Carbendazim toxicity and environmental fate: A critical review of mechanisms, impacts, and future research priorities
Puspendu Shit1,3, Partha Pratim Chakravorty1∗, Harekrishna Jana2
1Department of Zoology, Raja Narendra Lal Khan Women’s College (Autonomous), Paschim Medinipur–721102, WB, India
2Department of Microbiology, Raja Narendra Lal Khan Women’s College (Autonomous), Paschim Medinipur–721102, WB, India
3Department of Zoology, Debra Thana Sahid Kshudiram Smriti Mahavidyalaya (Autonomous), Paschim Medinipur–721124, WB, India
Abstract: Carbendazim (Methyl (1H-1,3-benzimidazol-2-yl)carbamate), a widely used systemic benzimidazole fungicide, represents a significant environmental and toxicological concern due to its persistence in ecosystems and documented reproductive and developmental toxicity. This comprehensive review integrates current knowledge on carbendazim’s toxicological mechanisms across multiple biological systems, including mammalian, avian, aquatic, and terrestrial organisms, with particular emphasis on its molecular basis of action through tubulin binding and the consequences of disrupted microtubule dynamics. Critical analysis reveals significant inconsistencies in reported toxicity thresholds across studies, likely attributable to methodological variations, species- specific sensitivity, and impurity profiles in technical-grade formulations. Regarding environmental fate, carbendazim demonstrates moderate persistence in soil (6–12 months half-life) but greater persistence in water systems (2–25 months), with degradation occurring primarily through microbial metabolism and photochemical pathways. This review identifies important knowledge gaps, including incomplete characterization of metabolite toxicity, limited field-based exposure studies, mixture toxicity scenarios, and the potential for bioaccumulation through food chains. Emerging evidence suggests that certain degradation products may exhibit comparable or even greater toxicity than the parent compound, necessitating revised risk assessment protocols. Integration of advanced mechanistic studies with standardized comparative approaches and field-relevant exposure scenarios is essential for developing robust regulatory frameworks and bioremediation strategies. The review underscores the need for urgent re-evaluation of maximum residue limits, particularly in dietary staples in regions with intensive carbendazim application.
Key Words: Carbendazim; Benzimidazole fungicide; Toxicity; Environmental fate; Bioremediation