The impact of life behavior and environment on particulate matter in chronic obstructive pulmonary disease.

BACKGROUND The effect of exposure to particulate matter (PM) on human health is a global public health concern. To develop an effective strategy to reduce PM exposure, we performed detailed questionnaire surveys regarding the type of lifestyle required to avoid PM exposure in patients with chronic obstructive pulmonary disease (COPD). We correlated the data with real-time PM concentration during the winter season. METHODS We enrolled 104 patients with COPD aged 40 years or older. Detailed questionnaire surveys were conducted among participants, and internet of things-based sensors were installed at their homes to measure the indoor PM2.5 concentration, which was continuously monitored between December 2019 and February 2020. The associations among PM2.5 concentration, patients' lifestyles, and the impact of both concentration and lifestyle on COPD exacerbation were analyzed. RESULTS Mean outdoor PM2.5 concentration was higher than mean indoor PM2.5 concentration during the study period (21.28 ± 5.09 μg/m3 vs. 12.75 ± 7.64 μg/m3), with a mean difference of 8.53 ± 7.99 μg/m3. Among the various social factors and practices that aim to avoid exposure to PM, six practices and economic statuses were confirmed to reduce indoor PM2.5 concentration compared to outdoor concentration; Contrarily, these practices created a significant difference between the outdoor and indoor PM2.5 concentrations. The six practice items that showed a significant difference were 1) checking air quality forecast (the difference: -13.31 ± 1.35 μg/m3, p = 0.013), 2) indoor air filter operated (-15.43 ± 1.32 μg/m3, p < 0.001), 3) ventilating home by opening the windows (-13.14 ± 1.28 μg/m3, p = 0.013), 4) checking filters of the air filter (-13.95 ± 1.50 μg/m3, p = 0.002), 5) refraining from going out when outside PM is high (-12.52 ± 1.37 μg/m3, p = 0.039), 6) wearing a mask when going out (-13.38 ± 1.32 μg/m3, p = 0.017). The higher the household income and economic level, the more significant the difference in the PM2.5 concentration. Severe exacerbation was more prevalent among patients with acute exacerbation as the exposure time of PM2.5≥35 μg/m3 or PM2.5≥75 μg/m3. CONCLUSION Lifestyle and economic levels can affect the indoor PM2.5 concentration, which may impact COPD exacerbation.