Global distribution of PFAS and their impacts on microbial greenhouse gas emission and mechanisms.

PER: and polyfluoroalkyl substances (PFAS) are persistent organic pollutants (POPs) widely distributed in environments, which overlaps with greenhouse gas (GHGs) emission hotspots. This review summarizes impacts of PFAS on microbial emission of three typical GHGs (CH4, N2O, and CO2), regional response patterns, and underlying mechanisms. The emission of N2O is the most sensitive, followed by CH4, while CO2 follows a "stimulation at low dose and inhibition at high dose" pattern with sensitivity depending on environmental medium. Mixed PFAS complicate response in real world, and real-world PFAS pollution mediates stronger enhancement of N2O and disrupts normal emission of CH4 and CO2. Mechanistically, PFAS induce oxidative stress, damage cell membranes (specifically targeting AMO/NOR/MCR), and alter microbial metabolism. Critical knowledge gaps remain in understanding complex effects of mixed PFAS in real environments, and future work should focus on combined pollution ecotoxicity, multi-omics technologies to decipher microbial adaptation, and prediction models.