Microplastic Contamination Research Articles

Aging Dynamics of Polyvinyl Chloride Microplastics in Three Soils with Different Properties.

Microplastic (MP) contamination in soil has been of great concern, but the dynamic aging process and potential pathways of MPs in natural soil systems remain poorly understood. Herein, poly(vinyl chloride) microplastics (5% w/w) were weathered for 12 months in sandy soil, silty clay, and silt loam. The results showed that the continuous increase of C═O and O-H groups (rate constant, k = 0.080-0.424 m-1) with time was observed on the surface of MPs aging in sandy soil due to the leading role of •OH induced by light irradiation. In the loam soil, the abundant coating of aluminosilicates and iron oxides on the MP surface by the formation of mineral-hydroxyl groups inhibited the generation of the C═O group (k < 0.165 m-1). The k of the characteristic bond C-Cl during the first 9 months was 9.51 and 1.93 times higher in clay compared to that in sandy and loam soil, respectively, revealing that dechlorination triggered the first step of the aging process for MPs in clay owing to the participation of degrading bacteria (Phenylobacterium and Caulobacteraceae). The results provide important insights into the aging dynamics of MPs in environmentally realistic circumstance, which account for understanding the different aging processes of MPs in different soils.

Microplastics in Water and Food: [Not]Awareness

Currently, the spread of micro- and nanoplastics in the food chain and the environment has become a relevant and social issue. They enter the human body mainly through food, water and drinks packaged in various plastic materials, bottles or containers. It has been established that most urban water sources are contaminated with microplastics due to wastewater. The main objective of the article was to study the awareness of microplastic sources, exposure levels and potential health risks associated with microplastic contamination of food and water by surveying a heterogeneous audience of Internet users. The preventive focus of the survey included: 1) holding an action at the medical faculty of KRSU “Day without plastic”; 2) development, publication and distribution of an information leaflet in the Internet community on the key sources of microplastics in the daily human diet. The test group consisted of 502 Internet users. The author's questionnaire included 26 questions: personal data (5 questions), the size of microplastics, sources of information, an assessment of the risk factors for microplastics entering the body, its content in food and water and the impact on human health (a list of 16 diseases associated with microplastics is provided). Statistical processing of the obtained results was carried out using SPSS version 28.0.1 software. Questionnaires of 502 respondents aged 14–50 years were obtained through an online survey from October 2023 to January 2024 using Google forms. The demographic structure reflected the predominance of female representatives - 52.4%, men accounted for 47.6%. In terms of education level, students dominated among the subjects, incomplete higher education (67.3%), then secondary (14.8%), higher (9.9%) and primary education (8.8%). Most of the respondents lived in the city (80.3%), compared to rural areas (19.7%). Since the survey involved young people, 49.8% of respondents correctly answered the question that microplastics are small particles measuring 5 microns. 50.2% of respondents answered incorrectly, indicating sizes of 10 and 15 microns. Respondents noted that microplastics are most often found in bottled water (29.5%), tea bags (17.3%), natural water (10.3%), fish (8.1%), salt (6.3%), seafood (5.5%) and honey (4.5%). All of the above were noted by 29.5% of respondents. Most respondents to the question: which vegetables are most often contaminated with microplastics, answered that none (38.5%), followed by root vegetables (30.4%), onions (13.1%), cabbage (9.7%) and legumes (8.3%). Among the presented sample - the correct answer is - root crops are most susceptible to contamination. The results of the survey show that in everyday life 45.8% of respondents most often used plastic bags (55.7%), food packaging (18.7%), then cosmetics and hygiene products (17.4%), toys (5.9%) and cutlery (2.3%). Living in a “plastic world”, Internet users somehow do not notice it, to the question of how often the respondents use plastic products, 64.7% of them answered that every day, 26.7% - sometimes, 8.6% — rarely. As the results of the survey showed, most often Internet users received information about the harm of microplastics from social networks 26.5%, Google search engine — 20.7%, scientific articles — 18.9%, news — 17.1%, while communicating with friends, family — 5.5%. At the same time, 11.3% of respondents were not interested in the problem. When comparing the assessment of awareness of the direct and indirect impact of plastic on human health during plastic production and consumer use of plastics, they were aware (46.0% and 37.1%, respectively), slightly aware (31.9% and 37.8%) and did not know (22.1% and 25.1%). The risk that plastic pollution poses to wildlife, as well as to human health, well-being and prosperity, was assessed by respondents as average. 34.6% of respondents were in favor of actively reducing the use of plastic products. 33.7% of survey participants are still at the level of awareness of the problem and attempts to reduce plastic consumption. 31.7% find it difficult to answer, since they do not see an alternative. When asked about awareness of the impact of microplastics (the silent killer) on the development of 16 specific diseases, respondents were most aware of: digestive diseases, allergies, chronic inflammation, respiratory problems, cancer and reproductive problems.

