May 1998
WASHINGTON, D.C. - Allergy and asthma sufferers could be in for a rough ride this season due to the unusually warm winter delivered to many parts of the country by the El Niņo weather patterns, according to data presented at the American Academy of Allergy, Asthma and Immunology's 54th Annual Meeting.
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The unusual warmth of parts of the Pacific Ocean has dramatically affected temperatures and precipitation across the country, as well as the 1997-1998 allergy season. Typically, tree pollen season begins around mid-March, although some areas, such as the South and California, normally have earlier tree pollen starts. Mold and grass pollens usually arrive in the late spring and early summer - but recent weather conditions have dramatically changed their arrival dates, as well.
The southern half of the country, from Arizona to Florida, is reporting higher-than-normal pollen activity. The rest of the country, particularly the mid-Atlantic states, saw the allergy season arrive two weeks earlier than normal this year. Increased rainfall is also promoting the growth of various molds and pollen-producing grasses and weeds, resulting in abundant pollens being released. In California, mudslides are leaving wide areas of disturbed soil that have become breeding grounds for ragweed. These conditions are prime for the possibility of a "bumper crop of ragweed."
Additionally, pollen rates can vary depending on the type of pollen producer. For example, a 200 rating for grass pollen is very high but for tree pollen can be considered very low, said allergists.
Sap was observed running from maple trees in the northeastern United States in February, a sign of early pollination. Oklahoma allergists reported seeing their cedar trees "on fire" - clouds of pre-pollen being released into the air one month ahead of schedule.
However, there is still hope that if the El Niņo's rains manage to wash away pollens before they get into the upper atmosphere, the grim forecast could change. Unlike trees and grass, which depend on the warm weather to release their pollens, ragweed is triggered by phototropism (when the day-night cycle gets back to equinox, or equal time) which makes it a much harder pollen force to reckon with, said allergists.
"Because of the unusual weather, allergy sufferers are experiencing symptoms earlier and longer," said Donald Pulver, MD, clinical assistant professor of medicine at the University of Rochester in New York. "Nature is unpredictable, yet if current conditions persist, the best guess is for an early release of tree pollen, increased growth of grasses and weeds and increased indoor and outdoor mold exposure."
Nine percent of the country's population suffers from pollen allergies, which led to 7.6 million doctor visits in 1992 alone, with more than 5,000 deaths recorded annually, according to data from the National Institute of Allergy and Infectious Diseases (NIAID) in Bethesda, Md. Fifteen million people suffer from asthma while 35 million suffer from allergies. In 1995, there were 8 million people diagnosed with allergic rhinitis.
In addition to the weather, the pollen has had another partner in exacerbating allergy and asthma conditions this season - pollution - in particular, diesel emission particles. Research indicates that diesel emission particles piggy-back on fractured grass particles and other pollens, and when inhaled can travel deep into a person's lungs. But the effects of El Niņo on this allergy season are going to be different depending on what part of the country the sufferer lives in, said Linda Ford, MD, an allergist at the University of Nebraska at Omaha and president of the American Lung Association.
"It's difficult to homogenize the entire country when one talks about asthma and allergies," she said. "For example, on the West Coast El Niņo has actually helped lower air pollution levels, but at the same time it has increased the amount of mold spores in the area due to those heavy rains," she said, adding that people should treat their allergies with antihistamines, prescription drugs or allergy shots once the symptoms begin.
For more information:
- Pulver D. Outdoor allergens and allergic disease. Presented at the 54th Annual Meeting of the American Academy of Allergy, Asthma and Immunology. March 13-18. Washington, DC.
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