Disposable surgical/medical face masks and filtering face pieces: Source of microplastics and chemical additives in the environment

The production and consumption of disposable face masks (DFMs) increased intensely during the COVID-19 pandemic, leading to a high amount of them being found in the terrestrial and aquatic environment. The main goal of this research study is to conduct a comparative evaluation of the water-leachability of microplastics (MPs) and chemical additives from various types of disposable surgical/medical face masks (MM DFMs) and filtering face pieces (FFPs). Fourier-Transform Infrared Spectroscopy was used for MPs analysis. Liquid Chromatography/High Resolution Mass Spectrometry was used to analyse analytes presented in the water-leachates of DFMs. FFPs released 3-4 times more microplastic particles compared to MM DFMs. The release of MPs into water from all tested DFMs without mechanical stress suggests potential MP contamination originating from the DFM production process. Our study for the first time identified bisphenol B (0.25-0.42 μg/L) and 1,4-bis(2-ethylhexyl) sulfosuccinate (163.9-115.0 μg/L) as leachables from MM DFMs. MPs in the water-leachates vary in size, with predominant particles <100 μm, and the release order from DFMs is MMIIR > MMII > FFP3>FFP2>MMI. The main type of microplastics identified in the water leachates of the investigated face masks was polypropylene, accounting for 93-97% for MM DFMs and 82-83% for FFPs. Other polymers such as polyethylene, polycarbonate, polyester/polyethylene terephthalate, polyamide/Nylon, polyvinylchloride, and ethylene-propylene copolymer were also identified, but in smaller amounts. FFPs released a wider variety and a higher percentage (17-18%) of other polymers compared to MM DFMs (3-7%). Fragments and fibres were identified in all water-leachate samples, and fragments, particularly debris of polypropylene fibres, were the most common MP morphotype. The findings in this study are important in contributing additional data to develop science-based policy recommendations on the health and environmental impacts of MPs and associated chemical additives originated from DFMs.

A versatile hot melt centrifugal spinning apparatus for thermoplastic microfibres production

The centrifugal spinning (CS) method could address common issues such as low production rate and high energy consumption in the industry of nonwoven textile fabrication. Similarly to cotton candy production, the high-speed rotating reservoir extrudes melt or solvent-based polymer from orifices to produce fibres. Using polymer melt avoids solvent elimination and toxicity, but the process is more difficult. Thus, a versatile lab-scale hot melt spinneret with the ability to pour pellets inside continuously to expand our knowledge of the CS method and investigating different extrusion geometries such as nozzlefree is developed. Among the controllable parameters are, the spinneret heating temperature (up to 300°C), its two interchangeable 3D printer nozzles. An Arduino code is used to stabilize the temperature. The system performance is investigated with polypropylene and polylactide. The results show that fibres under 15 μm in diameter are produced. This work is licensed under CC BY-NC 4.0. To view a copy of this license, visithttp://creativecommons.org/licenses/by-nc/4.0/.

Detection and characterisation of microplastics and microfibres in fishmeal and soybean meal

Aquaculture is an increasingly important source of nutrition for global food security, which is reliant on animal- and plant-based feeds. Anthropogenic particles, including microplastics and semi-synthetic cellulosic fibres, are prolific marine pollutants that are readily consumed by marine organisms, including small pelagic fish commonly used in fishmeal. Conversely, there is no indication plants can accumulate anthropogenic microparticles. We explore whether aquaculture feed presents a route of contamination for farmed fish. Commercially-sourced aquaculture feedstocks, including fishmeals and soybean meal, were processed (KOH digestion and ZnCl₂ density separation) and anthropogenic particles characterised using microscopy and spectroscopic methods. Both fishmeal and soybean meals contained anthropogenic particles, with concentrations ranging 1070-2000 particles kg^-1. The prevalence of anthropogenic particles in plant-based feeds indicates that the majority of contamination occurs post-harvest. Based on our findings, farmed Atlantic salmon may be exposed to a minimum of 1788-3013 anthropogenic particles from aquaculture feed across their commercial lifespan.

Effect of land use on microplastic pollution in a major boundary waterway: The Arvand River

The occurrence of microplastics (MPs) was investigated in the Arvand River (Iran). The Arvand River (200 Km) is a major water body that flows through land with diverse use and it meets the Persian Gulf. This study constitutes the first assessment of MP pollution (prevalence and physico-chemical characteristics) in the Arvand river, both in the sediment and in the water. MP monitoring has been carried out in 24 stations located along the river. The MP pollution found ranged between 1 and 291 items·L^-1 and 70 to 15,620 items·kg^-1 (dw), in water and sediment, respectively. The majority of MPs were fibres, black/grey and yellow/orange in colour, and mainly 250-500 μm and >1000 μm in size. Polyethylene terephthalate (PET), polypropylene (PP), nylon (NYL), high-density polyethylene (HDPE), and polystyrene (PS) were found in sediment samples. All these polymers, except HDPE, were also identified in the water samples. PET and PP were dominant in the water samples; whereas PET and PS were the most abundant in the sediments. The vicinity of urban wastewater effluents could be behind MP pollution in both water and sediments. Significant differences (p < 0.05) of MP concentrations were affected by different land uses when comparing MP levels in undisturbed natural area with urban areas. A strong correlation between MP fibres and fragments found with PCA biplots revealed their similar distribution in water. In the sediment samples, fibre and fragment MP particles were significantly correlated with colloidal particles (e.g., clay and organic matter) suggesting a relevant role of colloidal particles in the aquatic ecosystem of the Arvand River in transporting MPs. This study contributes to the better understanding of the presence of MP in major rivers, which are systems that have been scarcely investigated for this type of pollution, and it can inform interventions to reduce MP inputs to the river and sea.