Microplastic Contamination in Landfill Leachate and Surface Water: Assessment of Wastewater Treatment Efficiency at the Nonthaburi Waste Management Center, Thailand

Microplastics (MPs), plastic particles smaller than 5 mm, have emerged as a significant environmental concern, particularly as contaminants originating from landfills. Landfills can serve as a major source of MPs, potentially releasing them into surface water through leachate. This study aims to investigate the contamination of MPs in leachate and surface water, as well as to evaluate the efficiency of landfill wastewater treatment in removing these particles. The research was conducted at the Waste Management Center of the Nonthaburi Provincial Administrative Organization, Thailand, with samples collected in June 2023. Sampling included two leachate sources, influent and effluent from the treatment system and surface water. The abundance and characteristics of MPs in each sample were analyzed. Results indicated a significant presence of MPs in leachate, with an average concentration of 173.98 pieces/L, while concentrations in influent, effluent and surface water were 38.40 pieces/L, 10.80 pieces/L and 11.33 pieces/L, respectively. MPs in all samples were predominantly in the size range of 16-100 µm, corresponding to 71.28-93.75% of the total particles. Polypropylene was the dominant polymer in leachate (69.66%) and effluent (48.94%), whereas acrylate copolymer (96.53%) and polytetrafluoroethylene (44.12%) were the major types found in influent and surface water, respectively. The wastewater treatment system of the landfill demonstrated an overall removal efficiency of 71.88% for MPs in leachate. These findings highlight the extent of MP contamination in landfill environments and the importance of improving treatment processes to mitigate their release into surrounding ecosystems.

The Contamination of Microplastics Ingested by Freshwater Molluscs in the Mun River, Thailand

The Contamination of Microplastics Ingested by Freshwater Molluscs in the Mun River, Thailand

Inter riverine variability in microplastic distribution among two tropical rivers – Chalakudy and Periyar, Southwest India

ABSTRACT The study intends to bridge the lack of baseline information on microplastic (MPs) contamination in two river systems (Periyar: the longest river, lifeline of the Kerala State and Chalakudy: the fifth longest river) and hence is highly relevant. Sampling was carried out twice during December 2020 and January 2021. Elevated level of contamination was recorded at midstream sites in Chalakudy and downstream sites at Periyar. Small-sized particles (<100 µm) constituted the majority (>45%) in both river systems resulting from the disintegration of larger particles or direct release of primary MPs. Prevalence of fragment shape, accounting for ≈48–71% across all sites in both rivers, resulted from the disintegration of meso or macro plastics. Preponderance of blue-coloured particles (≈33–67%) inferred potential risk to aquatic organisms. Low-density polyethylene emerged as the dominant polymer group, originated from packaging materials and bottles. Overall abundance and recovery rate in both rivers indicate that MPs occur at all sites, irrespective of land use patterns, sourced to the degradation of abandoned fishing gears, shipping, tourism activities, and untreated waste disposal. The high risk of microplastic pollution in the study area was endorsed by polymer hazard index and coefficient of microplastic impact index.

