Particulate matter emissions from the iron and steel industry of China: Patterns, drivers, and implications

The iron and steel industry is a major particulate matter (PM) emitter. Using data from 99 Chinese sites, an LMDI model is applied to decompose PM emission changes into five process‑specific factors: steel output, energy consumption intensity, waste gas generation coefficient, stack emission concentration, and fugitive emission factor, separating stack from fugitive emissions. Nationally, PM emissions declined 23.6% from 2011-2016. The steel output effect drove an 83.7% increase in 2010-2011 but became a reduction driver after 2014. The waste gas generation coefficient effect consistently increased PM emissions (19,516 t in 2015-2016). The stack concentration effect was the dominant inhibitor (reduction up to -31,558 t in 2015-2016). The fugitive emission factor effect shifted from positive (5,037 t in 2010-2011) to strongly negative (-23,320 t in 2015-2016). Energy intensity effects were small (<25% contribution). Regional analysis reveals heterogeneity. Most regions followed the national trend, but South China and Northwest China showed annual PM increases, with positive stack emission concentration and fugitive emission factor effects. In Northwest China, the total effect was positive in five of six years, ranging from 1,408 t to 8,305 t annually, with fugitive emissions contributing up to 232% of the annual change. These findings imply that uniform national policies are insufficient. Targeted interventions of accelerating dust removal deployment in South/Northwest China and strengthening fugitive controls were proposed.Implications: The iron and steel industry is a critical PM emitter with implications for air quality and public health. This study quantifies key drivers of PM emissions across China's steel regions, revealing that while national emissions declined due to improved stack and fugitive controls, regional disparities persist, particularly in Northwest and South China where emissions increased. These findings underscore the need for regionally tailored policies prioritizing dust removal upgrades, fugitive containment, and energy efficiency. The analysis supports China's "blue sky" objectives and offers a replicable framework for other industrial sectors facing similar pollution challenges.