Quantitative characteristics and multiple probabilistic risk assessment of small-sized microplastics in the middle and lower reaches of the Hanjiang River, China.

Assessing the abundance, sources, and potential ecological risk assessment of microplastics using their particle and mass units in Uiam Lake, South Korea

Occurrence and emission characteristics of microplastics in agricultural surface runoff under different natural rainfall and short-term fertilizer application

To investigate the influence of factors such as tourism, agriculture, and population density on the presence of microplastic (MP) content in aquatic environments and their associated ecological risks, Jingpo Lake, a remote high-mountain lake situated away from urban areas, was selected as the research subject. This study examined the abundance, types, sizes, colors, and polymer compositions of MPs within the water body, fish, and sediments. By considering variables, including fishing practices, agricultural activities, population dynamics, and vegetation cover, an analysis was conducted to unravel the spatial and temporal distribution of MPs concerning human activities, ultimately leading to an assessment of the ecological risks posed by MP pollution. The findings revealed that the average abundance of MPs in the lake's surface water was recorded as (304.8 ± 170.5) n/m3, while in the sediments, it averaged (162.0 ± 57.45) n/kg. Inside the digestive tracts of fish, the MP abundance was measured at 11.4 ± 5.4 n/ind. The contamination of MPs within the aquatic environment of Jingpo Lake was found to be relatively minimal. Variations in MP loads across time and space were observed, with MPs predominantly falling within the size range of small planktonic organisms (50-1000 μm). Additionally, the prevalent colors of MPs in the water samples were white or transparent, constituting approximately 55.65% of the entire MP composition. Subsequently, they were black, red, and blue. This colors distribution were consistent across MPs extracted from fish and sediment samples. The chemical compositions of the MPs predominantly comprised PE (31.83%) and PS (25.48%), followed by PP (17.56%), PA (11.84%), PET (6.71%), EVA (4.56%), and PC (2.03%). Regarding the seasonal aspect, MP concentrations were highest during summer (46.68%), followed by spring (36.75%) and autumn (16.56%). The spatial distribution of MPs within Jingpo Lake's water body, fish, and sediments was notably influenced by human activities, as confirmed by Pearson correlation coefficients. A strong association was observed between MP levels and water quality indicators such as ammonium nitrogen (NH4-N), total phosphorus (TP), and chlorophyll-a (Chla), suggesting that human-related pollution contributed significantly to MP contamination. The diversity assessment of MP pollutants exhibited the highest variability in chemical composition (1.23 to 1.79) using the Shannon-Wiener Index. Subsequently, the diversity of colors ranged from 0.59 to 1.54, shape diversity from 0.78 to 1.30, seasonal diversity from 0.83 to 1.10, and size diversity from 0.44 to 1.01. The assessment results of ecological risk highlighted that the risk categories for MPs within the surface water, fish, and sediments of Jingpo Lake were categorized as I for the PHI and PLI and as "Minor" for the PERI. These relatively low-risk values were attributed to the predominantly low toxicity of the distributed MPs within the Jingpo Lake basin. Moreover, the results of the risk assessment were found to be interconnected with the distribution of the local population and agricultural activities around the sampling sections. Usage patterns of coastal land and population density were recognized as influential factors affecting MP loads within the water body, sediments, fish, and other components of the lake ecosystem.

Microplastics (MPs) are ubiquitous, persistent pollutants reported in abundance in all environments and biota. The main objective of this review is to identify the sources, distribution, and concentration of MPs in all aquatic environments and biota in the Indian region. On sources of the Web of Science (WoS), 45 papers on MPs were published in total between 2013 and 2020. To define the concentration of MPs in different aquatic environments, 3096 items/kg in marine sediments, 106 items/kg in biota, 59 items/L in seawater, 175 items/kg in sea salt, 33.9 items/L in lake water, 336 items/kg in lake sediments, 288 pieces/m3 in river water, and 328 items/kg in river sediments were investigated in previous studies. Consequently, we studied the distribution and occurrence of pollution from MPs in coastal and freshwater environments such as rivers, lakes, and biota. Therefore, we propose extending studies in all the above areas, knowing that there are many unique aquatic habitats and species that are yet unexplored. For future research, we suggest new methods for sampling MPs in all marine ecosystems and biota. Assessing research in each of these ways will allow for suggesting a MP threshold level and devising control initiatives to minimize plastic consumption and its eventual hazard to the aquatic ecosystem. Moreover, enforcing strict laws, enhancing legal initiatives, well-planned comprehensive waste management policies, and spontaneous public engagement is essential to create awareness of marine plastic pollution and reduce the adverse effects of land-based plastics. Marine sediments have a higher concentration of MPs than sea salt, biota, or seawater. Researchers should assess the findings in these ways to reduce plastic consumption and the threat it poses to the marine ecosystem.

