Impact of the 2023 floods on microplastic contamination in coastal groundwater: a comparative analysis of chennai’s pre- and post-flood conditions

Microplastic contamination in groundwater on a volcanic Jeju Island of Korea

A threat beneath the surface: Microplastic contamination in the groundwater of one of Europe's largest wetland complexes.

Microplastic contamination in urban groundwater: Risk assessment, citizen perception and policy imperatives - a case study of Kozhikode City, Kerala State, India.

Microplastics (MPs) contamination has increased significantly due to inadequate plastic waste, leading to MPs infiltration in marine organisms. Crustaceans, especially the anomuran crabs, represented significant benthic communities in the intertidal zone. The current investigation aims to check the variation in MP contamination in Hermit crab Clibanarius rhabdodactylus inhabiting the intertidal and subtidal zone of Gujarat state, India. A total of 50 crabs (25 males and 25 females) of C. rhabdodactylus were collected from both zones along the coast of Gujarat in January and February 2024. In the laboratory, hermit crabs were weighed, dissected, and processed for tissue digestion. Sediment and water samples also underwent digestion. All samples were then processed through flotation, filtration, microscopic observation, and chemical characterization. The higher contamination was recorded in intertidal specimens than in subtidal specimens. The MP contamination in C. rhabdodactylus varied significantly between intertidal and subtidal specimens. MP contamination in both habitats was greater in females than in males. MP contamination in sediment and water was higher in the intertidal region than in the subtidal region, with no significant difference. Morphometric examination of MPs indicated the maximum abundance of fibers in terms of MP shape, followed by fragments and films. Black coloured MPs with 0.5–1 mm size were recorded dominantly in both habitats. The isolated MPs were primarily composed of polyethylene and polypropylene polymers. This study proposed immediate measures to address the issue of effective management of plastic litter in the marine ecosystem of the state. The present study revealed that MPs are widely distributed in the intertidal region and possess a greater risk of MP accumulation than those in the subtidal region.

Microplastics: A potential threat to groundwater resources

New approach in estimation of seawater intrusion footprint (SWIF) for irrigated crops using coastal groundwater

Microplastic contamination has become widespread in natural ecosystems around the globe as a result of the tremendous rise in plastic production over the last 70 years. However, microplastic pollution in marine and riverine habitats has received more attention than that of terrestrial environments or even groundwater. This manuscript reviews the current issues, potential occurrences, and sources of the emerging problem of microplastic contamination in groundwater systems. The most prevalent types of plastic detected in groundwater are polyethylene and polyethylene terephthalate, and fibers and fragments represent the most commonly found shapes. The vertical transportation of microplastics in agricultural soils can affect groundwater aquifer systems, which is detrimental to those who use groundwater for drinking as well as to microorganisms present in the aquifers. Moreover, this review sheds light on the interlinkage between sustainable development goals and groundwater microplastic contamination issues as part of the strategies for the management of microplastic contamination in groundwater. Overall, this review reveals a lack of interest and a gap in knowledge regarding groundwater microplastic pollution and highlights future perspectives for research in this area.

Origins and processes of groundwater salinization and pollution in urban coastal aquifer under the influence of serious industrialization and urbanization were determined using major and trace element/ion geochemistry, microbial and environmental isotope analyses, and statistical correlation and hierarchical cluster analyses of chemical parameters. Electrical conductivities (EC) of the groundwater in the coastal aquifer ranged from 487 to 4280 µS/cm. Average groundwater EC values measured in wet and dry seasons were 1130 ± 420 µS/cm and 1096 ± 526 µS/cm, respectively. Wells with high EC values were noticed not only near the gulf coastline (1799–2801 µS/cm) but also at the further inland (1709–4280 µS/cm). Statistical evaluation of the groundwater analyses showed that EC had a relatively good correlation with Cl (r = 0.85–0.90, p < 0.01). Cl–Br ion couple also exhibited a significant correlation with a r squared value of 0.9545, suggesting that salinity of the coastal aquifer was controlled dominantly by single source. Piper diagram showed that predominant cation and anion types in the coastal groundwater exhibited shifts generally from Ca to Na, HCO3 to Cl and to less HCO3 to SO4. A significant variation observed in hydrogeochemical facies of the coastal groundwater resulted from dissolution of calcite, dolomite and gypsum, mixing with seawater, formation water and sewage effluents, and cation-exchange processes. Evaluation of Cl/Br mass ratio along with total nitrogen and microbiological contents of the groundwater samples indicated that seawater intrusion was occurring in the coastal aquifer. However, other sources such as mixing with saline formation water (paleo-seawater) and sewage effluents also contributed groundwater salinization locally at the inland. High seawater mixing ratios (2.5–5%) were obtained from wells close to the gulf coastline, while inland wells generally exhibited low mixing ratios (mean 0.36% ± 0.3). Fecal contamination in coastal groundwater was at notable levels. Varying redox environments (oxic/suboxic/anoxic) were observed in the coastal aquifer. Seasonal variation in the redox conditions controlled the Mn, Fe, and As enrichments in the coastal groundwater above their MCL values. This study also showed when employed with the other pollutant indicators, Cl/Br mass ratio could be used effectively to delineate the sources of contamination and salinization in coastal groundwater exhibiting low seawater mixing ratios.

