Health risk assessment of exposure near-future PM2.5 in Northern Thailand

The frequency and intensity of particulate pollution, particularly fine particulate matter (PM2.5), have grown in Northern Thailand because of significant social and environmental changes in rural areas. Therefore, PM2.5 has become a major concern for human health in this region because it thoroughly penetrates the respiratory system especially lungs. The purpose of this study was to evaluate the health risk associated with PM2.5 in Northern Thailand in the near future (2020-2029). We used the hazard quotient (HQ) to quantify the potential health risk of PM2.5, based on near future data from the Nested Regional Climate Model with Chemistry Simulation (NRCM-Chem). When compared to measurements in the year 2020, the performance of NRCM-Chem in simulating PM2.5 in Northern Thailand was remarkable. In the near future, daily mean PM2.5 concentrations in Northern Thailand likely range from 14 to 400 mu g/m(3) and 10 to 24 mu g/m(3) for dry (November-April) and wet (May-October) seasons, respectively. However, PM2.5 concentrations were substantially higher during the dry season, particularly in January and April, when they exceeded US Environmental Protection Agency (USEPA) and Thailand standards, ranging from 40 to 400 mu g/m(3). During this period, the mean HQ for PM2.5 was greater than one in all age groups, suggesting an unacceptable risk to human health.