Low Levels of Ozone Increase Respiratory Risk in Asthmatic Kids
Yale University researchers studied a group of 271 asthmatic children under age 12, living in Connecticut and Springfield, Massachusetts involved in a prospective study of asthma severity.
The children’s mothers tracked their asthma symptoms such as wheeze, persistent cough, chest tightness, and shortness of breath, and their medication use, on a daily basis.
The study published in the Journal of the American Medical Association, reported that a 50 ppb increase in 1-hour ozone concentrations dramatically increased the likelihood of wheeze (by 35%) and chest tightness (by 47%).
The study found that asthmatic children using maintenance medication were particularly vulnerable to ozone even after controlling for co-exposure to fine particles, and even at pollution levels below EPA’s current air quality standards for ozone.
The highest levels of ozone on a one-hour and eight-hour average basis were associated with increased shortness of breath and rescue medication use. PM2.5 was not significantly associated with a worsening of asthma when both ozone and fine particles were co-analyzed.
In an accompanying editorial, Dr. George Thurston and Dr. David Bates write that “air pollution is one of the most under-appreciated contributors to asthma exacerbations.”
Gent, J.F., Triche, E.W., Holford, T.R., Belanger, K., Bracken, M.B., Beckett, W.S. and Leaderer, B.P. Association of Low-Level Ozone and Fine Particles with Respiratory Symptoms in Children with Asthma. Journal of the American Medical Association. Vol. 290, No. 14, pp. 1859-1867, October 8, 2003.
Thurston, G.D. and Bates, D.V. Air Pollution as an Underappreciated Cause of Asthma Symptoms. Journal of the American Medical Association. Vol. 290, No. 14, pp. 1915-1917, October 8, 2003.
The American Medical Association [http://jama.ama-assn.org/] offers the abstract online.
