'Clean Air Act is working', claims research

Attempts for reducing air pollution by enforcing the US Clean Air Act have been successful, according to new research. A collaborative project that studied the Appalachian Mountains', West Virginia, cedar trees found that they have experienced accelerated growth since the act was passed.

According to researchers, since the introduction of the Clean Air Act in 1970, the cedar trees of the mountain region have grown faster and ecosystems throughout the region have been restored. The cedar trees of the area were heavily damaged throughout the 20th century by acidic pollution. This pollution was created by the Ohio River Valley coal plants, which were responsible for heavy falls of acid rain over the years.

Due to the increase in coal plants, the Appalachian Mountain region began to experience high levels of sulphur dioxide deposition - the cause of acid rain - throughout the 1900s. During the four-year study it was found that cedar trees throughout the area began to slow their growth throughout this time, despite the high levels of carbon dioxide.

The research pinpointed a time in 1982 where the forest and the trees altered their growth pattern, according to Doctor Jesse Nippert, associate professor of biology at Kansas State University. The trajectory of the trees' growth altered some ten years after the introduction of the Clean Air Act, once sulphur dioxide levels were reduced in the region. This led to the recovery of the ecosystem, which was stunted by heavy acidic pollution for a number of years, continued Doctor Nippert.

The study, published in the journal 'Proceedings of the Natural Academy of Sciences', primarily focused on the cedar trees in the area due to their sensitivity to environmental change. This type of tree is also known to grow rather slowly, allowing for more in-depth results to be attained. The scientists also found that the trees experienced an increase in growth speed during the 1930s, which they have surmised could be related to a lower production rate in the coal plants due to the Great Depression.