Microplastic occurrence in urban and industrial soils of Ahvaz metropolis: A city with a sustained record of air pollution

This study investigates, for the first time, the concentration, distribution, fate and chemical composition of microplastics (MPs) in urban and industrial soils of Ahvaz metropolis, SW Iran. MP concentrations ranged from 100 to 3135 and 80 to1220 unit·kg^-1 in urban and industrial soils, respectively, with corresponding means of 619 and 390 unit·kg^-1. The most contaminated urban sites were located in the city center. Precisely these areas were affected by insufficient sanitation infrastructure including sewer systems, surface runoff collection and sewage treatment, and also high traffic loading in a commercial zone. MPs were found in various shapes, colours and sizes. In particular, microfibres (white-transparent and < 250 μm) were the most abundant MPs found in urban (70%) and industrial (55%) soils. Based on the weathering observed in the MPs, a large number of them originated from the fragmentation of other plastics and could have been photobleached. Polyethylene terephthalate and nylon were the dominant polymers in the MPs found in both industrial and urban soils and they could originate from textiles and tyres.

Occurrence of microfibres in wild specimens of adult sea urchin Paracentrotus lividus (Lamarck, 1816) from a coastal area of the central Mediterranean Sea

This study investigates the occurrence of anthropogenic fibres inside wild Paracentrotus lividus at a Mediterranean coastal area in 2020. From each sea urchin, the coelomic fluid was directly analysed while digestive tracts and gonads were removed, pre-treated with trypsin (0.3%) and digested with H₂O₂ (10%) before analysis. A total of 260 fibres and 1 fragment were found in 100 specimens, with an average of 2.6 items/individual. Fibres were more abundant in the digestive system, less in gonads and in the coelomic fluid, respectively. Fourier transform infrared (FTIR) analysis of representative fibres identified 67% natural (cotton-based) and 33% synthetic polymers (polyester) suggesting their origin from textiles, possibly released from laundry sewages. Overall, these results encourage further in-depth investigations on fibres accumulation and potential transfer through the trophic chain up to humans.

Microplastic occurrence in settled indoor dust in schools

This study examines for the first time the characteristics and human exposure of microplastics (MPs) in settled indoor dust in schools. An average of 195 MPs·g^-1 of dust were detected in settled indoor composite dust samples from 28 schools in Shiraz. White-transparent microfibres with lengths 500-1000 μm were the most abundant type of MP found among the samples examined. Polyethylene terephthalate and polypropylene MPs were dominant across all types of MP found including microfibres. MPs had generally smooth morphology with sharp or regular edges which could have been released to the environment as primary MPs. Among all sampling sites, higher concentrations of MPs were found in the south and centre of the city. These were areas affected by high population density, high traffic load and high presence of industrial units and workshops. Principal Component Analysis (PCA) showed a positive strong correlation between sampling sites and MP physical characteristics. The PCA plots revealed that MP sheets and fragments were prevalent in sites in the North of Shiraz, whereas microfibres were mainly associated with sites in the South. The levels of MPs in the South of Shiraz were greater than in the rest of the country and the wind direction and topography were found to be important factors affecting the MP distribution observed. Compared to other population groups, elementary school students had relatively high exposure risk to MPs. This study reveals that microfibres are widespread in Shiraz' schools and pose a high exposure risk to MPs for young students.

Occurrence, abundance, and distribution of microplastics pollution: an evidence in surface tropical water of Klang River estuary, Malaysia

Microplastics have been considered as contaminants of emerging concern due to ubiquity in the environment; however, the occurrence of microplastics in river estuaries is scarcely investigated. The Klang River estuary is an important ecosystem that receives various contaminants from urbanised, highly populated areas and the busiest maritime centre in Selangor, Malaysia. This study investigates the abundance and characteristics of microplastics in surface water of the Klang River estuary. The abundance of microplastics ranged from 0.5 to 4.5 particles L^-1 with a mean abundance of 2.47 particles L^-1. There is no correlation between the abundance of microplastics and physicochemical properties, while there is a strong correlation between salinity and conductivity. The microplastics were characterised with a stereomicroscope and attenuated total reflection-Fourier transform infrared spectroscopy to analyse size, shape, colour, and polymer composition. The microplastics in the surface water were predominantly in the 300-1000 μm size class, followed by > 1000 μm and < 300 μm, and were mostly transparent fibres, fragments, and pellets. Polyamide and polyethylene were the main polymer types in the composition of the microplastics, suggesting that the microplastics originated from heavily urbanised and industrial locations such as the port, jetty, and residential areas. The widespread occurrence of microplastics in the environment and subsequent penetration of aquatic food webs may pose a serious threat to organisms. This study provides baseline data and a framework for further investigation of microplastic contamination in estuaries.

