By Janet Raloff
In healthy infants, even ozone concentrations well below those allowed by federal law trigger asthmalike symptoms, a new study shows.
The finding indicates that federal limits on this pervasive pollutant, a prime constituent of smog, don’t protect infants “from rather severe respiratory symptoms,” says epidemiologist Elizabeth W. Triche of the Yale University School of Medicine.
Triche’s team recruited 691 women with 3-to-5-month-old infants from nonsmoking households around Roanoke, Va. Sixty-one moms had asthma, signaling that their babies were at high risk for developing the disease. The researchers collected daily respiratory data, as reported by the mothers, on all the children for 83 days in summer—the peak ozone season—and then correlated the infant’s symptoms with outdoor measurements of several air pollutants.