Face mask and medical waste disposal during the novel COVID-19 pandemic in Asia

Forecasting medical waste in Istanbul using a novel nonlinear grey Bernoulli model optimized by firefly algorithm

Waste management has gained global importance, aligning with the escalating impact of the COVID-19 pandemic and the associated concerns regarding medical waste, which poses threats to public health and environmental sustainability. In Istanbul, medical waste is considered a significant concern due to the rising volume of this waste, along with challenges in collection, incineration and storage. At this juncture, precise estimation of the waste volume is crucial for resource planning and allocation. This study, thus, aims to estimate the volume of medical waste in Istanbul using the nonlinear grey Bernoulli model (NGBM(1,1)) and the firefly algorithm (FA). In other words, this study introduces a novel hybrid model, termed as FA-NGBM(1,1), for predicting waste amount in Istanbul. Within this model, prediction accuracy is enhanced through a rolling mechanism and parameter optimization. The effectiveness of this model is compared with the classical GM(1,1) model, the GM(1,1) model optimized with the FA (FA-GM(1,1)), the fractional grey model optimized with the FA (FA-FGM(1,1)) and linear regression. Numerical results indicate that the proposed FA-NGBM(1,1) hybrid model yields lower prediction error with a mean absolute percentage error value 3.47% and 2.57%, respectively, for both testing and validation data compared to other prediction algorithms. The uniqueness of this study is rooted in the process of initially optimizing the parameters for the NGBM(1,1) algorithm using the FA for medical waste estimation in Istanbul. This study also forecasts the amount of medical waste in Istanbul for the next 3 years, indicating a dramatic increase. This suggests that new policies should be promptly considered by decision-makers and practitioners.

A critical review of innovative strategies for the sustainable management of solid waste generated in the health institutions of Zimbabwe

Innovative frameworks and strategies for solid waste management have been brought forward by researchers to solve the phenomenon of accumulating waste in the environment globally. The sustainability of medical waste management then pivots on the ability of waste management in a way that proves harmless to humans, animals, plants and the environment at large. This review looks into the strategies for the sustainable management of solid waste generated in the health institutions of Zimbabwe. Waste management includes waste generation, waste segregation, waste storage, waste collection and transportation, waste treatment and disposal and waste reuse and recycling. Exhaustive literature review was conducted as the methodology for this review soliciting information on the solid medical waste management status worldwide. In Zimbabwe, hazardous medical solid waste segregation, storage, transportation and disposal is a responsibility of the medical institutions generating the waste. These include trip and fall hazards, infectious hazards, cuts and lacerations, drugs addictions and radioactive hazards. The environment also faces contamination to the land, underground water bodies through leaching, surface water bodies, damage to flora, poisoning of fauna and contamination of the atmosphere by methane and carbon monoxide. Findings of the study show that innovations for medical solid waste management include frameworks such as the Ladder of Lansink and the three 'R's. Innovative technologies include rotary kiln incinerators, automated segregation and engineered landfills. Therefore, the framework addresses issues impeding the adoption of these innovative strategies in Zimbabwe.

Photolysis of disposable face masks facilitates abiotic manganese oxide formation

During the COVID-19 pandemic, billions of face masks were discarded into aquatic environments, releasing micro/nanoplastics. This release threatens aquatic ecosystems, influences pollutant transport, and generates reactive oxygen species (ROS). These ROS can affect redox-active metal ions, such as manganese (Mn), in water. Mn oxide solids are commonly found in nature and serve as both electron donors and acceptors in various biogeochemical reactions of trace elements, metal ions, and organics in the environment. However, it remains unclear how disposable face masks, primarily made of polypropylene (PP), impact Mn oxidation and Mn oxides formation in natural surface waters under sunlight. This study, for the first time, reports the photolysis of PP mask layers and their impacts on the kinetics of Mn2+ (aq) oxidation to Mn oxide nanoparticles. We found that mask layers enhanced Mn2+(aq) photo-oxidation kinetics as their surface material packing density increased. Furthermore, the local concentrations of oxidized Mn2+ near the mask surfaces were two orders of magnitude greater than the bulk solution, facilitating heterogeneous Mn oxide formation near mask surfaces. Photoaging of masks further expedited Mn2+ oxidation. Superoxide radicals (O2•-) generated by mask photolysis were the main responsible ROS for boosting Mn oxidation. These findings highlight the influences of mask photolysis on Mn redox chemistry. Mn oxides formed on mask materials can alter the fate and transport of pollutants such as heavy metals and organic compounds, impacting surface water quality.

Evaluation of potentially toxic elements and pharmaceutical compounds in leachate and exhaust air from non-incineration medical waste treatment devices

This study assessed the health risks and toxicity of compounds found in the leachate and exhaust air of non-incineration devices used for hospital waste management. Specifically, it measured the levels of potentially toxic elements and pharmaceutical compounds in two disinfection waste treatment devices-hydroclave with shredder (device A) and autoclave without shredder (device B)-at a hospital in Tehran, Iran. Sampling occurred from October 2022 to March 2023. potentially toxic elements were analyzed using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), while cytotoxicity was evaluated with an ELISA reader.The results indicated that the exhaust air from device A contained high concentrations of barium (9.80 ± 1.60 µg/m3), zinc (8.60 ± 2.25 µg/m3), and chromium (8.45 ± 2.30 µg/m3). In contrast, barium and zinc were the most abundant potentially toxic elements in device B. Analysis of the leachate from device A showed that nickel and arsenic had the lowest concentrations, while barium, chromium, and zinc had the highest. Additionally, Leachate analysis from Device A also revealed high levels of barium, chromium, and zinc, while nickel and arsenic were found at lower concentrations. Significant concentrations of pharmaceutical compounds, such as azithromycin, ciprofloxacin, diclofenac, and naproxen, were detected in the effluent from both devices, with higher concentrations in Device A, indicating improper segregation and inadequate management of pharmaceutical waste. This underscores the urgent need for continuous training, supervision, and monitoring in pharmaceutical waste management. Cytotoxicity analyses showed that particulate matter and leachate from Device A had a more pronounced negative impact on human cell lines (HepG2 and A549) compared to Device B. Health risk assessments using Monte Carlo simulations indicated that the carcinogenic risks from potentially toxic elements (PTEs) in Device A, particularly arsenic and chromium, exceeded the permissible limits set by the USEPA, while Device B posed significantly lower risks. These findings highlight the importance of educating hospital staff on proper waste segregation, continuous monitoring, and implementing advanced waste management protocols to protect public health and the environment.

Micro- and mesoplastic pollution in the surface water and nekton from the eastern Indian ocean: Spatiotemporal variation, correlation and risk assessment

The pollution of micro- and mesoplastic (MMP) in the Eastern Indian Ocean (EIO) remains poorly understood. The present study revealed that MMP abundance in nekton from EIO in 2022 (mean: 2.30 ± 0.39 items individual-1 and 1.81 ± 0.54 items g-1) was significantly higher than that in 2021 (mean: 1.60 ± 0.22 items individual-1 and 0.80 ± 0.13 items g-1). In contrast, MMP abundance in surface water varied insignificantly between 2021 (mean: 0.04 ± 0.01 items m-3) and 2022 (mean: 0.05 ± 0.02 items m-3). The rise in predominant polymers-polypropylene (PP), rayon (RA), and polyester (PES)-in nekton from 2021 to 2022 may suggest increased pollution from face masks and home textiles along coastal regions. Notable spatial variation in PP and RA between the northeastern and southeastern regions was observed only in nekton, suggesting they are better indicators of MMP spatiotemporal variation than surface water. Shadow driftfish ingested more MMPs than purpleback flying squid and mackerel scad, likely due to its deeper habitat. By simultaneously considering color, composition, and shape, integrated MMP analysis showed insignificant correlation between MMP pollution in surface water and nekton, suggesting that nekton may ingest MMPs through multiple pathways beyond surface water. Risk indices for surface water and nekton reached moderate to upper levels globally, emphasizing the need for continued monitoring in the EIO. Epoxy resin, rubber, and PP + acrylic were identified as the most hazardous polymers, providing a valuable basis for developing effective strategies to mitigate plastic pollution.

