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Components of a surgical-type single-use face mask. (a) Elastic ear loop; (b) heat-wielded seam; (c) outer layer of spunbond polypropylene fabric; (d) central core of melt-blown polypropylene fabric; (e) inner layer of spunbond polypropylene fabric.
Source publication
Following the outbreak of the COVID-19 pandemic in March 2020, many governments recommended or mandated the wearing of fitted face masks to limit the transmission of the SARS-CoV-2 virus via aerosols. Concomitant with the extensive use of non-sterile, surgical-type single-use face masks (SUM) was an increase of such masks, either lost or discarded,...
Contexts in source publication
Context 1
... the majority of masks was found on the streets and car parks, lost or intentionally discarded when exiting vehicles ( Figure S17) [44], numerous masks ended up in creek lines or were washed into gutters and stormwater drains ( Figure S5). ...
Context 2
... the experiment a disposable surgical face mask was fitted to the face of the investigator, with the nose wire adjusted to ensure a tight fit. That mask was then placed on the lawn and run over with the lawn mower travelling in a straight line ( Figure S18). All lawn clippings caught in the leaf catcher were bagged, while all macroscopically visible pieces of the mask that were left on the lawn were photographed and collected. ...
Context 3
... attempt was made to screen the clippings under high magnification to extract microfibers. The pieces were then classified, sorted by size (Figures 4 and 5, Figures S19-S24)) and tabulated (Table 1). ...
Context 4
... consequence, the tensile strength of melt-blown fabric is higher, with mechanical impacts causing rapid disintegration into microfibers The differences between the three experiments are considerable. The fewest pieces were generated with a short lawn and a low mower setting (Table 1 (A)). In that experiment the mask was captured by the blade and thrown straight (and audibly) into the catcher which effectively reduced its exposure to the mower blade spinning at 3700 rpm. ...
Context 5
... largest number of fragments was generated at the intermediate setting (Table 1 (B)) where the mask was exposed for a prolonged period, shredding it, while the intermediate mower setting generated a vortex that dragged most pieces into the catcher. The highest setting generated a large number of pieces on both in the catcher and on the lawn (Table 1 (C)). Here the spinning blade shredded the mask, but the high setting had the effect of a reduced vortex, ensuring that mask fragments would be caught and retained in-between the leaves of the lawn. ...
Context 6
... a municipal sorting situation, in all reality, these items will escape detection and will continue through the processing stream. Further, larger pieces and possibly even entire masks, may escape detection, especially when saturated and dirtied ( Figure S17). ...
Context 7
... following are available online at www.mdpi.com/article/10.3390/su14010207/s1. Figure S1. A non-sterile single-use surgical type mask on a head form. ...
Context 8
... of a shredded disposable mask on a sporting field mowed by a club contractor (David Street, Albury, NSW). Figure S10. Example of a shredded disposable mask on a sporting field mowed by a club contractor (Macauley Street, Albury, NSW Street, Albury, NSW). Figure S11. ...
Context 9
... of a shredded disposable mask on a sporting field mowed by a club contractor (Macauley Street, Albury, NSW Street, Albury, NSW). Figure S11. Example of a shredded disposable mask on a footpath mowed by a local contractor (Poole Street, Albury, NSW. Figure S12. ...
Context 10
... of a shredded disposable mask on a footpath mowed by a local contractor (Poole Street, Albury, NSW. Figure S12. Example of a shredded disposable mask on a residential nature strip mowed by a resident (Alma Street, Albury, NSW). Figure S13. ...
Context 11
... of a shredded disposable mask on a residential nature strip mowed by a resident (Alma Street, Albury, NSW). Figure S13. Example of a shredded disposable mask on a residential nature strip mowed by a resident (Alma Street, Albury, NSW). Figure S14. ...
Context 12
... of a shredded disposable mask on a residential nature strip mowed by a resident (Alma Street, Albury, NSW). Figure S14. Examples of shredded disposable masks. ...
