文摘
The evidence is quite limited regarding the constituents of fine particulate matter (PM<sub>2.5sub>) responsible for lung dysfunction. We designed a time-series panel study in 28 patients to examine the effects of 10 major constituents of PM<sub>2.5sub> 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 PM<sub>2.5sub> constituents on morning/evening forced expiratory volume in 1-s (FEV<sub>1sub>) and peak expiratory flow (PEF) over a week. The cumulative decreases in morning FEV<sub>1sub>, evening FEV<sub>1sub>, morning PEF and evening PEF associated with an interquartile range (35.8 μg/m<sup>3sup>) increase in PM<sub>2.5sub> 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%CI:-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 FEV<sub>1sub>, and the associations of EC and sulfates with morning PEF were robust after controlling for PM<sub>2.5.sub> This study demonstrated that short-term exposure to PM<sub>2.5sub> was associated with reduced pulmonary function. Some constituents (EC, sulfate and nitrate) may be responsible for the detrimental effects.