Tuesday, June 8, 2010

Tree Tells Pollution Story

A 126 year-old tree that grew in Schenley Park may be painting a new picture of the environmental health of Pittsburgh. The red oak blew over in a storm in January of 2007 and eventually made its way into the hands of university of Pittsburgh undergrad Amelia Johnson. Johnson separated each ring and then using acid and a machine known as an I-C-P spectrometer measure the amount of 5 trace metals in the tree that she thought might indicate how much pollution the tree was being exposed to every year. She says the levels slowly increased through the 1900’s with a dip during the great depression, slid a bit in the 60’s and then went back up in the last 20 years of the tree’s life. “Which was extremely surprising because the steel and other manufacturing base of the Pittsburgh region has really sort of disappeared in the last 20 years. I was expecting that the trace metal levels would be lower, but based on what I have here, it seems tat there is still a lot of pollution within our environment,” Says Johnson. The metals measured where Zinc, Nickel, Copper, Cadmium, and Lead. Johnson says it is unclear if the material, which is mostly absorbed through the roots, is a remnant of the city’s industrial past of the product of some current condition such as increased car traffic. She says she hopes other will do similar studies in an effort to learn more.

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