Context 13
... of shredded disposable masks. Figure S15. Example of a shredded disposable mask on a residential nature strip mowed by a council contractor (Pemberton Street, Albury, NSW). ...
Context 14
... core area of distribution measures 4 × 13 m, with one piece located 20 apart. Figure S16. Example of a shredded disposable mask on a residential nature strip mowed by a resident (Alma Street, Albury, NSW). Figure S17. ...
Context 15
... of a shredded disposable mask on a residential nature strip mowed by a resident (Alma Street, Albury, NSW). Figure S17. Examples of a saturated and dirtied disposable masks in urban settings (Alma Street, Albury, NSW). Figure S18. ...
Context 16
... of a saturated and dirtied disposable masks in urban settings (Alma Street, Albury, NSW). Figure S18. Experiment C being conducted. ...
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The world is suffering from aggravating, waste-generated consequences, and the contribution of microplastics to this problem is only increasing. A contributing factor to increased microplastic usage is the change in the use of personal protective equipment (PPE) from specific use in limited locations (e.g., hospitals) to general use in widespread l...
Citations
... Menurut LIPI, 2021 menyatakan sampah APD menyumbang 15-16 persen atau 0,13 ton per harinya yang diolah secara tidak tepat diantaranya dilepaskan ke lingkungan sehingga menimbulkan bahaya ekologi (Ardusso, 2021) sebagai sumber mikroplastik (MP) (Ma, 2021).Masker sekali pakai terbuat dari polimer (Polipropilena/PP, Polikarbonat, Potietilen, dan Polister) (Potluri dan Needham, 2005). Masker sekali pakai terbuat dari tiga lapisan kain yaitu lapisan luar anti air yang memberikan kekuatan dan perlindungan mekanis, lapisan tengah dengan porositas tinggi agar dapat bernafas, dan lapisan dalam (Spennemann, 2022). ...
Masker sekali pakai merupakan Alat pelindung diri yang banyak digunakan selama pandemi COVID-19 hingga saat ini, limbah ini akan merusak ekosistem lingkungan jika tidak tepat dalam pengelolaannya. Limbah masker sekali pakai berasal dari bahan polipropilen (PP) yang merupakan salah satu jenis limbah plastic sehingga memerlukan porses dalam pengelolaan sampahnya sehingga tidak menimbulkan pencemaran. Pengabdian Masyarakat yang berbentuk sosialisasi ini dilaksanakan pada masa pandemic Covid-19. Untuk membantu program pemerintah dalam penanggulangan sampah khususnya sampah medis yakni masker sekali pakai pada skala rumah tangga yaitu pemanfaatan limbah masker untuk budi daya tanaman dengan system vertikultur. Sosialisasi ini meningkatkan pengetahuan dan keterampilan warga dalam budi daya vertikultur dengan memanfaatkan limbah masker sekali pakai untuk membantu ketahanan pangan dan ekonomi di masa pandemic dengan ramah lingkungan. Hasil yang diperoleh Penggunaan limbah masker sebagai media tanam dapat memberikan manfaat ganda dengan mengurangi limbah dan memanfaatkannya untuk budidaya tanaman di rumah, pemanfaatan limbah masker untuk budidaya tanaman di rumah dapat menjadi cara kreatif untuk memanfaatkan masker yang tidak terpakai dan berkontribusi pada praktik berkebun yang ramah lingkungan dan pemanfaatan Budi daya vertikultur bisa menjadi alternatif usaha untuk memenuhi kebutuhan pangan pada masa pandemic covid-19.
... Recently, microplastics (MPs) have been increasingly encountered in various aquatic and terrestrial environments at a global scale. The presence of MPs was reported in a wide variety of environments, including the ocean [2], surface and groundwater [3][4][5], soil [6,7], and indoor and outdoor air [8][9][10]. There is increasing evidence of MP presence in aquatic organisms [11][12][13], as well as the potential harmful effects of MPs on aquatic organisms [12,14]. ...
