Industrial pollutant emission and the major smog in China: from debates to action
Authors: Wei-Jie Guan, Xue-Yan Zheng, Nan-Shan Zhong
Journal: The Lancet Planetary Health (2017)

In December, 2016, consecutive waves of major smog shrouded China, particularly the North China Plain and Sichuan Basin, resulting in suspended schools, halted industrial production, and heavy traffic. Atmospheric levels of fine particulate matter (PM2·5) spiked to more than 500 μg/m3 in Henan and 1000 μg/m3 in Shijiazhuang.1China DailySmog spreads out as readings spike.http://www.chinadaily.com.cn/china/2016-12/20/content_27716831.htmGoogle Scholar Beijing even issued a red alert for pollution levels between Dec 16, 2016, and Dec 22, 2016. What causes smog events is under debate. According to new research,2Cheng Y Zheng G Wei C et al.Reactive nitrogen chemistry in aerosol water as a source of sulfate during haze events in China.Sci Advan. 2016; 12: e1601530Crossref Scopus (759) Google Scholar nitrogen dioxide and water vapour combine through a complex chemical chain reaction to form a sulphate-rich haze. Analysis of the chemical compositions of particulate matter suggests that its main sources include central heating, vehicle emissions, and road dust.3Chen R Cheng J Lv J et al.Comparison of chemical compositions in air particulate matter during summer and winter in Beijing, China.Environ Geochem Health. 2016; (published online Aug 8)https://doi.org/10.1007/s10653-016-9862-9Crossref Scopus (23) Google Scholar In the past decade, scientific evidence seemed to favour vehicle emissions as the main culprit behind smog in China. Nevertheless, these observations have overlooked the proportion of nitrogen oxide, sulphur dioxide, and particulate matter that is released by heavy industry. In fact, manufacturing of iron and steel, cement plants, coal combustion, and refinement of petroleum were proven to be the main sources of particulate matter leading to wintertime smog in Beijing.4Wang K Tian H Hua S et al.A comprehensive emission inventory of multiple air pollutants from iron and steel industry in China: temporal trends and spatial variation characteristics.Sci Total Environ. 2016; 559: 7-14Crossref PubMed Scopus (155) Google Scholar As such, heavy industry is more likely to be a greater source of intensive pollutant emissions than vehicles. Many heavy industrial enterprises in northern China emit excessive amounts of pollutants that are rich in sulphur dioxide and particulate matter, the ingredients of haze. More crucially, some industrial enterprises secretly release emissions at night, which is a prominent issue that is difficult to regulate. Reduction of anthropometric emissions is the most viable way to mitigate air pollution. Public attention should be immediately shifted back to implementing feasible urgent interventions. Suspension of heavy industry production might offer temporary relief but does not target the issue at its root. China has established stringent laws to curb industrial pollutant emission but is confronted with poor implementation. Stringent and unannounced inspections should be used to identify and fine industrial corporations emitting excessive amounts of pollutants (particularly those responsible for clandestine night-time emissions); however, it is important that these measures are implemented before, not after, smog has occurred.5Lin YC Hsu SC Chou CC et al.Wintertime haze deterioration in Beijing by industrial pollution deduced from trace metal fingerprints and enhanced health risk by heavy metals.Environ Pollut. 2016; 208: 284-293Crossref PubMed Scopus (89) Google Scholar Cleaner energy, such as solar energy and wind power, advocated by president Jinping Xi, is an appealing approach to reduce pollutant emissions but entails substantial financial burden requiring governmental investment and public support. China needs to abandon its convention of waiting for pollutants to cause a problem before managing their emission. The causes of major smog in China seem to be multifaceted—and include meteorological factors. However, excessive emissions from industrial enterprises remain crucial sources of air pollutants in northern China. Actions with integrated measures, including bundled composite interventions (eg, industrial upgrading and use of cleaner energy) and more stringent inspections according to environmental protection laws, are urgently needed. We declare no competing interests.