The MIT researchers from the US Environmental Protection Agency's (EPA) Clean Air Act played an important role in reducing the exposure of people to harmful pollutants and have saved more people than it was initially reported.
The EPA Clean Air Act saved lives against atmospheric organic aerosol, a chemically produced compound in the atmosphere from both natural and anthropogenical oxidation. It was the major component found in the atmospheric particulate matter directly emitted from fossil fuel combustion, open area fires, and residential burning.
In 2011 the EPA declared that the legislation was primarily responsible for a remarkable decrease in particulate in the atmospheric zone. An estimated of over 100,000 lives have been saved annually due to this from2000 to 2010.
The new study found there was a huge decrease in organic aerosol across the US, which may be responsible for more saving of lives than the EPA had actually speculated.
"The observations suggest that the decrease in organic aerosol had been six times larger than estimated between 2000 and 2010 in the EPA report," said David Ridley, the research scientist at MIT's Department of Civil and Environment Engineering (CEE).
"The changes in inorganic aerosol emissions are likely to be indirectly driven by controls by the EPA on different species, like black carbon from fuel burning and nitrogen dioxide from vehicles," said Ridley.
The study was published in the Proceedings of the National Academy of Sciences. In it, the researchers tracked the organic aerosol concentrations from 1990 to 2012 in a model.
The findings revealed that the organic aerosol had dramatically declined across the entire country in the winter and summer seasons, though it goes up during wildfires, residential burning, cloud cover, and temperature changes.
Almost half of the decline in organic aerosol occured due to changes in human emission behaviour, such as smoke pollution, vehicle emissions, residential burning, and wildfires.
"While there are costs and benefits to implementing regulations such as those in the Clean Air Act, it seems that we are reaping even greater benefits from the reduced mortality associated with the particulate matter because of the change in organic aerosol," said he.