The Removal and Mitigation Effects of Biochar on Microplastics in Water and Soils: Application and Mechanism Analysis

Due to their widespread distribution, microplastics (MPs) are endangering the soil ecological environment system, causing water pollution and altering the soil’s physicochemical and microbiological features. Because of its unique pore structure and strong stability, biochar is widely used as an adsorbent. However, the effects of MP–biochar interactions in water and soil environment are still unclear. This review outlines the application and mechanism of biochar as an adsorbent in a water environment for the removal of MPs. Also, biochar serves as remediation material for MPs in soils as it mitigates the adverse effects of MPs on soil properties, enzyme activities and soil microbial community. It was found that woody biochar had the highest yield and was more effective in adsorbing MPs. Further research should focus on the combined effects of biochar and MPs, the environmental risks of biochar, the modification of biochar application of MP-removal technologies, the characterization of MP properties, the remediation of combined contamination of MPs and other pollutants, and the transportation of MPs.

Impacts of microplastics on ecosystem services and their microbial degradation: a systematic review of the recent state of the art and future prospects.

Microplastics are tiny plastic particles with a usual diameter ranging from ~ 1 μ to 5µm. Recently, microplastic pollution has raised the attention of the worldwide environmental and human concerns. In human beings, digestive system illness, respiratory system disorders, sleep disturbances, obesity, diabetes, and even cancer have been reported after microplastic exposure either through food, air, or skin. Similarly, microplastics are also having negative impacts on the plant health, soil microorganisms, aquatic lives, and other animals. Policies and initiatives have already been in the pipeline to address this problem to deal with microplastic pollution. However, many obstacles are also being observed such as lack of knowledge, lack of research, and also absence of regulatory frameworks. This article has covered the distribution of microplastics in water, soil, food and air. Application of multimodel strategies including fewer plastic item consumption, developing low-cost novel technologies using microorganisms, biofilm, and genetic modified microorganisms has been used to reduce microplastics from the environment. Researchers, academician, policy-makers, and environmentalists should work jointly to cope up with microplastic contamination and their effect on the ecosystem as a whole which can be reduced in the coming years and also to make earth clean.

Fibrous foes: First report on insidious microplastic contamination in dietary fiber supplements

Regular consumption of health supplements to balance dietary intake has gained popularity worldwide. One such supplement that has gained popularity among consumers is dietary fibers. Microplastic (MPs) contamination in various food products is being reported worldwide. However, there is a paucity of understanding of the occurrence of MPs in dietary supplements. This study addresses this gap by investigating the degree of MPs contamination in dietary fiber supplements. Nine commonly consumed (powder and gummy-based) over-the-counter dietary fiber supplements in Australia were tested in this study. Microscopic examination revealed the presence of MPs fibers and fragments in all the tested products. Further categorization showed that MPs particles were of various colours, including black, blue, red, green, and white. The order of polymer abundance was Polyamide > Polydiallyl Phthalate > polyethylene polypropylene diene > Polyurethane = Polyethylene terephthalate > Polyethylene = Ethylene acrylic acid copolymer. Among the supplements, powder-based samples had higher MPs (at the adult dosage suggested by the manufacturer) than gummy-based product. The average predicted ingestion of microplastics from these supplements (all nine samples) was 5.89 ± 2.89 particles day−1. The dietary exposure for children and adults ranged from 0.1–0.48 and 0.18–4.08 particles day−1, respectively. Based on the microplastic contamination factor (MCF), among the nine samples tested, 69.81% exhibited a moderate level, while 20.76% showed a significant level of microplastic contamination. The polymer risk index (pRi) indicates products with very high and high-risk categories. The possible sources of MPs contamination in the products were studied. To our knowledge, this is the first study to record and quantify the presence of MPs in dietary fiber supplements, which is a direct source of MPs exposure to humans via., ingestion.

Microplastics Contamination in Environment and Marine Animals at Kodek Bay, Lombok, Indonesia

Microplastics Contamination in Environment and Marine Animals at Kodek Bay, Lombok, Indonesia

Microplastic pollution unveiled: the consequences of small unregulated dumping in villages, spanning from soil to water.

