School Absences Rise With Ozone Levels

Many more children stay home sick from school when ozone air pollution levels rise, according to a USC study.

For every rise in ozone levels by 20 parts per billion, absences from school increased 83% because of respiratory illness such as sneezing, sore throats and coughs, according to the study. Ozone can average 30 ppb in the Los Angeles Basin, and levels on a smoggy day can exceed 100 ppb.

Researchers looked at school absences among 2,081 students in the fourth grade at 27 schools during the first six months of 1996. They called parents to ask why their children missed school and tracked the daily levels of pollutants in the air.

A university official said researchers hope the study will influence parents to keep their children indoors when ozone levels are high.