Ozone hikes cardiovascular risk

Ozone pollution appears to cause potentially dangerous changes in the heart at levels that might be encountered in the world’s most polluted cities. Scientists have uncovered signs of inflammation and heart rhythm disturbances in 23 healthy young volunteers who briefly inhaled elevated levels of ozone, the primary irritant in urban smog.

The alterations, reported online June 25 in Circulation, go a long way toward explaining population data that have started linking ozone to an elevated risk of death from heart attacks and stroke (SN: 12/11/04, p. 372).

Many air pollution scientists, “including me, have in the past thought associations with ozone [and disease outside the lung] were really associations with particles or some other pollutant,” says Douglas Dockery of the Harvard School of Public Health in Boston. But he says the new study now directly shows ozone is causing acute — and even chronic — risk for heart attacks.