Waste management and disease spread potential: A case study of SARS-CoV-2 in garbage dumping sites in Bangkok and its vicinity

During the coronavirus disease 2019 (COVID-19) pandemic, hospitals and households have used personal protective equipment (PPE), such as masks and gloves. Some of these potentially infectious materials were discarded with other household wastes in garbage dumping sites. Thus, this study aimed to detect the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in contaminated wastes, environments, and mammals scavenging around these sites. From September to October 2022, we visited three garbage dumping sites located in Bangkok, Nakhon Pathom, and Nonthaburi provinces of Thailand. Oral, nasal, rectal swabs, and blood samples were collected from small mammals, stray dogs, and cats. Masks, gloves, soil, and water samples from the sites were additionally collected. Of the 582 samples collected from 238 animals, none tested positive for SARS-CoV-2 in the virus isolation, real-time reverse-transcription polymerase chain reaction, and neutralizing antibody detection. However, one sample (1.18 %; 1/85) from a rat (Rattus spp.) captured in Nonthaburi was serologically positive in the indirect enzyme-linked immunosorbent assay. The surveillance of coronaviruses in rats is strongly encouraged because rats may harbor different zoonotic pathogens, including unknown potentially zoonotic coronaviruses. Moreover, two face mask samples (4.65 %; 2/43) collected from the dumping site in Nakhon Pathom tested positive for SARS-CoV-2 by real-time RT-PCR. To reduce environmental contamination, detecting the SARS-CoV-2 viral genome in contaminated face masks highlights the critical need for proper waste management in households and communities in Thailand. Thus, to minimize exposure and prevent onward transmission, waste management personnel, including garbage dump staff and waste pickers, should be equipped with appropriate PPE and receive regular training on safe handling and disposal.

Viral diseases and the environment relationship

Viral diseases have been present throughout human history, with early examples including influenza (1500 B.C.), smallpox (1000 B.C.), and measles (200 B.C.). The term "virus" was first used in the late 1800s to describe microorganisms smaller than bacteria, and significant milestones include the discovery of the polio virus and the development of its vaccine in the mid-1900s, and the identification of HIV/AIDS in the latter part of the 20th century. The 21st century has seen the emergence of new viral diseases such as West Nile Virus, Zika, SARS, MERS, and COVID-19. Human activities, including crowding, travel, poor sanitation, and environmental changes like deforestation and climate change, significantly influence the spread of these diseases. Conversely, viral diseases can impact the environment by polluting water resources, contributing to deforestation, and reducing biodiversity. These environmental impacts are exacerbated by disruptions in global supply chains and increased demands for resources. This review highlights the intricate relationship between viral diseases and environmental factors, emphasizing how human activities and viral disease progression influence each other. The findings underscore the need for integrated approaches to address the environmental determinants of viral diseases and mitigate their impacts on both health and ecosystems.

Partial consumption of medical face masks by a common beetle species

The widespread distribution of microplastics (MPs) in the environment has motivated research on the ecological significance and fate of these pervasive particles. Recent studies have demonstrated that MPs may not always have negative effects, and in contrast, several species of Tenebrionidae beetles utilized plastic as a food source in controlled laboratory experiments. However, most studies of plastic-eating insects have not been ecologically realistic, and thus it is unclear whether results from these experiments apply more broadly. Here, we quantified the ability of mealworms (Coleoptera: Tenebrionidae) to consume MPs derived from polypropylene and polylactic acid face masks; these are two of the most commonly used conventional and plant-based plastics. To simulate foraging in nature, we mixed MPs with wheat bran to create an environment where beetles were exposed to multiple food types. Mealworms consumed approximately 50% of the MPs, egested a small fraction, and consumption did not affect survival. This study adds to our limited knowledge of the ability of insects to consume MPs. Understory or ground-dwelling insects may hold the key to sustainable plastic disposal strategies, but we caution that research in this field needs to proceed concomitantly with reductions in plastic manufacturing.

Microfibre pollution: An emerging contaminant, alarming threat to the global environment

Microfibres, mostly obtained from home laundry, textiles, industrial materials, sewage effluents, and sludge, are considered the main source of environmental pollution, which has become a prevalent threat to terrestrial and aquatic creatures. Global population growth and industrialization have led to a rise in fibre consumption and production, which spread its network in drinking water, beer, and seafood. Focusing on the alarming threat of microfibre towards the natural environment, we have penned an extensive review article about microfibre pollution. The manuscript is divided into various subparts, such as the introductory portion, which briefly summarizes the sources and presence of various hazardous pollutants in the environment, followed by a detailed discussion about microfibre. The second part elaborates on the sources and distribution of microfibreous pollutants and the third portion discloses the toxic chemicals utilized or produced from functionalization, as well as the negative implications of microfibre on the environment. The fourth part discloses the leading application strategies to diminish microfibre pollution by controlling the sources and the development of various remediations. The last portion deals with the future and critical aspects of microfibre contamination. The authors hope this review article will boost its domain in environmental chemistry, sustainable development and environmental engineering from academic to industrial level as it helps researchers in particular and academics in general.

Management of COVID-19 healthcare waste based on the circular economy hierarchy: A critical review

The overall objective of this work was to conduct a critical literature review on the application of the circular economy (CE) hierarchy for the management of COVID-19 healthcare waste (HCW). To describe the problem created by COVID-19 HCW, first, the subsystems of the overall management system, including generation, segregation, classification, storage, collection, transport, treatment and disposal, were reviewed and briefly described. Then, the CE hierarchy using the 10R typology was adapted to the management of COVID-19 HCW and included the strategies Refuse, Reduce, Resell/Reuse, Repair, Reprocess, Refurbish, Remanufacture, Repurpose, Recycle and Recover (energy). Disposal was added as a sink of residues from the CE strategies. Using the detailed 10R CE hierarchy for COVID-19 HCW management is the novelty of this review. It was concluded that R-strategy selection depends on its position in the CE hierarchy and medical item criticality and value. Indicative HCW components, which can be managed by each R-strategy, were compiled, but creating value by recovering infectious downgraded materials contaminated with body fluids and tissues is not currently possible. Therefore, after applying the circular solutions, the end of pipe treatment and disposal would be necessary to close material cycles at the end of their life cycles. Addressing the risks, knowledge gaps and policy recommendations of this article may help to combat COVID-19 and future pandemics without creating environmental crises.

Experimental study on recycling rubber to increase the impact resistance of cement mortar

The COVID-19 pandemic has led to a surge in medical waste generation, posing hazards to both the environment and global health. The impacts of the COVID-19 pandemic's medical waste hazard may persist long after the pandemic itself subsides. Improper disposal of medical waste can contaminate environment, posing risks to ecosystems and public health. Discarded medical rubber gloves, for example, can become a source of infection, improper disposal of these gloves can escalate the spread of infectious diseases and increase the risk of transmission of the virus to the general public. This study proposes an innovative and sustainable method to reinforce cement mortar by adding recycled glove rubber as an additive to cement mortar to increase its resistance to impact loads. This study conducted uniaxial compression tests, separating hopkinson pressure bar (SHPB) experiments and SEM observations to evaluate the quasi-static compressive strength and dynamic stress of recycled rubber fiber mortar (RRFM) with varying recycled rubber fiber (RRF) contents (0, 1%, 2%, 3%). Strain curves, dynamic increase factor (DIF), energy absorption rules, failure modes, and microstructure of RRFM mixtures. The experimental results demonstrate that with the addition of RRF, the dynamic stress-strain curve flattens and the peak strain gradually increases. The RRFM sample shows stronger toughness. In comparison to regular cement mortar (NM), RRFM has a higher DIF and specific absorbed energy, a faster increase in dynamic compressive strength, and the ability to absorb more energy per unit volume. Under the same impact load, RRFM has fewer and smaller cracks than NM. Scanning electron microscopy (SEM) testing also observed that RRF formed a strong connection pattern with the cement mortar matrix.