Microplastic contamination in soil ecosystems is a major environmental concern in the world. The current study aims to explore the extent of microplastic pollution in unregulated village dumpsites in India, focusing on the movement of these pollutants from soil to aquatic environments. Soil samples from eight distinct sites (A to H) in six villages were analyzed for various properties, including pH, bulk density, porosity, water retention capacity, hydraulic conductivity, and particle size distribution. The attenuated total reflection-Fourier-transform infrared spectroscopy (ATR-FTIR) method was used to identify prevalent plastic types. The research classifies microplastics by their shape and color, identifying a wide range of particles such as sheets, fibers, foams, fragments, and films. The study also examines the presence and concentration of microplastics in both soil and sediment samples. It was found that PE and PP microplastics are significantly present across different size fractions. Sample A contains a variety of items in the 1-5mm size range, mainly PE, while the 0.3-1mm fraction is largely PP. Samples B to H are mostly composed of PE microplastics in different forms. Sample F is unique with a mix of PE, EPS, and a higher amount of red and blue foam particles in the 0.3-1mm fraction. Microplastics were quantified using stereomicroscopy, revealing concentrations between 80 and 840 numbers per kilogram in soil and 20 to 60 numbers per kilogram in sediments. The findings emphasize the widespread nature of microplastic pollution across ecosystems and the importance of developing effective strategies for monitoring and mitigating their impact on environmental health and human well-being.

Levels and Classification of Microplastics and Their Impact on the Wellbeing of Selected Commercially Important Fish Species in Kisumu Bay, Lake Victoria.

Microplastics (MPs) are emerging pollutants of concern in aquatic ecosystems. Fish ingest MPs accidentally during normal feeding because they resemble prey or by ingesting prey that previously consumed them. Despite severe plastic pollution in Africa, some countries, including Kenya have implemented laws to curb this pollution menace. MPs have scantly been studied in African freshwaters. This study provides empirical data and describes the levels of MPs in four commercially important fish species in Lake Victoria. A total of 95 fish samples were collected from four sampling sites (inshore-offshore waters) between March and May 2022. Microscopy and Attenuated Total Reflectance Fourier Transformed Infrared (ATR-FTIR) spectroscopy methods were used to identify MPs. In this study, 62 out of 95 (65.26%) of the gastrointestinal tracts of the sampled fish contained MPs. The four species showed different proportions of detected MPs among the sampled individuals: 75.00% (Clarias gariepinus), 75.00% (Synodontis victoriae), 71.43% (Lates niloticus), and 59.26% (Oreochromis niloticus). Polystyrene (PS) and poly (perfluorobutadiene) were the main plastic polymers in the fish samples. The condition factors estimated for O. niloticus, S. victoriae, and L. niloticus were > 1 and < 1 for C. gariepinus, respectively. Positive correlations were observed between microplastic numbers and fish length and microplastic numbers and fish weight. However, the low R2 values obtained implied no strong relationship exists between these parameters. These findings provide evidence of microplastic contamination in fish in Kisumu Bay.

Indoor Airborne Microplastics: Human Health Importance and Effects of Air Filtration and Turbulence

Microplastics (MPs) are omnipresent particles that receive special attention because of their persistent nature and their potential impact on human disease and on the environment. Most MPs are generated by the degradation of larger plastic items such as clothing, car tires, and discarded plastic materials. In indoor environments, where human beings spend most of their time, aerial MP levels are higher, and the majority are fibers produced from textiles. Airborne MPs indoors are a greater potential danger to humans than MPs ingested in food and drink. Fragments small enough to remain substantially suspended in the air column, the small airborne microparticles that are measured as PM10 and PM2.5, become available for assimilation by human beings through respiration, potentially producing various health problems. Larger MPs act by ingestion and skin contact. MPs can carry microorganisms and micropollutants adsorbed to their surfaces, facilitating their uptake and survival within the human body. Indoor airborne MPs thus represent emerging pollutants of fast-growing concern that are especially important as potential invaders of the human respiratory system, reaching the alveoli of the lungs and finally entering the circulatory system and other tissues. Since this direct human exposure to MP contamination via indoor air is so important, we discuss in this article the ways in which MP concentration and dispersal in indoor air can be affected by air turbulence that is induced by anthropogenic objects such as air conditioners, filters, and purifiers. Much evidence is equivocal and further research is necessary.

