Death Rates Higher In Polluted Cities New Study Finds Increase In Every Cause Of Death Due To Tiny Particles

Death rates in 20 large American cities rise steadily with the increase of tiny combustion particles in the air, according to a new study.

The Johns Hopkins study, published in today’s New England Journal of Medicine, bolsters work already done at Harvard and the University of Washington.

Some additional studies into the link between small particle pollution and public health are also being conducted in Spokane.

For each 10-microgram increase in particulate pollution per cubic meter of air over a 24-hour period, the death rate for all causes rises 0.5 percent, the Johns Hopkins study says.

For instance, if an average of 100 people die each day in a large city and the particulate pollution increases by 20 micrograms over 24 hours, one more person will die.

The new study says it’s the particles themselves - not weather or other factors - that are responsible for increases in daily death rates.

The results show “consistent evidence” that fine particulates in the air are linked to the risk of death from all causes and from cardiovascular and respiratory illnesses.

“These findings strengthen the rationale for controlling the levels of respirable particles in outdoor air,” the study concludes.

An industry coalition has challenged the science in past pollution studies because varying methods were used, said Jane Koenig, a UW professor.

The Johns Hopkins research addresses that criticism, said Koenig, director of the Northwest Research Center for Particulate Air Pollution and Health.

“Here we have a comparison of 20 cities by the same investigators using identical methods. They tell us that particulates are the most likely culprit each time,” Koenig said.

She is studying a group of people with asthma in Spokane to understand how they are affected by fluctuating air pollution. Results are due early next year.

In the Johns Hopkins study, Los Angeles averaged 148 deaths a day from 1987 to 1994, the period of the study. New York averaged 190.9, Chicago 113.9, and Seattle, 25.6.

Mean particulate levels in Los Angeles, the most polluted city studied, were nearly twice those of Seattle, which averaged 25.3 micrograms of particulates per cubic meter of air.

Daily particulate levels in the 20 cities ranged from 20 micrograms per cubic meter to nearly 50 micrograms - less than one-third of the EPA’s 24-hour limit of 150 micrograms.

In Spokane, most wood stove use is banned when particulates reach 60 micrograms, said Eric Skelton, Spokane County Air Pollution Control Authority director.

The new study is helpful to the U.S. Environmental Protection Agency, which is seeking to tighten small-particle standards over the objections of industry and farmers.

In 1987, EPA set its 150-microgram limit for particles less than 10 microns in size. In 1997, the agency added standards for particles under 2.5 microns - the size that can penetrate deep into the lungs.

They are present in auto exhaust, industry smokestacks, wood stove emissions and agricultural smoke.

The EPA’s new PM 2.5 standard is under assault by an industry coalition, which argued recently before the U.S. Supreme Court that the EPA should consider the costs of industry compliance and not only public health impacts.

This sidebar appeared with the story: BY THE NUMBERS Deadly statistics

If an average of 100 people die each day in a large city and the particulate pollution increases by 20 micrograms over 24 hours, one more person will die.

The Associated Press contributed to this report.