Can pyrolysis handle biomedical wastes?: Assessing the potential of various biomedical waste treatment technologies in tackling pandemics

Globally, COVID-19 has not only caused tremendous negative health, social and economic impacts, but it has also led to environmental issues such as a massive increase in biomedical waste. The biomedical waste (BMW) was generated from centralized (hospitals, clinics, and research facilities) and extended (quarantine camps, COVID-19 test camps, and quarantined homes) healthcare facilities. Many effects, such as the possibility of infection spread, unlawful dumping/disposal, and an increase in toxic emissions by common BMW treatment facilities, are conjectured because of the rise in waste generation. However, it is also an opportunity to critically analyze the current BMW treatment scenario and implement changes to make the system more economical and environmentally sustainable. In this review, the waste disposal guidelines of the BMW management infrastructure are critically analyzed for many functional parameters to bring out possible applications and limitations of individual interventions. In addition, an investigation was made to select appropriate technology based on the environmental setting.

A New Paradigm on Waste-to-Energy Applying Hydrovoltaic Energy Harvesting Technology to Face Masks

The widespread use of single-use face masks during the recent epidemic has led to significant environmental challenges due to waste pollution. This study explores an innovative approach to address this issue by repurposing discarded face masks for hydrovoltaic energy harvesting. By coating the face masks with carbon black (CB) to enhance their hydrophilic properties, we developed mask-based hydrovoltaic power generators (MHPGs). These MHPGs were evaluated for their hydrovoltaic performance, revealing that different mask configurations and sizes affect their efficiency. The study found that MHPGs with smaller, more structured areas exhibited better energy output, with maximum open-circuit voltages (VOC) reaching up to 0.39 V and short-circuit currents (ISC) up to 65.6 μA. The integration of CB improved water absorption and transport, enhancing the hydrovoltaic performance. More specifically, MHPG-1 to MHPG-4, which represented different sizes and features, presented mean VOC values of 0.32, 0.17, 0.19 and 0.05 V, as well as mean ISC values of 16.57, 15.59, 47.43 and 3.02 μA, respectively. The findings highlight the feasibility of utilizing discarded masks in energy harvesting systems, offering both environmental benefits and a novel method for renewable energy generation. Therefore, this work provides a new paradigm for waste-to-energy (WTE) technologies and inspires further research into the use of unconventional waste materials for energy production.

Understanding of environmental pollution and its anthropogenic impacts on biological resources during the COVID-19 period

The global outbreak of the COVID-19 pandemic has given rise to a significant health emergency to adverse impact on environment, and human society. The COVID-19 post-pandemic not only affects human beings but also creates pollution crisis in environment. The post-pandemic situation has shown a drastic change in nature due to biomedical waste load and other components. The inadequate segregation of untreated healthcare wastes, chemical disinfectants, and single-use plastics leads to contamination of the water, air, and agricultural fields. These materials allow the growth of disease-causing agents and transmission. Particularly, the COVID-19 outbreak has posed a severe environmental and health concern in many developing countries for infectious waste. In 2030, plastic enhances a transboundary menace to natural ecological communities and public health. This review provides a complete overview of the COVID-19 pandemic on environmental pollution and its anthropogenic impacts to public health and natural ecosystem considering short- and long-term scenarios. The review thoroughly assesses the impacts on ecosystem in the terrestrial, marine, and atmospheric realms. The information from this evaluation can be utilized to assess the short-term and long-term solutions for minimizing any unfavorable effects. Especially, this topic focuses on the excessive use of plastics and their products, subsequently with the involvement of the scientific community, and policymakers will develop the proper management plan for the upcoming generation. This article also provides crucial research gap knowledge to boost national disaster preparedness in future perspectives.

The toxic effects of polystyrene microplastic/nanoplastic particles on retinal pigment epithelial cells and retinal tissue

The increasing use of contact lenses, artificial tears, and anti-vascular endothelial growth factor (anti-VEGF) drug injections for age-related macular degeneration has heightened the likelihood of eye exposure to microplastic particles. Extensive research has established that microplastic particles can induce oxidative stress on the ocular surface, resulting in damage. However, the impact of these particles on the retina remains unclear. Therefore, this study investigated whether microplastics/nanoplastics (MPs/NPs) cause retinal damage. In vitro human retinal pigment epithelial (RPE) cells were exposed to polystyrene MPs and NPs for 48 h. Assessment of cell viability using WST-8; evaluation of TNF-α and IL-1β expression; observation of cell morphology and particle invasion via TEM; measurement of ROS levels using the DCFDA reagent; and western blot analysis of SOD2, FIS1, Drp1, and LC3B expression were conducted. In vivo experiments involved intravitreal injection of MPs/NPs in rats, followed by retinal H&E staining 24 h later and evaluation of TNF-α and IL-1β expression. Results indicated that exposure to MPs did not significantly alter RPE cell viability, whereas exposure to NPs led to a noticeable decrease. TEM images revealed NPs' penetration into cells, causing increased oxidative stress (SOD2), mitochondrial fission (FIS1, Drp1), and mitochondrial autophagy (LC3B). In vivo experiments demonstrated an increase in inflammatory cells in retinal tissues exposed to NPs, along with elevated levels of TNF-α and IL-1β. Conclusively, both MPs and NPs impact the retina, with NPs displaying greater toxicity. NPs significantly elevate ROS levels in the retina and induce mitochondrial fission and mitophagy in RPE cells compared to MPs.

Global daily mask use estimation in the pandemic and its post environmental health risks: Analysis based on a validated dynamic mathematical model

The outbreak of the COVID-19 pandemic led to a sharp increase in disposable surgical mask usage. Discarded masks can release microplastic and cause environmental pollution. Since masks have become a daily necessity for protection against virus infections, it is necessary to review the usage and disposal of masks during the pandemic for future management. In this study, we constructed a dynamic model by introducing related parameters to estimate daily mask usage in 214 countries from January 22, 2020 to July 31, 2022. And we validated the accuracy of our model by establishing a dataset based on published survey data. Our results show that the cumulative mask usage has reached 800 billion worldwide, and the microplastics released from discarded masks due to mismanagement account for 3.27% of global marine microplastic emissions in this period. Furthermore, we illustrated the response relationship between mask usage and the infection rates. We found a marginally significant negative correlation existing between the mean daily per capita mask usage and the rate of cumulative confirmed cases within the range of 25% to 50%. This indicates that if the rate reaches the specified threshold, the preventive effect of masks may become evident.

Immobilization of polypyrrole on waste face masks using a novel in-situ-surface polymerization method: removal of Cr(VI) from electroplating wastewater

In this work, polypyrrole (PPy) was synthesized on the surface of waste surgical face masks (SFM) with a novel environmentally-friendly in-situ-surface polymerization approach and used as an adsorbent for removing hexavalent chromium (Cr(VI)). In this method, the SFM surface was activated using KMnO4, resulting in the immobilization of porous MnO2, on which pyrrole can be polymerized efficiently. The novelty of this method is the presence of the oxidant on the surface before the polymerization step, which results in a better surface modification with polypyrrole. This method provides adsorbents with higher adsorption capacity compared to the conventional polymerization method with ammonium persulfate (APS). The adsorbent prepared at the mass ratios of 1.0 and 2.0; respectively, for KMnO4/SFM and pyrrole/SFM showed the highest performance. The adsorbent characterization revealed the successful polymerization of pyrrole on the surface of SFM. Reusability of the KMnO4 and pyrrole solutions were successful with remarkable results, showing the advantage of this technique compared to the conventional polymerization method with APS. The effect of different factors on the adsorption process was investigated. The removal rate was around 98% under the optimum conditions (pH, 2; adsorbent dosage, 3 g L-1; contact time, 60 min). The equilibrium data were well fitted by Langmuir isotherm (R2 =  0.9999). Kinetic investigations revealed that the adsorption process fitted well with the pseudo-second-order model. The adsorbent was regenerated for up to five cycles. One of the most important advantages of the proposed method compared to other methods is the reduction of wastewater during the synthesis process.

Domestic Facemask Waste Policy Based on Environmental Ethics in the Covid-19 Pandemic: Urgency and Challenges

Introduction

The Covid-19 pandemic greatly affected various aspects of life. To prevent and control its spread, people are morally and legally obliged to wear face facemasks. The use of facemasks brings many waste problems. However, the Indonesian policy on facemask waste management does not regard the massive environmental consequences, as the amount of domestic facemask waste reaches hundreds of tons daily with limited management capacity application. Hence, this study aims to assess current issues and policies on facemask waste from the perspective of environmental ethics.

