We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Spatial–vertical distribution, polymer degradation, and ecotoxicological risk of microplastics in the aquatic matrices of Punnakayal Estuary and upstream Thamirabarani River, Southeast India
AI summary Read the abstract
Scientists found tiny plastic particles (microplastics) throughout a river and estuary system in India, in the water near the surface, deeper water, and the sediment below, with the highest concentrations floating at the top and worsening pollution levels as the river meets the sea. Common plastics like polyethylene (used in bags and bottles) and polyester-type fibers showed up most, and many particles were breaking down further from sun and water exposure, which can make them easier for fish and other wildlife to absorb. Since these estuaries connect to fisheries and coastal food sources, this pollution buildup matters for anyone who eats seafood from aff
This study presents the first integrated assessment of spatial-vertical MPs distribution, polymer degradation, and ecotoxicological risk in the upstream stretches of Thamirabarani River and Punnakayal Estuary, a biodiversity-sensitive system adjacent to the Gulf of Mannar. Triplicate samples were collected from five sites (three riverine, two estuarine) across three environmental matrices: surface water (0-20 cm), subsurface water (4 m depth), and surface sediments. MPs were detected in all samples, with highest abundance in surface water (28 ± 2 items L⁻¹), followed by subsurface water (19 ± 4 items L⁻¹) and sediments (19 ± 1 items kg⁻¹). One-way ANOVA confirmed significant vertical stratification (p < 0.05), while spatial variation across sites was not statistically significant. Fibres predominated (> 53%), and ATR-FTIR identified six polymer types, polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene: polypropylene (PE: PP), polyamide (PA), and polyurethane (PU). PE and PP dominant in water and PU and PA enriched in sediments, reflecting density-driven partitioning. Weathering indices indicated progressive oxidative degradation: carbonyl index (CI) ranged 0.07-1.05 (PE), 0.32-1.03 (PP), and 0.75-1.29 (PU), while vinyl index (VI) ranged 0.75-1.40. Multi-index risk assessment revealed moderate contamination in riverine zones (PRI: 14.8-16.2; PLI-MPs: 1.34-1.45; PERI-MPs: 61.2-72.4) escalating to higher ecological risk in the estuary (PRI: 23.9-26.4; PLI-MPs: 1.61-1.67; PERI-MPs: 118.7-131.6). Size-based risk indices further confirmed elevated bioavailability risks in estuarine zones. These findings demonstrate that hydrodynamics, polymer properties, and weathering collectively govern MPs fate, establishing estuaries as critical accumulation hotspots with implications for coastal ecosystem management.
More Papers Like This
A baseline study of microplastic pollution in a Southern Indian Estuary
AI summary Read the abstract
This baseline study characterized microplastic distribution across surface, middle, and bottom water layers of the Udyavara River Estuary in southwest India, finding that concentrations varied by depth and season. The vertical distribution data improve understanding of how estuarine hydrodynamics influence microplastic accumulation and exposure risks to benthic organisms.
Microplastic Pollution in the Water Column and Sediment of Cochin Estuary, India: Abundance, Characteristics, and Potential Ecological Risk Assessment
AI summary Read the abstract
Scientists found tiny plastic particles (called microplastics) throughout the water and mud of Cochin Estuary in India, a busy waterway near a major city. Most of these plastic bits were extremely small—smaller than a grain of sand—which makes them easy for fish, crabs, and shellfish to accidentally eat, and could allow them to build up in seafood that people eventually consume. While this study didn't test human health effects directly, it adds to growing evidence that plastic pollution in our waterways may be finding its way onto our dinner plates.
Microplastics pollution in tropical estuary (Muttukadu Backwater), Southeast Coast of India: Occurrence, distribution characteristics, potential sources and ecological risk assessment
AI summary Read the abstract
Scientists surveyed microplastic contamination in the water and sediments of a tropical estuary on India's southeast coast. They found moderate to high levels of microplastic pollution, with common polymers like polyethylene and polystyrene contributing the most to ecological risk. The presence of trace metals on microplastic surfaces suggests these particles may also serve as carriers for heavy metal contamination in coastal ecosystems.
Spatial heterogeneity of microplastic pollution and associated emerging contaminants in tropical estuarine environments: Novel insights into distribution, bioavailability, and ecological risk
AI summary Read the abstract
Scientists found tiny plastic particles in water, mud, and seafood like shellfish and crabs in two river areas in India. These microplastics carry harmful chemicals and are getting into the food chain, which could affect the safety of seafood that people eat. While the current risk appears low, this research shows we need better policies to reduce plastic pollution to protect both ocean ecosystems and human food sources.
Ecological assessment of microplastic contamination in surface water and commercially important edible fishes off Kadalundi estuary, Southwest coast of India
AI summary Read the abstract
Researchers documented microplastic contamination in both the surface water and 12 commercially important fish species from the Kadalundi estuary in India. Fibers were the most common type of microplastic found, with contamination levels varying across fish species. The findings are significant because this estuary is Kerala's first community reserve, and the contaminated fish are widely consumed by local populations.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.