Propolis as a bioindicator of microplastic contamination in the environment of the Republic of Moldova
DOI:
https://doi.org/10.52673/18570461.25.4-79.04Keywords:
propolis, bioindicator, microscopic analysis, FTIR-ATR analysis, microplastic, environmentAbstract
Honey bees, due to their morphological characteristics, as well as beekeeping products, are considered relevant indicators of environmental pollution with toxic substances, whether it is microplastic particles (MP) or other toxic contaminants. The objective of this study was to evaluate the potential of propolis to be used as a bioindicator of microplastic contamination in various geographical areas of the Republic of Moldova. Eight samples of raw propolis, collected by beekeepers during the period 2023– 2024, were analyzed. Microscopic examination was performed to characterize the morphological and chromatic characteristics of the detected particles. The morphological analysis revealed that the predominant forms were fibers, in five different types, and one type of fragment. The fragments were quantitatively identified in a larger number – 53%, and fibers made up 47%, presenting a high structural and chromatic diversity, compared to the fragments. To confirm the polymeric nature and determine their chemical composition, infrared absorption spectra (FTIR) were recorded. The spectra of the microplastic particles from the propolis were compared with those of the reference substance – polyethylene terephthalate (PET). It was found that all the recorded spectra of the microplastic particles from the propolis showed characteristic bands of polyethylene terephthalate (PET). Thus, the results obtained indicate that propolis can serve as an effective indicator of microplastic pollution.
References
1. Barganska, Z.; Slebioda, M.; Namiesnik, J. Honey bees and their products: Bioindicators of environmental conta-mination, în: Critical Reviews in Environmental Science and Technology, 2016, nr. 46(3), 235-248, https://doi.org/10.1080/10643389.2015.1078220
2. Cortes-Corrales, L.; Flores, J.J.; Rosa, A.; Van Der Ste-en, J.J.M.; Vejsnaes, F.; Roessink, I.; Martínez-Bueno, M.J.; Fernández-Alba, A.R. Evaluation of microplastic polluti-on using bee colonies: An exploration of various sampling methodologies, în: Environmental Pollution, 2024, nr. 350, 124046, https://doi.org/10.1016/j.envpol.2024.124046
3. Murcia-Morales, M.; Tzanetou, E.N.; Garcia Gallego, G.; Kasiotis, K.M.; Vejsnaes, F.; Brodschneider, R.; Hatjina F.; Machera, K.; Van Der Steen, J.J.M. Environmental as-sessment of PAHs through honey bee colonies – a matrix selection study, în: Heliyon, 2024, nr. 10, https://doi.org/10.1016/j.heliyon.2023.e23564
4. Edo, C.; Fernández-Alba, A.R.; Vejsnaes, F.; Van Der Steen, J.J.M.; Fernandez-Pinas, F.; Rosal, R. Honeybees as active samplers for microplastics, în: Science of the Total Environment, 2021, nr. 767, https://doi.org/10.1016/j.scitotenv.2020.144481
5. Sarda, P.; Hanan, J.C.; Lawrence, J.G.; Allahkarami, M. Sustainability performance of polyethylene terephthalate, clarifying challenges and opportunities, în: Journal of Poly-mer Science, 2022, nr. 60, 7-31, https://doi.org/10.1002/pol.20210495
6. Kibria, M.G.; Masuk, N.I.; Safayet, R.; Nguyen H.Q.; Mourshed, M. Plastic waste: challenges and opportunities to mitigate pollution and effective management, în: Inter-national Journal of Environmental Research and Public Health, 2023, nr. 17, p. 20, https://doi.org/10.1007/s41742-023-00507-z
7. Liebezeit, G.; Liebezeit, E. Non-pollen particula-tes in honey and sugar, în: Food Additives & Contami-nants: Part A. 2013, nr. 30, 2136-2140, https://doi.org/10.1080/19440049.2013.843025
8. Osman, A.I.; Hosny, M.; Eltaweil, A.S. et al. Micro-plastic sources, formation, toxicity and remediation: a re-view, în: Environmental Chemistry Letters, 2023, nr. 21, 2129-2169, https://doi.org/10.1007/s10311-023-01593-3
9. Duis, K.; Coors, A. Microplastics in the aquatic and terrestrial environment: sources (with a specific focus on personal care products), fate and effects, în: Environ-mental Sciences Europe, 2016, nr. 28, 1-25, https://doi.org/10.1186/s12302-015-0069-y
10. Anderson P.J. et al. Microplastic contamination in lake Winnipeg Canada, în: Environmental Pollution. 2017, nr. 225, 223-231, https://doi.org/10.1016/j.env-pol.2017.02.072
11. He, S. et al. Biofilm on microplastics in aqueous en-vironment: Physicochemical properties and environmen-tal implications, în: Journal of Hazardous Materials, 2022, nr. 424, https://doi.org/10.1016/j.jhazmat.2021.127286
12. Guvernul Republicii Moldova. Hotărârea nr. 815/2020 cu privire la aprobarea Cerințelor de calitate pen-tru produsele apicole, inclusiv ceara de albine, propolisul, lăptișorul de matcă și polenul, destinat consumului uman, în: Monitorul Oficial al Republicii Moldova, nr. 313-317 art. 988, din 27 noiembrie 2020.
13. International Organization for Standardization, Bee propolis – Specification, first edition, Switzerland, 2023, ISO 24381:2023.
14. Sholokhova, A.; Ceponkus, J.; Sablinskas, V. et al. Abundance and characteristics of microplastics in tre-ated organic wastes of Kaunas and Alytus regional waste management centres, Lithuania, în: Environmental Science and Pollution Research, 2022, nr. 29, 20665-20674, https://doi.org/10.1007/s11356-021-17378-6
15. Böke, J.S.; Popp, J.; Krafft, C. Optical photothermal infrared spectroscopy with simultaneously acquired Ra-man spectroscopy for two-dimensional microplastic iden-tification, în: Scientific reports, 2022, nr. 12, https://doi.org/10.1038/s41598-022-23318-2
16. Mercedes, A.; Peltzer, M.; Simoneau, C. Report of an interlaboratory comparison from the European Refe-rence Laboratory for Food Contact: ILC002 2013 – Iden-tification of polymeric materials. Luxembourg: Publicati-ons Office of the European Union, 2013. 39 p., https://doi.org/10.2788/6233
