Revised research finds air pollution health risks were overstated

| 6/11/2002

Researchers revising a study of tiny pollution particles from diesel engines and power plants have uncovered a computer glitch that could mean less health risk than previously thought. The flawed findings have some wondering if it means a possible delay in new federal rules.

Scientists at Johns Hopkins University determined the software used for the study of 90 American cities overestimated the increase in the typical mortality rate. The software in question could be a problem for the Environmental Protection Agency as it prepares to issue even stricter clean air regulations by the end of next year. Many of the more than 100 studies the agency is examining use the software.

A spokesperson with the university's biostatistics department said they still believe strongly in the link between the particulate matter and the health effects it creates. In fact, the new research doesn't weaken the largely accepted link between air pollution and premature death. But it cut by half the previous estimate about the rate of increase in the death rate compared to increases in the number of particles in the air.