Heavy Metal Contamination and Risk Assessment in Soil Environments

Heavy metal contamination of soils arises from diverse sources including mining, industrial emissions, agricultural inputs and urban runoff. These metals—such as cadmium, lead, arsenic, mercury and nickel—are non-degradable and can accumulate to toxic levels in soils, posing risks to plant growth, food safety and human health. Understanding their speciation, mobility and bioavailability is critical for evaluating exposure pathways through ingestion, inhalation and dermal contact. Risk assessment frameworks combine chemical analyses with indices and modelling to estimate hazard quotients and carcinogenic or non-carcinogenic risks. Global research has increasingly focused on integrating geochemical mapping, pollution index schemes and mechanistic studies of plant uptake to guide sustainable land management and remediation strategies, including phytoremediation, soil amendments and novel immobilisation techniques. Standardised protocols for sampling and risk characterisation are informing policy decisions and remediation priorities worldwide.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Heavy Metal Contamination and Risk Assessment in Soil Environments publication trend

The graph below shows the total number of articles in heavy metal contamination and risk assessment in soil environments across all publications each year (not limited to Nature Index journals).

Technical terms

Bioavailability: The proportion of a heavy metal in soil that is accessible for uptake by organisms or leaching.

Pollution index: A dimensionless ratio comparing measured metal concentration to a reference or background level, used to quantify contamination severity.

Bioaccumulation factor (BAF): The ratio of a contaminant’s concentration in an organism (e.g., plant tissue) to its concentration in soil, indicating uptake efficiency.

Hazard Quotient (HQ): A risk characterisation metric calculated as the ratio of estimated exposure to a reference dose; HQ > 1 suggests potential adverse effects.

Phytoremediation: The use of plants to extract, stabilise or degrade pollutants from soils and water through natural physiological processes.

References

1. Enhanced passivation of thallium, vanadium and arsenic in contaminated soils: critical role of Fe–Mn-biochar. Biochar (2024).
2. Heavy Metals and Pesticides Toxicity in Agricultural Soil and Plants: Ecological Risks and Human Health Implications. Toxics (2021).
3. Pollution indices as useful tools for the comprehensive evaluation of the degree of soil contamination–A review. Environmental Geochemistry and Health (2018).