Microplastics (MPs) have been extensively studied in the marine environment in recent years, but their occurrence in recreational waters, and recreational activities as a source of MPs, have been less explored. In this study, we investigate the temporal variation of MPs in the Salt River, a natural surface waterway heavily used for recreation, and in community swimming pools in nearby Tempe, Arizona. Samples were processed using established methodologies and MP shapes and number concentrations were obtained by optical microscopy. The MP concentrations in samples of surface water collected during recreational activity ranged from 27,798 to 222,391 MPs/m3, with the highest concentrations occurring at 16:00 and lowest at 8:00, consistent with recreational activities. Fibers were the dominant shape (≥ 71%) of MPs overall in the Salt River, accounting for as much as 96% of all MPs at peak activity time (16:00). MP concentrations in water samples from apartment community swimming pools ranged from 59,160 to 254,574 MPs/m3. In terms of shape, fibers were again dominant (sometimes as high as 87%) in these water samples. Raman spectroscopic characterization of the MPs revealed the presence of polyethylene (PE), polyvinyl chloride (PVC), polyester (PES), polyamide (PA), and polypropylene (PP), showing a larger variety of polymers in the pool samples, while more MP pieces remained chemically unidentifiable. The prevalence of PES and PA fibers indicates that release from synthetic fabrics such as swimwear is a substantial source of MPs in the environment.

Microplastics (MPs) are ubiquitous pollutants in the ocean, and there is a general concern about their persistence and potential effects on marine ecosystems. We still know little about the smaller size-fraction of marine MPs (MPs <300 μm), which are not collected with standard nets for MPs monitoring (e.g., Manta net). This study aims to determine the concentration, composition, and size distribution of MPs down to 10 μm in the Kattegat/Skagerrak area. Surface water samples were collected at fourteen stations using a plastic-free pump-filter device (UFO sampler) in October 2020. The samples were treated with an enzymatic-oxidative method and analyzed using FPA-μFTIR imaging. MPs concentrations ranged between 11 and 87 MP m−3, with 88% of the MPs being smaller than 300 μm. The most abundant shape of MPs were fragments (56%), and polyester, polypropylene, and polyethylene were the dominant synthetic polymer types. The concentration of MPs shows a significant positive correlation to the seawater density. Furthermore, there was a tendency towards higher MPs concentrations in the Northern and the Southern parts of the study area. The concentration of MPs collected with the UFO sampler was several orders of magnitude higher than those commonly found in samples collected with the Manta net due to the dominance of MP smaller size fractions. Despite the multiple potential sources of MPs in the study area, the level of MPs pollution in the surface waters was low compared (<100 MP m−3) to other regions. The concentrations of MPs found in the studied surface waters were six orders of magnitude lower than those causing negative effects on pelagic organisms based on laboratory exposure studies, thus is not expected to cause any impact on the pelagic food web.

Physicochemical characteristics of airborne microplastics of a typical coastal city in the Yangtze River Delta Region, China

