Characterization of water-soluble ions in PM₁₀ over an industrial area in northern Colombia: Temporal variations and...

This study was designed to assess the concentrations of nine water-soluble ions in PM₁₀ mass at two sites of an open-pit coal mine and to analyze the correlation and variation of the spatial distribution of sulfate ions with the PM₁₀ sulfate aerosol optical depth at 550 nm (suaod550) in two (North and South) stations of the study area. The daily average of PM₁₀ concentrations ranged from 20.48 to 53.10 μg/m³ and thus did not exceed the daily average maximum permissible level of PM₁₀ (100 μg/m³) established in the Colombia standard at any station. The concentrations of nine water-soluble ions in PM₁₀ (Cl^-, NO₃^-, PO₄^3-, SO₄²- Na⁺, NH₄⁺, K⁺, Mg²⁺, and Ca²⁺) were determined. The ions under analysis, SO4^2-, Na⁺, and NH₄⁺ had the highest concentrations. Combined, they accounted for 75% of the mass of water-soluble ions in a total of 210 samples. The SO₄^2- concentrations in PM₁₀ significantly correlated with suaod550 (r ranging from 0.57 to 0.66), emphasizing the strong effect of suaod550 from Venezuela (Lake Maracaibo) on central and northern Colombia. These results demonstrate that the effects of local sulfate emissions near monitoring sites can be predicted and assessed using satellite data.