Study: global warming boosts poison ivy

The Associated Press
Seattle Post Intelligencer
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Washington (US):
Another reason to worry about global warming: more and itchier poison ivy. The noxious vine grows faster and bigger as carbon dioxide levels in the atmosphere rise, researchers report Monday.
And a CO2-driven vine also produces more of its rash-causing chemical, urushiol, conclude experiments conducted in a forest at Duke University where scientists increased carbon-dioxide levels to those expected in 2050.
Carbon dioxide is a greenhouse gas - a chemical that traps heat similar to the way a greenhouse does - that's considered a major contributor to global warming.
Poison ivy's itchy, sometimes blistering rash is one of the most widely reported ailments to poison-control centers, with more than 350,000 reported cases a year.
Compared to poison ivy grown in usual atmospheric conditions, those exposed to the extra-high carbon dioxide grew about three times larger - and produced more allergenic form of urushiol, scientists from Duke and Harvard University reported.
Their study appears in this week's Proceedings of the National Academy of Sciences.
May 29. 2006