Microplastics pollution has become a matter of global concern because of its effects on aquatic life and the ecosystem. This study investigated the abundance and types of microplastics found in an urban canal of Thailand. Water quality and the relationship between microplastics pollutants and the physicochemical properties of water quality were also analyzed to provide evidence for this study. The mean abundance of microplastics was 370 ± 140 particle(p)/m3. The highest number and concentration of microplastics were found on surface water corelated with urbanization. Transparent brown and transparent colors in the form of film and fiber/lines were the predominant morphology. Polypropylene (PP) and polyethylene (PE) were the most abundant polymer type in all surface water samples. Furthermore, water quality was related with microplastic pollution. The physicochemical properties of turbidity (0.99), conductivity (0.97), total solid (0.95) and biological oxygen demand (0.84) were accounted for greatest influences on microplastics distribution. The estimated equation of microplastics was also closely corelated with water quality. These results demonstrate that microplastic pollution has progressed more in poor water quality than good water quality, indicating that the inflow process and sources of microplastics are similar to those of other pollutants. Therefore, this study is expected to encourage and enforce solid waste and wastewater management policies that prevent microplastics pollution in the environment.

Plastic production has inevitably increased in the past few decades and is one of the diverse material used in today’s world. With this increasing production and wider use, the aquatic ecosystems have become the trash barrel for all kinds of plastic resulting in it becoming a looming spectre to the habitat and functions of both inland and offshore ecosystems. Plastic pollution is considered as an emerging global environmental concern which could significantly affect the biological diversity and may have potential to cause inimical effects on human health. These plastics have shown to gradually degrade into micro fragments and are reported to cause toxic effects on the aquatic organisms. In comparison to the studies on presence of microplastic in marine ecosystems, the studies on the presence of it in freshwater ecosystems have received relatively lesser attention although some studies have shown that the contamination is as grievous as that of in marine environment. This review article focuses on the literature available on the reports of microplastic occurrence, its distribution in freshwater ecosystems across the world and its insidious effects which are of emerging concern. The effect of such microplastic ingestion in both aquatic organisms and the potential health hazards due to such plastic consumption in humans have also been examined. The paper also discusses the existing knowledge gaps so that future research directions can be taken accordingly and the findings in this paper would significantly help all the countries across the world to understand the present plastic pollution scenario and work towards the mitigation of the same.

The problem of pollution of aquatic ecosystems with microplastics has been actively studied by the world scientific community. Most of this research has been devoted to marine ecosystems, whereas scant research has been conducted on fresh water bodies. Lake Baikal (Russia) is a unique natural reservoir. Previous studies devoted to the amount of microplastics in the waters of Lake Baikal were carried out singularly and were not of a systemic character; therefore, previously obtained data does not reflect a complete picture of the state of the lake. Within the framework of this study, our goal was to study the composition and morphological structure of microplastic particles in the ice of Lake Baikal at different distances from the coastline. To do this, a number of ice samples were taken from the upper and lower sides at five different points in South Baikal opposite the village of Bolshiye Koty. Later these samples were analyzed for the types of microplastics and their amount. In the samples taken, two types of microplastics were found—fragments and fibers—with fibers being predominant. The median values of the number of microplastics particles are higher in samples taken at the interface between water and ice, compared to samples taken from the ice surface. Presumably, main part of microplastic fibers found opposite the village of Bolshiye Koty were brought in by a constant circular current from the opposite east coast. In turn, the low number of fragments in the samples may be due to the freezing of the coastline.

Microplastics are widely used to manufacture diverse products such as textiles, skin care products, and household products such as detergents and soaps. However, microplastic pollution and its potential health risks are raising concerns worldwide. This study characterized and determined the safety of microplastics in water and sediments obtained from three locations, namely Ibeshe, Amuwo Odofin, and Ojo along Badagry lagoon, Lagos, Nigeria. The samples of the lagoon's surface water and sediments were treated and analyzed for the abundance of microplastics, as well as their shapes, sizes, and types of polymers. The risk index of the polymers in the microplastics was also estimated. Microplastics were found to be more abundant (p ≤ 0.05) in the sediments (283–315 particles/kg) than in the surface water (108–199 particles/L). In both the water and sediments at all the locations, the dominant shapes were fibers (52%–90%), followed by fragments (3%–32%) and films (1%–25%). In order of significance, the microplastic size range of 0-100µm and 100-500µm dominated the surface water, while the size range of 1000-5000µm and 500-1000µm dominated the sediments at all the locations. The dominant polymers in both the water and sediments at all the locations were polyethylene, polypropylene, and polyamide, while the least was polystyrene. In both the water and sediments at all the locations, the dominant risk score among the polymers is III (moderate risk). The results obtained suggest that microplastic pollution poses environmental and health risks to the lagoon, aquatic organisms, and humans. As such, the lagoon required microplastic remediation and control.

