Industrialization and heavy metals: Impacts on earthworm biodiversity and soil health

Abstract:

Soils are dynamic ecosystems that sustain terrestrial life through nutrient cycling, organic matter decomposition, and fertility regulation. Earthworms, recognized as ecosystem engineers, play a pivotal role in restructuring soil, enhancing microbial activity, and maintaining ecological balance. India’s diverse agro climatic zones harbor rich earthworm diversity, yet rapid industrialization and land use change have disrupted their populations. Comparative studies consistently reveal higher abundance, biomass, and diversity indices in non industrial soils compared to industrial soils, underscoring their sensitivity to anthropogenic stressors. Heavy metals such as cadmium, lead, chromium, and mercury accumulate in industrial soils and bioaccumulation in earthworm tissues, impairing growth, reproduction, and DNA integrity, thereby compromising ecological functions. Functional classifications epigeic, endogeic, and anecic illustrate their unique contributions to decomposition, aeration, and nutrient cycling, while emerging research highlights microbiome interactions as next generation bioindicators of soil health. Climate change further compounds stress by altering rainfall and temperature regimes, reshaping distribution patterns. The Rewari district of Haryana exemplifies the ecological costs of industrialization, where non industrial soils sustain biodiversity and fertility, while industrial soils exhibit contamination and decline. This review emphasizes the need for integrated comparative assessments, remediation strategies, and sustainable land use planning to safeguard soil biodiversity and ecosystem resilience in rapidly industrializing regions.