Since the COVID-19 pandemic, a huge number of face masks have been used to prevent the spread of the coronavirus on a global scale. Unfortunately, several studies have reported the presence of used face masks in marine litter in different countries around the world. Face masks produced from synthetic polymers can increase the environmental burden and contradict sustainability. This study aimed to investigate the environmental behavior of face masks when exposed to natural environmental conditions following improper disposal. New and naturally aged surgical and FFP2 masks were exposed to deionized water (DI) and sea water conditions to understand the environmental behavior of face masks when exposed to different environmental conditions. Following natural aging and DI and sea water exposure, face masks were characterized with Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM), and compared with new masks. According to the results, the middle layers of both mask types were exposed to more severe degradation. Aging resulted in higher microplastic (MP) release than new masks in DI and seawater for both types of face masks. Compared to new ones, aging and seawater exposure caused 11 to 13 and 14 to 22 times higher MP release from surgical and FFP2 face masks, respectively. Following seawater exposure, aged FFP2 mask released higher amounts of MP (4.36–6.20 × 106) than aged surgical masks (4.03–5.45 × 106). According to the results, a significant portion of the released MPs were <10 µm for both types of masks. However, when aged FFP2 masks were exposed to seawater, a remarkable increase was found in the fraction of 10–50 µm and 50–100 µm, suggesting that aged FFP2 masks also became fragmented in seawater conditions. FTIR and SEM analyses confirmed the transformation in the structure and chemical composition of the materials. A significant change was observed in chemical and physical structure of the masks after being exposed to weathering conditions in a relatively short period of time (one month).
... Several studies have been undertaken to this effect. A study by Spennemann [10] conducted field observations in Albury, New South Wales. It could be seen that most of the mask debris collected was below 10 mm 2 in size and had been shredded by leaf blowers or lawnmowers. ...
... This leads to the separation of individual fibers and fragmentation. Eventually, brittle fracturing produces micro-and nano-plastic fibers [10]. It could take 450 years for these microfibres made of medicalgrade PP to break down in nature [31]. ...
The unprecedented COVID-19 pandemic has caused socioeconomic, physical, mental, and environmental upheaval. Personal protective equipment, such as face masks, was mandatory to curb the spread of the virus. The unexpected increase in demand for face masks resulted in an alarming increase in plastic waste globally. The non-biodegradable nature of the raw materials and the potential threat of microplastic pollution amplify the problem. This puts a lot of pressure on policymakers and the global supply chain to develop long-term plans to make face masks less harmful. By reviewing existing life cycle assessment studies, this study aims to provide an overview on how sustainable face masks are. Various challenges in the facemask industry such as microplastic pollution and waste management are discussed. A critical analysis on the various process hotspots is also conducted. Recommendations from this study can motivate focused research into an important field and enable the transitions towards a sustainable facemask industry.
... Surgical or medical masks consist of three layers, which can provide protection and increase air permeability. 3,4 The outer layer is a waterproof nonwoven fabric used to isolate the patient's liquid spray. The¯lter layer in the middle is made from melt-blown material used to stop the microbes from entering and exiting the mask. ...
... Other materials, such as polystyrene, polycarbonate, polyethylene, or polyester, are also used to make masks; all components are not easily degraded and must be put into a garbage can to avoid polluting the environment. 3,4 Wearing a medical mask while going out has been mandatory in Taiwan after the outbreak of COVID-19. While walking on the streets, dropped masks may be seen, although the Taiwanese government insists it is illegal. ...