Methods

This research used the juridical-normative method, where legal rules and principles were processed to address current issues, supported by literature sources. This research employed qualitative approach to collect and analyze data.

Results

Results showed that there was a legal void which caused terrible facemask waste management in Indonesia. There was confusion in categorizing facemask waste, whether it is domestic or infectious waste, causing hazards in its management. From a deep ecology perspective, the applied facemask waste management was only beneficial for humans while completely neglecting biotic and abiotic components. To overcome this, several suggestions were: 1) categorizing domestic disposable facemask waste as hazardous waste, 2) applying sanctions for the violation of norms and tight social control on first-level management of facemask waste, and 3) using reusable facemask.

Conclusion

The obligation of wearing facemasks that were protective for humans during the Covid-19 pandemic must be followed with policies regulating facemask waste management that consider the environment and its biotic and abiotic components.

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.

Does medical waste research during COVID-19 meet the challenge induced by the pandemic to waste management?

The COVID-19 pandemic has resulted in an unprecedented amount of medical waste, presenting significant challenges for the safe disposal of hazardous waste. A systematic review of existing research on COVID-19 and medical waste can help address these challenges by providing insights and recommendations for effective management of the massive medical waste generated during the pandemic. This study utilized bibliometric and text mining methods to survey the scientific outcomes related to COVID-19 and medical waste, drawing on data from the Scopus database. The results show that the spatial distribution of medical waste research is unbalanced. Surprisingly, developing countries rather than developed countries lead research in this area. Especially, China, a major contributor to the field, has the highest number of publications and citations, and is also a centre of international cooperation. The main study authors and research institutions are also mainly from China. And the research on medical waste is a multidisciplinary field. Text mining analysis shows that COVID-19 and medical waste research is mainly organized around four themes: (i) medical waste from personal protective equipment; (ii) research on medical waste in Wuhan, China; (iii) threats of medical waste to the environment and (iv) disposal and management of medical waste. This would serve to better understand the current state of medical waste research and to provide some implications for future research.

Engineering surgical face masks with photothermal and photodynamic plasmonic nanostructures for enhancing filtration and on-demand pathogen eradication

The shortage of face masks and the lack of antipathogenic functions has been significant since the recent pandemic's inception. Moreover, the disposal of an enormous number of contaminated face masks not only carries a significant environmental impact but also escalates the risk of cross-contamination. This study proposes a strategy to upgrade available surgical masks into antibacterial masks with enhanced particle and bacterial filtration. Plasmonic nanoparticles can provide photodynamic and photothermal functionalities for surgical masks. For this purpose, gold nanorods act as on-demand agents to eliminate pathogens on the surface of the masks upon near-infrared light irradiation. Additionally, the modified masks are furnished with polymer electrospun nanofibrous layers. These electrospun layers can enhance the particle and bacterial filtration efficiency, not at the cost of the pressure drop of the mask. Consequently, fabricating these prototype masks could be a practical approach to upgrading the available masks to alleviate the environmental toll of disposable face masks.

A review on medical waste treatment in COVID-19 pandemics: Technologies, managements and future strategies

Since the outbreak of COVID-19 few years ago, the increasing of the number of medical waste has become a huge issue because of their harmful impact to environment. A major concern associated to the limitation of technologies for dealing with medical waste, especially conventional technologies, are overcapacities since pandemic occurs. Moreover, the outbreak of new viruses from post COVID-19 should become a serious attention to be prevented not only environmental issues but also the spreading of viruses to new pandemic near the future. The high possibility of an outbreak of new viruses and mutation near the future should be prevented based on the experience associated with the SARS-CoV-2 virus in the last 3 yr. This review presented information and strategies for handling medical waste during the outbreak of COVID-19 and post-COVID-19, and also information on the current issues related to technologies, such as incineration, pyrolysis/gasification, autoclaves and microwave treatment for the dealing with high numbers of medical waste in COVID-19 to prevent the transmission of SARS-CoV-2 virus, their advantages and disadvantages. Plasma technology can be considered to be implemented as an alternative technology to deal with medical waste since incinerator is usually over capacities during the pandemic situation. Proper treatment of specific medical waste in pandemics, namely face masks, vaccine vials, syringes, and dead bodies, are necessary because those medical wastes are mediums for transmission of the SARS-CoV-2 virus. Furthermore, emission controls from incinerator and plasma are necessary to be implemented to reduce the high concentration of CO2, NOx, and VOCs during the treatment. Finally, future strategies of medical waste treatment in the perspective of potential outbreak pandemic from new mutation viruses are discussed in this review paper.Implications: Journal of the air and waste management association may consider our review paper to be published. In this review, we give important information related to the technologies, managements and strategies for handling the medical waste and control the transmission of SARS-CoV-2 virus, starting from proper technology to control the high number of medical waste, their pollutants and many strategies for controlling the spreading of SARS-CoV-2 virus. Moreover, this review also describes some strategies associated with control the transmission not only the SARS-CoV-2 virus but also the outbreak of new viruses near the future.

Recycling facemasks into civil construction material to manage waste generated during COVID-19

Growing plastic pollution in the context of COVID-19 has caused significant challenges, exacerbating this already out-of-control issue. The pandemic has considerably boosted the demand for personal protective equipment (PPE), such as facemasks and gloves, all over the globe, and mismanaging this growing plastic pollution has harmed the environment and wildlife significantly. To mitigate negative environmental impacts, it is necessary to develop and implement effective waste management strategies. This present study estimated the daily facemask generation throughout the pandemic in Iran based on the distribution of urban and rural populations and, likewise, the daily generation of hand gloves in the COVID-19 era and the amount of medical waste generated by COVID-19 patients were calculated. In the next step, the quantities of discarded facemasks dumped into the Caspian Sea, the Persian Gulf, and the Gulf of Oman from the coastal cities were determined. Finally, the innovative alternatives for repurposing discarded facemasks in civil construction materials such as concrete, pavement, and partition wall panel were discussed.

Towards environmentally sustainable management: A review on the generation, degradation, and recycling of polypropylene face mask waste

There has been a considerable increase in the use of face masks in the past years. Managing face mask waste has become a global concern, as the current waste management system is insufficient to deal with such a large quantity of solid waste. The drastic increase in quantity, along with the material's inability to degrade plastic components such as polypropylene, has led to a large accumulation of plastic waste, causing a series of environmental and ecological challenges. In addition, the growing use also imposes pressure on waste management methods such as landfill and incineration, raising concerns about high energy consumption, low value-added utilization, and the release of additional pollutants during the process. This article initially reviews the impact of mask-related plastic waste generation and degradation behavior in the natural environment. It then provides an overview of various recently developed methods for recycling face mask plastic waste. The article also offers forward-looking strategies and recommendations on face mask plastic waste management. The review aims to provide guidance on harnessing the complexities of mask waste and other medical plastic pollution issues, as well as improving the current waste management system's deficiencies and inefficiencies in tackling the growing plastic waste problem.

Effect of microfibers induced toxicity in marine sedentary polychaete Hydroides elegans: Insight from embryogenesis axis

Presence of surgical face masks in the environment are more than ever before after the COVID-19 pandemic, and it poses a newer threat to aquatic habitats around the world due to microfibers (MFs) and other contaminants that get discharged when these masks deteriorate. The mechanism behind the developmental toxicity of MFs, especially released from surgical masks, on the early life stages of aquatic organisms are not well understood. Toxicity test were developed to examine the effects of MFs released from surgical facemask upon deterioration using the early gametes and early life stages of marine sedentary polychaete Hydroides elegans. For MFs release, cut pieces of face masks were allowed to degrade in seawater for different time points (1 day, 30 days and 120 days) after which the fibers were obtained for further toxicity studies. The gametes of H. elegans were exposed to the MFs (length < 20 μm) separately for 20 min at a concentration of 50 MFs/ml before fertilization. In addition, we also analyzed the experimental samples for heavy metals and organic substances released from face masks. Our findings demonstrated that gametes exposed to MFs affected the percentage of successful development, considerably slowed down the mitotic cell division and significantly postponed the time of larval hatching and also produced an adverse effect during embryogenesis. When the sperm were exposed fertilization rate was decreased drastically, whereas when the eggs were exposed to MFs fertilization was not inhibited but a delay in early embryonic development observed. In addition the release of heavy metals and other volatile organics from the degrading face masks could also contribute to overall toxicity of these materials in environment. Our study thus shows that inappropriately discarded face masks and MFs and other pollutants released from such face masks could pose long-term hazard to coastal ecosystems.

