Microplastics (MPs) and phthalic acid esters (PAEs) have garnered significant global attention over the past decade due to their persistence, widespread occurrence, and potential toxicity; however, their distribution and interrelationship in freshwater systems remain largely underexplored. This study investigates the occurrence of MPs in environmental samples including catchment soil, lake water, and sediments collected from the Upper Lake (UL) watershed and Shahpura Lake (SL) in Bhopal, Central India. The co-occurrence and interrelationship between MPs and PAEs in sediment/soil samples are also examined to better understand their combined environmental impact. In Upper Lake, the abundance of MPs ranged from 20–192 particles/L in water and 1100–9260 particles/kg in sediments. In Shahpura Lake, MPs ranged from 22–88 particles/L in water and 3950–9890 particles/kg in sediments. Most MPs consisted of polyethylene, polypropylene, polystyrene, and polyethylene terephthalate polymers, appearing as pellets/beads, fragments, and fibres. PAE concentrations in surface sediments ranged from 2.72–14.34 µg/g in Upper Lake and 12.14–44.03 µg/g in Shahpura Lake. Diethyl phthalate (DEP) isomers and di(2-ethylhexyl) phthalate (DEHP) were the dominant PAEs, frequently exceeding recommended environmental risk thresholds in both sediment and soil samples. Spatially, the highest concentrations of MPs and PAEs in Upper Lake were observed in the urbanized eastern region, while Shahpura Lake, a typical urban lake, showed no clear spatial variation. This study reveals that freshwater lakes in Central India are significantly impacted by plastic pollution relative to other Indian and global freshwater systems. Furthermore, principal component analysis and log-transformed regression results revealed significantly high positive loadings of different PAEs with MPs and a strong positive correlation (r = 0.87, p < 0.001) in sediments and soils, suggesting that PAEs could serve as potential proxies for monitoring plastic pollution across diverse environmental matrices.
Ahmad et al. (Mon,) studied this question.