In the microwave-radiofrequency spectrum, Wi-Fi is a short-range wireless broadband technology, which transmits at a frequency of 2.5 GHz. This type of technology has been positioned itself as one of the most widely used technological advances in recent years. It has been reported that direct exposition to radiofrequencies can induce physiological changes in different animals and plants species. One of the degenerative effects that Wi-Fi can cause is the production of reactive oxygen species, inducing tissue damage and DNA alterations. In fungi, the effect of exposure to electromagnetic radiation in the UV spectrum has been extensively studied, the physiological effect to radiofrequencies such as Wi-Fi is unknown. In that sense, the aim of this study was to detect the main changes in metabolism of some acid fatty and ergosterol of the fungus Serpula himantioides, using gas chromatography - mass spectrometry (GC–MS), and evaluate the antioxidant activity of metabolites obtained from in vitro cultures of S. himantioides exposed to Wi-Fi at 2.5 GHz. The results showed an increment in the content of some the fatty acids and ergosterol, in total extracts from the fungus mycelium. Antioxidant analysis revealed that the total extracts of S. himantioides culture medium showed antioxidant capacity associated with an increment in the content of phenolic compounds. Our results suggest that direct exposition to Wi-Fi radiation produces oxidative damage by modifying cellular components in the fungus S. himantioides.

Residential heater replacement programs in Chile have been evaluated primarily through fine particulate matter (PM) reduction metrics, without considering chemical speciation of the organic aerosols. This screening-level study characterized and compared particle-bound polycyclic aromatic hydrocarbon (PAH) and nitro-PAH emission factors from a residential firewood and a wood pellet heater, under controlled combustion conditions, and assessed their potential toxic equivalency (BaP-TEQ). Compound quantification used 1-nitropyrene as an index calibration compound; all results are semi-quantitative estimates with a combined analytical uncertainty of approximately 13–32%. Firewood combustion yielded a PAH-dominated emission profile with a total BaP-TEQ EF of 187.8 ng/kg, driven primarily by benzo[a]pyrene (BaP; individual contribution: 183.9 ng/kg). Wood pellet combustion showed a nitro-PAH-dominated profile under the applied semi-quantitative analytical conditions, with concentrations expressed as 1-nitropyrene-equivalent estimates and several compounds identified tentatively by NIST library matching, yielding a total screening-level BaP-TEQ EF of 972.1 ng/kg, approximately five-fold higher than firewood under the applied TEF framework and driven primarily by 6-nitrochrysene (toxic equivalency factor, TEF = 10). This screening-level estimate should not be interpreted as a direct human health risk between the two heating systems. Mean PM emission factors were 1.05 ± 0.55 g/kg for firewood combustion and 0.69 ± 0.15 g/kg for pellet combustion (approximately 1.5-fold difference). These results are reported descriptively given the screening-level nature of the analysis. The shift in particulate chemical profile from PAH-dominated in the firewood system to nitro-PAH-dominated in the pellet system suggests that wood pellets from pine may not be a sustainable approach to address air quality problems in Chile, since reductions in PM emissions alone may not capture relevant differences in the organic toxicological profile between these combustion systems. These findings provide a regional baseline for the chemical speciation of residential biomass emissions in Chile.