Children Have Asthma Symptoms at Ozone Levels Approved by the Environmental Protection Agency, Study Finds
Children under age 12 with severe asthma start to experience symptoms even when air quality levels fall within the Environmental Protection Agency's "good" range, according to a study published Wednesday in the Journal of the American Medical Association, Reuters/Los Angeles Times reports (Reuters/Los Angeles Times, 10/8). Janneane Gent, an associate research scientist in epidemiology and public health at Yale School of Medicine, and colleagues studied 271 children with asthma in Connecticut and Springfield, Mass., from April 1, 2001 to Sept. 30, 2001. The children's parents kept daily records of respiratory symptoms, including wheezing, persistent cough, chest tightness and shortness of breath. The Connecticut and Massachusetts departments of environmental protection provided daily data on ozone levels and amounts of fine particles in the air. During the study, the mean ozone level was 59 parts per billion for the one-hour average and 51 ppb for the eight-hour average (AP/Hartford Courant, 10/8). According to the EPA's air quality index, ozone levels up to 60 ppb are considered "good," 60 ppb to 120 ppb are "moderate" and levels over 120 ppb are not in compliance with air quality rules.
Researchers found that children began coughing, had trouble breathing and experienced tightness in their chests when levels reached 52 ppb on the day before (Reuters/Wall Street Journal, 10/8). They also found that for children with severe asthma -- defined as requiring maintenance medications to control asthma -- a 50 ppb increase in the one-hour ozone level was associated with a 35% increased likelihood of wheezing and a 47% increased likelihood of chest tightness. At the highest ozone levels, children with severe asthma had a 32% increase in shortness of breath and an 8% increase in rescue medication use (AP/Hartford Courant, 10/8). No significant associations between pollution levels and symptoms in children with less severe asthma were observed (Gent et al., Journal of the American Medical Association, 10/8). Gent said that when ozone levels are considered moderate, "parents of asthmatic children would be well advised to keep their children indoors and make sure they have a low level of activity" (Reuters/Wall Street Journal, 10/8). The study is available online. NPR's "All Things Considered" on Tuesday reported on the JAMA study. The segment includes comments from John Bachman, associate director for scientific policy with the EPA's Office of Air Quality Standards and Planning; Gent; and Dr. George Thurston, associate professor of environmental health at New York University (Que, "All Things Considered," NPR, 10/7). The full segment is available online in RealPlayer.This is part of the California Healthline Daily Edition, a summary of health policy coverage from major news organizations. Sign up for an email subscription.