Smoke Danger From California Wildfires

Skies in Southern California have an
eerie, dirty look as smoke spews from the numerous wildfires that began raging
Sunday and may still be days from containment.

Where there is smoke, there are health hazards, experts warn, perhaps even
for healthy residents living miles from the fire zones.

"Even as far away as 20 miles, you can see some unhealthy effects of the
fire damage," says Zab Mosenifar, MD, a pulmonologist and director of the
Cedars-Sinai Medical Center Women's Guild Pulmonary Disease Institute in Los
Angeles. A Malibu resident, Mosenifar awoke Tuesday morning to find his yard
and family cars covered in ash as the fire continued to blaze not far from his
beach house.

Residents in fire zones and nearby areas are urged  to take
precautions, pay attention to symptoms that may be related to smoke exposure,
and check the air quality in their immediate vicinity before spending any time
outdoors, especially when exercising, Mosenifar and other experts tell
WebMD.

Particle Size Determines Risk

Smoke from wildfires includes small particles of ash and other substances,
water vapor, and gases such as carbon monoxide. The sizes of these particles
affect the body differently, Mosenifar tells WebMD. Larger particles generally
can't get into the nose and upper respiratory tract, he says, although they
might irritate the eyes, outside of the nose, mouth, and skin.

But smaller particles -- those so tiny they are about 30 times smaller than
the diameter of a human hair --can easily get into your respiratory system, he
says. And there they can cause irritation in the lungs, runny noses, burning
eyes, and aggravate existing heart and lung problems such as emphysema, asthma,
and congestive heart failure.

While the bigger, heavier particles drop to the earth as the smoke billows
out from the fire, the smaller particles can travel some distances, he says,
depending on winds, temperatures, and other factors.  "If you live 15
or 20 miles from a fire, you are still exposed to particles, but the particle
size is smaller," he says.

How to Gauge the Smoke Danger

Use your senses to gauge the level of pollution from smoke exposure, says
Frank Gilliland, MD, PhD, professor of preventive medicine at the University of
Southern California Keck School of Medicine, who studied the health effects of
the 2003 California wildfires on children. "We tell people if they can
smell smoke, it's at very high levels. They should use their own senses to tell
them what they should be doing [in terms of outdoor activity]."

If people feel eye or throat irritation while outdoors, Gilliland tells
WebMD, "they ought to alter their activity  [and exercise indoors]
until the levels abate."

Paying attention to symptoms -- and taking precautions such as exercising
indoors -- is advised for a period of time after the fire is out, he adds.
Those living in the California wildfire zones are probably wise to take
precautions for two weeks, he says, depending on how quickly the smoke
dissipates.

Are You Smoke-Sensitive?

Some people are more susceptible to the effects of smoke and other
particulates, Gilliland and others say. Not surprisingly, the very young and
very old tend to be more susceptible, as do those with respiratory problems
such as asthma. But surprisingly, Gilliland and his colleagues have found that
susceptibility isn't limited to those who have asthma and other airway
problems.

In research conducted after the California wildfires in 2003, Gilliland's
team surveyed more than 6,000 elementary and high school students in
communities affected by wildfires and found that those who didn't have asthma
tended to have stronger symptoms from the smoke exposure than those who did,
perhaps because those who had asthma took more precautions such as staying
indoors during the fires.

Their study was published in 2006in the American Journal of Respiratory
and Critical CareMedicine.

Genetic makeup  plays a role, Gilliland says. A genetic variation found
in about half the population increases the risk of airway sensitivity,
Gilliland tells WebMD, citing research.

Steps to Reduce the Health Hazards of Smoke

Simple measures can go a long way to reduce exposure to the particulate
matter.  "If you are driving through the [fire-stricken] areas, keep
your windows closed and your air conditioners on 'recirculate' instead of
outdoor air," says Anthony Gerber, MD, a volunteer spokesman for the
American Lung Association of California and an assistant professor of medicine
at the University of California San Francisco Department of Medicine.

If you must go outdoors and it's smoky, wear a dust mask or hold a wet towel
over your face.  Masks, available at some hardware stores and medical
supply stores, filter out particles of various sizes.  Gerber worries that
masks may give a false sense of security. "You're not going to be fully
protected by wearing a mask," he says.

When indoors, keep on the air-conditioning if it's smoky outside and use the
recirculating setting if it's available, he says.  Those with lung
conditions such as asthma should continue taking their medication and call
their doctor if their symptoms seem worse.

How Widespread Will the Effect of Smoke Be?

Predicting how far the smoke from California's wildfires will travel is
difficult, Gerber and others say. Winds can carry it farther, for instance, and
rain can dampen the spread.

"It could diffuse across the Mexico border," Gerber says of the San
Diego wildfire smoke.

"The most northern Mexico towns will be affected," agrees Mosenifar.
But he does not think neighboring states -- Arizona, Oregon, Nevada -- will be
affected by California wildfire smoke.

By Kathleen Doheny
Reviewed by Louise Chang
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