Effects of heating activities in winter on characteristics of PM2.5-bound Pb, Cd and lead isotopes in cities of China

Fossil fuel combustion was often mentioned as the most important source of air pollution, but coal-fired heating was rarely isolated to discuss its impact on air quality. In winter, the northern part of China will carry out a large area of continuous coal-fired heating activities, which contributes to a high degree of heavy metals in PM2.5. And combined with the liquidity of atmospheric particles, tends to create regional and even international problems. But many air control policies ignore this control measure. Twenty-five representative cities in heating and non-heating area in China were selected for spatial difference analysis of PM2.5-bound Pb and Cd. In addition, using the HYSPLIT model and Pb isotope ratios to verify whether coal-fired heating in heating areas (Tianjin) contribute to heavy metals in atmospheric particulate matter in non-heating areas (Shanghai). Results showed that the average Pb and Cd concentrations in the heating cities were 3.5 and 2.9 times of those in the non-heating cities, respectively. Long-distance transportation would affect the concentrations of PM2.5 in Shanghai and Tianjin, while coal-fired emissions from heating cities had a greater impact on PM2.5-bound heavy metal concentrations in non-heating cities. Therefore, cross-border environmental impact assessments need to be standardized, and monitoring of regional activities need to be strengthened. [Display omitted] •Pb and Cd in PM2.5 in heating cities were higher than those in non-heating cities.•Coal-burning and stationary industrial emissions were the main sources of Pb and Cd in PM2.5 during the winter haze period.•Long-distance transportation would affect PM2.5 concentrations in northern cities.•Improving coal-fired heating facilities in the suburbs.