Development of a new framework to estimate the environmental risk of heavy metal(loid)s focusing on the spatial heterogeneity of the industrial layout

Industrialization and urbanization have increased the risk of heavy metal(loid)s coming from a wide range of pathways and processes. Regional environmental risk assessment mainly focuses on the regional functional layout, industrial orientation, and enterprise location. These aspects may generate immense environmental risks and hazards. However, many gaps in regional environmental risk assessment remain, particularly concerning the spatial heterogeneity of environmental processes and mechanisms affected by the industrial layout. Most of the risk estimation often neglected the risk factor interaction. Here, we developed a framework to estimate the environmental risk of heavy metal(loid)s focusing on the spatial heterogeneity of the industrial layout. This framework was operationalized by performing an integrated risk detection of heavy metal(loid)s, spatial heterogeneity identification of the industrial layout, the power of risk factors and factor interaction examination, risk factor condition quantification and key risk source apportionment. Shaoguan city, one of six trial zones for China's pollution prevention and control of heavy metal(loid)s, was taken as a case study. Among all of the natural and socioeconomic factors, the running time of the industry was the most important risk factor of the Cd, As and Pb in soil and rice in all subregions. These subregions were divided based on the spatial heterogeneity of the industrial layout. The threshold of the running time of the industry for soil Cd was 11.97 years. The power of other dominant risk factors was different in different subregions, and the joint risk of the dominant risk factors was larger than the single risk of the running time of the industry. Our results suggest that the environmental risk of heavy metal(loid)s in Shaoguan could be mitigated by adjusting the industrial structure and controlling the running time of enterprises. Our study also indicates that estimating the regional environmental risk of heavy metal(loid)s focusing on the spatial heterogeneity of the industrial layout can help define specific strategies to achieve environmentally friendly industrial development.