Analysis of West Virginia trees downwind from Ohio Valley coal plants showed health improvements following the Great Depression and the Clean Air Act, according to a TG Daily article.
Looking at tree rings dating back 100 years, Kansas State University and West Virginia University researchers found shifts in growth patterns following the decline of emissions.
Red cedar trees were studied living in the Central Appalachian Mountains, which receive emissions from Ohio Coal plants. Stable carbon isotopes, which record physiological changes in the trees, were analyzed in KSU’s mass spectrometer.
They found a shift in growth patterns about ten years following the 1970 enactment of the Clean Air Act, which reduced acidic sulfur emissions. A similar trend was observed following the Great Depression, when an economic crash hampered industrial production.
The full study can be seen in the Proceedings for the National Academy of Sciences.
Image: Analysis of red cedar tree rings showed a shift in growth patterns after times of industrial emission decline (Credit: Dendroica cerulea, via Flickr)