Migration of Microplastics and Phthalates from Face Masks to Water.

Since the outbreak of COVID-19, face masks have been introduced in the complex strategy of infection prevention and control. Face masks consist of plastic polymers and additives such as phthalates. The aim of this study was to evaluate the migration of microplastics (MP) and phthalates from face masks to water. Four types of masks including FFP2 masks and surgical were studied. Masks were first characterized to determine the different layers and the material used for their fabrication. Then, masks were cut into 20 pieces of 0.5 cm2, including all their layers, placed in water, and the migration of MP and phthalates was evaluated according to the conditions stated in EU Regulation No 10/2011 on plastic materials and articles intended to come into contact with food. For MP, the morphological analysis (shape, dimension, particle count) was performed using a stereomicroscope, while the identification of both masks and MP released was conducted using µ-Fourier-transform infrared spectroscopy (µ-FT-IR). Migration of phthalates was assessed by ultra-high-performance liquid chromatography coupled to triple quadrupole mass spectrometer (UPLC-MS/MS). Face masks analyzed in the present study were made of atactic polypropylene (PP) as stated by the manufacturer. The µ-FT-IR confirmed that PP and polyamide (PA) were released as fragments, while both PP and polyester (PES) were released as fibers. In addition, 4 phthalates were identified at concentrations between 2.34 and 21.0 µg/mask. This study shows that the migration study can be applied to evaluate the potential release of MP and phthalates from face masks to water and could give a hint for the potential impact of their incorrect disposal on the aquatic resources.

Microplastics and nanoplastics released from a PPE mask under a simulated bushfire condition.

Due to COVID-19, large amounts of personal protective equipment (PPE) have been used, and many PPE units are made of plastics, such as face masks. The masks can be burned naturally in a bushfire or artificially at the incineration plants, and release microplastics and nanoplastics from the mask plastic fibres. A fire can cause the plastic, such as polypropylene (PP) fibres, to be molten and stick to the solid surface, such as glass, soil, concrete or plant, as films or islands, due to the binding property of the molten plastic material. Once the films or islands are peeled off in the processes such as weathering, ageing, or treatment and clean-up, there are residuals leftover, which are identified as nanoplastics and microplastics via Raman imaging, with the significant release amount of ~1100 nanoplastics / 10 µm2 or ~11 billion / cm2, and ~50 microplastics / 420 µm2 or ~12 million / cm2. Moreover, surface group is deviated on the plastic surface, which can also be distinguished and visualised as well via Raman imaging, down to nano size. This test validates the Raman imaging approach to capture microplastics and nanoplastics, and also provides important information about the fate and transportation of PPE mask in the environment, particularly when subjected to a fire. Overall, Raman imaging can be an effective option to characterise the microplastics and nanoplastics, along with the deviated surface group.

Post COVID-19 pandemic: Disposable face masks as a potential vector of antibiotics in freshwater and seawater.

With the outbreak and widespread of the COVID-19 pandemic, large numbers of disposable face masks (DFMs) were abandoned in the environment. This study first investigated the sorption and desorption behaviors of four antibiotics (tetracycline (TC), ciprofloxacin (CIP), sulfamethoxazole (SMX), and triclosan (TCS)) on DFMs in the freshwater and seawater. It was found that the antibiotics in the freshwater exhibited relatively higher sorption and desorption capacities on the DFMs than those in the seawater. Here the antibiotics sorption processes were greatly related to their zwitterion species while the effect of salinity on the sorption processes was negligible. However, the desorption processes were jointly dominated by solution pH and salinity, with greater desorption capacities at lower pH values and salinity. Interestingly, we found that the distribution coefficient (Kd) of TCS (0.3947 L/g) and SMX (0.0399 L/g) on DFMs was higher than those on some microplastics in freshwater systems. The sorption affinity of the antibiotics onto the DFMs followed the order of TCS > SMX > CIP > TC, which was positively correlated with octanol-water partition coefficient (log Kow) of the antibiotics. Besides, the sorption processes of the antibiotics onto the DFMs were mainly predominated by film diffusion and partitioning mechanism. Overall, hydrophobic interaction regulated the antibiotics sorption processes. These findings would help to evaluate the environmental behavior of DFMs and to provide the analytical framework of their role in the transport of other pollutants.