Goats may suffer from rumen bloat for many reasons, e.g. improperly concentrated ratio or obstruction. The disease can be caused by eating undigested items, e.g. plastic rope or bags. Since the COVID-19 pandemic, it has often become mandatory for people to wear medical masks. People are generally unaware that masks left on the ground pose a risk to goats who may eat them. This case report describes the rumen bloat caused by medical masks in a male goat reared in an elementary school. After physical examination, the goat showed a bloated rumen, anorexia, depression, and weakness. The heart rate was normal, but respiratory patterns were fast and deep. Fewer defecated feces were noted by the owner. Furthermore, the owner’s complaints and ultrasound images revealed that undigested items in the rumen were the cause. After performing a standard rumenotomy, we scooped out four medical masks, one plastic bag, and one high-density nylon rope from the rumen. We believe this was the first report describing the risk of medical masks in goats. Promoting life and animal welfare education is essential to inform others of the harm medical masks pose to animals.
... [8][9][10] The high demand for face masks during the COVID-19 pandemic led to a rapidly expanded production and use of non-sterile, surgical-type single-use face masks, the majority of which was sourced from Chinese manufacturers [11]. Since these were far more common than washable masks from cotton and other fabrics, [12][13][14] single-use face masks soon posed environmental issues [15,16]. The quantity of single-use face masks manufactured is staggering, with China exporting more than 200 billion masks in 2020 alone [17]. ...
... usage of reusable vs disposable fitted face masks. This could be achieved through observational studies of face mask use [24], assessments of lost and discarded [14,25] as well as donated masks [13], and through a documentation of the longer-term fate of discarded single-use face masks in the urban and peri-urban environment [15,16,26]. While the majority of mainstream research focused on the environmental aspects of discarded masks [27][28][29][30][31][32][33][34][35][36][37][38][39][40], several authors have conducted work on masks in the social acceptability [41][42][43][44][45] and the future heritage space [46][47][48][49][50]. Now, three years after COVID-19 first became a global health emergency, the majority of people have 'learned to live with the virus' [51,52] with the majority of people, at least in the more affluent countries, being fully vaccinated. ...
As the COVID-19 pandemic begins to abate and national public health systems are treating the SARS-Cov-2 virus as endemic, many public health measures are no longer mandated, but remain recommended with voluntary participation. One of these is the wearing of fitted face masks, initially mandated to contain, or at least slow, the spread of SARS-CoV-2 which is primarily transmitted via aerosols emitted while breathing, coughing, or sneezing. While the habit of once wearing fitted face masks recedes into memory for much of the population, so does the knowledge of the various types of masks that were once en vogue. To create a record for the future, this paper provides the first comprehensive documentation of the nature and range of fitted facemasks that circulated during the COVID-19 pandemic.
... They have become a global requirement in the past two years to limit SARS-CoV-2 diffusion as one of the precautionary measures to slow down the transmission rate of coronavirus disease 2019 (COVID-19) [1]. Consequently, their production has increased at an unprecedented rate since the middle of 2020 [2] to cover the need for around 130 billion disposable masks per month [3]. ...
... The materials used for the manufacture of face masks are fundamentally synthetic thermoplastic polymers, polypropylene (PP) being the most commonly used [1], so the increase in their consumption is undoubtedly contributing to the already alarming problem of plastic pollution in the environment [2]. Due to their long-term stability and durability, which may be estimated in the order of tens to hundreds of years, plastics tend to accumulate in the environment [4]. ...
... Single-use polymeric materials are considered one the main sources of microplastics (particles with a diameter of less than 5 mm) since they may degrade and fragment under environmental conditions. These microplastics threaten terrestrial and marine ecosystems, global food security, and the tourism industry and exacerbate climate change and the spread of pathogens [2]. Although the weathering and the degradation under different conditions of the most important classes of industrial polymers (including PP) were extensively studied [6][7][8][9][10], their aging behavior in the form of nonwoven fabrics, such as those used for the manufacture of disposable face masks, has been investigated mostly in general terms, essentially focusing on field observations and within recycling proposals [2,[11][12][13][14][15]. ...
