Agricultural Burning Smoke Exposure and Health Effects Assessment in Eastern Washington

Abstract

<bold>Background:</bold> The prescribed burning of vegetation and crop residue is a common agricultural practice. However, the health effects of agricultural field burning smoke exposure has not been well determined. <bold>Objective:</bold> Investigate associations between peak 1-hour fine particulate matter (PM_2.5) concentrations over the previous 24 hours with exhaled nitric oxide (FeNO), forced expiratory volume in 1 second (FEV₁), and forced expiratory flow 25-75% (FEF_25-75), and to determine if use of an asthma controller medication would modify these relationships. <bold>Methods:</bold> Generalized estimating equations were used to estimate the effect of peak 1-hour central site PM_2.5 concentrations with repeated measures of FeNO, FEV₁, and FEF_25-75 obtained from 32 health non-smoking adults with intermittent to moderate persistent asthma. <bold>Results:</bold> Peak 1-hour central site PM_2.5 concentrations ranged between 4.9 and 42.6 μg/m<super>3</super>. There was no significant effect of a 10 μg/m<super>3</super> increase in peak 1-hour central site PM_2.5 concentrations over the previous 24 hours on FeNO, FEV₁, and FEF_25-75. There was no evidence of a significant interaction between PM_2.5 concentrations and use of an asthma controller medication. <bold>Conclusion:</bold> At the observed range of exposures, episodic short-term exposure to PM_2.5 related to agricultural field burning does not exert detectable changes in FeNO, FEV₁, and FEF_25-75 among healthy adults with intermittent to moderate persistent asthma.