Air pollution effects on peak expiratory flow rate in children.

Airway mucus hypersecretion Health effects caused by air pollutants may range from subtle biochemical or physiological signs, such as mildly reduced lung function, to difficult breathing, wheezing, coughing and exacerbation of existing respiratory conditions such as asthma. The aim of this study was measuring the adverse health effects of air pollution on lung function of primary school students. The lung function of students was measured daily for seven weeks in two elementary schools in District 12 of Tehran, after obtaining permission from the two principals and signed parents' consent forms. Twenty four hourly air pollution levels were used as potential predictors of lung function. The principal analysis conducted was a logistic regression on a subset of the data using a case-crossover design. The outcomes data consisted of the results of lung function tests for 356 female and 206 male students over the six-week period. Using the difference between mean (87) and maximum (125) concentration of moving average of NO in this period to judge the size of the effect, such an increase in NO is predicted to lead to an increase in the probability of poor lung function (OR=20) based on population-based predicted value. This study has shown strong and consistent associations between children's poor lung function and outdoor air pollutants in District 12 of Tehran for some pollutants. The strong association found in this study was an increase in seven-day moving average of NO using both definitions.