Environmental and health problems due to sulfur dioxide (SO₂) emission are serious issues in China. In this study, we developed a model to assess the total economic and environmental impact on an area subsequent to installation of desulfurization facilities. A model based on the number of new patients with respiratory illness in Shenyang City, China and the corresponding environmental SO₂ concentration was first constructed and subsequently integrated into an air diffusion model for SO₂. Changes in the SO₂ concentration and the number of patients were then simulated, and the effects of desulfurization by-products on salt-affected soil amelioration were assessed in a number of scenarios where desulfurization facilities were installed in combustion plants. From the data, it is projected that the introduction of a wet limestone–gypsum process in large plants, an integrated desulfurization and water-film dust collection process in medium- and small-scale plants, and coal bio-briquettes in households should result in SO₂ concentrations below the stipulated SO₂ limit for urban residential areas in China. Moreover, a large decrease in the number of new patients and in the total number of patients at the year-end was forecasted for the years following the introduction of these facilities. Additionally, the present findings indicate that amelioration of salt-affected soil using desulfurization by-products is a prospectively effective method for increasing corn and rice production for potential alleviation of food shortages in China.