Due to the copious disposal of plastics, marine ecosystems receive a large part of this waste. Microplastics (MPs) are solid particles smaller than 5 millimeters in size. Among the plastic polymers, polystyrene (PS) is one of the most commonly used and discarded. Due to its density being greater than that of water, it accumulates in marine sediments, potentially affecting benthic communities. This study investigated the ingestion of MP and their effect on the meiofauna community of a sandy beach. Meiofauna are an important trophic link between the basal and higher trophic levels of sedimentary food webs and may therefore be substantially involved in trophic transfer of MP and their associated compounds. We incubated microcosms without addition of MP (controls) and treatments contaminated with PS MP (1-µm) in marine sediments at three nominal concentrations (103, 105, 107particles/mL), for nine days, and sampled for meiofauna with collections every three days. At each sampling time, meiofauna were collected, quantified and identified to higher-taxon level, and ingestion of MP was quantified under an epifluorescence microscope. Except for Tardigrada, all meiofauna taxa (Nematoda, turbellarians, Copepoda, Nauplii, Acari and Gastrotricha) ingested MP. Absorption was strongly dose dependent, being highest at 107 particles/mL, very low at 105 particles/mL and non-demonstrable at 103 particles/mL. Nematodes accumulated MP mainly in the intestine; MP abundance in the intestine increased with increasing incubation time. The total meiofauna density and species richness were significantly lower at the lowest MP concentration, while at the highest concentration these parameters were very similar to the control. In contrast, Shannon-Wiener diversity and evenness were greater in treatments with low MP concentration. However, these results should be interpreted with caution because of the low meiofauna abundances at the lower two MP concentrations. At the highest MP concentration, abundance, taxonomic diversity and community structure of a beach meiofauna community were not significantly affected, suggesting that MP effects on meiofauna are at most subtle. However, lower MP concentrations did cause substantial declines in abundance and diversity, in line with previous studies at the population and community level. While we can only speculate on the underlying mechanism(s) of this counterintuitive response, results suggest that further research is needed to better understand MP effects on marine benthic communities.

Combined sewer overflows (CSOs) release a significant amount of pollutants, including microplastics (MPs), due to the discharge of untreated water into receiving water bodies. Constructed Wetlands (CWs) offer a promising strategy for CSO treatment and have recently attracted attention as a potential solution for MP mitigation. Nevertheless, limited research on MP dynamics within CSO events and MP removal performance in full-scale CW systems poses a barrier to this frontier of application. This research aims to address both these knowledge gaps, representing the first investigation of a multi-stage CSO-CW for MP removal. The study presents one year of seasonal data from the CSO-CW upstream of the WWTP in Carimate (Italy), evaluating the correlation of MP abundance with different water quality/quantity parameters and associated ecological risks. The results show a clear trend in MP abundance, which increases with rainfall intensity. The strong correlation between MP concentration, flow rate, and total suspended solids (TSS) validates the first flush phenomenon hypothesis and its impact on MP release during CSOs. Chemical characterization identifies acrylonitrile-butadiene-styrene (ABS), polyethylene (PE), and polypropylene (PP) as predominant polymers. The first vertical subsurface flow (VF) stage showed removal rates ranging from 40 % to 77 %. However, the unexpected increase in MP concentrations after the second free water surface (FWS) stage suggests the stochasticity of CSO events and the different hydraulic characteristics of the CW units have diverse effects on MP retention. These data confirm filtration as the main retention mechanism for MP within CW systems. The MP ecological risk assessment indicates a high-risk category for most of the water samples, mainly related to the frequent presence of ABS fragments. The results contribute to the current understanding of MPs released by CSOs and provide insights into the performance of different treatment units within a large-scale CSO-CW system, suggesting the requirement for further attention.

Microplastics (MPs), identified as emerging contaminants, have been detected across diverse environmental media. Their enduring presence and small size facilitate the adsorption of organic pollutants and heavy metals, leading to combined pollution effects. MPs also accumulate in the food chain thus pose risks to animals, plants, and human health, garnering significant scholarly attention in recent years. Aerobic granular sludge (AGS) technology emerges as an innovative approach to wastewater treatment. However, the impacts of MPs on the operational efficiency and microbial characteristics of AGS systems has been insufficiently explored. This study investigated the effects of varying concentration (10, 50, and 100 mg/L) of biodegradable MPs (Polylactic Acid, PLA) and non-biodegradable MPs (Polyethylene Terephthalate, PET) on the properties of AGS and explored the underlying mechanisms. It was discovered that low and medium concentration of MPs (10 and 50 mg/L) showed no significant effects on COD removal by AGS, but high concentration (100 mg/L) of MPs markedly diminished the ability to remove COD of AGS, by blocking most of the nutrient transport channels of AGS. However, both PLA and PE promoted the nitrogen and phosphorus removal ability of AGS, and significantly increased the removal efficiency of total inorganic nitrogen (TIN) and total phosphorus (TP) at stages II and III (P < 0.05). High concentration of MPs inhibited the growth of sludge. PET noticeably deteriorate the sedimentation performance of AGS, while 50 mg/L PLA proved to be beneficial to sludge sedimentation at stage II. The addition of MPs promoted the abundance of Candidatus_Competibacter and Acinetobacter in AGS, thereby promoting the phosphorus removal capacity of AGS. Both 50 mg/L PET and 100 mg/L PLA caused large amount of white Thiothrix filamentous bacteria forming on the surface of AGS, leading to deterioration of the sludge settling performance and affecting the normal operation of the reactor. Comparing with PET, AGS proved to be more resistant to PLA, so more attention should be paid to the effect of non-biodegradable MPs on AGS in the future.

