Investigation on daily exposure to PM2.5 in Bandung city, Indonesia using low-cost sensor.

Daily exposure to PM2.5 in developing countries has not been thoroughly studied partly due to limited resources available. In this research, personal PM2.5 exposures in urban communities in Indonesia were examined using a low-cost sensor, AS-LUNG. Fifty subjects were recruited in both wet and dry seasons. Their personal PM2.5 concentrations, environmental temperature, and relative humidity were measured using corrected AS-LUNG Portable worn or placed in their vicinity. Details on their activities and locations, air quality (air pollution sources), and weather conditions during monitoring were recorded in time-activity diaries completed at 30 min intervals. Results revealed mosquito coil burning as the source of highest exposure, reaching 241.5 μg/m3 but with significant difference between wet and dry seasons. With ambient PM2.5 and relative humidity controlled for, mosquito coil burning contributed 12.02 μg/m3 and 4.84 μg/m3 of personal PM2.5 exposure in wet and dry season, respectively, which was several times higher than the contribution from vehicle emission. The second most contributive source was factory smoke, which increased 4.99 μg/m3 and 3.17 μg/m3 of exposure in wet and dry season, respectively. Findings on contributive factors of high daily personal exposures can serve as useful references for formulating policies and recommendations on exposure reduction and health protection.