The big O

An 18-year study of nearly a half-million people is the first to show that long-term, low-level exposure to ozone pollution can be lethal. The results are reported in the New England Journal of Medicine. It’s no secret that spikes in ozone during times of heavy pollution can cause short-term effects, such as asthma attacks or deaths from heart attacks. But this study found that ozone pollution increases the yearly risk of death from respiratory diseases by 40 to 50 percent in heavily polluted cities like Los Angeles and by about 25 percent for the rest of the country. Ozone is the major component of smog and forms when tailpipe emissions meet sun and hot air.