Luminescent Metal-Organic Frameworks for Electrochemiluminescent Detection of Water Pollutants

The modern lifestyle has increased our utilization of pollutants such as heavy metals, aromatic compounds, and contaminants that are of rising concern, involving pharmaceutical and personal products and other materials that may have an important environmental impact. In particular, the ultimate results of the intense use of highly stable materials, such as heavy metals and chemical restudies, are that they turn into waste materials, which, when discharged, accumulate in environmental water bodies. In this context, the present review presents the application of metal-organic frameworks (MOFs) in electrochemiluminescent (ECL) sensing for water pollutant detection. MOF composites applied as innovative luminophore or luminophore carriers, materials for electrode modification, and the enhancement of co-reaction in ECL sensors have enabled the sensitive monitoring of some of the most common contaminants of emerging concern such as heavy metals, volatile organic compounds, pharmaceuticals, industrial chemicals, and cyanotoxins. Moreover, we provide future trends and prospects associated with ECL MOF composites for environmental sensing.

COVID-19's environmental impacts: Challenges and implications for the future

Strict measures have curbed the spread of COVID-19, but waste generation and movement limitations have had an unintended impact on the environment over the past 3 years (2020-2022). Many studies have summarized the observed and potential environmental impacts associated with COVID-19, however, only a few have quantified and compared the effects of these unintended environmental impacts; moreover, whether COVID-19 policy stringency had the same effects on the main environmental topic (i.e., CO2 emissions) across the 3 years remains unclear. To answer these questions, we conducted a systematic review of the recent literature and analyzed the main findings. We found that the positive environmental effects of COVID-19 have received more attention than the negative ones (50.6 % versus 35.7 %), especially in emissions reduction (34 % of total literature). Medical waste (14.5 %) received the highest attention among the negative impacts. Although global emission reduction, especially in terms of CO2, has received significant attention, the positive impacts were temporary and only detected in 2020. Strict COVID-19 policies had a more profound and significant effect on CO2 emissions in the aviation sector than in the power and industry sectors. For example, compared with 2019, international aviation related CO2 emissions dropped by 59 %, 49 %, and 25 % in 2020, 2021, and 2022, respectively, while industry related ones dropped by only 3.16 % in 2020. According to our developed evaluation matrix, medical wastes and their associated effects, including the persistent pollution caused by antibiotic resistance genes, heavy metals and microplastics, are the main challenges post the pandemic, especially in China and India, which may counteract the temporary environmental benefits of COVID-19. Overall, the presented results demonstrate methods to quantify the environmental effects of COVID-19 and provide directions for policymakers to develop measures to address the associated environmental issues in the post-COVID-19 world.

Carbon dioxide gasification characteristics of disposable COVID-19 masks using bubbling fluidized bed reactor

The global demand for masks has increased significantly owing to COVID-19 and mutated viruses, resulting in a massive amount of mask waste of approximately 490,000 tons per month. Mask waste recycling is challenging because of the composition of multicomponent polymers and iron, which puts them at risk of viral infection. Conventional treatment methods also cause environmental pollution. Gasification is an effective method for processing multicomponent plastics and obtaining syngas for various applications. This study investigated the carbon dioxide gasification and tar removal characteristics of an activated carbon bed using a 1-kg/h laboratory-scale bubble fluidized bed gasifier. The syngas composition was analyzed as 10.52 vol% of hydrogen, 6.18 vol% of carbon monoxide, 12.05 vol% of methane, and 14.44 vol% of hydrocarbons (C2-C3). The results of carbon dioxide gasification with activated carbon showed a tar-reduction efficiency of 49%, carbon conversion efficiency of 45.16%, and cold gas efficiency of 88.92%. This study provides basic data on mask waste carbon dioxide gasification using greenhouse gases as useful product gases.

Event-related potentials for investigating the willingness to recycle household medical waste

Household medical waste (HMW) recycling in the reverse supply chain has become a primary channel for infectious, toxic, or radioactive substances for environmental protection and a circular economy. Recycling managers need to understand the recycling decision-making mechanisms of households to improve the intention-behavior gap and recycling participation rate, especially in cognitive neuroscience. This study designed an event-related potential (ERPs) experiment to explore the differences in ERPs components between the willingness and unwillingness to make recycling decisions. Our findings confirmed that willingness and unwillingness to recycle can lead to a significant difference in the P300 and N400 scores. A larger P300 was evoked by willingness rather than unwillingness in the prefrontal, frontal, and frontal-temporal regions. This indicates that willingness to recycle results from a rational choice in the decision-making process. However, a larger N400 was evoked by unwillingness rather than willingness in the parietal, parietal-occipital, and occipital regions. A negative wave was evoked in households unwilling to recycle because they thought it was dangerous and unsanitary, causing a higher conflict with intrinsic cognition. The combination of HMW recycling decisions and neurology may accurately measure pro-environmental decision-making processes through brain science. Advancing the knowledge of psychological and brain mechanism activities for understanding pro-environmental choices. In turn, this can help recycling managers to accurately understand household demands for increasing the recycling intention and designing effective HMW take-back systems to solve the intention-behavior gap related to the global recycling dilemma.

Material flow analysis-based assessment of polypropylene-fiber-containing microplastics released from disposable masks: Characterizing distribution in the environmental media

With the upsurge in the use of disposable masks during the coronavirus disease pandemic, improper disposal of discarded masks and their negative impact on the environment have emerged as major issues. Improperly disposed of masks release various pollutants, particularly microplastic (MP) fibers, which can harm both terrestrial and aquatic ecosystems by interfering with the nutrient cycling, plant growth, and the health and reproductive success of organisms. This study assesses the environmental distribution of polypropylene (PP)-containing MPs, generated from disposable masks, using material flow analysis (MFA). The system flowchart is designed based on the processing efficiency of various compartments in the MFA model. The highest amount of MPs (99.7 %) is found in the landfill and soil compartments. A scenario analysis reveals that waste incineration significantly reduces the amount of MP transferred to landfills. Therefore, considering cogeneration and gradually increasing the incineration treatment rate are crucial to manage the processing load of waste incineration plants and minimize the negative impact of MPs on the environment. The findings provide insights into the potential environmental exposure associated with the improper disposal of waste masks and indicate strategies for sustainable mask disposal and management.

Combined effects of P25 TiO2 nanoparticles and disposable face mask leachate on microalgae Scenedesmus obliquus: analysing the effects of heavy metals

Disposable surgical face masks extensively used during the COVID-19 outbreak would release microplastics into the aquatic environment. The increasing usage of titanium dioxide nanoparticles (nTiO2) in various consumer items has led to its ubiquitous presence in freshwater systems. This study determined the quantity and kind of microplastics discharged from disposable surgical face masks. The mask-leached microplastics were identified to be polypropylene of varying shapes and sizes, spanning from 1 μm to 15 μm. In addition, heavy metals like Cd, Cr, and Hg leached from the face masks were quantified. Four concentrations of nTiO2, 0.5, 1, 2, and 4 mg L-1, were mixed with leached solution from the face masks to perform the combined toxicity test on freshwater algae, Scenedesmus obliquus. A dose-dependent decrease in algal cell viability was observed upon treatment with various concentrations of nTiO2 individually. The mixtures of nTiO2 and the leached solution from the face masks exhibited significantly more toxicity in the algal cells than in their pristine forms. nTiO2 promoted increased production of oxidative stress and antioxidant enzyme activities resulting in cellular damage and decreased photosynthesis. These impacts were elevated when the algal cells were treated with the binary mixture. Furthermore, the heavy metal ions leached from face masks also contributed to the toxic effects. Our study shows that the leachates from disposable surgical face masks, combined with nTiO2, may pose a severe environmental threat.