The main purpose of this work is to contribute to understanding the mechanism of oxidation of the polymeric components of common disposable masks used during the COVID-19 pandemic to offer the chemical basis to understand their long-term behavior under typical environmental conditions. Artificial aging of representative mask layers under isothermal conditions (110 °C) or accelerated photoaging showed that all the PP-made components underwent a fast oxidation process, following the typical hydrocarbon oxidation mechanism. In particular, yellowing and the melting temperature drop are early indicators of their diffusion-limited oxidation. Morphology changes also induced a loss of mechanical properties, observable as embrittlement of the fabric fibers. Results were validated through preliminary outdoor aging of masks, which allows us to predict they will suffer fast and extensive oxidation only in the case of contemporary exposure to sunlight and relatively high environmental temperature, leading to their extensive breakdown in the form of microfiber fragments, i.e., microplastics.
... The Istituto Superiore della Sanit a (Italian Higher Institute of Health) suggested including masks coming from households as urban unsorted waste with European List of Waste Code EER 200301, whereas all others to EER 150203 "absorbents, filter materials, rags and protective clothing" (ISS, 2020). Market pressure has increased both the consumption and the production of masks and increased risks of soil and marine pollution from microplastics (Fadare and Okoffo, 2020) and recycled urban green waste (Spennemann, 2022). Disposable single-use masks provide higher protection, although carrying environmental burdens. ...
Purpose
International outbreak of the SARS-CoV-2 infection has fostered the Italian government to impose the FFP2 protective facial masks in closed environments, including bar, restaurants and, more in general, in the food sector. Protective facial masks are rocketing, both in mass and in costs, in the food sector imposing efforts in fostering reuse strategies and in the achievement of sustainable development goals. The scope of the present paper is to depict possible strategies in manufacturing and reuse strategies that can reduce the carbon footprint (CF) of such devices.
Design/methodology/approach
To implement circular economy strategies in the protective facial masks supply chain, it was considered significant to move towards a study of the environmental impact of such devices, and therefore a CF study has been performed on an FFP2 facial mask used in the food sector. Different materials besides the mostly used polypropylene (PP) (polyethylene (PE), polycarbonate (PC), poly (lactic acid) (PLA), cotton, polyurethane (PUR), polystyrene (PS) and nylon 6,6) and different sanitisation alternatives as reuse strategies (both laboratory and homemade static oven, ultraviolet germicidal irradiation) readily implemented have been modelled to calculate the CF of a single use of an FFP2 mask.
Findings
The production of textiles in PP, followed by disposal was the main contributor to CF of the single-use FFP2 mask, followed by packaging and transportations. PP and PE were the least impacting, PC, cotton and Nylon 6-6 of the same weight results the worst. PLA has an impact greater than PP and PE obtained from crude oil, followed by PUR and PS. Static laboratory oven obtained an 80.4% reduction of CF with respect to single use PP-made FFP2 mask, whereas homemade oven obtained a similar 82.2% reduction; UV cabinet is the best option, showing an 89.9% reduction.
Research limitations/implications
The key strategies to reduce the environmental impacts of the masks (research for new materials and reuse with sanitisation) should ensure both the retention of filtering capacities and the sanitary sterility of the reused ones. Future developments should include evaluations of textile recycling impacts, using new materials and the evaluation of the life cycle costs of the reused masks.
Practical implications
This paper intends to provide to stakeholders (producers, consumers and policy makers) the tools to choose the best option for producing and reuse environmentally friendly protective facial masks to be used in the food sector, by using both different materials and easily implemented reuse strategies.
Social implications
The reduction of the CF of protective facial masks in the food sector surely will have relevant positive effects on climate change contributing to reach the goals of reducing CO 2 emissions. The food sector may promote sustainable practices and attract a niche piece of clients particularly sensible to such themes.
Originality/value
The paper has two major novelties. The first one is the assessment of the CF of a single use of an FFP2 mask made with different materials of the non-woven filtering layers; as the major contribution to the CF of FFP2 masks is related to the non-woven textiles manufacturing, the authors test some other different materials, including PLA. The second is the assessment of the CF of one single use of a sanitised FFP2 mask, using different sanitation technologies as those allowed in bars or restaurants.