Pathogen-Repellent Plastic Warp with Built-In Hierarchical Structuring Prevents the Contamination of Surfaces with Coronaviruses.

Amidst the COVID-19 pandemic, it is evident that viral spread is mediated through several different transmission pathways. Reduction of these transmission pathways is urgently needed to control the spread of viruses between infected and susceptible individuals. Herein, we report the use of pathogen-repellent plastic wraps (RepelWrap) with engineered surface structures at multiple length scales (nanoscale to microscale) as a means of reducing the indirect contact transmission of viruses through fomites. To quantify viral repellency, we developed a touch-based viral quantification assay to mimic the interaction of a contaminated human touch with a surface through the modification of traditional viral quantification methods (viral plaque and TCID50 assays). These studies demonstrate that RepelWrap reduced contamination with an enveloped DNA virus as well as the human coronavirus 229E (HuCoV-229E) by more than 4 log 10 (>99.99%) compared to a standard commercially available polyethylene plastic wrap. In addition, RepelWrap maintained its repellent properties after repeated 300 touches and did not show an accumulation in viral titer after multiple contacts with contaminated surfaces, while increases were seen on other commonly used surfaces. These findings show the potential use of repellent surfaces in reducing viral contamination on surfaces, which could, in turn, reduce the surface-based spread and transmission.

How blood met plastics, plant and animal extracts: Material encounters between medicine and industry in the twentieth century.

Twentieth-century medicine saw the remarkable rise of complex machines and infrastructures to process blood for medical purposes, such as transfusion, dialysis, and cardiac surgery. Instead of attributing these developments to technological ingenuity, this article argues for the primacy of material encounters as a promising focal point of medical historiography. In fact, blood's special properties consistently clashed with most materials used in medical practice, provoking a series of material exchanges. Drawing on a combination of epistemological and network approaches, three exemplary cases are presented to examine blood's encounters with plastics, plant and animal extracts: William M. Bayliss's (1860-1926) injections of dissolved gum acacia to expand diminished blood volume; Charles H. Best's (1899-1978) production of the anticoagulant heparin from animal organs; and the preservation of fragile blood cells by silicone coatings inside of John H. Gibbon Jr.'s (1903-1973) heart-lung machine. The case studies demonstrate how the complementarity of blood and these materials produced hybridizations between medicine and a range of industrial branches, from colonial forestry and meatpacking to commercial chemistry. In this light, the paper concludes by discussing the dependencies of today's healthcare environments on globally distributed, capitalistically appropriated resources in the face of crises like the COVID-19 pandemic.

Stepping towards benign alternatives: sustainable conversion of plastic waste into valuable products.

The extensive use of plastic and the absence of efficient and sustainable methods for its degradation has raised critical concerns about its disposal and degradation. Furthermore, the escalated use of personal protective equipment (PPE) and masks during the ongoing COVID-19 pandemic has put us under tremendous pressure of generating huge amounts of plastic waste. Traditional plastic waste disintegration protocols, while effective, pose additional inevitable environmental risks. Owing to this, almost all the used plastic is directly discarded into the marine and terrestrial bodies, causing great harm to the flora and fauna. Plastic has even started entering the food chain in the form of micro- and nano-plastics, leading to deleterious effects. Considering the global need for finding sustainable ways to degrade plastic, several approaches have been developed. Herein we highlight and rationally compare the recent reports on the development of benign alternatives for the sustainable disintegration of plastic detritus into value-added products. Here we discuss, in depth, photoreforming of a variety of polymers to liquid fuels under natural conditions; enzyme-based deconstruction of polymeric materials via microorganisms and their engineered mutants into useful virgin monomers at ambient temperature; and pyrocatalytic degradation of polyethylene through efficient synthetic materials into valuable fuels and waxes. By critically analyzing the methods, we also provide our opinion on such sustainable techniques and discuss newer approaches related to bioinspired and biomimetic chemistry principles for the management of plastic waste.

