Air pollution in major US cities is the largest cause of premature mortality, a new study has revealed. An average of 200,000 people have their lives cut short by about a decade every year because of continuous exposure to toxic fumes.

Researchers from MIT’s Laboratory for Aviation and the Environment carried out a nationwide study, tracing ground-level emissions and their effect on citizen mortality. The team of investigators looked at sources such as car exhausts, industrial smokestacks and commercial and residential heating and found that an average of 200,000 people die prematurely each year because of exposure.



Steven Barrett, an assistant professor of aeronautics and astronautics at MIT, said the new research confirmed already existing fears. He stressed that prolonged exposure to toxic emissions could shorten people’s lives by up to a decade.



“In the past five to 10 years, the evidence linking air-pollution exposure to risk of early death has really solidified and gained scientific and political traction,” said Barrett, adding that something must be done to mitigate the problem.



In the study sources of air pollution were divided into six different categories: electric power generation, industry, commercial and residential sources, road transportation, marine transportation, and rail transportation. Data on each of the categories was then fed into an air quality simulation program to assess their impact on the atmosphere.



Out of all 50 states, California is the worst offender, with over 21,000 premature deaths mostly attributed to exposure to car exhaust fumes and emissions from heating and cooking. Moreover, the US Environmental Protection Agency says that more than 1 million southern Californians are at a greater risk of contracting a respiratory disorder because they live within 300 meters of a highway.





Transport biggest killer



The primary cause of premature death in the US was found to be transport emissions, responsible for 53,000 of the 200,000 premature deaths. Fumes from electrical power generation followed closely behind, claiming 52,000 lives annually. Early deaths from industrial activities were found to be particularly prevalent in the Midwest, as well as in Los Angeles, Philadelphia and Atlanta.



“It was surprising to me just how significant road transportation was,” Barrett observed, “especially when you imagine [that] coal-fired power stations are burning relatively dirty fuel.”



Domestic emissions sources were also flagged as part of the problem, with pollution from cooking and heating behind a large number of premature deaths. Although they may seem harmless the use of these appliances produces carbon dioxide which can cause health problems after prolonged exposure.



“A public health burden of this magnitude clearly requires significant policy attention, especially since technologies are readily available to address a significant fraction of these emissions,” Jonathan Levy, a professor of environmental health at Boston University, commented to MIT.



The US Environmental Agency recently introduced new guidelines that will require air pollution monitors to be installed on the side of major highways in over 100 cities across the country. However, fossil fuels still remain the principle source of US power, accounting for 42 percent of the country's electricity production in 2011.



