Biological PCB remediation in soils requires integrated and site-specific strategies for effective field-scale application

Polychlorinated biphenyls (PCBs) remain among the most persistent and toxic soil contaminants worldwide, despite long-standing production bans, largely due to their hydrophobicity, chemical stability, and resistance to biological degradation. Consequently, remediation of PCB-contaminated soils continues to present significant environmental, technical, and economic challenges. This review examines the evidence and synthesizes findings on whether biological remediation strategies for PCBs in soils, although promising under laboratory conditions, are constrained by factors such as limited bioavailability, strong site-specificity, and scalability challenges, which hinder their effective large-scale field application. To address this, we synthesize and critically evaluate evidence from peer-reviewed original research published between 1993 and 2026. We acknowledge that reliance on published studies may introduce biases, particularly publication bias toward positive results and the scarcity of field-scale data. To address these limitations, we critically evaluate reported efficiencies and explicitly highlight existing knowledge gaps. Major biological pathways are analyzed, including phytotechnologies, microbial degradation under aerobic and anaerobic conditions, fungal-mediated biotransformation, and algal phycoremediation. Particular emphasis is placed on plant–microbe interactions within the rhizosphere, as well as emerging role of multiomics approaches (e.g., metagenomics and transcriptomics) in elucidating degradation mechanisms and optimizing remediation performance. Notably, growing evidence suggests that integrating biological approaches with mild physicochemical techniques, such as electrokinetic biostimulation and nano-enabled bioremediation, can enhance PCB bioavailability and degradation efficiency. Future progress will likely require a shift toward integrated, multi-process remediation frameworks supported by omics-driven insights. However, bridging the gap between laboratory-scale success and field-scale implementation remains a critical challenge, requiring system-level design and interdisciplinary strategies.