Health impact ofenvironmental pollution and protective effect of masks in Japan

Abstract

Background/Aim: The health effects of cross-border air pollution and Asian dust (AD) originating from drylands, such as the Gobi Desert and Taklamakan Desert, have been a concern in Asia. To overcome the global issue of air pollution, wearing masks is recommended. However, the protective effect of wearing masks are unclear. We assessed the health impact of air pollution and the protective effect of masks.Methods: We administered diary-style web-based questionnaires to 48 volunteers who lived in Yonago City in Japan between 2015 and 2016. The results were evaluated using a 4-level subjective symptom score (29 variables include respiratory, nasal, ocular, and skin symptoms), history of the disease, and preventive behaviors (e.g., mask use). Association between the symptom scores and analyzed components for AD, splash sea salt, sulfate aerosol, nitrate aerosol, Organic carbon, Black carbon were assessed using a linear mixed model. Data regarding climate (temperature, humidity, and atmospheric pressure) and environmental factors were used as covariates. Regarding symptom prevention measures, we measured particle leakage rates of participants’ masks. Results: The association between respiratory symptoms and sulfate aerosol was significant (P trend=0.013, odds ratio [OR] of the highest quartile [Q4] vs. the lowest[Q1]=1.34, 95% CI=1.10 to 1.65). The relationship between symptoms and sulfate aerosol was also significant in the mask-wearing groups. Even with N95 or virus filtration efficiency masks, the leakage rate was high, suggesting that fitting is more important in addition to mask filter quality.Conclusions: We found that exposure to air pollution increased the risk of adverse subjective symptoms. We also found that it is essential to wear a mask that fits the facial features without a gap between the face and mask.