RODALE NEWS, EMMAUS, PA—Given the millions of allergy sufferers held hostage by the drippy noses, burning, watery eyes, and continuous sneezing sessions it induces,
ragweed may be one of the most hated plants on the planet. And a new the U.S. Department of Agriculture (USDA)-led study published in the
Proceedings of the National Academy of Sciences confirms what many allergy sufferers and allergists have already been noticing—hay fever season caused by ragweed seems to be getting more intense and lasting longer.
The study is the latest to make the connection between
climate change and a more potent allergy season. (Allergy-related issues cost the United States about $21 billion a year, so a warming planet affects economics, too.) "The main takeaway is that we are already seeing a significant increase in the season length of ragweed; and that this increase in season length is associated with a greater warming at northern latitudes, consistent with the Intergovernmental Panel on Climate Change projections regarding climate change," explains lead study author Lewis Ziska, PhD, research plant physiologist with USDA's Crop Systems and Global Change Lab.
THE DETAILS: Researchers used ragweed pollen and temperature data recorded between the late 1990s and 2005 in 10 different locations in the U.S. and Canada and found that in all but two of the areas analyzed, the ragweed pollen season increased—in some cases by nearly a month. The lengthening of the allergy season coincides with an increase in warmer, frost-free days. Researchers noticed a general trend—the ragweed allergy season grew longest in the higher latitudes of the northern United States and Canada. Winnipeg, Ontario, allergy sufferers endured a 27-day-longer ragweed pollen season in 2005 compared to just 16 years earlier. In the U.S., Fargo, ND, and Minneapolis, MN, experienced a more than two-week increase in ragweed allergy season, with LaCrosse and Madison, WI, not far behind.
WHAT IT MEANS: Climate change threatens human health in
a number of ways, but allergies may be the most immediate, easy-to-recognize ailment thus far. And our increasingly chaotic climate's allergy-accelerating properties are already afflicting millions of people. Ragweed is one of the most common weed allergens, affecting about 10 percent of the population. Among allergy sufferers, nearly a third endure hay fever misery brought on by ragweed pollen. Under normal circumstances, a single ragweed plant creates 1 million pollen grains; but a climate change–charged, more CO2-rich environment boosts that number to upwards of 3 to 4 million pollen grains per plant, according to Clifford Bassett, MD, medical director of Allergy and Asthma Care of New York and a member of the public-education committee at the American College of Allergy, Asthma and Immunology. (Don't your eyes water just thinking of it?)
And scientists are also suspect of other potentially climate change–infused weed species. Ziska says there are concerns that other specific plant allergens are worsening due to climate change. His research group is working with Rutgers University in New Jersey and the Environmental Protection Agency to begin assessing pollen production and season length for other annual weeds like lambsquarters, mugwort, and plaintain, in addition to ragweed.
Consuming less,
using less energy,
eating organic, and demanding that
clean energy subsidies replace incentives to fund dirty fossil fuels like coal, oil, and
natural gas that make us sick are all important tactics to help stabilize global climate and protect our health. It's also important to realize that we've already set ourselves up for a lifetime of climate-related problems. Here's how to deal with the allergy aspect as we all work to keep things from getting worse.
Here are some solutions to think about now, before ragweed allergies strike later this year:
• Make sure you're actually allergic to ragweed. It may sound silly, but allergists recommend being tested to confirm you're allergic to what you actually think is making you sneeze. If ragweed is really making your life miserable (the longer you're exposed to the allergen, the worse the symptoms become), consider getting allergy shots. The ongoing climate shift could be a cue to reassess your antiallergy options. "It might make people who previously had mild ragweed seasons to consider interventions they hadn't though of before, like getting ragweed allergy shots," says study coauthor Jay Portnoy, MD, chief of allergy, asthma, and immunology at Children's Mercy Hospitals and Clinics in Kansas City, MO.
• Plan vacations accordingly. For many people, February still marks the cold season, months away from hay fever hell. But take your ragweed allergy into consideration as you plan this year's summer or fall getaway. Dr. Bassett notes that pollen counts are generally lower around water. So if you vacation during prime ragweed season—summer and fall, or year-round in places like Florida or Hawaii—plan some time on the beach or around rivers and lakes for some ragweed relief.
