Bad allergies: blame climate change?

Global climate change may be most closely associated with warmer temperatures and rising sea levels, but it may also be responsible for another (less devastating) scourge: An increase in

allergies. A new study from Quest Diagnostics finds that sensitivity to two common airborne allergens is increasingly common, and may be tied to climate change. Here, a guide to the study:

ALLERGIES ARE ON THE RISE? They sure are. The number of people afflicted by allergies increased by about 6 percent from 2005 to 2008. And allergies to common ragweed (up 15 percent) and mold

(up 12 percent) jumped even more "dramatically," according to the Quest report. SUBSCRIBE TO THE WEEK Escape your echo chamber. Get the facts behind the news, plus analysis from

multiple perspectives. SUBSCRIBE & SAVE SIGN UP FOR THE WEEK'S FREE NEWSLETTERS From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered

directly to your inbox. From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox. AND THIS IS REALLY TIED TO CLIMATE CHANGE?

Yes, accordng to the study. As the planet gets hotter, ragweed and mold are better able to thrive, and that prevalence leads to an increase in allergies, says the Quest report. Already,

earlier studies had found that the growth of fungal spores increased with rises in carbon dioxide, and that the ragweed pollen season has gotten nearly a month longer since 1995, says

Susanne Rust in _California Watch_. So "if you like it hot, be prepared to suffer the consequences," says Dennis Romero in _LA Weekly_. HOW WAS THIS NEW STUDY DONE? Quest examined

nearly 14 million blood samples from more than 2 million allergy patients over the course of four years. Quest's blood tests looked for antibodies to 11 common allergens, including

ragweed, mold, dust mites, and dog dander. The company says this was the largest allergy study ever done in the U.S. A free daily email with the biggest news stories of the day – and the

best features from TheWeek.com HOW COMMON ARE ALLERGIES OVERALL? They affect 1 in 5 Americans. "Allergies account for more than 17 million physician office visits, 30,000 emergency room

visits, and several hundred deaths each year." The study also found that allergies are more prevalent among men than women, and more common among children than adults. Earlier studies

had suggested that women suffered more from allergies. AND WHERE ARE ALLERGIES WORST? "In the United States, the western region has been hit the hardest, with the largest increases

being seen in California, Nevada and Arizona," says Lynn Walbrecht at _Health News_. Phoenix, Las Vegas, and Overland Park, Kan., had the highest rates of ragweed sensitivity, while

Miami, San Francisco, and Portland, Ore., had the lowest. SOURCES: _California Watch_, _Health News_, _LA Weekly_, _UPI_ (2)