Continuous in-home PM(2.5) concentrations of smokers with and without a history of respiratory exacerbations in Iowa, during and after an air purifier intervention

BACKGROUND: Americans spend most of their time indoors. Indoor particulate matter 2.5 microns and smaller (PM(2.5)) concentrations often exceed ambient concentrations. Therefore, we tested whether the use of an air purifying device (electrostatic precipitator, ESP) could reduce PM(2.5) in homes of smokers with and without respiratory exacerbations, compared to baseline. METHODS: We assessed PM(2.5) concentrations in homes of subjects with and without a recent (≤3 years) history of respiratory exacerbation. We compared PM(2.5) concentrations during one month of ESP use to those during one month without ESP use. RESULTS: Our study included 19 subjects (53–80 years old), nine with a history of respiratory exacerbation. Geometric mean (GM) PM(2.5) and median GM daily peak PM(2.5) were significantly lower during ESP deployment compared to the equivalent time-period without the ESP (GSD=0.50 and 0.37 μg/m(3), respectively, p<0.001). PM(2.5) in homes of respiratory exacerbators tended (p<0.14) to be higher than PM(2.5) in homes of those without a history of respiratory exacerbation. CONCLUSION: Subjects with a history of respiratory exacerbation tended to have higher: mean, median and mean peak PM(2.5) concentrations compared to homes of subjects without a history of exacerbations. The ESP intervention reduced in-home PM(2.5) concentrations, demonstrating its utility in reducing indoor exposures.