Regulation of biomedical waste management in Kazakhstan during the pandemic in the context of best practices

The COVID-19 pandemic actualized questions about the proper management of biomedical waste while creating several regulatory challenges and requiring countries to look for an appropriate response. These issues have become particularly relevant for Kazakhstan, where waste management issues traditionally face inefficient legal regulation and are particularly acute. This study aims to answer the question of what regulatory problems Kazakhstan currently face in the area of proper biomedical waste management, and how existing foreign experience can help solve them. The present study highlights several pertinent challenges within the context of medical waste management. These include issues concerning the licencing activities associated with waste management, the absence of well-defined regional plans for the management of medical waste and the lack of effective strategies to address the proper handling and disposal of this specific category of waste. At the same time, there are reasons to say that the country requires additional technical and expert support in the field of medical waste management.

Mercury budgets in the suspended particulate matters of the Yangtze River

Riverine processes are crucial for the biogeochemical cycle of mercury (Hg). The Yangtze River, the largest river in East Asia, discharges a substantial amount of Hg into the East China Sea. However, the influencing factors of the Hg budget and its recent trends remain unclear. This study quantitatively analyzed the total Hg concentration (THg) in suspended particulate matter (SPM) in the Yangtze River and calculated the Hg budget in 2018 and 2021. The results showed that the total Hg concentrations varied substantially along the river, with concentrations ranging from 23 to 883 μg/kg in 2018 and 47 to 146 μg/kg in 2021. The average Hg flux to China Sea in 2018 and 2021 were approximately 10 Mg/yr, lower than in 2016 (48 Mg/yr). Over 70% of the SPM was trapped in the Three Gorges Dam (TGD), and 22 Mg/yr of Hg settled in the TGD in 2018 and 10 Mg/yr in 2021. Hg fluxes in the Yangtze River watershed were driven by various factors, including decreased industrial emissions, increased agriculture emissions, and decreased soil erosion flux. We found that in the upper reach of the Yangtze River changed from sink to source of Hg possibly due to the resuspension of sediments, which implies that the settled sediments could be a potential source of Hg for downstream. Overall, emission control policies may have had a positive impact on reducing Hg flux to the East China Sea from 2016 to 2021, but more efforts are needed to further reduce Hg emissions.

A cross-jurisdictional comparison on residential waste collection rates during earlier waves of COVID-19

There is currently a lack of studies on residential waste collection during COVID-19 in North America. SARIMA models were developed to predict residential waste collection rates (RWCR) across four North American jurisdictions before and during the pandemic. Unlike waste disposal rates, RWCR is relatively less sensitive to the changes in COVID-19 regulatory policies and administrative measures, making RWCR more appropriate for cross-jurisdictional comparisons. It is hypothesized that the use of RWCR in forecasting models will help us to better understand the residential waste generation behaviors in North America. Both SARIMA models performed satisfactorily in predicting Regina's RWCR. The SARIMA DCV model's performance is noticeably better during COVID-19, with a 15.7% lower RMSE than that of the benchmark model (SARIMA BCV). The skewness of overprediction ratios was noticeably different between jurisdictions, and modeling errors were generally lower in less populated cities. Conflicting behavioral changes might have altered the residential waste generation characteristics and recycling behaviors differently across the jurisdictions. Overall, SARIMA DCV performed better in the Canadian jurisdiction than in U.S. jurisdictions, likely due to the model's bias on a less variable input dataset. The use of RWCR in forecasting models helps us to better understand the residential waste generation behaviors in North America and better prepare us for a future global pandemic.

Face masks: a COVID-19 protector or environmental contaminant?

Face masks, a prime component of personal protective equipment (PPE) items, have become an integral part of human beings to survive under the ongoing COVID-19 pandemic situation. The global population requires an estimated 130 billion face masks and 64 billion gloves/month, while the COVID-19 pandemic has led to the daily disposal of approximately 3.5 billion single-use face masks, resulting in a staggering 14,245,230.63 kg of face mask waste. The improper disposal of face mask wastes followed by its mismanagement is a challenge to the scientists as the wastes create pollution leading to environmental degradation, especially plastic pollution (macro/meso/micro/nano). Each year, an estimated 0.15-0.39 million tons of COVID-19 face mask waste, along with 173,000 microfibers released daily from discarded surgical masks, could enter the marine environment, while used masks have a significantly higher microplastic release capacity (1246.62 ± 403.50 particles/piece) compared to new masks (183.00 ± 78.42 particles/piece). Surgical face masks emit around 59 g CO2-eq greenhouse gas emissions per single use, cloth face masks emit approximately 60 g CO2-eq/single mask, and inhaling or ingesting microplastics (MPs) caused adverse health problems including chronic inflammation, granulomas or fibrosis, DNA damage, cellular damage, oxidative stress, and cytokine secretion. The present review critically addresses the role of face masks in reducing COVID-19 infections, their distribution pattern in diverse environments, the volume of waste produced, degradation in the natural environment, and adverse impacts on different environmental segments, and proposes sustainable remediation options to tackle environmental challenges posed by disposable COVID-19 face masks.

Personal protective equipment-derived pollution during Covid-19 era: A critical review of ecotoxicology impacts, intervention strategies, and future challenges

During the COVID-19 pandemic, people used personal protective equipment (PPE) to lessen the spread of the virus. The release of microplastics (MPs) from discarded PPE is a new threat to the long-term health of the environment and poses challenges that are not yet clear. PPE-derived MPs have been found in multi-environmental compartments, e.g., water, sediments, air, and soil across the Bay of Bengal (BoB). As COVID-19 spreads, healthcare facilities use more plastic PPE, polluting aquatic ecosystems. Excessive PPE use releases MPs into the ecosystem, which aquatic organisms ingest, distressing the food chain and possibly causing ongoing health problems in humans. Thus, post-COVID-19 sustainability depends on proper intervention strategies for PPE waste, which have received scholarly interest. Although many studies have investigated PPE-induced MPs pollution in the BoB countries (e.g., India, Bangladesh, Sri Lanka, and Myanmar), the ecotoxicity impacts, intervention strategies, and future challenges of PPE-derived waste have largely gone unnoticed. Our study presents a critical literature review covering the ecotoxicity impacts, intervention strategies, and future challenges across the BoB countries (e.g., India (162,034.45 tons), Bangladesh (67,996 tons), Sri Lanka (35,707.95 tons), and Myanmar (22,593.5 tons). The ecotoxicity impacts of PPE-derived MPs on human health and other environmental compartments are critically addressed. The review's findings infer a gap in the 5R (Reduce, Reuse, Recycle, Redesign, and Restructure) Strategy's implementation in the BoB coastal regions, hindering the achievement of UN SDG-12. Despite widespread research advancements in the BoB, many questions about PPE-derived MPs pollution from the perspective of the COVID-19 era still need to be answered. In response to the post-COVID-19 environmental remediation concerns, this study highlights the present research gaps and suggests new research directions considering the current MPs' research advancements on COVID-related PPE waste. Finally, the review suggests a framework for proper intervention strategies for reducing and monitoring PPE-derived MPs pollution in the BoB countries.

A multi-jurisdictional study on the quantification of COVID-19 household plastic waste in six Latin American countries

This study examines urban plastic waste generation using a citizen science approach in six Latin American countries during a global pandemic. The objectives are to quantify generation rates of masks, gloves, face shields, and plastic bags in urban households using online survey and perform a systematic cross-jurisdiction comparisons in these Latin American countries. The per capita total mask generation rates ranged from 0.179 to 0.915 mask cap-1 day-1. A negative correlation between the use of gloves and masks is observed. Using the average values, the approximate proportion of masks, gloves, shields, and single-use plastic bags was 34:5:1:84. We found that most studies overestimated face mask disposal rate in Latin America due to the simplifying assumptions on the number of masks discarded per person, masking prevalence rate, and average mask weight. Unlike other studies, end-of-life PPE quantities were directly counted and reported by the survey participants. Both of the conventional weight-based estimates and the proposed participatory survey are recommended in quantifying COVID waste. Participant' perception based on the Likert scale is generally consistent with the waste amount generated. Waste policy and regulation appear to be important in daily waste generation rate. The results highlight the importance of using measured data in waste estimates.

