[Evaluating the fate of gamma-HCH using fugacity model in Tianjin environment].

This study taking Tianjin as the study area calculated the concentration and transfer flux of gamma-HCH in all bulks using Matlab based on the assumption of steady state fugacity model. The calculated values agree well with the observed values, the concentrations of gamma-HCH in air, water, soil, sediment, fish, crop, and vegetable were 1.57 x 10(-11), 7.95 x 10(-7), 1.17 x 10(-4), 4.58 x 10(-4), 6.03 x 10(-4), 1.60 x 10(-4), 6.42 x 10(-5) mol/m3 respectively. The result indicated that the main source of gamma-HCH was agricultural application and wastewater from pesticide industries, the biggest bulk sinks were soil and sediment (accounting for 99% of total amount in the environment). Among all transfer processes deposition and diffusion on the water-sediment and air-soil interface were the primary, and mineralization was the key route for gamma-HCH to disappear in the environment.