Road transportation is the main source of air pollution in the U.S., closely followed by power generation and commercial and residential emissions.
This is the conclusion of an extensive study conducted by scientists from MIT’s Laboratory for Aviation and the Environment. They established that annually in the U.S a total of 200,000 early deaths are caused by toxic emissions, out of which 53,000 are attributed to road transportation.
The study was published in the journal Atmospheric Environment and it was conducted by Steven Barrett, an assistant professor of aeronautics and astronautics at MIT, and his team. The researchers collected data from across the U.S., tracking emissions from various pollution sources.
The most polluted state was found to be California, where each year around 21,000 deaths occur as a result of contaminated air. Locally, the city of Baltimore was found to have the highest number of deaths caused by emissions, with 1 out of 1000 people dying every year due to long-term exposure.
The team established that on average air pollution reduces the lifespan of an American citizen by 10 years. This was estimated using the most recent data on emissions collected from the EPA’s National Emissions Inventory. The researchers compared the values with population density of each state.
The most surprising observation was that road transportation affects mortality rates more than power generating facilities, although the difference between the two is only 1,000 early deaths per year. Oil refineries and coal-powered plants were found to have the highest impact on citizens in the Midwest, Philadelphia, Atlanta, Los Angeles and the Gulf Coast. Marine-derived pollution from ports and shipping was found most significant in Southern California, while commercial and residential pollution sources cause the highest number of deaths along the East and West coasts.
One limitation of the study is the fact that EPA could provide data only from 2005. The authors claim that the findings are representative for the current situation, although some might argue that the situation has worsen.
