Evaluation of the effectiveness of reducing microorganisms inside vehicles using chlorine dioxide diffuser card technology

Indoor air quality, such as inside motor vehicles, has been a growing concern due to the presence of potentially pathogenic bioaerosols.This study evaluated the microbiological effectiveness of the CleansAir system, based on the controlled release of chlorine dioxide (ClO), in reducing the microbial load in the air of passenger vehicles.Twenty-one vehicles were evaluated over 30 days, with microbiological collections performed at three different times: before installation of the diffuser card (T1), after 15 days (T2), and after 30 days (T3).Air samples were collected with a microbiological impactor (Mini CAPT PMS) and seeded in selective media for fungi and bacteria.Counts were expressed in colony-forming units per cubic meter (CFU/m), and isolated microorganisms were identified by MALDI-TOF.A significant reduction in the average CFU of bacteria was observed between T1 (48.9 CFU/m) and T2 (27.0 CFU/m), with a slight increase in T3 (32.8CFU/m), remaining below initial levels.For fungi, the load fluctuated over time, with a final reduction in T30 (15.6 CFU/m) compared to T0 (17.9 CFU/m).In addition, there was complete elimination of pathogenic genera such as Staphylococcus spp., Aspergillus spp., Cladosporium spp., and Penicillium spp. in part of the fleet.Although overall statistical significance was not achieved, the results demonstrate the potential of CleansAir as a complementary biosafety technology in vehicular environments.Such strategies may be especially relevant in contexts of high user turnover or transportation of immunocompromised patients.