A GIS Model for PM10 Exposure from Biomass Burning in the North of Thailand

Abstract

Human exposure to particulate matter with an aerodynamic diameter below 10 µm (PM₁₀) is found to be associated with biomass burning in Thailand. Recent investigations confirm that primary sources of PM₁₀ are natural forest fires and agricultural waste burning. Incidence of atmospheric haze increases significantly during the dry season from January to April. PM₁₀ exposure in eight provinces in Northern Thailand were determined using GIS through spatial interpolation. Daily average ambient PM₁₀ concentrations from 10 monitoring stations were used as the input data for the GIS model. Three interpolation techniques: Inverse Distance Weighted (IDW), Kriging and Spline, were compared. The predicted PM₁₀ concentrations were verified with field measurements. GIS-based maps illustrated the variability of PM₁₀ distribution and high-risk locations, which were found to be associated with wind direction and forest fire frequencies. Mae Hong Son, Chiang Rai and Phrae were found to be at highest risk of PM₁₀ exposure during the dry season.