The outbreak of COVID-19 may have influenced the evaluation of air control policies during China 's 13 th FYP . Some previous studies have demonstrated the short - term health implications of improvements in air quality in China using measured PM 2.5 data   and comparing PM 2.5 concentrations between lockdown and non - lockdown cities ( He et al . , 2020 ) , the 2020 situation and 2019 baselines ( Wang et al . , 2020c;Zheng et al . , 2020 ) . Here , we expanded this analysis based on 12 months of air quality data in 325 Chinese cities ( excluding four anomalous cities with large fluctuations after data validation ) and compared the chronic health effects under the COVID-19 situation and normal conditions . The comparison between the annual predicted data and observed data showed no significant difference , though the reduction reached approximately 9.8 % and 13.5 % in comparison with the annual average data in 2019 , respectively .