Cold atmospheric plasma decontamination of indoor mold

Abstract Indoor molds damage building materials and can compromise occupant health. Correction of the moisture source and physical removal of contaminated material remain central to remediation, but inactivation of residual viable growth may be useful as an adjunct where heat or liquid biocides are unsuitable. Here we combine controlled building-material experiments with a nonlinear logistic inactivation model to test whether fungal response to cold atmospheric plasma (CAP) is governed by threshold behavior at the time of treatment. Aspergillus brasiliensis , Cladosporium halotolerans , and Fusarium solani were grown on gypsum plasterboard or wood fiberboard and exposed to diffuse coplanar surface barrier discharge plasma (300 W, 10 min). Time-lapse imaging was used to quantify surface coverage for model fitting. The model captured the observed species- and substrate-dependent outcomes and identified a critical relationship between the inactivation rate and mycelial coverage at CAP activation. F. solani regrew on both substrates, A. brasiliensis regrew on plasterboard but showed no further visible expansion on fiberboard, and C. halotolerans showed no further visible expansion on plasterboard. Reactive oxygen and nitrogen species (RONS), coupon water content, dry-spore resistance, and treatment throughput were not measured, and absence of visible regrowth does not establish sterility or removal of fungal residues. The results therefore provide a proof-of-concept laboratory framework rather than a stand-alone building-remediation protocol.