Assessment of mold infestation of conditioning devices and indoor air

Introduction. Indoor air quality is an essential component of a healthy human environment. Air conditioning units can affect indoor air quality, including mycogenic contamination of the air if the condition is not adequately monitored. Material and method. The paper presents the results of a mycological study of air samples and flushes from the surface of filters and gratings of air conditioning devices taken from 40 residential and office premises. Results. The presence of micromycetes fungi was noted in 100% of the samples taken from the surface of filters and air conditioning grids and 81.6% of air samples. A greater species diversity of fungi (26 species) was revealed in air samples compared to air conditioning devices (15 species). A higher frequency of occurrence of dark-coloured species of fungi, incl. Aspergillus spp. and Alternaria spp., and fungal species belonging to the third group of pathogenicity, were noticed on the surface of air conditioners, compared with air samples, in which Penicillium spp., Fusarium spp., Trichoderma spp. were more often detected. It was found that the surface of air conditioners functioned sporadically. For a short time (28 rooms), there is a large species diversity of mycobiota at a low or moderate level of seeding (no more than 10 3 CFU). In rooms with long-term continuous air conditioners (12 rooms), a high level of seeding (more than 10 4 CFU) by 1-2 species of fungi was more often noted. The existence of a close relationship, confirmed by the values of the Pearson contingency coefficient, between the species composition of the mycobiota of air conditioning devices and air, and a higher level of mycogenic contamination in rooms with long-term continuous operation of air conditioners, were shown. Conclusion. Thus, air conditioning devices can be a source of mycogenic air contamination, especially during long-term continuous operation, which must be taken into account to ensure indoor air quality. Contribution: Khaldeeva E.V. — the concept and design of the study; collection and processing of material, writing a text; Glushko N.I. — collection of literature data, collection and processing of material; Lisovskaya S.A. — editing, collection and processing of material. All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version. Conflict of interest. The authors declare no conflict of interest. Acknowledgment. The work was carried out within the framework of the State Assignment in accordance with the Branch Research Program of the Federal Service for Surveillance on Consumer Rights Protection and Human Well-being (Rospotrebnadzor) “Problem-oriented scientific research in the field of epidemiological surveillance of infectious and parasitic diseases” (for 2016-2020) p. 2.4.8.