“…However, China has very few estimates of tobacco's costs, and past studies have been to focus on the estimation of economic burden associated with smoking-related diseases [5,9], while overlooking the economic costs of SHS exposure, especially in rural areas. Seventy percent of China's population lives in the countryside, and rural residents have higher prevalence rate of smoking and SHS exposure than urban inhabitants [3,10]. Based on past research conducted both inside and outside China, smoking has been demonstrated to be important contributors to COPD, asthma, coronary heart disease (CHD), stroke, hypertension and peptic ulcer [1,2,5,[11][12][13][14], which indicated that smoking increased the risk of overall mortality, accounting for more deaths than any other single cause.…”