Soil Chromium Accumulation in Industrial Regions Across China: Pollution and Health Risk Assessment, Spatial Pattern, and Temporal Trend (2002–2021)

This study conducted a nationwide specific assessment of soil chromium (Cr) contamination status in 506 of China's industrial regions. The overall soil Cr concentrations were 0.74-37,967.33 mg/kg, and the soil Cr content in 4.15% of the regions exceeded the reference screening value (2500 mg/kg). Geochemical accumulation index (Igeo) and monomial potential ecological risk index (E) revealed Cr salt production and tanning were the primary control industries. The non-carcinogenic risks posed by Cr salt production and tanning industries were higher than the national average values, and children were the most vulnerable groups. The heavily polluted regions were mainly located at the Yangtze River Delta, the Bohai Rim, the Pearl River Delta, the Yangtze River Basin, and the Yellow River Basin. The Yangtze River Delta was further identified as the high priority control area based on the class distribution of Igeo and E. Regression analysis showed the soil Cr concentrations in industrial regions increased during 2002-2009 and then turned into a declining trend in 2009-2021. This paper gives detailed insights into soil Cr pollution status in industrial regions across China and the results may serve as references for formulating tailored control measures for different industries and areas.