Soil Contamination by Heavy Metals and Pesticides: A Critical Review of Toxicological Mechanisms, Sustainable Remediation Strategies, and One Health Implications

Abstract

Background: Soil contamination by heavy metals and pesticides remains a persistent global challenge with far-reaching consequences for agricultural productivity, ecosystem stability, and human health. Despite extensive research, existing studies remain fragmented across soil science, toxicology, and environmental health, limiting efforts to integrate soil nutrient status, contaminant dynamics, and their implications for plant stress, food-web integrity, and environmental well-being. Objectives: The review aims to conceptualize and critically evaluate advancements in soil nutrient dynamics, pollutant toxicology, and remediation strategies, with emphasis on heavy metals and pesticides. It integrates soil ecological processes, plant stress responses, environmental toxicology, and human health within a unified “One Health” perspective. Methodology: This review employs a focused yet transparent evidence-mapping approach – short of a holistic protocol but still structured and traceable under PRISMA – to integrate soil profiling, contaminant toxicology, and sustainable remediation within the One Health framework. Through a targeted literature search using defined inclusion criteria and multidisciplinary keywords, the review critically evaluates soil nutrient dynamics, toxicological pathways of heavy metals and pesticides, and emerging mitigation strategies while identifying key knowledge gaps relevant to sustainable agroecosystem management. Results: Soil functions as a complex biogeochemical system whose fertility, nutrient cycling, and ecosystem services depend on the interplay between organic matter, microbial communities, and physicochemical properties across soil horizons. Anthropogenic pressures – industrial emissions, mining, waste disposal, agrochemicals, and excessive fertilization – introduce heavy metals and pesticides that disrupt nutrient dynamics, degrade soil structure, impair microbial processes, and trigger plant physiological stress. Evidence demonstrates that agrochemical overuse destabilizes soil microbial ecology and nutrient–microbe interactions, causing contamination, reduced biodiversity, nutrient imbalance, and increased risks to food security and environmental quality. Integrating these findings reveals that soil health is tightly linked to contaminant behaviour, plant–soil interactions, and ecosystem resilience, emphasizing the need for sustainable management and remediation strategies to preserve soil-based ecosystem services. Conclusion: Heavy metal and pesticide contamination undermines soil functioning, plant productivity, ecosystem stability, and public health, reaffirming that soil integrity is a core component of the “One Health” continuum. Evidence indicates that while physicochemical remediation offers rapid mitigation, biologically driven and green-chemistry approaches – such as biochar, phytoremediation, and microbial degradation – provide more sustainable, scalable, and ecologically restorative solutions. Advancing soil health and sustainable agriculture requires interdisciplinary collaboration, long-term field research, integrated contaminant modeling, and globally harmonized regulatory frameworks to safeguard ecosystems, food security, and human well-being.