... At the same time, if disinfection is being conducted on single-use face masks, it greatly reduces the structural integrity of the mask material and leads to withering over time. Earlier, Spennemann [28] stated that 75% of all pieces of surgical-type single-use face mask fabric decays into microfibers and are disposed of together alongside general waste, adding to the municipal waste stream, while also presenting a long-term source of microplastics in urban waste [28]. On another note, if a structurally compromised mask is being used, the plastic microfibers can probably be inhaled, which may result in health complications [29][30][31]. ...
... At the same time, if disinfection is being conducted on single-use face masks, it greatly reduces the structural integrity of the mask material and leads to withering over time. Earlier, Spennemann [28] stated that 75% of all pieces of surgical-type single-use face mask fabric decays into microfibers and are disposed of together alongside general waste, adding to the municipal waste stream, while also presenting a long-term source of microplastics in urban waste [28]. On another note, if a structurally compromised mask is being used, the plastic microfibers can probably be inhaled, which may result in health complications [29][30][31]. ...
... The face masks are mainly made from petrochemicalbased polypropylene material and medical-grade polypropylene microfibers that could take up to 450 years to degrade in nature [16]. In the meantime, these fibers can travel across the biosphere and cause microplastic pollution in various ecosystems [23,28,37] in addition to encouraging a dynamic relationship between pollution and economic growth, to which conscious efforts at reducing pollution rates can promote the attainment of health and well-being of citizens and sensitize for good sanitation and hygiene standards as set by the community in general [38]. ...
At the peak of the COVID-19 pandemic, the estimated daily use of face masks was at its highest, thereby creating huge public health and environmental challenges associated with the indiscriminate disposal of used ones. The present study assessed Abu Dhabi University students’ handling and disposal of single-use face masks during the pandemic. A cross-sectional study using an online survey questionnaire was used to gather data from 255 students from the target group. Face mask type was found to be significantly influenced by both the student’s gender and age, while the participant’s habit of hand washing after handling a used face mask was found to be significantly influenced by the student’s age. The student’s educational level significantly influenced group decisions regarding the most appropriate face mask to use, as well as environmental and health consequences awareness of indiscriminate face mask disposal. While the students are adequately aware of COVID-19’s impact and had good knowledge of face mask use, a high proportion professed to the unsafe disposal of used face masks in public areas, thereby adding to microplastic pollution in the environment and its associated impacts. The study alluded to the need for strengthening the participant’s knowledge, attitude, and practices as precautionary measures that mitigate the environmental effect of the indiscriminate disposal of used face masks. The findings also call for a collaborative partnership among stakeholders toward designing effective educational campaigns to minimize the environmental impacts posed by face mask disposal.
... Given the billions of single-use face masks produced, used and discarded during the COVID-19 pandemic (Aragaw & Mekonnen, 2021;Patel et al., 2017;Prata, Silva, Walker, Duarte, & Rocha-Santos, 2020), it is not surprising that a large quantity has escaped the standard waste management stream (Benson, Bassey, & Palanisami, 2021;Benson, Fred-Ahmadu, Bassey, & Atayero, 2021;Topal & Arslan Topal, 2021) and has entered the natural environment in various settings (Chowdhury, Chowdhury, & Sait, 2021;Mejjad et al., 2021;Okuku et al., 2021;Ormaza-González & Castro-Rodas, 2020;Spennemann, 2021f, 2022a where the masks undergo various processes of environmental decay. Decaying single use facemasks will shed large amounts of microfibers as their bonds break, either due to UV-induced photo-oxidation, (Du, Xie, & Wang, 2021;Rathinamoorthy & Balasaraswathi, 2022;Spennemann, 2022d) due to mechanical impact (Liang et al., 2022;Pizarro-Ortega et al., 2022;Saliu et al., 2021;Spennemann, 2022a;Wu, Li, Lu, Tang, & Cai, 2022) or immersion in turbulent waters (Saliu et al., 2021;Shen et al., 2021). While observations of the presence of masks in natural environmental settings has received the greatest amount of public and academic attention (see above), a longitudinal observational study has shown that 66.3% of all lost or discarded masks were found in dedicated car parks, at curbside parking spots and on the street (Spennemann, 2021f). ...