Microplastics in soils during the COVID-19 pandemic: Sources, migration and transformations, and remediation technologies

The COVID-19 pandemic has led to a notable upsurge of 5-10 % in global plastic production, which could have potential implications on the soil quality through increased microplastics (MPs) content. The elevated levels of MPs in the soil poses a significant threat to both the environment and human health, hence necessitating the remediation of MPs in the environment. Despite the significant attention given to MPs remediation in aqueous environments, less consideration has been given to MPs remediation in the soil. Consequently, this review highlights the major sources of MPs in the soil, their migration and transformation behaviors during the COVID-19 pandemic, and emphasizes the importance of utilizing remediation technologies such as phytoremediation, thermal treatment, microbial degradation, and photodegradation for MPs in the soil. Furthermore, this review provides a prospective outlook on potential future remediation methods for MPs in the soil. Although the COVID-19 pandemic is nearing its end, the long-term impact of MPs on the soil remains, making this review a valuable reference for the remediation of MPs in the post-pandemic soil.

A novel investigations on medical and non-medical mask performance with influence of marine waste microplastics (polypropylene)

The entire human race is struggling with the spread of COVID-19. Worldwide, the wearing of face masks is indispensable to prevent such spread. Despite numerous studies reporting on the fabrication of face masks and surgical masks to reduce spread and thus human deaths, this novel work is considered the marine waste of microplastics, namely Polypropylene (PP) polymer, used to fabricate non-woven fabric masks through the melt-blown process. This experimental work aims to maximize the mask's quality and minimize its fabrication cost by optimizing the melt-blown process parameters and using microplastics. The melt-blown process was used to make masks. Parameters such as extruder temperature, hot air temperature, melt flow rate, and die-to-collector distance (DCD) were investigated as independent variables. The quality of the mask was investigated in terms of bacterial filtration efficiency (BFE), particle filtration efficiency (PFE), and differential pressure. The Taguchi L16 orthogonal array and Taguchi analysis were employed for experimental design and statistical optimization, respectively. The results reveal that the higher BFE and PFE are recorded at 96.7 % and 98.6 %, respectively. The surface morphological investigation on different layers ensured the fine and uniform porosity of the layers and exhibited minimum breath resistance (a low differential pressure of 0.00152 kPa/cm2). Hence the chemically treated marine waste microplastics improved the masks' performance.

Impact of disposable mask microplastics pollution on the aquatic environment and microalgae growth

The COVID-19 pandemic has mandated people to use medical masks to protect the public. However the improper management of disposable mask waste has led to the increase of marine pollution, in terms of water quality, and the decline in aquatic microorganisms. The aim of this research was to investigate the impact of disposable mask waste on fresh water and microalgae biomass quality. Disposable masks (untreated or treated with Enterococcus faecalis) were placed in 10-L glass reactors containing fresh water or water containing algal Chlorella sp. and its growth supplements (Chlorella medium) (four 10-L reactors in total) and kept in controlled conditions for 3 months. Water and biomass yield quality were evaluated using water quality analysis, spectroscopy, scanning electron microscopy (SEM), and proximate lipid and protein analysis. Disposable masks, incubated in either fresh water or Chlorella medium, affected several water quality parameters such as chemical oxygen demand (COD), biological oxygen demand (BOD), dissolved oxygen (DO), and pH. Microplastic identification revealed that some fibers were present in the water following a 100-day treatment process. Fourier transform-infrared spectroscopy (FTIR) analysis was used to determine the change in important, organic functional groups and highlighted the disappearance of a peak at 1530 cm-1 corresponding to the primary protein (C-N) and the appearance of new peaks at 1651 cm-1 and 1270 cm-1 corresponding to methyl alcohol (CH2OH) and ketone (C = O), respectively. This indicated the detrimental effect of disposable mask fragmentation on the biomass quality. The SEM investigation has shown a damage to the surface membrane of Chlorella sp. cells. Altogether, disposable masks decreased the water quality and damaged microalgae by inhibiting their growth. Therefore, the disposable mask contaminated by various microbes, after being used by a human, may be one of the most dangerous hazards to the environment.

Biogenic production of silver, zinc oxide, and cuprous oxide nanoparticles, and their impregnation into textiles with antiviral activity against SARS-CoV-2

Nanotechnology is being used to fight off infections caused by viruses, and one of the most outstanding nanotechnological uses is the design of protective barriers made of textiles functionalized with antimicrobial agents, with the challenge of combating the SARS-CoV-2 virus, the causal agent of COVID-19. This research is framed within two fundamental aspects: the first one is linked to the proposal of new methods of biogenic synthesis of silver, cuprous oxide, and zinc oxide nanoparticles using organic extracts as reducing agents. The second one is the application of nanomaterials in the impregnation (functionalization) of textiles based on methods called "in situ" (within the synthesis), and "post-synthesis" (after the synthesis), with subsequent evaluation of their effectiveness in reducing the viral load of SARS-CoV-2. The results show that stable, monodisperse nanoparticles with defined geometry can be obtained. Likewise, the "in situ" impregnation method emerges as the best way to adhere nanoparticles. The results of viral load reduction show that 'in situ' textiles with Cu2O NP achieved a 99.79% load reduction of the SARS-CoV-2 virus.

Electrospun nanofibers for medical face mask with protection capabilities against viruses: State of the art and perspective for industrial scale-up

Face masks have proven to be a useful protection from airborne viruses and bacteria, especially in the recent years pandemic outbreak when they effectively lowered the risk of infection from Coronavirus disease (COVID-19) or Omicron variants, being recognized as one of the main protective measures adopted by the World Health Organization (WHO). The need for improving the filtering efficiency performance to prevent penetration of fine particulate matter (PM), which can be potential bacteria or virus carriers, has led the research into developing new methods and techniques for face mask fabrication. In this perspective, Electrospinning has shown to be the most efficient technique to get either synthetic or natural polymers-based fibers with size down to the nanoscale providing remarkable performance in terms of both particle filtration and breathability. The aim of this Review is to give further insight into the implementation of electrospun nanofibers for the realization of the next generation of face masks, with functionalized membranes via addiction of active material to the polymer solutions that can give optimal features about antibacterial, antiviral, self-sterilization, and electrical energy storage capabilities. Furthermore, the recent advances regarding the use of renewable materials and green solvent strategies to improve the sustainability of electrospun membranes and to fabricate eco-friendly filters are here discussed, especially in view of the large-scale nanofiber production where traditional membrane manufacturing may result in a high environmental and health risk.

Assessing the challenges to medical waste management during the COVID-19 pandemic: Implications for the environmental sustainability in the emerging economies

Emerging economies are struggling with proper and efficient management of waste due to their constrained resources and weak management. In recent days, this crisis has worsened due to the outbreak of the highly contagious COVID-19 pandemic. To avoid building up stockpiles and contaminating communities with potentially contagious medical waste (MW), and to ensure sustainability in the current and post-COVID-19 era, it is a dire need to develop and implement a safe and efficient medical waste management (MWM) system. This research, thereby, aims to identify, assess, and prioritize the key challenges to efficient and sustainable MWM to mitigate the impacts of the disruptions caused by situations like the pandemic in emerging economies. An integrated approach consisting of the Best-Worst Method (BWM), Interpretive Structural Modeling (ISM), and Cross-Impact Matrix Multiplication Applied to Classification (MICMAC) has been proposed to achieve the objectives. Based on the literature review and expert feedback, a total of seventeen challenges were identified and later prioritized by using BWM. The top twelve challenges have been further analyzed using ISM-MICMAC to examine their interrelationships. This study reveals that lack of proper law enforcement and insufficient financial support from investors and the government are two crucial challenges for efficient MWM implementation. The research insights can assist healthcare facility administrators, practitioners, and city managers in identifying the associated challenges and shaping strategic decisions for establishing and managing efficient MWM systems to ensure sustainable development in the post-COVID-19 era.

