A new study said particulate matter emissions related to the shipping industry might be responsible for as many as 60,000 premature deaths due to cardiopulmonary disease and lung cancer.
The study, published this week in the American Chemical Society's journal, Environmental Science and Technology, said most of those deaths occur near coastlines in Europe, East Asia and South Asia.
The authors add that, "under current regulation and with the expected growth in shipping activity, we estimate that annual mortalities could increase by 40 percent by 2012."
The study correlates the global distribution of particulate matter -- black carbon, sulfur, nitrogen and organic particles -- released from ships' smokestacks with heart disease and lung cancer mortalities in adults.
The journal's Web site notes that the report was released as a subcommittee of the International Maritime Organization met in London Wednesday to continue discussions of sulfate emissions controls and other issues.
The study was done by a team led by James Corbett of the University of Delaware and James Winebrake of the Rochester Institute of Technology.
According to the journal, the study provides "some of the first estimates of premature mortality (PM) from exposure to particulate matter, nitrogen oxides (NOx), and sulfate in global ship emissions."
The paper said, "an important PM-related health effect is premature mortality; in particular, increases in concentrations of PM with aerodynamic diameters of 2.5 mm or less."
It says these small PM 2.5 particles "have been closely associated with increases in cardiopulmonary and lung cancer mortalities in exposed populations," with one group of researchers suggesting they result in 800,000 deaths per year, or about 1.2 percent of global premature mortalities each year.
In an interview, Corbett and Winebrake said that many of these particles are formed because of the high sulfur content in the bunker fuel -- sulfur levels than can be 15 times higher than that found in the distillate fuel that trucks burn, for example.
The authors conclude that their work "demonstrates that mortality and health benefits in multiple regions globally could be realized from policy action to mitigate ship emissions of primary PM 2.5 formed during engine combustion and secondary PM 2.5 aerosols formed from gaseous exhaust pollutants."
The study notes that the debate around controlling shipping is focused on two major areas.
One is whether there should be global or more regional areas for control of emissions.
The second is what are the best strategies to reduce emissions. Among approaches being debated are:
Having ships switch from bunkers to distillate fuels as the tanker owner organization Intertanko has proposed.
After-treatment technologies such as scrubbers on ship stacks.
Operational changes such as plugging ships into the land-based power grid instead of running engines to generate power, what's called "cold-ironing" in industry argot.
Corbett and Winebrake said there could be a dramatic reduction in pollution if ships switched to distillate fuel. How quickly that would lead to improved health is difficult to assess, since many of the health care problems associated with particle exposure come from long-term exposure. But the study is useful getting a global assessment of the health consequences of the explosive growth in world trade, they said.
"This study will help inform policymakers about some of the health impacts associated with ship emissions and the long range transport of those emissions to population centers," Winebrake said. "We now have a benchmark by which we can begin to evaluate the benefits of emission reduction policies."
Annual deaths related to shipping emissions in Europe are estimated at 26,710, while the mortality rate is 19,870 in East Asia and 9,950 in South Asia. North America has about 5,000 premature deaths, concentrated mostly in the Gulf Coast region, the West Coast and the Northeast, while the eastern coast of South America has 790 mortalities.
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