Characterization and ecological health risks of microplastics in the water and sediment of Xinyanggang River Estuary

ABSTRACT Microplastic (MP) pollution in aquatic environment has increased concerns. This study comprehensively examined properties and health risk to ecosystem of MPs in Xinyanggang River Estuary. Monthly sampling in 2023 detected MPs in water column (6.7 ± 0.55–11.6 ± 0.63 particles/L) and sediment (6.2 ± 0.78–10.2 ± 0.53 particles/g), with abundance peaking in summer, coinciding with the rainy season. The major features of the detected MPs included transparency and fiber, rayon, PVDF, PS, PE and PP composition. The dominant size fraction of detected MPs was 0.001–0.25 mm. Ecological risk assessment suggested relatively low load of MPs entering the Xinyanggang Estuary. However, polymer risk index (PRI) and potential ecological health risk index (PERI) suggested that MPs in Xinyanggang River are hazardous to ecosystem. This study firstly characterized MP contamination in Xinyangang River Estuary, and the provided results can guide the management of MPs in water environment more broadly.

Characterization of microplastics in soil, leachate and groundwater at a municipal landfill in Rayong Province, Thailand

Recent years have witnessed a dramatic increase in global plastic production, leading to heightened concerns over microplastics (MPs) contamination as a significant environmental challenge. MP particles are ubiquitously distributed across both continental and marine ecosystems. Given the paucity of research on MPs in Thailand, particularly regarding MPs contamination in terrestrial environments, this study focused on investigating the distribution and characteristics of MPs in a landfill area. We collected 15 soil samples, 2 leachate samples, and 5 groundwater samples from both inside and outside a municipal landfill situated in the urbanized coastal region of Rayong Province. Our findings revealed variability in MPs concentration across different sample types. In soil, the MP count ranged from 240 to 26,100 pieces per kg of dry soil, 58.71 % of all sample sizes are lower than 0.5 mm. Similarly, the size found in the leachate sample, and the average MP in the leachate samples was 139 pieces per liter of MPs. The groundwater samples showed a fluctuation in MPs count from 26 to 94 pieces per liter, and the size of MPs ranged mostly from 0.5 to 1 mm. The predominant forms of MPs identified were sheets, followed by fragments, fibers, and granules. According to μ-FTIR analysis, the majority of the MPs were composed of polyethylene and polypropylene, commonly used in plastic packaging and ropes. The observed high concentrations and extensive distribution of MP contamination underscore the urgency for further studies and effective management strategies to mitigate the adverse impacts of this pollution on various organisms and ecosystems.

Microplastics pollution in tropical estuary (Muttukadu Backwater), Southeast Coast of India: Occurrence, distribution characteristics, potential sources and ecological risk assessment

Around the world, microplastic pollution is pervasive and is regarded as the biggest threat to all ecosystems. We conducted the present study to determine the prevalence of microplastics (MPs), their polymer hazard risk (PHI), and any potential sources of these particles in the estuary of Muttukadu Backwater, Southeast Coast of India. Microplastics were extricated from surface water and sediment by the wet peroxide method, identified by a stereo zoom microscope (SM), and characterized by ATR-FTIR and SEM-EDS analysis. The average microplastic abundance in sediment and surface water was 815±158 particles Kg−1 and 195±38 particles m−3, respectively. The most common microplastics based on shapes were fibers and fragments in both sediment and surface water, with blue and green-colored microplastics being the most frequently observed colors. Type II polymer particles (<3.00 mm–1.00 mm) are dominant particles in sediment (36 %), and type I (5.00 mm–3.00 mm) particles dominate in surface water samples (49 %). Energy dispersive X-ray spectrometer (EDS) results showed that the following chemical elements, such as O, C, Cl, Fe, Na, Al, K, Ca, and Si, as well as the order of the trace metal Pb > Cr > Ni > Co > As > Cu > Cd > Zn, are observed by microplastics of all sediment sampling location. The pollution load index (PI), polymer hazard index (PHI), and potential ecological risk (PER) index models revealed varying level of risk. The polymer hazard index (PHI) reveals that both water and sediments are moderate to highly MP contamination. The hazards of polymers such as polyethylene, polystyrene, polyester, and polyamide significantly contributed to hazard level IV. Inadequate plastic waste management, human habitation and tourism, rapid industrialization, and coastal construction are the main sources of microplastic contamination in the study area. The proper guidelines, potential policies, and technological interventions are much needed to reduce the microplastic contamination along Southeast Coast of India.

