Storms not a breath of fresh air

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Storms not a breath of fresh air

New study finds link to increase in acute asthma attacks in metro Atlanta as

conditions stir up triggers.

By Ken Foskett

The Atlanta Journal-Constitution

Published on: 08/02/08

http://www.ajc.com/services/content/printedition/2008/08/02/asthmanat.html

Think those refreshing summer thunderstorms clear out Atlanta's unhealthy air

and let you breathe easier? Think again.

Researchers from the University of Georgia and Emory University found that acute

asthma attacks in metro Atlanta increased after downpours.

The new study, analyzing 12 years of data, is the first in the United States

establishing a link between thunderstorms and asthma, a serious respiratory

condition exacerbated by pollen, pollution and cigarette smoke.

Researchers theorize that rain, wind —- even lightning —- activate known asthma

triggers such as pollen and mold, making asthmatics more susceptible to an

attack.

Bottom line?

" You might want to stay indoors, " says Grundstein, a UGA climatologist

and co-author of the study.

Asthmatics should pay attention to weather reports and keep medications close

during and after thunderstorms, adds Stefanie Ebelt Sarnat, an epidemiologist at

Emory's Rollins School of Public Health and another author of the study.

In Georgia, asthma affects about 210,000 children under 17, and 480,000 adults,

causing about 117 deaths each year, according to the state division of public

health. Genetic factors influence who gets asthma, but environmental conditions

also play a key role.

Scientists had previously theorized that thunderstorms could trigger the release

of more asthma-causing irritants into the air. But no U.S. study had looked for

a link to asthma attacks.

Grundstein and the UGA-Emory research team believed Atlanta was the perfect test

city. The city has seasonally high pollen counts, and the region experiences an

average of 50 to 60 thunderstorm days a year.

The researchers compiled data on emergency room visits from 41 hospitals in a

20-county area around metro Atlanta between 1993 and 2004. Over the same time

period, they identified 564 thunderstorm days.

They looked for an association between thunderstorms and emergency room visits

by asthma sufferers. Visits by asthmatics averaged 3 percent higher on the day

after a thunderstorm, they found.

" This 3 percent was very highly statistically significant, " said Grundstein. " It

wasn't just a blip in the data. We really saw a connection. "

The total number of asthmatics experiencing breathing difficulty after

thunderstorms could actually be higher, Sarnat says, because the Georgia study

only recorded patients whose condition was so serious they required immediate

intervention in the emergency room, or didn't have proper medication at home.

The study, first published in the online edition of the journal Thorax, didn't

capture asthmatics who had breathing problems but were able to medicate

themselves without a trip to the hospital.

The thunderstorm-asthma link was strongest during storms with moderate-to-high

wind gusts. The researchers also found that moisture was a key ingredient. They

didn't find a link during storms that produced no rain.

Grundstein said the findings challenged what he'd previously assumed. " I thought

the rain would clear the air, " he says.

In a thunderstorm, researchers theorize, rain causes pollen grains to burst into

even tinier particles, releasing allergens that are easier for someone to

inhale. Windy downdrafts, typical of storms, force the particles to shoot into

the air instead of settle on the ground.

Thunderstorms also can increase the release of mold spores, another asthma

trigger, Grundstein says.

Some studies suggest that lightning sparks a chemical reaction that generates

asthma triggers such as nitrogen dioxide and ozone, pollutants associated with

smog, by making those gases more prevalent in the air.

Although the UGA-Emory study did not examine the precise mechanism that causes

these allergens to trigger an asthma attack, Grundstein said some computer

modeling has suggested that thunderstorms charge pollen grains and mold spores

in such a way that they stick more easily to lung tissue.

" There is a whole lot more research we need to do in this area, " he says.

Climatologists have also projected that the number of severe thunderstorms

striking the Atlanta area could double by the end of the century due to global

warming, increasing the need for public awareness about air quality after a

storm.

" It's possible we'll see more thunderstorms and we'll see more impact on

asthmatics, " says Sarnat.

JEMAL R. BRINSON / Staff

ER VISITS FOR ASTHMA

Fulton and DeKalb had the highest rates of asthma emergency room visits in the

metro area in 2004, the latest figures available. Researchers have found that

visits increase after thunderstorms.

Georgia ER visits: 46,152

Georgia ER visits per 100,000: 510

...........ER visits ..ER visits per

.......................100,000 people

Clayton ..1,435 ......494

Cobb......2,800 ......412

DeKalb....5,175 ......758

Fulton....7,945 ......958

Gwinnett..2,943 ......396

Source: Georgia Hospital Association