Spatial distribution and characteristics of microplastics and associated contaminants from mid-altitude lake in NW Himalaya. (June 2023) - Bulbul, Mehta
Abstract: Despite the worldwide concern over the impact of microplastics (MPs) and associated organic contaminants, the information regarding the occurrence and characteristics of these emerging class of pollutants is limited in freshwater environment. We present data on the distribution and concentration levels of MPs and phthalate esters (PAEs) from Rewalsar Lake, a shallow eutrophic lake in Northwest Himalaya. The MPs were identified in all samples, with concentration of 13–238 particles L −1 and 750 to 3020 particles kg −1 dry weight (dw) in surface water and sediments respectively. Majority of MPs were dominated by polystyrene, polyethylene, polypropylene polymers that principally occurred in the form of pellets and fragments. The MPs distribution was different among sampling sites, being more abundant to sites in the proximity of domestic sewage effluents and high level of religious and tourist activities. The di-isobutyl phthalate, dibutyl phthalate (DBP) and its branched isomer, di(2-ethylhexyl) phthalate (DEHP) are the identified PAE congeners in sediments, and the measured total concentrations of Σ3 PAE ranged from 1.69 μg/g to 4.03 μg/g dw. Notably, concentration values of DEHP were higher as compared to other detected phthalates, and exceeded recommended environmental risk limit. The findings of this study emphasize the requirement for proper waste management measures in the region to reduce entry of these pollutants into the ecosystem. Further, this work contributes to the understanding of MPs and PAEs potential contamination profiles and sources in freshwater environments, and provides valuable information for future management decisions. Graphical abstract: Image 1 Highlights: Microplastics and phthalate compounds were ubiquitous in the Rewalsar Lake. The microplastic abundance was higher at the marginal areas. Polystyrene, polyethylene and polypropylene are abundant polymers. The PAE congeners identified in surface sediments were DIBP, DBP and DEHP. The high concentration levels of DEHP in sediments posed a high potential environmental risk.