Distribution, Potential Sources, and Health Risk of Microplastics (MPs) in Street Dust during and after COVID-19 Lockdown in Bangladesh

The advent of the COVID-19 era has ushered in significant changes to both the environment and daily life. During the COVID-19 lockdown, a unique opportunity emerged to improve environmental quality and mitigate certain impacts on the planet. The distribution and health risks of microplastics (MPs) in the street dust of Dhaka city, Bangladesh during and after COVID-19 lockdowns were examined in this study. The study covered sites selected based on land usage, including an industrial area (IA), commercial area (CA), public facilities area (PFA), and residential area (RA). The particles in the dust samples were analyzed using a fluorescent microscope and attenuated total reflectance Fourier-transform infrared spectroscopy. The results show that the maximum number of MP particles/g of street dust sample was recorded from industrial areas (17.33 MP particles/g) and the minimum was recorded from residential areas (13.99 MP particles/g) without lockdown. The trends in the MPs were as follows: without lockdown > partial lockdown > complete lockdown. Risk analysis showed that the MPs in dust pose low non-carcinogenic risk to inhabitants of the study area and across lockdown periods. Principal component analysis showed that during the partial lockdown period, comparable sources were detected for the cellulose/low-density polyethylene (LDPE)/high-density polyethylene (HDPE), polychloroprene (PCP)/polyethylene terephthalate (PET)/polypropylene (PP)/polyacrylamide (PAA)/nylon, and polyethylene (PE)/polydimethylsiloxane (PDMS)/polyvinyl alcohol (PVA)/fiber groups of MPs, but various sources were discovered during the complete and without lockdown periods. The results further showed that all MP types would pose no non-carcinogenic or carcinogenic risks in dust from all land-use areas. However, the highest risks were obtained from inhaling dust. The study shows that human activities have a significant impact on the generation and distribution of MPs in the environment. The changes in MP type distribution during lockdown suggest that reducing human activities, such as traffic and industrial activity, can lead to a decrease in the quantity of MPs generated and released into the environment.