Assessing the Microplastic Pandemic: Prevalence, Detection, and Human Health Impacts in Asian Aquatic Environments

Microplastics pose a major threat to the globe due to their increased pollution and concerning effects on biota and humans. Presently, every terrestrial and marine region is affected diversely by microplastic contamination. The most polluted locations are industrialized metropolitan areas and coastal regions with considerable human activity. In this study, we choose representative samples of freshwater, marine, and biota in water, as well as sediments with different levels of microplastic pollution and distinct geographical conditions. For individually chosen aquatic areas and matrices, we reviewed, assessed, and summarized the current microplastic pollution and various methods of microplastic pollution assessment. The highest concentration of microplastics in data collected in Asia was found to be 372 ± 14.3 item/L and 9630 ± 2947 item/kg in the water and sediments of the Mumbai, India, coast. This huge abundance might be generated by human activities near the coastal areas as well as due to migration and tourism. This could also be due to sewage discharge and untreated domestic wastewater that is being dumped into the environment. Consuming of microplastic particles can put humans at risk for cytotoxicity, hypersensitivity, an unwanted immune response, and acute responses such as haemolysis, autoimmune diseases, cancer, and neurological conditions. Focusing on pollution status and potential mitigation path for microplastics from freshwater to oceans, we compared the distribution and important characteristics of microplastics in different locations. This study leads researchers to emphasis the reduction of MP pollution in densely populated areas like Asia.

The impact of microplastics on lake communities: A mesocosm study

Plastics are pervasive pollutants that are being produced at an increasing rate to meet consumer demands. After entering the environment, plastics can break down, creating smaller fragments, including secondary microplastics. Microplastic contamination in lakes has been recorded worldwide, and the ingestion of microplastics has been documented in zooplankton, macroinvertebrates, and fish. Microplastic ingestion and exposure can cause varying deleterious effects on these organism groups, but the impact of realistic microplastic concentrations on whole freshwater food webs requires further study. We addressed these knowledge gaps by conducting an 8-week experiment factorially crossing microplastic addition at a concentration of 1.5 particles/L with a fish predator (perch, Perca fluviatilus) presence in 1200-L outdoor mesocosms. Microplastic exposure had time-varying effects on zooplankton abundance, with a lower abundance of zooplankton in plastic treatments at the end of the experiment. Although microplastics had no impact on total macroinvertebrate abundance, there were effects on individual taxa. In the presence of microplastics, the cased caddisfly Triplectides spp. had a significantly lower abundance, which may have led to an increase in the snail Gyraulus spp. in week eight. Across the benthic and pelagic invertebrate communities, there were near-significant compositional differences between control and plastic treatments. These findings indicate that microplastic exposure may negatively impact freshwater invertebrate communities, even at low, field-realistic concentrations representative of the densities currently found in lakes.

Potential ecological risk assessment of microplastics in environmental compartments in Mexico: A meta-analysis.

