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.

Synthetic fibers with diameters of several tens of micrometers are the most abundant type of microplastics in the marine environment, yet the most unknown regarding dynamics in the water column. Experiments proposed here are a proof-of-concept of qualitative and quantitative characteristics of fibers’ motion in still water and in the presence of thermal convection. For 12 sets of fine fibers (nylon (1.12 g/cm³) and polyester (1.35 g/cm³), 1.9–14.8 mm long, diameters 13 and 20 μm), 84 measurements of sinking velocity in still water were acquired. In still conditions, fibers settled smoothly and slowly, preserving their initial (accidental) orientation. Sinking rates of fibers with lengths <5 mm varied between 0.5 and 3.7 mm/s (the bulk mean of 1.6 mm/s). Fibers with similar properties showed 4-fold different sinking velocity, which is supposed to be the effect of their different orientation while settling: vertically oriented fibers (19% in the experiments) settled faster than those with inclined orientation (48%), and horizontally oriented fibers (33%) settled with the smallest velocities.Convective mixing of water, heated from below, principally changed the manner of sinking of fibers: their motions became unsteady and 3-dimensional. In 78 measurements for 4-mm long nylon fibers (using the “light knife” technique), only about 56% of fibers showed downward velocity component (mean 1.33 ± 0.78 mm/s), which was twice as small as in still water, however the ratio of max/min values increased up to 14. Fibers could move in different directions and follow circular motions of a convective cell. Our findings suggest two possible mechanisms retaining fibers in the water column: entrainment of some particles in horizontal and vertical motions and slowed sinking due to unsteady flow around the fiber. The retention of fibers leads to decrease in integral downward particle flux (up to 4 times in our experiments).

Microplastics have recently been detected in atmospheric fallout in Greater Paris. Due to their small size, they can be inhaled and may induce lesions in the respiratory system dependent on individual susceptibility and particle properties. Even though airborne microplastics are a new topic, several observational studies have reported the inhalation of plastic fibers and particles, especially in exposed workers, often coursing with dyspnea caused by airway and interstitial inflammatory responses. Even though environmental concentrations are low, susceptible individuals may be at risk of developing similar lesions. To better understand airborne microplastics risk to human health, this work summarizes current knowledge with the intention of developing awareness and future research in this area.

Evidence of microplastic (MP) pollution in Antarctic terrestrial environments reinforces concerns about its potential impacts on soil, which plays a major role in ecological processes at ice-free areas. We investigated the effects of two common MP types on soil physicochemical properties and microbial responses of a marine terrace from Fildes Peninsula (King George Island, Antarctica). Soils were treated with polyethylene (PE) fragments and polyacrylonitrile (PAN) fibers at environmentally relevant doses (from 0.001% to 1% w w−1), in addition to a control treatment (0% w w−1), for 22 days in a pot incubation experiment under natural field conditions. The short-term impacts of MPs on soil physical, chemical and microbial attributes seem interrelated and were affected by both MP dose and type. The highest PAN fiber dose (0.1%) increased macro and total porosity, but decreased soil bulk density compared to control, whereas PE fragments treatments did not affect soil porosity. Soil respiration increased with increasing doses of PAN fibers reflecting impacts on physical properties. Both types of MPs increased microbial activity (fluorescein diacetate hydrolysis), decreased the cation exchange capacity but, especially PE fragments, increased Na+ saturation. The highest dose of PAN fibers and PE fragments increased total nitrogen and total organic carbon, respectively, and both decreased the soil pH. We discussed potential causes for our findings in this initial assessment and addressed the need for further research considering the complexity of environmental factors to better understand the cumulative impacts of MP pollution in Antarctic soil environments.