Why does SARS-CoV-2 survive longer on plastic than on paper?

The Covid-19 coronavirus, SARS-CoV-2, is inactivated much faster on paper (3 h) than on plastic (7 d). By classifying materials according to virus stability on their surface, the following list is obtained (from long to short stability): polypropylene (mask), plastic, glass, stainless steel, pig skin, cardboard, banknote, cotton, wood, paper, tissue, copper. These observations and other studies suggest that SARS-CoV-2 may be inactivated by dryness on water absorbent porous materials but sheltered by long-persisting micro-droplets of water on waterproof surfaces. If such physical phenomenons were confirmed by direct evidence, the persistence of the virus on any surface could be predicted, and new porous objects could be designed to eliminate the virus faster.

Application of Plastic Sheet Barrier and Video Intubating Stylet to Protect Tracheal Intubators During Coronavirus Disease 2019 Pandemic: A Taiwan Experience.

Since its outbreak in China, the Coronavirus disease 2019 (COVID-19) pandemic has caused worldwide disaster. Globally, there have been 71,581,532 confirmed cases of COVID-19, including 1,618,374 deaths, reported to World Health Organization (data retrieved on December 16, 2020). Currently, no treatment modalities for COVID-19 (e.g., vaccines or antiviral drugs) with confirmed efficacy and safety are available. Although the possibilities and relevant challenges of some alternatives (e.g., use of stem cells as immunomodulators) have been proposed, the personal protective equipment is still the only way to protect and lower infection rates of COVID-19 among healthcare workers and airway managers (intubators). In this article, we described the combined use of a plastic sheet as a barrier with the intubating stylet for tracheal intubation in patients needing mechanical ventilation. Although conventional or video-assisted laryngoscopy is more popular and familiar to other groups around the world, we believe that the video-assisted intubating stylet technique is much easier to learn and master. Advantages of the video stylet include the creation of greater working distance between intubator and patient, less airway stimulation, and less pharyngeal space needed for endotracheal tube advancement. All the above features make this technique reliable and superior to other devices, especially when a difficult airway is encountered in COVID scenario. Meanwhile, we proposed the use of a flexible and transparent plastic sheet to serve as a barrier against aerosol and droplet spread during airway management. We demonstrated that the use of a plastic sheet would not interfere or hinder the intubator's maneuvers during endotracheal intubation. Moreover, we demonstrated that the plastic sheet was effective in preventing the spread of mist and water spray in simulation models with a mannequin. In our experience, we found that this technique most effectively protected the intubator and other operating room personnel from infection during the COVID-19 pandemic.

Pyrolysis dynamics of two medical plastic wastes: Drivers, behaviors, evolved gases, reaction mechanisms, and pathways.

The public has started to increasingly scrutinize the proper disposal and treatment of rapidly growing medical wastes, in particular, given the COVID-19 pandemic, raised awareness, and the advances in the health sector. This research aimed to characterize pyrolysis drivers, behaviors, products, reaction mechanisms, and pathways via TG-FTIR and Py-GC/MS analyses as a function of the two medical plastic wastes of syringes (SY) and medical bottles (MB), conversion degree, degradation stage, and the four heating rates (5,10, 20, and 40 °C/min). SY and MB pyrolysis ranged from 394.4 to 501 and from 417.9 to 517 °C, respectively. The average activation energy was 246.5 and 268.51 kJ/mol for the SY and MB devolatilization, respectively. MB appeared to exhibit a better pyrolysis performance with a higher degradation rate and less residues. The most suitable reaction mechanisms belonged to a geometrical contraction model (R2) for the SY pyrolysis and to a nucleation growth model (A1.2) for the MB pyrolysis. The main evolved gases were C4-C24 alkenes and dienes for SY and C6-C41 alkanes and C8-C41 alkenes for MB. The pyrolysis dynamics and reaction pathways of the medical plastic wastes have important implications for waste stream reduction, pollution control, and reactor optimization.