Atmospheric benzo[a]pyrene in the Yangtze River Delta, China: pollution level and lung cancer risk in 2016 and future predictions

The Yangtze River Delta (YRD) has undergone widespread polycyclic aromatic hydrocarbon (PAH) pollution. In this study, we simulated the spatial distribution of atmospheric benzo[a]pyrene (BaP, the most carcinogenic PAH) in the YRD in 2016 and 2030 under different emission scenarios using a 3-D atmospheric transport model and evaluated the lung cancer risks posed by BaP during the study years. The purpose of this study is to suggest targeted policy recommendations for policy-makers to mitigate BaP pollution through numerical simulation. Our results showed that the average BaP concentration in the YRD was 0.30 ng/m 3 in 2016; however, a significant spatial variation was observed, with the highest BaP concentration in Shanghai (0.59 ng/m 3 ). The population-weighted incremental lifetime lung cancer risk (PILCR) was 6.67 × 10 –6 in 2016, whereas it ranged from 2.70 × 10 –6 to 1.05 × 10 –5 in 2030 under the five emission scenarios. A higher future population density in the YRD region could increase lung cancer risk. In all scenarios, Shanghai had the highest number of lung cancer cases (range: 208–476). The results suggest that BaP pollution could be effectively improved through the synergistic effect of reducing activity levels and improving technology. Finally, we provide specific suggested pollution control strategies (e.g., accelerating the use of clean energy in rural areas) for atmospheric BaP in the YRD. Graphical abstract