The pollution of microplastics in sediments of the Yangtze River Basin: Occurrence, distribution characteristics, and basin-scale multilevel ecological risk assessment.

The presence of microplastics (MPs) along with agrochemicals is being widely reported from lakes, ponds, and rivers. Microplastic (MP) in association with agrochemicals could have synergistic or antagonistic effects on non-target aquatic organisms and pose ecological risks. The present study explored the combined effects of MP, the insecticide chlorpyrifos (CPF) and MP preconditioned with CPF (MP^CPF) on two cladocerans, Ceriodaphnia cornuta, and Echinisca triserialis in short-term and long-term laboratory bioassay tests. The experimental protocol included an acute bioassay at five different concentrations of MP (25, 40, 100, 200, and 500 particles mL-1), CPF (0.01, 0.05, 0.1, 0.5, and 1 µgL-1) and MP^CPF. Whereas, CPF (0.01 µg L-1), MP (25 particles mL-1), and MP^CPF in 0.01 µg L-1 of CPF were selected for the chronic bioassay. Upon exposure to CPF, C. cornuta and E. triserialis displayed a dose-dependent mortality pattern with a 48 h LC50 value of 0.06 µgL-1. No mortality was observed in the MP only treatment, but when MPs were preconditioned with CPF, the 48 h LC50 value was 0.02 µgL-1. Chronic exposure to MP, CPF, or MP^CPF resulted in reduced survival and reproductive output in both the cladocerans. However, C. cornuta was more vulnerable than E. triserialis. A significant delay in age at first reproduction and shorter generation time were observed in the presence of MP^CPF, suggesting MP-mediated enhanced toxicity of CPF, wherein CPF could have accumulated onto the MP surface, thus, intensifying its toxicity. The enhanced toxicity of organic pollutants by MPs in aquatic environments especially in pelagic organisms is a matter of concern.

Characterization and ecological risks of microplastics in urban road runoff

This study assessed the abundance, size, weight, shape, and polymer composition of microplastics (MPs) in 11 commercial compost products using ATR-FTIR spectroscopy. MPs were present in all samples, with an average abundance of 137.65 ± 6.01 items/kgdw, and concentrations up to 631.14 mg/kgdw. Eco-labeled composts showed significantly lower MPs abundance, size, and concentration than non-eco products. The most contaminated compost was a blonde peat substrate, while an algae-based humus showed the lowest MPs load. MPs larger than 1 mm were predominant, and films were the most common shape, likely resulting from plastic bags and packaging materials. A total of 15 polymer types were identified, with chipboard/agglomerate, modified cellulose, and polyethylene being the most frequent. Polymer diversity was greater in commercial universal composts and positively associated with anthropogenic activities. Physicochemical analysis revealed significant correlations between MPs concentration and compost quality. The presence of MPs was negatively correlated with pH and nitrogen content, but positively with organic matter. Vermicompost exhibited higher nitrogen and pH levels compared to other composts. MPs also influenced the distribution of trace elements: significant negative correlations were found between MPs levels and several elements, including As, Cd, Cr, and Pb. These findings suggest MPs may adsorb heavy metals, reducing their bioavailability. A “diversity index” (DI) of petroleum-based polymers, excluding cellulosic particles, was developed and showed significant correlations with Pb and Cd concentrations, indicating that human-related plastic waste contributes to metal contamination in compost. The results underscore the need for improved waste separation and composting processes to reduce MP and heavy metal contamination. Future regulations mandating separate collection of biowaste and textiles may mitigate these impacts.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-17034-w.

Influence of microplastics on antibiotic resistance genes across diverse environments: A comprehensive meta and machine-learning analysis.