A new study has determined that unseen and odourless,microscopic particles of air pollution wafting overseas and across continents kill some 3,80,000 people each year.
According to a report in Discovery News, Junfeng Liu of Princeton University and a team of researchers carried out the study. Exhaust from diesel engines, sulfur from coal-fired power plants and desert dust swirl into an insidious cocktail of tiny particles that can spend weeks airborne.
The most harmful are the smallest, less than 2.5 microns in diameter. When inhaled,they can irritate the lungs or pass directly into the bloodstream and damage arteries.
Scientists and regulators know this is a major public health problem, especially in developing countries. But less clear is the effect that air pollution generated in regions like China and Southeast Asia has on far-off lands, like, North America.
Particulate pollution born overseas that floats into Canada, Mexico and the United States accounts for 6,600 premature deaths each year, Liu and a team of researchers found.
Similarly, their study suggests that a dust plume from Africa and a fog of pollution from Europe converge on the Indian subcontinent, condemning nearly 2,00,000 people to early deaths.
Globally, the team estimates that some 3,80,000 people die prematurely as the result of particulates emigrating from foreign lands.
"It's clear that this is having an impact on health," said Denise Mauzerall of Princeton University, a co-author on the study. "If we want to develop a strategy to deal with anthropogenic pollution, we should consider the health aspect as well as climate implications," she added.
Mauzerall said that regulating diesel exhaust would be particularly beneficial. Diesel engines emit both black carbon, which absorbs sunlight and warms the
atmosphere and microparticles.