Mechanisms controlling spatial variability of geogenic ammonium in coastal aquifers: Insights from Holocene sedimentary evolution.

This review investigates the growing concern of microplastic (MP) contamination in groundwater systems, an area that has received relatively limited attention compared to surface water environments. Drawing from a comprehensive review of recent literature, the study identifies key sources of MPs in groundwater, including landfills, septic systems, agricultural runoff, and wastewater infiltration. Polyethylene (PE) and polypropylene (PP) were consistently found to be the most prevalent polymer types. The paper synthesizes evidence on MP transport mechanisms—such as movement through the hyporheic zone, soil macropores, and karst aquifers—highlighting the role of hydraulic conductivity, seasonal flow variations, and soil structure. Findings also emphasize the influence of particle characteristics (e.g., size, shape, density) on mobility and persistence in subsurface environments. The review further discusses analytical challenges in detecting MPs at small scales and underscores health and ecological risks, such as bioaccumulation, heavy metal adsorption, and disruption to groundwater fauna. The study calls for standardized sampling methods, increased monitoring, and integrated management strategies to mitigate MP pollution in groundwater. These insights are critical for informing policy decisions and advancing research on this emerging threat to freshwater sustainability.

Microplastics contamination in groundwater of a drinking-water source area, northern China

Managed Aquifer Recharge (MAR) belong to the nature-based engineering approaches poised to play an increasingly positive role in climate change adaptation. In fact, the increased groundwater availability thank to MAR can buffer future temporal water shortages driven by forecast longer droughts. However, one concern of MAR regards the quality of the infiltrating water as it affects groundwater quality.There is growing concern about groundwater contamination by microplastics (MP) delivered by the infiltrated surface water. Indeed, MPs have been found in rivers globally. Groundwater contamination by MPs could then have direct detrimental consequences on groundwater management and availability for human uses.In this study, we measured MPs larger than 20 &amp;#181;m in the different important stages of a major MAR-water supply system in Switzerland. The MAR system has been diverting an average of 95,000 m3/day of Rhine water through channels and ponds since 1958. Samples of filtered water were taken in triplicates from the Rhine River near Basel, the treatment stages before the managed infiltration outlets, the pumped groundwater, before and after the activated carbon filters. The methodology involved the analysis of the filters by means of micro-Fourier Transform InfraRed (FTIR) spectroscopy and MPs identification by means of the machine-learning model developed by the Purency company. The possible contamination by MPs smaller than 20 &amp;#181;m could not be assessed due to practical challenges for water filtration in the field and quantification (reliable micro-FTIR measurements down to 20 &amp;#181;m). Before analyses, we added surrogate particles of polyethylene with an average size of 60 &amp;#181;m for quality assurance and quality control.The measurements revealed satisfactory MPs reduction along the MAR system. While the number of MPs in the raw Rhine River had to be quantified still, MPs average concentration decreased from about 9.75 particles/l in the treatment stage to about 1.3 particle/l after the activated carbon filter. MPs average concentration increased to 7 particles/l between the pumped groundwater and the activated carbon filters. The increase was driven by a high count of polypropilene MPs in one of the triplicates. Our study could not exclude a possible MPs contamination by construction materials used in the facility. The measured concentrations referred to a randomised scan of about 50% of the area of the filters encompassing the centre and the edges of the filters. Most of the surrogate particles accumulated along the edges. Yet, we only considered particles with a value of the Relevance and Similarity metrics greater than 0.3.Acknowledgements: We thank our colleague Reto Britt who supported with the sampling campaign and laboratory measurements and the drinking water supplier for allowing us to carry out the study within their premises.

Tidal pumping controls transport of foodborne microbial pathogens between coastal groundwater and seawater.

Impact of microplastics on strength parameters of clayey, Sandy, silty soil: A comparative assessment

Literature provides only a few examples of contamination of groundwater with microplastics, mainly investigated using a chemical approach. Little importance is given to the hydrogeological processes able to affect the contamination, such as river–groundwater interactions. This study was carried out with two aims. The first aim is the formulation of a method with a high result-to-cost ratio, based on the hydrogeological aspects of the investigated area. Microplastics were extracted from samples through filtration and successively counted and characterized morphologically through analysis of optical microscopy images. The second aim is to evaluate the presence of microplastics in some portions of an alluvial aquifer using this methodology. Microplastics in groundwater showed a higher circularity and Feret diameter than those found in surface waters, indicating that in porous aquifers the transport is likely more influenced by the microplastics’ shape than by their size. The aquifer recharge did not modify the microplastics’ characteristics in groundwater, whereas in surface water the flood wave promoted the resuspension of microplastics with lower circularity. These findings provide new pieces of evidence on the presence and transport of microplastics in both groundwater and surface waters, underlining how the hydrogeological characteristics of the area can be one of the main drivers of microplastics’ contamination.