As the Spring arrives earlier and earlier each year, allergies also start up earlier as well new research claims. The fact that our planet is warming, directly impacts the production of ragweed pollens making many person's discomfort parallel to the start of the warm weather months. One in 10 Americans test positive for ragweed sensitivity, and allergies have risen in the United States and elsewhere over the last 30 years.
Paul Beggs of Macquarie University in Australia comments on new research:
"This is an outstanding piece of research. This research adds to the mounting evidence that one of the most important impacts of climate change on human health will be the adverse impacts on allergic respiratory diseases such as allergic rhinitis (hay fever) and asthma. Indeed, the significant lengthening of the ragweed pollen season, particularly in the higher latitudes of North America, over the last 15 or so years, revealed in this research, adds to the likelihood that climate change has for some time now already been having an adverse impact on human health."
Higher carbon dioxide (CO2) levels associated with global warming may have doubled the amount of pollen that ragweed produces, mostly over the past four or five decades. Another doubling could occur by the end of this century. Pollen production rose almost 400% with a 200% increase in the amount of CO2. Findings show that high CO2 levels have increased the potential production of ragweed pollen and may produce pollen earlier.
In a study released in 2000, Lewis H. Ziska, a plant physiologist with USDA's Agricultural Research Service, who led most of the research, comments on his own findings on warming and ragweed counts:
"I was surprised to see the signal as strong as it was. I thought we might see something fairly weak, but I was surprised that even in the last couple of decades we could see things."
Ziska, conducting his research in collaboration with Johns Hopkins University School of Public Health, Towson University and Multidata Corporation, says this ongoing experiment should show how global warming and higher CO2 levels are increasing ragweed pollen count especially in cities. Although less ragweed grows in cities, exposure to air pollutants such as ground-level ozone can make people more sensitive to ragweed pollen.
Ragweed allergy is a significantly common allergy caused by Ragweed pollen which is released by the Ragweed Plant which is a flowering plant from the sunflower family. Ragweed is also known as bitterweeds or bloodweeds in some regions and it can come in common and also giant form.
Most commonly Ragweed is found in warmer regions of the Northern Hemisphere and also South America. It thrives on dry plains, sand soils and the banks of rivers as well as on dry roadsides and any sort of open and unattended land or waste land. This means that it is not just found rurally but in urban areas too. Ragweed pollen is spread primarily by the wind and can be carried for many miles and for prolonged periods of time on dry and windy days.
Patrick Kinney of Columbia University's Mailman School of Public Health adds:
"We know that exposure to pollen exacerbates disease and also can cause sensitization in people that aren't yet allergic, so more exposure is bad. This is suggesting that the length of the season has gone up and therefore that exposure has gone up."
While extra days of misery or potentially serious symptoms like asthma attacks are enough to make the new findings bad news for allergy sufferers, the authors also cite the Centers for Disease Control's estimate that "allergic disorders" cost Americans $21 billion annually.
Written by Sy Kraft, B.A.