Pollution by plastics is a global problem, in particular through the contamination of aquatic environments and biodiversity. Although plastic contamination is well documented in the aquatic fauna of the oceans and large rivers of the world, there are few data on the organisms of headwater streams, especially in tropical regions. In the present study, we evaluated the contamination of small fish by plastics in Amazonian streams. For this, we evaluated the shape and size, and the abundance of plastics in the gastrointestinal tracts and gills of 14 fish species from 12 streams in eastern Brazilian Amazon. We used a Generalized Linear Mixed Model (GLMM) to compare the levels of contamination among species and between organs. Only one individual of the 68 evaluated (a small catfish Mastiglanis cf. asopos) contained no plastic particles, and no difference was found in the contamination of the gills and digestive tract. However, Hemigrammus unilineatus presented less contamination of both the gills and the digestive tract than the other species, while Polycentrus schomburgkii had less plastic in the gastrointestinal tract, whereas Crenicichla regani and Pimelodella gerii both had a larger quantity of plastic adhered to their gills in comparison with the other species. Nanoplastics and microplastics adhered most to the gills, while plastic fibers were the most common type of material overall. This is the first study to analyze plastic contamination in fish from Amazonian streams, and in addition to revealing high levels of contamination, some species were shown to possibly be more susceptible than others. This reinforces the need for further, more systematic research into the biological and behavioral factors that may contribute to the greater vulnerability of some fish species to contamination by plastics.Amazonian stream fish show contamination by plastics. The species respond differently. The smaller the particle, the easier it is to adhere to the gills.

Seawater, sediments, and three genera of wild scleractinian corals were collected from four coral reef areas nearshore Liuqiu Island, southwestern Taiwan. Abundance, characteristics (sizes, colors, shapes, and polymer types), and enrichment of microplastics (MPs) in the corals, and their impacts on coral cover were determined. The average MPs abundances were 0.95, 0.77, and 0.36 item/g for Galaxea sp, Acropora spp, and Pocillopora sp, respectively. The MPs abundance was relatively higher on the coral surfaces than inside the skeletons, dominated by blue rayon-fibers, correspondingly observed in seawater and sediments. Large-size colorless MPs tended to be mis-ingested by Galaxea sp. (71%) compared with Pocillopora sp. (43%) and Acropora spp. (31%). The low hard coral cover (12.5%) observed at Yufu (L1) on the northeastern coastal zone nearby tourism center of Liuqiu Island where correspondingly associated with high MPs abundance in seawater (10 item/L), sediments (260 item/kg), and corals (0.60 item/g). Tourism induced sewage discharges and sailing activities significantly contributed to the MPs pollution, probably contributing to the loss of coral cover. High MPs enrichment in corals (EFMP = 25–283) shows that the marine MPs pollution can critically threaten coral reef ecosystems. Fibrous MPs present inside the coral skeleton serve as potential indicator of MPs’ impact on corals—with the dominance of textile-related rayon and polyester/PET microfibers in the coral reef zones. This study provided valuable information for coral conservation and coastal management.

Microplastics have become an inevitable component of our environment. Worldwide, free public fountains are common and one of the best sources of drinking water which are being installed with one of the viewpoints of reducing single-use plastics bottle consumption. However, the state of knowledge on how microplastics might be affecting in those free public drinking fountains is unknown. In this study, free drinking water fountains from 42 metro stations in Mexico City were being looked into for the occurrence of microplastics and investigated their shape type, size, abundance, distribution, polymer composition and surface morphology. Microplastics were detected in all the samples analyzed. The results revealed the significant abundance of microplastics ranging from 5 ± 2 to 91 ± 14 L⁻¹ in drinking water with an overall average of 18 ± 7 microplastics L⁻¹. Transparent fibers (69%) were predominant in the identified microplastics followed by blue (24%) and red colored (7%) fibers. The most frequent microplastics dimensions ranged between 0.1 and 1 mm which is approximately 75% of the total microplastics. Micro-Raman spectroscopy analysis indicated that microplastics contained in drinking water were mainly polyesters (poly (trimethylene terephthalate)) and epoxy resin suggesting the possible contribution of wastewater discharges for microplastics contamination. Thus, this study findings show that free public drinking water fountains are potential microplastics hotspot for human consumption and provide useful references for mitigation measures.

We provide a baseline assessment of the density and types of microplastics in the western equatorial Atlantic. The highest microplastics density was found in coastal stations near urbanized sites, large tropical estuaries, and fishing grounds. With regard to microplastics composition, most of the identified particles were fibers/filaments, styrofoam, hard and soft plastic, paint, and glass/acrylic. Fibers/filaments were the most abundant (~80%) and occurred at all stations, in both types of mesh nets. Hard plastic particles were frequent (78%) only in the 120 μm mesh net. The mean density recorded in the 120 μm mesh net was about seven times greater than that in the 300 μm mesh net, suggesting that the larger mesh size net did not lead to an accurate description of microplastics density in the pelagic environment or the degree of risk to which organisms are exposed.