Contribution of transregional transport to particle pollution and health effects in Shanghai during 2013-2017

Transregional transport plays an important role in air pollution. This study investigated the impact of transregional transport on particle pollution in Shanghai from 2013 to 2017. A conditional potential source contribution function (CPSCF) method with high time resolution (1 h) PM_2.5 and PM₁₀ data was used to quantify the contribution of transregional transport. The corresponding health impact was also assessed. The average annual contribution of transregional transport to PM_2.5 (PM_{2.5_CTRT}) and PM₁₀ (PM_{10_CTRT}) was 22 and 30 μg/m³, 18 and 24 μg/m³, 19 and 24 μg/m³, 14 and 19 μg/m³, and 14 and 19 μg/m³, for 2013 to 2017, respectively, thus accounting for 31-37% of total PM_2.5 and PM₁₀. As PM_{2.5_CTRT} is a dominant component of PM_{10_CTRT}, the health effects related to PM_{2.5_CTRT} were assessed to avoid double counting. The number of annual deaths associated with PM_{2.5_CTRT} in Shanghai during the study period ranged from 636 (95% confidence intervals: 350, 936) to 1039 (573, 1530), among which cardiovascular disease and respiratory disease accounted for 62.8-67.6% and 16.6-19.5% of mortality, respectively. PM_{2.5_CTRT}-related deaths accounted for 5.3-8.2‰ of the total mortality in Shanghai during the study period. Between 9764 (9251, 10,277) and 12,190 (11,549, 12,830) cases of all-cause hospital admissions were attributable to PM_{2.5_CTRT} in Shanghai in one year, among which cardiovascular disease and respiratory disease hospital admissions accounted for 15.9-20.0% and 7.9-9.2%, respectively. Internal medicine and pediatrics outpatient visits related to PM_{2.5_CTRT} ranged from 70,684 (39,009, 100,829) to 97,380 (53,788, 138,793) cases and 23,185 (8302, 37,173) to 32,702 (11,726, 52,361) cases, respectively. The current work provides scientific evidence of the impact of transregional transport on air pollution and its health burden in Shanghai.