Fungal biotechnology for air-pollution mitigation: Mechanistic pathways, engineered systems and exposure-centered...

Air pollution comprises complex mixtures of chemically reactive pollutants, including PM₂․₅, soot, transition metals, aldehydes, polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs) that contribute to cardiopulmonary, neurological and dermatological injury, particularly in high-burden regions such as the Indo-Gangetic Plain. Conventional filtration systems efficiently remove particulate mass but often exhibit limited interaction with chemically reactive pollutant fractions within indoor and semi-enclosed microenvironments where human exposure is greatest. This review evaluates fungal biotechnology as a mechanistically relevant, exposure-centered complement to conventional air-pollution mitigation. Extracellular oxidoreductases may facilitate the oxidative transformation of aromatic VOCs and PAHs, while chitin-glucan-melanin cell-wall polymers contribute to immobilization of metal- and soot-associated toxicants. In parallel, porous mycelial architectures support particulate interception and extended pollutant-surface interaction under controlled conditions. Evidence from laboratory and pilot-scale studies of active mycofilters, immobilized-enzyme reactors, mycelium-based composites and hybrid fungal-biochar systems suggests potential for partial reduction of chemically reactive pollutant fractions under laboratory and pilot-scale conditions. Emerging translational approaches include mycelium-based composites, immobilized-enzyme systems and low-energy hybrid remediation platforms designed for localized exposure reduction. However, important limitations remain, including enzymatic instability, fouling, mixed-pollutant interference, biosafety concerns and the absence of standardized certification frameworks. Current evidence is further constrained by limited long-term field validation and substantial variability across experimental systems. Overall, fungal biotechnology represents a promising mechanistically informed approach for interacting with exposure-relevant pollutant chemistry that may not be fully addressed by purely capture-based filtration systems under certain indoor or chemically heterogeneous conditions. This review synthesizes mechanistic fungal biology, engineered remediation systems and exposure-centered air-quality perspectives relevant to emerging fungal air-remediation technologies.