Microplastic (MP) environmental contamination has been widely studied in Mexico; however, the evaluation of the associated risk to MP in environmental compartments is scarce. Therefore, this study addresses this issue using diverse indicators such as the Pollution Load Index (PLI), the Polymer Risk Index (PRI), and the Potential Ecological Risk Index (PERI). The results of a meta-analysis revealed high MP contamination levels in most of the studied compartments, which included marine and estuarine waters, beach sand, freshwater, sediments, and biota. Regarding the risk assessment indicators, PLIs indicated low (56%), dangerous (22%), moderate (12%), and high (10%) levels across compartments. Meanwhile, PRIs displayed concerning values, with 36%, 35%, 20%, and 9% exhibiting dangerous, high, moderate, and low levels, respectively. Thus, high PRI values emphasized the significant rise in MP pollution, largely attributed to high-hazard polymer compositions. Otherwise, PERIs showed low (56%), very dangerous (29%), moderate (6%), high (5%), and dangerous (4%) levels. Thus, the ecological risk in Mexico is widespread and mainly linked to MP abundance, polymer type, environmental matrix, and organisms' characteristics. This study represents the first attempt at MP ecological risk assessment in Mexico, providing crucial insights for developing mitigation strategies to address concerns about MP contamination.

Challenges in Raman Spectroscopy of (micro)Plastics: The interfering role of colourants

Rising plastic consumption leads to widespread microplastic (MP) contamination. Raman spectroscopy is widely used for MP identification due to its ability to analyse particles as small as 1 μm. However, it faces challenges such as interference from pigments and additives. In this study, we aim to assess the accuracy of Raman micro-spectroscopy in identifying coloured plastic samples by applying various oxidative treatments to eliminate the possible interference effect caused by colourants associated with the sample. Standard and coloured microplastics were analysed using a Raman imaging microscope. Coloured plastics were treated with H2O2 30%, Sodium hypochlorite 5%, and Fenton reagent ( H2O2 30% and Ferrous sulphate 0.2 M) for 24, 48, and 72 hours. The Raman spectra were acquired after treatment to assess the impact of the treatment procedure on the polymer identification. Our results revealed that colourants significantly impact Raman spectra by peak broadening and/or fluorescence effects, which reduces identification accuracy and match scores Red pigments particularly obscure polymer identification. Treatments like oxidation and Fenton's reagent showed limited effectiveness. Additives in plastic samples can affect the accuracy of polymer identification by the Raman spectroscopy technique. Common treatment procedures do not improve the accuracy of identification. In order to improve the reliability of Raman analysis, essential factors such as utilizing multiple excitation lasers and appropriate CCD detectors, establishing a comprehensive reference library of colourants and additives, and employing advanced techniques like time-gated Raman spectroscopy or Surface-Enhanced Raman Spectroscopy (SERS) should be considered.

Vertical Transport of HDPE Microplastics through Sandy and Silty Soil

Microplastic pollution is an emerging concern and poses a potential risk to soil ecosystems and subsequently can lead to groundwater contamination. The sandy and silty soils are the major soil types covering more than 31 % of the land area globally. The vertical transport of microplastic in sandy and silty soil and further possible groundwater contamination is still unclear and not fully understood in the literature. The present study focuses on the movement of High-Density Polyethylene (HDPE) microplastics in quartz sand and silty soil using column experiments. Detailed flow through laboratory experiments are performed to understand the effect of varying the critical parameters in contaminant transport such as pore volumes (1PV,2PV,3PV,4PV,5PV,6PV,7PV,8PV,9PV,10PV) and flow rates (20,40,60,80,100,120 ml/min) on HDPE microplastic movement in sandy and silty soil separately. The maximum depth of microplastic transport in sandy soil was 20-22 cm for a flow rate of 120 ml/min, and 10-12 cm for 20 ml/min. In silty soil, the maximum depth of microplastic transport was 12-14 cm for 120 ml/min and 6-8 cm for 20 ml/min. The study also estimates the number of years required for microplastic contamination to reach groundwater under field conditions by considering the L/S ratio. The study estimated that it could take 144 years for microplastics to penetrate sandy soil and 356 years for silty soil, under the study conditions. The study highlights the significant threat posed by microplastics to groundwater contamination. The results suggest that soils may serve as both a sink for microplastics and a potential pathway for their entry into subsurface environments, such as underground habitats and water sources.