Abstract:
Affected by the unfavorable topographical conditions and the massive residential coal combustion in the winter heating season, haze events occur frequently in the Guanzhong area of Shaanxi Province. Since the implementation of the residential coal combustion control policies in 2017, the regional air quality has improved significantly. Based on the field investigation of the residential coal usage and local statistical data, the residential coal control in 7 cities (districts) in Guanzhong area from 2017 to 2020 was evaluated. In this study, the contribution of residential coal combustion to ambient PM
2.5 was estimated by the Box model, and the health and economic benefits were evaluated by the Poisson regression model. The results showed that residential coal combustion was effectively controlled in Guanzhong area from 2017 to 2020, with a total reduction of 77.79×10
4 t. The reduction in Xi'an and Weinan were the biggest, and the substitution rate reached 100% in Yangling District. From 2017 to 2020, the residential coal control reduced the daily average PM
2.5 concentration during heating season in Guanzhong area by 7.2 μg/m
3, and the contribution from resident coal sector to ambient PM
2.5 decreased by about 5.4%, accounting for 17.4% of the PM
2.5 improvement. Due to PM
2.5 emission reduction from residential coal combustion, the premature mortality rate of residents decreased by 1.50×10
−5 (95% confidence interval (CI): 3.66×10
−6-2.62×10
−5), with a reduction rate of 98.2%. The morbidity rate (incidence of outpatient, hospitalization and chronic bronchitis) decreased by 4.11×10
−4 (95%CI: 1.71×10
−4-6.59×10
−4), with a reduction rate of 98.3%. The research showed that the comprehensive substitution rate of residential coal in Guanzhong area reached 98.36%, and the corresponding PM
2.5 emission reduction exceeded 0.5×10
4 t from 2017 to 2020. The health benefit population was estimated to be 10,662 and the economic benefit was estimated to be as high as 1,411.65×10
6 RMB from the residential coal control in the Guanzhong area.