Properties of Composites Based on Recycled Polypropylene and Silico-Aluminous Industrial Waste

There is an ever-growing interest in recovering and recycling waste materials due to their hazardous nature to the environment and human health. Recently, especially since the beginning of the COVID-19 pandemic, disposable medical face masks have been a major source of pollution, hence the rise in studies being conducted on how to recover and recycle this waste. At the same time, fly ash, an aluminosilicate waste, is being repurposed in various studies. The general approach to recycling these materials is to process and transform them into novel composites with potential applications in various industries. This work aims to investigate the properties of composites based on silico-aluminous industrial waste (ashes) and recycled polypropylene from disposable medical face masks and to create usefulness for these materials. Polypropylene/ash composites were prepared through melt processing methods, and samples were analyzed to get a general overview of the properties of these composites. Results showed that the polypropylene recycled from face masks used together with silico-aluminous ash can be processed through industrial melt processing methods and that the addition of only 5 wt% ash with a particle size of less than 90 µm, increases the thermal stability and the stiffness of the polypropylene matrix while maintaining its mechanical strength. Further investigations are needed to find specific applications in some industrial fields.

Literature mapping of waste sorting and recycling behavior research: a visual analysis using CiteSpace

As the severity of global waste pollution continues to escalate, governments are increasingly prioritizing the promotion of waste sorting. This study engaged in the literature mapping of waste sorting and recycling behavior research currently available on the Web of Science using CiteSpace. First, studies on waste sorting behavior have grown rapidly since 2017. The top three continents publishing on this topic were Asia, Europe, and North America. Second, the top journals, Resources Conservation and Recycling and Environment and Behavior, were important to this field. Third, analyses of waste sorting behavior were mainly conducted by environmental psychologists. Ajzen had the highest co-citation count, as the theory of planned behavior has widely been used in this field. Fourth, the top three co-occurring keywords were "attitude," "recycling behavior," and "planned behavior." There was also a recent focus on "food waste." The research trend was found to be refined and accurately quantified.

Unmasking effects of masks: Microplastics released from disposable surgical face masks induce toxic effects in microalgae Scenedesmus obliquus and Chlorella sp

During the COVID-19 pandemic billions of face masks were used since they became a necessity in everyone's lives. But these were not disposed properly and serve as one of the most significant sources of micro and nano plastics in the environment. The effects of mask leached plastics in aquatic biota remains largely unexplored. In this work, we quantified and characterized the released microplastics from the three layers of the mask. The outer layer of the face mask released more microplastics i.e., polypropylene than middle and inner layers. We investigated and compared the acute toxic effects of the released microplastics between Scenedesmus obliquus and Chlorella sp. The results showed a decrease in cell viability, photosynthetic yield, and electron transport rate in both the algal species. This was accompanied by an increase in oxidative stress markers such reactive oxygen species (ROS) and malondialdehyde (MDA) content. There was also a significant rise of antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT) in both the algal cells. Furthermore, morphological changes like cell aggregation and surface chemical changes in the algae were ascertained by optical microscopy and FTIR spectroscopy techniques, respectively. The tests confirmed that Scenedesmus obliquus was more sensitive than Chlorella sp. to the mask leachates. Our study clearly revealed serious environmental risk posed by the released microplastics from surgical face masks. Further work with other freshwater species is required to assess the environmental impacts of the mask leachates.

Different weathering conditions affect the release of microplastics by masks

A generation of microplastics caused by improper disposal of disposable masks has become a non-negligible environmental concern. In order to investigate the degradation mechanisms of masks and the release of microplastics under different environmental conditions, the masks are placed in 4 common environments. After 30 days of weathering, the total amount and release kinetics of microplastics released from different layers of the mask were studied. The chemical and mechanical properties of the mask were also discussed. The results showed that the mask released 25141±3543 particles/mask into the soil, which is much more than the sea and river water. The release kinetics of microplastics fit the Elovich model better. All samples correspond to the release rate of microplastics from fast to slow. Experiments show that the middle layer of the mask is released more than the other layers, and the amount of release was highest in the soil. And the tensile capacity of the mask is negatively correlated with its ability to release microplastics in the following order, which are soil > seawater > river > air > new masks. In addition, during the weathering process, the C-C/C-H bond of the mask was broken.

Healthcare waste in Bangladesh: Current status, the impact of Covid-19 and sustainable management with life cycle and circular economy framework

COVID-19 has accelerated the generation of healthcare (medical) waste throughout the world. Developing countries are the most affected by this hazardous and toxic medical waste due to poor management systems. In recent years, Bangladesh has experienced increasing medical waste generation with estimated growth of 3 % per year. The existing healthcare waste management in Bangladesh is far behind the sustainable waste management concept. To achieve an effective waste management structure, Bangladesh has to implement life cycle assessment (LCA) and circular economy (CE) concepts in this area. However, inadequate data and insufficient research in this field are the primary barriers to the establishment of an efficient medical waste management systen in Bangladesh. This study is introduced as a guidebook containing a comprehensive overview of the medical waste generation scenario, management techniques, Covid-19 impact from treatment to testing and vaccination, and the circular economy concept for sustainable waste management in Bangladesh. The estimated generation of medical waste in Bangladesh without considering the surge due to Covid-19 and other unusual medical emergencies would be approximately 50,000 tons (1.25 kg/bed/day) in 2025, out of which 12,435 tons were predicted to be hazardous waste. However, our calculation estimated that a total of 82,553, 168.4, and 2300 tons of medical waste was generated only from handling of Covid patients, test kits, and vaccination from March 2021 to May 2022. Applicability of existing guidelines, and legislation to handle the current situation and feasibility of LCA on medical waste management system to minimize environmental impact were scrutinized. Incineration with energy recovery and microwave sterilization were found to be the best treatment techniques with minimal environmental impact. A circular economy model with the concept of waste minimizaton, and value recovery was proposed for sustainable medical waste management. This study suggests proper training on healthcare waste management, proposing strict regulations, structured research allocation, and implementation of public-private partnerships to reduce, and control medical waste generation for creating a sustainable medical waste management system in Bangladesh.

Plasma degradation of contaminated PPE: an energy-efficient method to treat contaminated plastic waste

The use of PPE has drastically increased because of the SARS-CoV-2 (COVID-19) pandemic as disposable surgical face masks made from non-biodegradable polypropylene (PP) polymers have generated a significant amount of waste. In this work, a low-power plasma method has been used to degrade surgical masks. Several analytical techniques (gravimetric analysis, scanning electron microscopy (SEM), attenuated total reflection-infra-red spectroscopy (ATR-IR), x-ray photoelectron spectroscopy (XPS), thermogravimetric analysis/differential scanning calorimetry (TGA/DSC) and wide-angle x-ray scattering (WAXS)) were used to evaluate the effects of plasma irradiation on mask samples. After 4 h of irradiation, an overall mass loss of 63 ± 8%, through oxidation followed by fragmentation, was observed on the non-woven 3-ply surgical mask, which is 20 times faster than degrading a bulk PP sample. Individual components of the mask also showed different degradation rates. Air plasma clearly represents an energy-efficient tool for treating contaminated PPE in an environmentally friendly approach.

Knowledge and practice of facemask disposal among university students in Thailand: A new normal post the COVID-19 pandemic

The use of facemasks is essential to prevent the transmission of COVID-19. University students are a significant demographic that generates substantial infectious waste due to the new normal practice of using disposable facemasks. In this cross-sectional study, we investigated the facemask disposal knowledge and practices among university students in Thailand between September and October 2022. We used a self-report questionnaire comprising 29 questions to determine the students' demographic characteristics and facemask disposal knowledge and practices. We then applied a logistic regression model to estimate the association between the students' facemask disposal knowledge and practices and their demographic characteristics. A total of 433 participants completed the questionnaire comprising health science (45.27%) and non-health science (54.73%) students. Surgical masks were the most popular masks (89.84%), followed by N95 (26.33%) and cloth masks (9.94%). While their levels of knowledge regarding facemask disposal were poor, the students' practices were good. The factors associated with proper facemask disposal were sex (AOR = 0.469, 95% CI: 0.267, 0.825), academic grade (AOR = 0.427, 95% CI: 0.193, 0.948), and knowledge level (AOR = 0.594, 95% CI: 0.399, 0.886). No demographic factors influenced knowledge. Our findings highlight the influence of facemask disposal knowledge on students' disposal practices. Information promoting the appropriate disposal practices should therefore be promoted extensively. Furthermore, continuous reinforcement by raising awareness and educating students on proper facemask disposal combined with the provision of adequate infectious waste disposal facilities could help reduce the environmental contamination of infectious waste and thus improve general waste management.