Fine Particulate Constituents and Lung Dysfunction: A Time-Series Panel Study

The evidence is quite limited regarding the constituents of fine particulate matter (PM2.5) responsible for lung dysfunction. We designed a time series panel study in 28 patients to examine the effects of 10 major constituents of PM2.5 on lung function with repeated daily measurements from December 2012 to May 2013 in Shanghai, China. We applied a linear mixed-effect model combined with a distributed lag model to estimate the cumulative effects of PM2.5 constituents on morning/evening forced expiratory volume in 1-s (FEV1) and peak expiratory flow (PEF) over a week. The cumulative decreases in morning FEV1, evening FEV1, morning PEF and evening PEF associated with an interquartile range (35.8 mu g/m(3)) increase in PM2.5 concentrations were 33.49 [95% confidence interval-(CI):2.45,54.53] mL, 16.80 (95%CI:3.75,29.86) mL, 4.48 (95%CI:2.30,6.66) L/min, and 1.31 (95%0:-0.85,3.47) L/min, respectively. These results were not substantially changed after adjusting for gases in two-pollutant models. The associations of elemental carbon (EC) and nitrates with morning/evening FEV1, and the associations of EC and sulfates with morning PEF were robust after controlling for PM2.5. This study demonstrated that short-term exposure to PM2.5 was associated with reduced pulmonary function. Some constituents (EC, sulfate and nitrate) may be responsible for the detrimental effects.