China's retrofitting measures in coal-fired power plants bring significant mercury-related health benefits

Abstract

China has implemented retrofitting measures in coal-fired power plants (CFPPs) to reduce air pollution through small unit shutdown, the installation of air pollution control devices (APCDs), and power generation efficiency improvement. The reductions in highly toxic Hg emissions and their related health impacts by these measures remain poorly understood. Here, we evaluated the health benefits of reduced Hg emissions via retrofitting measures during China's 12^th Five-Year Plan (2011–2015) by combining plant-level Hg emission inventories with the China Hg Risk-Source-Tracking Model. We found that the measures reduced Hg emissions by 23.5 tons (approximately 1/5 of that from CFPPs in 2010), preventing 30,484.77 total points of intelligence quotient decrement and 114 deaths between 2011 and 2015. These benefits were dominated by CFPP shutdowns and APCD installations, and nearly 50% of provincial health benefits were attributable to Hg reductions in other regions. We suggest that Hg control strategies should consider various factors, such as CFPP location, population density, and trade-offs between reductions in total Hg and in Hg²⁺. A total of 128 countries, including China, ratified the legally binding Minamata Convention in 2017 to mitigate highly toxic mercury (Hg), primarily targeting coal-fired power plants (CFPPs). China committed to reducing Hg emissions via various retrofitting measures in CFPPs, including the closure of small unit CFPPs, installation of efficient air pollution control devices, and power generation efficiency improvement. However, the effectiveness of these measures on Hg emissions and the related health effects remain poorly understood. In this study we found that Hg emissions have been reduced by 23.51 tons during 2011–2015, which prevented 114 deaths and 30,484.77 points of IQ decrement. Hg mitigation also produces significant mutual health benefits across regions. However, more stringent and effective Hg control measures are urgently needed, and various factors, including CFPP location, population density, and trade-offs between reductions in total Hg and in Hg²⁺, must be carefully considered. As coal-fired power plants (CFPPs) are one of the largest sources of mercury, China has implemented a series of control policies among CFPPs, but the effects of emission reductions and related health benefits remain to be assessed. Li et al. comprehensively evaluate the health benefits of reducing mercury emissions via retrofitting measures of CFPPSs during 2011–2015 in China. They analyze the health benefits of various retrofitting measures and discuss the policy implications comprehensively.