Computer Glitch May Have Overstated Health Risks From Diesel Pollution

Researchers revising a study on particulates discovered a computer glitch that could mean less health risk than previously thought.

The Associated Press reported last week that research by investigators at Johns Hopkins University found the software used for a study of 90 American cities overestimated the rise in the typical mortality rate. Although the study they were revising is just one of more than 100 the government is looking at as it develops new clean-air regulations, the software in question was used by many of those other studies, as well.
The discovery could delay new EPA rules, which the agency had hoped to issue by the end of 2003. However, an EPA spokesman told the AP that the agency still believes strongly in the tie between particulate matter and health effects.
Indeed, the new research doesn’t invalidate the widely accepted link between air pollution and premature death. But it halves previous estimate about the rate of increase in the death rate compares to increases in the number of particulates in the air. Particulates are tiny pollution particles found in diesel exhaust and put out by power plants.