Ecological risk assessment of soil cadmium in China's coastal economic development zone: a meta-analysis

The coastal area of China has faced major strategic planning and environmental pollution, including heavy metals pollution. This study aimed to provide a comprehensive evaluation of the effects of Cd pollution on the ecology in coastal areas of China. A soil Cd pollution database of 300 counties or districts in coastal areas was screened from academic dissertations and academic journal papers. Based on the database, the ecological risk was evaluated using entropy methods and probabilistic ecological risk assessment (PERA), and the advantages and disadvantages of these methods were analyzed. In China's coastal areas, the soil Cd content in 10.33% of the counties was higher than the minimum of risk control value (1.5 mg/kg), and in 4.00% of the counties was higher than the maximum of risk control value (4.0 mg/kg). The ecological risks were highly compatible with national strategic planning areas. Guangxi Province, Zhejiang Province, and Guangdong Province ranked among the top three coastal areas for soil Cd contamination, and the ecological risks were 18.80%, 17.89%, and 15.77% at the maximum no-effect concentration/lowest effect concentration (NOEC/LOEC) level. This study can provide insights to policymakers regarding the protection of ecosystems threatened by heavy metals in the process of regional strategic planning.