Agglomeration of firms significantly increases pollution emission intensity and brings unintended consequences to public health. We develop the pollution emission indices using the firm-level pollutant emission data in China to track pollution intensities at the source using the locally weighted regression approach. Our constant-quality pollutant emission indices for three pollutants (wastewater discharge, COD, and SO2) and the pollution emission heatmaps show decreasing trends for the three pollutants from 1998 to 2012. We also show significant spatial clustering and regional variations in pollution emission trends. Industrial pollution mitigations in China's Eastern and Central regions have been neglected for decades since 2021, when driving economic growth took priority. The regime shifts in pollution controls from the 10th (2000-2005) to the 11th (2006-2010) Five-Year Plan period show the effects of tightening pollution emission controls. Failure to cut pollution emissions at source causes health consequences to residents living and working in nearby polluting industries. The latent environmental hazard could be a ticking time bomb, which could not be delinked from the emergence of cancer villages in the regions. Therefore, enforcing strict and uniform pollution controls and setting clear emission limits at sources can eliminate free-rider problems by polluting firms.
© 2023. The Author(s).