... Unlike masks that have been caught in lawn mowing equipment and are, by and large, shredded into larger fragments (Spennemann, 2022a), masks that are degraded and destroyed by vehicular traffic result in an instant and continual generation of microfiber fragments of varied lengths. These fiber fragments are then displaced and distributed into the wider environment through wind action (natural or vehicle draught) and surface water flows (rainfall) as well as adherence to vehicle tires (such as being caught in the tread). ...
During the COVID-19 pandemic large numbers of single-use, surgical style face masks were lost or discarded in public spaces, primarily in on public streets and car parking settings. Many of these masks were blown onto the road surfaces where they were subjected to degradation through the tire impact of passing vehicle traffic. As series of field observa-tions as well as experimental simulations show that the three-ply polypropylene mask fabric is subjected to shear forces when compressed between the tire and the road surface. The mechanical action breaks the bonds between the fibers (both spunbonded and meltblown) leading to a continual shedding of microfibers. Wind disperses these into the environ-ment along road sides, while surface water action moves them into stormwater drains and from there into the water-ways. As the decay is rapid, municipal agencies only have a short window of time to remove stray face masks from the urban environment if micro-fiber pollution is to be reduced.
... They have become a global requirement in the past two years to limit SARS-CoV-2 diffusion as one of the precautionary measures to slow down the transmission rate of the Coronavirus disease 2019 (COVID-19) [1]. Consequently, their production has increased at an unprecedented rate since the middle of 2020 [2] to cover the need for around 130 billion disposable masks per month [3]. ...
... The materials used for the manufacture of face masks are fundamentally synthetic thermoplastic polymers, being polypropylene (PP) the most commonly used [1], so the increase in their consumption is undoubtedly contributing to the already alarming problem of plastic pollution in the environment [2]. Due to their long-term stability and durability, which may be estimated in the order of tens to hundreds of years, plastics tend to accumulate in the environment [4]. ...
... Single-use polymeric materials are considered one the main sources of microplastics (particles with a diameter of less than 5 mm) since they may degrade and fragment under environmental conditions. These microplastics are a threat not only to terrestrial and marine ecosystems but also to global food security, the tourism industry, climate change, and the spread of pathogens [2]. Although the weathering and the degradation under different conditions of the most important classes of industrial polymers (including PP) were extensively studied [6][7][8][9][10], their ageing behaviour in the form of nonwoven fabrics, such as those used for the manufacture of disposable face masks, has been investigated mostly in general terms, essentially focusing on field observations and within recycling proposals [2,[11][12][13][14][15]. ...
The main purpose of this work is to contribute to understanding the mechanism of oxidation of the polymeric components of common disposable masks used during the COVID-19 pandemic to offer the chemical basis to predict their long-term behaviour under typical environmental conditions. Artificial ageing of representative mask layers under isothermal conditions (110℃) or accelerated photoageing showed that all the PP-made components underwent a fast oxidation process, following the typical hydrocarbon oxidation mechanism. In particular, yellowing and the melting temperature drop are early indicators of their diffusion-limited oxidation. Morphology changes also induced a loss of mechanical properties, observable as embrittlement of the fabric fibres. Results were validated through preliminary outdoor ageing of masks, which allows us to predict they will suffer fast and extensive oxidation only in the case of contemporary exposure to sunlight and relatively high environmental temperature, leading to their extensive breakdown in the form of microfiber fragments, i.e., microplastics.
