Research from MIT's Space & Environment Laboratory indicates that air pollution causes approximately 200,000 premature deaths annually in the United States, based on data from industrial chimneys, vehicle exhaust pipes, ship and rail transport, and residential and commercial heating systems.
Those whose deaths are related to air pollution are dying at an age that is mostly ten years earlier. Emissions from road transport are the most deadly, causing 53,000 premature deaths each year, followed by power plants, which cause 52,000 premature deaths each year.
Lead researcher Steven Barrett, an assistant professor in MIT's Department of Aerospace Engineering, pointed out, "Over the past five to ten years, there has been a great deal of scientific evidence and political attention focused on the relationship between air pollution and premature death. Air pollution is a common problem in all cities and urgently needs to be addressed."
The research team collected data from the U.S. Environmental Protection Agency's National Emissions Register for 2005. 2005 data was the most recent available at the time the study was conducted. Although the data only reflects emissions in 2005, Barrett stated that the findings still reflect the health risks associated with air pollution today.
Barrett's research team divided the raw data into six groups based on pollution sources: power generation, industry, residential and commercial, road transport, marine transport, and rail transport. They then input the emission data from these six groups into an air quality model simulating the effects of particulate and gaseous emissions in the atmosphere. To determine which emissions had the greatest impact, the team removed each emission group from the simulation and observed changes in pollutant concentrations.
Researchers analyzed air pollution emissions from 5,695 U.S. cities and found that California has the most severe air pollution problem, causing 21,000 premature deaths each year. The main sources of air pollution are road transport and emissions from residential and commercial heating and cooking. Baltimore has the highest air pollution-related mortality rate, with 130 out of every 100,000 residents potentially dying each year from long-term exposure to air pollution.
When asked why land transportation caused 53,000 premature deaths, while power plants caused only 52,000, the researchers explained, "Most vehicles travel in densely populated areas, increasing the amount of pollutants that a large number of people are exposed to, while power plants are mostly located in remote areas and their emissions tend to drift towards higher latitudes."
Jonathan Levy, a professor in the Department of Environmental Health at Boston University, said that Barrett's findings are consistent with the conclusions of the U.S. Environmental Protection Agency. "These large-scale public health problems require policy-based solutions, and current technology has advanced to the point where we can address them," Levy said.
The research team then compared the simulated data with a map of population density in the United States to understand which sources of pollution the population in each region was most likely to be exposed to.
Industrial air pollution is most severe in the Midwest, particularly between Chicago and Detroit. Cities like Philadelphia, Atlanta, and Los Angeles also experience high levels of industrial air pollution. In the eastern and western Midwest, air pollution from power plants has the most significant impact on early mortality because eastern power plants use coal with much higher sulfur content than western power plants.
Premature deaths caused by residential and commercial air pollution, such as from heating and cooking emissions, occur most frequently in densely populated areas along the east and west coasts of the United States. Industrial air pollution along the Gulf Coast is also significant, as it is home to the largest oil refineries in the country. Southern California suffers the most from air pollution from transportation and ports, causing 3,500 premature deaths annually. Premature deaths related to air pollution from rail transport are relatively minor and consistently concentrated in the central-eastern and Midwestern United States.
Sources: Environmental Information Center (2013-09-04)
