Characteristics of biomass burning aerosol and its impact on regional air quality in the summer of 2003 at Gwangju, Korea

The main objective of this study is to investigate the chemical characteristics of biomass burning aerosol and its impact on regional air quality during an agricultural waste burning period in early summer in the rural areas of Korea. A 12-h integrated intensive sampling of biomass burning aerosol in the fine and coarse modes was conducted on 2-20 June 2003 in Gwangju, Korea. The collected samples were analyzed for concentrations of mass, ionic, elemental, and carbonaceous species. Average concentrations of fine and coarse mass were measured to be 67.9 and 18.7 μg m ^{- 3} during the biomass burning period, 41.9 and 18.8 μg m ^{- 3} during the haze period, and 35.6 and 13.3 μg m ^{- 3} during the normal period, respectively. An exceptionally high PM _2.5 concentration of 110.3 μg m ^{- 3} with a PM _2.5/PM ₁₀ ratio of 0.79 was observed on 6 June 2003 during the biomass burning period. The potassium ratio method was used to identify biomass burning samples. The average ratio of potassium in the fine mode to the coarse mode (FK/CK) was 23.8 during the biomass burning period, 6.0 during the haze period, and 4.7 during the normal period, respectively. A FK/CK ratio above 9.2 was considered a criterion for biomass burning event in this study. Particulate matter from the open field burning of agricultural waste has an adverse impact on visibility, human health, and regional air quality.