Tao S, Yang Y, Cao H Y, Liu W X, Coveney R M, Xu F L, Cao J, Li B G, Wang X J, Hu J Y, Fang J Y
Laboratory for Earth Surface Processes, College of Environmental Sciences, Peking University, Beijing 100871, China.
Environ Pollut. 2006 Jan;139(1):183-93. doi: 10.1016/j.envpol.2004.12.013. Epub 2005 Aug 8.
A level IV fugacity model was used to simulate the dynamic changes of gamma-hexachlorocyclohexane (gamma-HCH) concentrations in environmental media in Tianjin, China. A similar model (level III) was previously used and validated under steady state conditions; this paper explores its dynamic behavior. Application of the level IV fugacity model has been validated using independently observed gamma-HCH concentrations in various media during the early 1980s and during 2001. Sensitivity analysis was conducted using coefficient-of-variation normalized sensitivity coefficients. The model was also subject to uncertainty analysis using Monte Carlo simulation. It was found that concentrations of gamma-HCH reached within 95% of their steady-state levels in all media after less than 15 years. Around one order-of-magnitude decreases in gamma-HCH concentrations in various media occurred between 1993 and 2001. We project that gamma-HCH concentrations will decrease another 1.7-1.9 orders of magnitude to reach 1.1 (0.9-1.2) x 10(-14), 2.7 (2.5-3.0) x 10(-10), 1.2 (1.1-1.3) x 10(-7), and 6.1 (5.4-6.8) x 10(-8) mol/m(3), in air, water, soil, and sediment, respectively, by 2020. The sensitivities and true uncertainty of the model are discussed.
采用四级逸度模型模拟了中国天津环境介质中γ-六氯环己烷（γ-HCH）浓度的动态变化。之前曾使用过一个类似的模型（三级模型）并在稳态条件下进行了验证；本文探讨了其动态行为。利用20世纪80年代初和2001年期间在各种介质中独立观测到的γ-HCH浓度对四级逸度模型的应用进行了验证。使用变异系数归一化灵敏度系数进行了敏感性分析。还使用蒙特卡罗模拟对该模型进行了不确定性分析。结果发现，不到15年后，所有介质中γ-HCH的浓度均达到其稳态水平的95%以内。1993年至2001年期间，各种介质中γ-HCH的浓度下降了约一个数量级。我们预计，到2020年，γ-HCH在空气、水、土壤和沉积物中的浓度将分别再下降1.7 - 1.9个数量级，达到1.1（0.9 - 1.2）×10⁻¹⁴、2.7（2.5 - 3.0）×10⁻¹⁰、1.2（1.1 - 1.3）×10⁻⁷和6.1（5.4 - 6.8）×10⁻⁸mol/m³。文中讨论了该模型的敏感性和实际不确定性。
