Entries in Ragweed (3)


Fall Allergy Season May Be Longest, Strongest this Year

George Doyle/Stockbyte(NEW YORK) -- With record pollen counts already on the board for August, this fall is gearing up to be one of the worst, and longest, allergy seasons yet, according to experts.

Thanks to a particularly wet summer, ragweed pollen levels are surging and standing water left over from summer flooding and Hurricane Irene has increased the amount of mold, a common year-round allergen, in the air.

"We're going to have an allergy double whammy," says Dr. Clifford Bassett, medical director of Allergy and Asthma Care of New York.

To top it all off, the allergy season is expected to last a few weeks longer than usual this year, according to research published earlier this year in the Proceedings of the National Academy of Sciences.

While spring allergies usually come from pollen from trees and grass, fall allergies are caused almost exclusively by ragweed pollen.  The season usually runs from mid-August until the first frost of the year, around early October, but if the frost is delayed, as is predicted for this year, the allergy season goes on indefinitely until it comes.

For many years, the allergy seasons have been "getting longer and longer ... partly due to global warming," says Estelle Levetin, chairwoman of the aerobiology committee for the American Academy of Allergy, Asthma and Immunology.

"As we're seeing warmer and warmer weather, the fall gets warmer and longer and the effect is that there's no frost to kill the ragweed and end the allergy season," she says.

Rising temperatures have produced a similar lengthening of the spring allergy season, which is now starting about a month earlier than it did decades ago, she says.

Climate change isn't only affecting the length of the allergy season, it's affecting the severity.

"A single ragweed plant produces a million pollen grains, but if you expose it to greenhouse gases, it produces three to four times that much," says Bassett.  "So you have climate change making for a longer season, more plants and more potent pollen.  It's like a perfect storm," he says.

Copyright 2011 ABC News Radio


Ragweed and Mold Allergies on the Rise, Report Suggests

Jupiterimages/Thinkstock(MADISON, N.J.) -- Up to 20 percent of Americans suffer their way through the spring and summer because of ragweed allergies, and new research says the problem could be getting worse.

A report by Quest Diagnostics, a company that provides diagnostic testing services, suggests that allergies are on the rise nationwide, mostly due to an increase in the amount of ragweed and mold in the environment.

The company evaluated 14 million blood test results from about 2 million patients over a four-year period. Each test determined sensitivity to a specific allergen, and the company looked at 11 different allergens. They said people's sensitivity to ragweed increased 15 percent and mold sensitivity grew 12 percent.

"We believe this is the first large national study to show that the growing prevalence of allergies, suggested by other studies, is largely due to increases in environment-based allergens previously associated with climate change," said Dr. Stanley J. Naides, Quest's medical director of immunology.

The study also ranked the 30 worst metropolitan areas for ragweed allergies. They said Phoenix, Las Vegas, Kansas City, Riverside-San Bernardino, Calif., and Dallas topped the list. 

Copyright 2011 ABC News Radio´╗┐


Study: Allergy Season Getting Longer Each Year

Photo Courtesy - Getty Images(WASHINGTON) -- Allergy season is looming, and for the millions of Americans who suffer from the seasonal sneezing and watery eyes, this year may seem worse than years past.

According to a new study published in the Proceedings of the National Academy of Sciences, spring keeps arriving a little earlier each year as warming temperatures force winter to start later and end earlier.  This climate change, in turn, is allowing more time for plants to produce pollen, causing those with allergies to battle their symptoms longer.

Researchers studied 15 years worth of data on climate and ragweed from various locations in the U.S. and Canada.  They found that the ragweed season had been extended by nearly a month in some areas.´╗┐

Copyright 2011 ABC News Radio

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