The Black Sea receives increasing amounts of microplastics from rivers. In this study, we explore options to reduce future river export of microplastics to the Black Sea. We develop five scenarios with different reduction options and implement them to a Model to Assess River Inputs of pollutaNts to seA (MARINA-Global) for 107 sub-basins. Today, European rivers draining into the Black Sea export over half of the total microplastics. In 2050, Asian rivers draining into the sea will be responsible for 34–46% of microplastic pollution. Implemented advanced treatment will reduce point-source pollution. Reduced consumption or more collection of plastics will reduce 40% of microplastics in the sea by 2050. In the optimistic future, sea pollution is 84% lower than today when the abovementioned reduction options are combined. Reduction options affect the share of pollution sources. Our insights could support environmental policies for a zero pollution future of the Black Sea.

peer reviewed | The northern fulmar Fulmarus glacialis ingests a larger number of (micro)plastics than many other seabirds due to its feeding habits and gut morphology. Since 2002, they are bioindicators of marine plastics in the North Sea region, and data are needed to extend the programme to other parts of their distribution areas, such as the Arctic. In this study, we provide data on ingested plastics by fulmars collected in 1997 in Kongsfjorden, Svalbard. An extraction protocol with KOH was used and for half of the birds, the gizzard and the proventricular contents were analysed separately. Ninety-one percent of the birds had ingested at least one piece of plastic with an average of 10.3 (±11.9 SD) pieces. The gizzards contained significantly more plastics than the proventriculus. Hard fragments and polyethylene were the most common characteristics. Twelve percent of the birds exceeded the EcoQO value of 0.1 g.

peer reviewed | Microplastic contamination is an emerging issue in the marine environment including the Arctic. However, the occurrence of microplastics in the Arctic fjords remains less understood. Sample collections were conducted by trawling horizontally in surface water (0-0.4-m depth) and trawling vertically in the water column (0-200-m depth) to investigate the abundance, composition, and distribution of microplastics in the Rijpfjorden, Northern Svalbard, in the summer of 2017. Laser Direct Infrared chemical imaging technique was applied for the counting and identification of microplastic particles. A total of 1010 microplastic particles and 14 mesoplastics were identified from 41,038 particles in eight samples from the Rijpfjorden. The abundance of microplastics larger than 300 µm was 0.15 ± 0.19 n/m3 in surface water, and 0.15 ± 0.03 n/m3 in the water column of the Rijpfjorden. The microplastic particles identified in Rijpfjorden water consisted of 10 types of polymers. The dominant microplastics are polyurethane, polyethylene, polyvinyl acetate, polystyrene, polypropylene, and alkyd varnish. Historical ship activities and newly melted sea ice might be major sources of microplastics in the seawater of Rijpfjorden. In general, contamination of microplastics larger than 300 µm in Rijpfjorden water is at a low level in comparison to other polar waters. Further research is needed to confirm the origin and fate of microplastics below 300 µm in Arctic fjords.

Microplastics (MPs) pollution in Tangxun Lake, the largest urban lake in China, was investigated. The average MPs pollution in sediment (1.81 ± 1.75 × 10⁴ items kg⁻¹) is at a high level, while the MPs in lakeshore water (917.77 ± 742.17 items m⁻³) is in the middle to low level compared with existing studies, which is related to the government's protection. Fragments and fibers are the most common shapes in sediment and water, respectively. MPs size <1 mm dominates in the sediment, while the MPs in water has a larger size. The distribution of MPs in the inner lake shows that pellets tend to “hidden” in sediments. Suspected MPs are randomly selected for polymer detection by Micro-Raman microscopy. Polypropylene (PP), polyethylene (PE) and polyethylene terephthalate (PET) are the most common polymer types in water, sediment and atmospheric deposition MPs samples. The input of wastewater, fishery and surrounding human activities are the main sources of MPs in sediment. Atmospheric deposition has a great impact on the distribution of MPs, while the contribution of surface runoff to lake MPs is not remarkable. In addition, MPs in sediments have exceeded the environmental carrying capacity. More attention should be focused on the sediment, where huge amounts of MPs are “hidden”.

Dissolved organic matter (DOM) plays a significant role in the photochemical behavior of nano- and micro-plastic particles (NPs/MPs). We investigated the influence of DOM on the mechanism on the photoaging of NPs/MPs with different molecular structures under UV₃₆₅ irradiation in water. DOM components used in this study are mainly humic acid and fulvic acid. The results showed that DOM promoted the weathering of aliphatic NPs/MPs (polypropylene (PP)), but inhibited or had only a minor effect on the photoaging of aromatic NPs/MPs (polystyrene (PS) NPs/MPs, carboxyl-modified PS NPs, amino-modified PS NPs, and polycarbonate MPs). NPs with a large surface area may adsorb sufficient DOM on the particle surfaces through π-π interactions, which competes with NPs for photon absorption sites, thus, can delay the photoaging of PS NPs. Aromatic MPs may release phenolic compounds that quench •OH, thereby weakening the photoaging process. For aliphatic MPs, the detection of peracid, aldehyde, and ketone groups on the polymer surface indicated that DOM promoted weathering of PP MPs, which was primarily because the generation of •OH due to DOM photolysis may attack the polymer by C–C bond cleavage and hydrogen extraction reactions. This study provides insight into the UV irradiation weathering process of NPs/MPs of various compositions and structures, which are globally distributed in water.

Microplastic pollution has attracted significant attention as an emerging global environmental problem. One of the most important issues with microplastics is the leaching of harmful additives. This review summarizes the recent advances in the understanding of the leaching phenomena in the context of the phase equilibrium between microplastics and water, and the release kinetics. Organic additives, which are widely used in plastic products, have been introduced because they have diverse physicochemical properties and mass fractions in plastics. Many theoretical and empirical models have been utilized in laboratory and field studies. However, the partition or distribution constant between microplastics and water (Kₚ) and the diffusivity of an additive in microplastics (D) are the two key properties explaining the leaching equilibrium and kinetics of hydrophobic organic additives. Because microplastics in aquatic environments undergo dynamic weathering, leaching of organic additives with high Kₚ and/or low D cannot be described by a leaching model that only considers microplastic and water phases with a fixed boundary. Surface modifications of microplastics as well as biofilms colonizing microplastic surfaces can alter the leaching equilibrium and kinetics and transform additives. Further studies on the release of hydrophobic organic additives and their transformation products under various conditions are required to extend our understanding of the environmental fate and transport of these additives in aquatic environments.