted
during combustion measuring less than 2.5 microns in diameter.
These may come from smoke from coal-fired power plants, factories,
wood-burning stoves, agricultural burning or soot from the exhaust
of diesel trucks, buses or heavy equipment. Since these particles
easily become embedded deep in the lungs, they can cause serious
health effects.
Carbon monoxide, which comes primarily from car
and truck exhaust, is colorless and odorless but deadly in high
concentrations and damaging at lower levels for persons with breathing
problems or heart disease. Generally, carbon monoxide levels are
highest during morning and afternoon traffic hours, particularly
during winter.
Sulfur dioxide, a precursor of acid rain, results
mainly from burning of fossil fuels, such as from power plants,
metal smelting or other heavy industry.
Nitrogen dioxide emissions include high-temperature
combustion processes such as automobiles, power plants, home heaters
and gas stoves.
One study of children in Bronx County, New York found a direct
relationship between hospitalizations for asthma and levels of
sulfur dioxide in the atmosphere, with apparently a dose/response
relationship.
Asthma occurs even in highly competitive athletes, and one reason
may be exposure to polluted air. In one study involving children
in 12 communities in southern California with varying levels of
air pollution, the risk of developing asthma was three times higher
among children exposed to high ground-level ozone levels who participated
in three or more outdoor sports.
In
low-ozone communities, outdoor sports had little effect on asthma
risk. And children in high-ozone areas who did not participate
in outdoor sports had a lower risk.
Asthma patients–and others–should avoid heavy outdoor
exercise and stay inside as much as possible on days when the
pollution level is high. Runners, walkers and bikers should avoid
routes close to heavily traveled thoroughfares.
While polluted air can occur anywhere, those living in the low
rent district–near freeways, factories or power plants–or
in crowded conditions have an elevated risk. An African American
child is three times more likely than other children to die of
an asthma attack, and one reason may be socioeconomic conditions
affecting the quality of both outdoor and indoor air.
Most
Americans spend about 90 percent of their time indoors, but pollutants
can leak in from the outside and the enclosed air has its own
set of hazards. Some believe that tightly enclosed modern buildings
may be at least partially to blame for the increase in asthma.
Tobacco smoke, either first- or second-hand is a major pollutant
of indoor air. Don’t smoke indoors, particularly around
children or asthma patients.
Wood-burning stoves and some gas appliances can also emit harmful
pollutants. Be sure your furnace, stoves and space heaters are
properly vented and inspected each year.
In addition, persons with asthma are frequently sensitive to dust
mites, mold, cockroaches, pet allergens and pollens. Careful vacuuming,
cleaning and laundering is necessary, and humidity levels should
be kept between 30 and 50 percent to inhibit the growth of molds.
Precautions about allergens apply mainly to those with asthma,
but clean air is everyone’s business. Even if you don’t
start to wheeze or cough, pollutants in the air are having negative
health effects on your lungs, heart and blood vessels.
Do your part to keep yourself and others breathing freely by trying
to find alternatives to your solo driving ventures–walking,
biking, public transportation, car pooling. When you drive, avoid
jack rabbit starts and idling your engine for extended periods.
Lawn mowers, snow blowers, weed trimmers all have a negative effect
on the air we breathe. Do what you can to minimize their use.
Use an electric starter rather than charcoal lighter fluid to
light the barbecue.
If you’re a smoker, quit. Otherwise, respect the rules restricting
public smoking. They may seem like a nuisance but are necessary
to protect you and others around you.
One and a half million emergency room visits are made each year
because of asthma attacks, many related to air quality. About
six thousand Americans die as a result. Keeping the air clean
is a way of keeping these people healthy and alive.
