Environmental Science and Pollution Research最新文献

The accumulation of microplastics (MPs) in ecologically and commercially significant fish species is a growing concern, particularly those consumed by humans. This study investigated the presence of MPs in both the water and farmed rainbow trout (Oncorhynchus mykiss) a species of high commercial value collected from the upstream region of the Chehel Chai River in Golestan Province, Iran. A total of 50 fish were analyzed, with MPs examined in the digestive tract (GT), gills, and skin, revealing 55 particles in total. The frequency of occurrence of MPs in fish was 100%, indicating universal exposure among sampled individuals. MP abundance in water samples ranged from 0 to 4 items/L, with a mean ± SD concentration of 2.11 ± 1.04 items/L. In the digestive tracts of fish, MPs were detected at a mean ± SD concentration of 1.88 ± 0.94 items/g. Larger MPs (400-700 µm) were more frequently observed than smaller particles (100-250 µm and 250-500 µm) in both fish and water samples. Fibers were the most prevalent MP shape, followed by fragments and films. Micro-Fourier transform infrared spectroscopy (μ-FTIR) identified 40 MP particles, with a mean ± SD of 1.57 ± 0.29 particles per fish. Four polymer types were detected: polyethylene (PE, 44.4%), polypropylene (PP, 30.5%), polystyrene (PS, 19.4%), and polyethylene terephthalate (PET, 5.5%). Most MPs were detected in the gastrointestinal tracts (GIT) of fish, reflecting ingestion as the dominant exposure pathway. In contrast, water concentrations showed a spatial gradient, increasing from upstream to downstream sampling stations. Our findings indicate widespread plastic contamination in both fish and water across all sampling stations. These findings underscore the pervasiveness of plastic pollution even in high-altitude systems and highlight the potential for multiple exposure pathways (ingestion, respiration, adhesion) in farmed fish, with implications for ecosystem health and aquaculture sustainability.

Solid waste pollution is a multifaceted global challenge affecting the environment, economy, and human health, yet our understanding of environmental solid waste dynamics, such as waste type, weight(W), and volume(V), which inform waste management initiatives and policy frameworks remains limited in Sub-Saharan Africa. In this longitudinal study, we mapped informal waste disposal sites using transect-walks and drones in urban Malawi. Monthly characterisation of selected individual waste piles was undertaken for 12 months. Sampling (200L/waste pile) included both surface and compacted sections. (60 cm depth), which were characterised by weight(kg/m²), volume(m³), and individual counts of plastic items(m²). Three-way ANOVA and a linear mixed-effect model were used to predict percentage recovery for the interactions between month, waste pile depth, and waste type as fixed factors. Fourteen out of 56 waste piles received detailed temporal characterisation. Waste piles were located along rivers(50%), streams(29%), and open-dumping spaces(21%). Soil (W:60%, V:19%), organic material (W:22%, 33%), and plastics (W:8%, V:24%) were the highest components by weight, and volume, making plastics the highest non-organic category of waste. Seven plastic polymer types were identified, with Low-Density Polyethylene being the most common (83% plastic items/m²). Seasonality, waste pile depth, and waste type (F(171, 4284) = 11.44, p < .001, η² = .31) significantly affected percentage recovery of waste items, indicating their effect on waste pile dynamics. Sustainable waste management initiatives need to account for seasonal changes, material characteristics, and waste pile stratification to effectively improve waste management systems and the public health implications of waste piles.

In India, a large number of workers in plastic manufacturing industries may be exposed to airborne microplastics (MPs). However, data on occupational exposure levels remain limited. This study aimed to assess occupational exposure to MPs in small, medium, and large-scale plastic manufacturing industries in Nagpur, India. Nagpur, a major industrial hub, provided a representative setting for evaluating such exposures across diverse industry scales. Airborne respirable samples (n = 30; 10 per industry type) were collected during 8-h work shifts using a Sidekick-51MTX dust sampler. Respirable dust collected on PVC filter papers was analyzed for MPs using stereomicroscopy for visualization, fluorescence microscopy for quantification, and ATR-FTIR spectroscopy for polymer characterization. The highest airborne microplastic concentration was observed in medium-scale industries (43 ± 8 particles/m³), followed by small-scale (38 ± 10 particles/m³) and large-scale industries (30 ± 10 particles/m³) for time-weighted average (TWA₈) in shifts. The corresponding filter-based counts were 12 ± 5.8, 13.7 ± 6.5, and 9.5 ± 4.9, respectively. MPs exhibited fibres and fragments, mostly < 1 mm, with fiber lengths ranging from 21 to 1353 µm. Trace elements (Pb, Cd, As, Hg, Ni) were analyzed using hot block digestion (NIOSH 7303 method) and were within permissible limits under the Factories Act, 1948. This study shows the presence and characteristics of airborne microplastics across plastic manufacturing industries, along with associated occupational exposure to trace elements, and provides baseline information for future studies in Indian settings.