Synthesis of dominant plastic microfibre prevalence and pollution control feasibility in Chinese freshwater environments

Microplastic pollution of freshwaters is known to be a great concern in China and these pollutants can be discharged into the coastal environment through fluvial processes, posing threats to the global marine ecosystem. This paper reviewed the literature measuring microplastic pollution in the Chinese freshwater environment and found that microfibres dominate other plastic morphologies in more than 65% of samples collected in surface water, sediments and effluents of wastewater treatment plants and domestic sewers. Current potential sources of microfibre pollution are identified including fishery activities, laundry sewage, and waste textiles according to previous research. Recommendations are offered using the circular economy management framework, such as textile waste reuse and recycling systems in China, for improving current control measures for microplastics in freshwaters.

Microplastics in municipal wastewater treatment plants in Turkey: a comparison of the influent and secondary effluent concentrations

Wastewater treatment plants are one of the primary pathways through which microplastics enter aquatic environments. In this study, we have determined the microplastic concentrations of the influent and secondary effluent water of two wastewater treatment plants in Turkey. For this purpose, we have taken samples of the influent and effluent water of Seyhan and Yüreğir wastewater treatment facilities for 6 days in August 2017 and determined their microplastics' content both visually and using μ-Raman spectroscopy. The results showed that the influent of the wastewater treatment contained 1 million-6.5 million particles per day, while the effluent contained 220,000-1.5 million particles per day. The removal rate of microplastics was found to be between 73 and 79%. In total, seven different types of polymers were detected. The most frequently observed polymer type was polyester.

Quantification of microfibre levels in South Africa's beach sediments, and evaluation of spatial and temporal variability from 2016 to 2017

The microfibre content of beach sediment samples was established at 175 sampling sites along over 2700 km of South Africa's coastline in 2016 and again in 2017. The average microfibre content was 80 ± 102 F/dm³ in Feb/March 2017 (n = 161), and 87 ± 84 F/dm³ in May/June 2016 (n = 128). These average values, and the observed ranges of 0 to 797 F/dm³ in 2017 and 4 to 772 F/dm³ in 2016, are consistent with global observations. The highest microfibre levels were observed at sampling sites close to large coastal waste water treatment work discharge points. Several instances of temporal variability are observed, only some of which can be associated with seasonal changes in river runoff. This baseline data set is a valuable reference point for identification of priority study sites for more detailed study of marine ecosystem response to microfibre pollution.

Degradation of common polymer ropes in a sublittoral marine environment

Contamination by microplastic particles and fibres has been observed in sediment and animals sampled from the Firth of Clyde, West Scotland. In addition to microplastics released during clothes washing, a probable source is polymer ropes in abandoned, lost and discarded fishing and recreational sailing gear. The fragmentation of polypropylene, polyethylene, and nylon exposed to benthic conditions at 10m depth over 12months was monitored using changes in weight and tensile properties. Water temperature and light levels were continuously monitored. The degree of biofouling was measured using chlorophyll a, the weight of attached macroalgae, and colonising fauna. Results indicate microplastic fibres and particles may be formed in benthic environments despite reduced photodegradation. Polypropylene, Nylon, and polyethylene lost an average of 0.39%, 1.02%, and 0.45% of their mass per month respectively. Microscope images of the rope surface revealed notable surface roughening believed to be caused by abrasion by substrate and the action of fouling organisms.

No microplastics in benthic eelpout (Zoarces viviparus): An urgent need for spectroscopic analyses in microplastic detection

Monitoring the ingestion of microplastics is challenging and suitable detection techniques are insufficiently used. Thus, misidentifying natural for synthetic microfibres cannot be avoided. As part of a framework to monitor the ingestion of microplastics in eelpout, this short report addresses the accurate identification of microfibres. We show that, following visual inspections, putatively synthetic microfibres are indeed of natural origin, as ascertained by spectrometric analyses. Consequently, we call for an inclusion of spectroscopic techniques in standardized microplastic monitoring schemes.

Using a forensic science approach to minimize environmental contamination and to identify microfibres in marine sediments

There is growing evidence of extensive pollution of the environment by microplastic, with microfibres representing a large proportion of the microplastics seen in marine sediments. Since microfibres are ubiquitous in the environment, present in the laboratory air and water, evaluating microplastic pollution is difficult. Incidental contamination is highly likely unless strict control measures are employed. Here we describe methods developed to minimize the amount of incidental post-sampling contamination when quantifying marine microfibre pollution. We show that our protocol, adapted from the field of forensic fibre examination, reduces fibre abundance by 90% and enables the quick screening of fibre populations. These methods therefore allow an accurate estimate of microplastics polluting marine sediments. In a case study from a series of samples collected on a research vessel, we use these methods to highlight the prevalence of microfibres as marine microplastics.