WASHINGTON: Scientists have found that the noxious vine called poison ivy grows faster and larger with more carbon dioxide available in the atmosphere.
The vine, which subsists on carbon dioxide, produces a chemical, urushiol, which causes itching and sometimes blistering rash. The condition is one of the most widely reported ailments at poison-control centers. An estimated 350,000 cases are reported every year.
Poison ivy is commonly see in woods around the country.
The studies were conducted at an enclosed forest area at Duke University at Durham, North Carolina, where scientists increased the level of carbon dioxide to that expected in uncontrolled situation in 2050. They found that the vine grew about three times larger and produced a more allergenic form of urushiol.
The results of the study appear in the latest issue of Proceedings of the National Academy of Sciences.
The report on the study said, the "fertilization effect of rising CO2 on poison ivy … and the shift toward a more allergenic form of urushiol have important implications for the future health of both humans and forests."
Duke University botanist William Schlesinger says the vine's exuberant response to carbon dioxide may have unsettling implications for human health as the level of the gas in the atmosphere continues to increase.
Higher levels of carbon dioxide also impacts the health of forests, which some botanists feel, are already suffering because of the uncontrolled growth of vines at the expense of trees and other plants.
The study lasted six years and scientists compared the "biomass" in the high-carbon dioxide area with those grown in control area where similar plants grew in normal air. They found that overall trees and other woody plants in the high-carbon dioxide area grew about 31 per cent faster. But, the poison ivy in this area grew 149 per cent faster than in the control area. They also found the concentration of urushiol in the vine grown in the high-carbon dioxide area was 153 per cent higher.
