An Assessment of Annual Mortality Attributable to Ambient PM_2.5 in Bangkok, Thailand

Multiple studies indicate that PM_2.5 is the most deleterious air pollutant for which there are ambient air quality standards. Daily concentrations of PM_2.5 in Bangkok, Thailand, continuously exceed the World Health Organization (WHO) and the Thai National Ambient Air Quality Standards (NAAQSs). Bangkok has only recently begun to measure concentrations of PM_2.5. To overcome this paucity of data, daily PM_2.5/PM₁₀ ratios were generated over the period 2012-2018 to interpolate missing values. Concentration-response coefficients (β values) for PM_2.5 versus non-accidental, cardiopulmonary, and lung cancer mortalities were derived from the literature. Values were also estimated and were found to be comparable to those reported in the literature for a Chinese population, but considerably lower than those reported in the literature from the United States. These findings strongly suggest that specific regional β values should be used to accurately quantify the number of premature deaths attributable to PM_2.5 in Asian populations. Health burden analysis using the Environmental Benefits Mapping and Analysis Program (BenMAP) showed that PM_2.5 concentration in Bangkok contributes to 4240 non-accidental, 1317 cardiopulmonary, and 370 lung cancer mortalities annually. Further analysis showed that the attainment of PM_2.5 levels to the NAAQSs and WHO guideline would reduce annual premature mortality in Bangkok by 33%and 75%, respectively.