| Abstract [eng] |
Microplastics are widespread environmental pollutants found not only in water bodies and soil but also in indoor environments. Microplastics accumulated in indoor air and dust are considered a significant source of human exposure because fine particles can be inhaled. The aim of this study was to determine the concentration of microplastics in indoor dust samples collected at the Faculty of Chemical Technology of Kaunas University of Technology, evaluate their distribution in different rooms, and compare the application of stereomicroscopy and fluorescence microscopy methods for microplastic identification. The study included a review of scientific literature, dust sample collection, and laboratory analyses. Stereomicroscopy and fluorescence microscopy methods were applied for the identification and quantitative assessment of microplastics, while statistical data analysis and calculations of potential human exposure values were also performed. The study found that microplastic concentrations in dust samples ranged from 144 to 895 MP/g of dust, with an average concentration of 472 ± 196 MP/g. The highest microplastic concentration was detected in Laboratory 038, where intensive material preparation activities are carried out. High concentrations of microplastics were also identified in some organic chemistry and polymer laboratories. In lecture rooms, the highest concentration of microplastics was found on the eastern side of the building; however, the difference compared with concentrations measured in laboratories located on the western side was not statistically significant. Fine microplastic particles predominated in the samples, while particles within the size range of 50–100 μm accounted for the largest proportion of all detected particles (32.8%). Fibrous microplastics constituted approximately 20% of the total microplastic concentration. Comparison of results obtained by stereomicroscopy and fluorescence microscopy showed that lower microplastic concentrations were identified using the fluorescence microscopy method in all investigated environments. Statistical analysis demonstrated that the differences between the methods were statistically significant both in lecture rooms (p = 0.002) and laboratories (p < 0.001), with larger differences observed in laboratory samples. A very strong correlation between the results of the two methods was determined (R2 ≈ 0.94). Assessment of potential human exposure to microplastics showed that the calculated EDI values ranged from 0.0034 to 0.0365 MP/kg body weight per day. The obtained results indicate that indoor dust may serve as a significant medium for microplastic accumulation and a potential source of human exposure to microplastics. |
