Panel Studies of Air Pollution on Children's Lung Function and Respiratory Symptoms: A Literature Review

Objective. This article reviews panel studies of air pollution on children's respiratory health and proposes future research directions. Methods. The PubMed electronic database was used to search published original epidemiological studies in peer-reviewed journals from 2000 to November 2011. Children's age was limited to <= 18 years old. A total of 33 relevant articles were obtained, with 20 articles relating to lung function, 21 articles relating to respiratory symptoms, and 8 articles examining both. Results. Most studies suggested the adverse effects of air pollution on children's lung function and respiratory symptoms. Particles and NO2 showed more significant results, whereas effects of SO2 were not consistent. A few studies indicated that O-3 interacted with temperature and sometimes seemed to be a protective factor for children's respiratory health. Negative associations between air pollutants and pulmonary health were more serious in asthmatic children than in healthy subjects. However, many outcomes depended on the number of lag days. Peak expiratory flow (PEF) was the most usual measurement for children's lung function, followed by forced expiratory volume in 1 second (FEV1). Conclusions. There are significant adverse effects of air pollution on children's pulmonary health, especially for asthmatics. Future studies need to examine the lag effects of air pollution on children's lung function and respiratory symptoms. Ambient temperature is predicted to change worldwide due to climate change, which will threaten population health. Further research is needed to examine the effects of ambient temperature and the interactive effects between air pollution and ambient temperature on children's lung function and respiratory symptoms.