Do endocrine disrupting compounds impact earthworms? A comprehensive evidence review

Endocrine-disrupting compounds (EDCs) are ubiquitous in soil, posing serious risks to soil biota, especially earthworms, which have been found to be affected by these compounds, despite not being their typical target organisms. Earthworms are essential for sustaining soil health and quality, by promoting soil aeration, organic matter decomposition and nutrient cycling, among other functions. This review synthesizes available literature evidencing the negative impact of EDC exposure, through traditional endocrine pathways and other toxicological mechanisms, on histopathological, biochemical, molecular and reproductive endpoints of earthworms. The compounds described, in the consulted literature, to induce histopathological, biochemical, genotoxicity and molecular and reproductive alterations include antibiotics, antimicrobial additives, flame retardants, fragrances, fungicides, herbicides, hormones, inorganic ions, insecticides, organic UV filters, parabens, perfluoroalkyl substances, pesticides, petroleum derivatives, plasticizers and polychlorinated biphenyls. These compounds reach soil through direct application or via contaminated organic amendments and water derived from potentially polluted sources. The findings gather in the present review highlight the vulnerability of earthworms to a broad spectrum of chemicals with endocrine disrupting capacity. Additionally, these studies emphasize the physiological disruptions caused by EDC exposure, underscoring the critical need to protect biodiversity, including earthworms, to ensure soil quality and ecosystem sustainability. Ongoing research has provided insights into molecular mechanisms responsive to EDCs in earthworms, including the identification of putative hormone receptors that exhibit functional similarity to those present in vertebrates. In conclusion, this review emphasizes the impact of EDCs in earthworms, especially through non-hormonal mediated pathways, and addresses the need for strong regulatory frameworks to mitigate the detrimental effects of EDCs on soil invertebrates in order to safeguard soil ecosystems.

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