Regional Policies Targeting Residential Solid Fuel and Agricultural Emissions Can Improve Air Quality and Public Health in the Greater Bay Area and Across China

Abstract

Air pollution exposure is a leading public health problem in China. The majority of the total air pollution disease burden is from fine particulate matter (PM2.5) exposure, with smaller contributions from ozone (O3) exposure. Recent emission reductions have reduced PM2.5 exposure. However, levels of exposure and the associated risk remain high, some pollutant emissions have increased, and some sectors lack effective emission control measures. We quantified the potential impacts of relevant policy scenarios on ambient air quality and public health across China. We show that PM2.5 exposure inside the Greater Bay Area (GBA) is strongly controlled by emissions outside the GBA. We find that reductions in residential solid fuel use and agricultural fertilizer emissions result in the greatest reductions in PM2.5 exposure and the largest health benefits. A 50% transition from residential solid fuel use to liquefied petroleum gas outside the GBA reduced PM2.5 exposure by 15% in China and 3% within the GBA, and avoided 191,400 premature deaths each year across China. Reducing agricultural fertilizer emissions of ammonia by 30% outside the GBA reduced PM2.5 exposure by 4% in China and 3% in the GBA, avoiding 56,500 annual premature deaths across China. Our simulations suggest that reducing residential solid fuel or industrial emissions will reduce both PM2.5 and O3 exposure, whereas other policies may increase O3 exposure. Improving particulate air quality inside the GBA will require consideration of residential solid fuel and agricultural sectors, which currently lack targeted policies, and regional cooperation both inside and outside the GBA.

Sensitivity of Air Pollution Exposure and Disease Burden to Emission Changes in China Using Machine Learning Emulation

“…The simulations differed only in the scaling of the anthropogenic emissions over China, determined from separate maxi−min Latin hypercube space–filling designs (Tables S1 and S2 in Supporting Information S1 ). The version of WRFChem used here was described and evaluated in our previous work (Conibear, Reddington, Silver, Chen, et al., 2021 ; Conibear, Reddington, Silver, Knote, et al., 2021 ; Reddington et al., 2019 ; Silver, Conibear, et al., 2020 ).…”

“…The RR was a function of the parameters θ, α, μ, and ν (Equation 2 ) as defined in Supplementary Table 2 of Conibear, Reddington, Silver, Knote, et al. ( 2021 ). We used the GEMM for non−accidental mortality (non−communicable disease, NCD, plus lower respiratory infections, LRI), using parameters that included the China cohort, with age−specific modifiers for adults over 25 years of age in five−year intervals.…”

“…In recent years, particulate air quality has improved, primarily attributed to reductions in anthropogenic emissions (Cheng et al., 2019 ; Ding et al., 2019 ; Li et al., 2020 , 2019 ; Silver, Conibear, et al., 2020 ; Silver, He et al., 2020 ; Silver et al., 2018 ; Zhai et al., 2019 ). However, the loss of healthy life from air pollution exposure remains substantial (Conibear, Reddington, Silver, Knote, et al., 2021 ; Silver, Conibear, et al., 2020 ; Zhao et al., 2018 ) and further emission reductions are required to improve air quality.…”

The contribution of emission sources to the future air pollution disease burden in China

“…Under CLE, the contribution from residential emissions decreases moderately by 2050. While under the best air pollution technologies, these reductions can be much larger, highlighting the potential of further action in this sector (Zhao et al 2018, Conibear et al 2021b. As the future contributions from these five sectors decreases, the proportional contribution from other sources increases.…”

Emission Sector Impacts on Air Quality and Public Health in China From 2010 to 2020

“…An ensemble of these estimates finds these contributions to be 30% from industry, 26% from residential, 16% from agricultural, 14% from power generation, and 7% from land transport emissions (C. Reddington et al., 2019 ). Despite the recent reductions in emissions and PM 2.5 concentrations in China, PM 2.5 exposure remains high, O 3 exposure is increasing, and the associated disease burden is substantial (Conibear, Reddington, Silver, Knote, et al., 2021 ; Silver, Conibear, et al., 2020 ; B. Zhao et al., 2018 ).…”