In this study, CALPUFF was coupled with the MM5 model to estimate H2S pollution exposure from an accidental sour well blowout. The model takes into account of detailed meteorological patterns, wet deposition and chemical transformations. An intercomparison of the performance of CALPUFF against the observed data is discussed and an examination of scatter plots and QQ plots is provided. The statistics show that the correlation coefficient and RMSE between the modeled and observed data are 0.8805 and 2.3304, respectively. The calculated H2S concentrations are greatest close to the source, spread further downwind (approximately 20 km), and show heterogeneity characteristics. The model results also provide estimates of H2S effects on mortality; a significant relationship was found between short-term exposure to H2S and mortality in the process of the accidental sour well blowout. Additional key findings: public health exposure was higher in the valley than that on the mountain; model results imply that the CALPUFF coupled with the MM5 model is applicable in any setting where H2S concentration events occur following an uncontrolled sour gas well blowout.