Heavy metals primarily originate from emissions generated during agricultural and industrial production processes. Fertilizers and organic manures used in agricultural production both contain heavy metals. Industrial emissions—including waste gases, dust, and smoke—also harbor heavy metals, which enter the soil through rainfall and natural sedimentation. Moreover, wastewater discharged from industrial activities typically has high concentrations of heavy metals. Additionally, current levels of heavy metals in urban sewage significantly exceed regulatory standards, making it another major source of pollution.

　　1 What is the current status of heavy metal contamination in China’s soils?

　　Hou Yuxuan, a researcher in the environmental protection industry at Zhongtu Consultant: Currently, China’s soil is severely contaminated by heavy metals, exceeding... 10% The cultivated land has been contaminated by heavy metals, resulting in an annual grain yield reduction of approximately 10 million tons. Additionally, 12 million tons of grain have become unfit for consumption due to heavy-metal contamination, causing economic losses of at least 20 billion yuan. 2008 So far this year, the country has experienced more than 100 major pollution incidents, including over 30 incidents involving heavy-metal contamination, which have posed significant threats to people’s lives and health.

　　2 What is the primary source of heavy metal pollution?

　　Hou Yuxuan, a researcher specializing in the environmental protection industry at Zhongtu Consultant: Heavy metals primarily originate from emissions generated during agricultural and industrial production processes. Fertilizers and organic fertilizers used in agricultural production both contain heavy metals. Industrial emissions—including waste gases, dust, and smoke—also harbor heavy metals, which enter the soil through rainfall and natural sedimentation. Moreover, wastewater discharged from industrial activities typically has high concentrations of heavy metals. Additionally, the current heavy-metal levels in urban sewage significantly exceed regulatory standards, making it another major source of pollution.

　　3 Facing the current state of pollution and its sources, what measures—on different levels—do you think should be taken to prevent and address it?

　　Hou Yuxuan, a researcher specializing in the environmental protection industry at Zhongtu Consultants: From a technical perspective, there are three main types of preventive and remedial measures. First is engineering-based treatment, which primarily employs physical or physicochemical principles—such as topsoil addition, soil replacement, electrochemical methods, and chelation—to address heavy-metal contamination. Second is agricultural regulation, which involves adjusting soil pH, moisture levels, and organic matter content to alter the bioavailability of heavy metals in the soil, thereby reducing their toxicity to crops. Finally, there’s bioremediation, which leverages the metabolic activities of plants, animals, and microorganisms to degrade or immobilize heavy metals. From a legislative standpoint, it’s crucial to refine relevant laws and regulations, providing law enforcement agencies with a solid legal basis for their work. From the government’s perspective, strengthening the construction of related laws and increasing the costs of illegal activities are essential steps.

　　4 Given that soil is a non-renewable resource, what are your expectations regarding the country’s policies on land pollution?

　　Hou Yuxuan, Researcher in the Environmental Protection Industry at Zhongtu Consultants: 2015 The year is the International Year of Soils, and it has been [a certain number of] years since the release of the “Soil Environmental Quality Standards.” 20 Year, in this 20 Throughout the year, China's efforts to address soil pollution have consistently been a focus of national policy. 2014 The “Catalog of Remediation Technologies for Contaminated Sites” was issued year after year. ( The first batch ) 》、《Guidance on Phytoremediation Technology for Contaminated Agricultural Land Soils ( Pilot program ) Several policies related to soil pollution control, including the “...”, have been introduced. However, the legislative process remains lagging behind, and standard-setting is also progressing relatively slowly. Moreover, there is still ambiguity regarding the identification of responsible parties. It is anticipated that in the future, land pollution policies will be issued more frequently, and the legal framework will become increasingly comprehensive.