Global warming could worsen allergies: report

NEW YORK (Reuters Health) - If your hayfever becomes worse than ever this fall, you might be able to blame global warming, a new research review suggests.

The report, published in the Journal of Allergy and Clinical Immunology, details the evidence that global warming is placing asthma and allergy sufferers at risk of "worsening disease, more symptomatic days, and reduced quality of life."

The problem is that climate change affects air quality -- boosting both air pollution and pollen counts, according to the report authors, led by Dr. Katherine M. Shea of the University of North Carolina, Chapel Hill.

Warmer temperatures mean longer pollen seasons, the researchers explain, while studies have shown that increased levels of carbon dioxide in the air increase pollen concentrations.

Climate change, Shea and her colleagues say, has already been linked with longer pollen seasons for late-summer weeds, including ragweed.

Ragweed is the main cause of fall-allergy woes, affecting an estimated 36 million Americans, according to the American Academy of Allergy, Asthma & Immunology (AAAI).

Future air quality will depend on large-scale factors like energy use, economic development and population growth, Shea and her colleagues write. But, they add, individuals can take measures that not only combat greenhouse gas emissions, but also improve their health.

Riding a bike or walking instead of driving cuts automobile exhaust and boosts physical fitness, the researchers point out. And if enough people do it, local air quality might improve, which in turn would be a boon to people's lung health.

Similarly, eating locally grown, organic produce is good for the body, while it also reduces emissions from food transport and processing, and from the use of petroleum-based pesticides and nitrogen fertilizers.

According to the AAAI, ragweed-allergy sufferers can also take immediate steps to combat their fall misery: keeping windows closed to keep the pollen outside; showering before bed to remove pollen from the hair and face and to keep it off the sheets; checking daily pollen counts, and staying inside when counts are high; and changing clothes after spending time outdoors.

SOURCE: Journal of Allergy and Clinical Immunology, September 2008.