ABSTRACT
The pandemic of COVID-19 has led to a surge increase in the production of masks. Due to the rapid propagation of COVID-19 and the long survival time of plastic surfaces, a large number of masks are discharged into the environment without treatment. In this paper, the release of microplastics (MPs) in nature was simulated by using mask samples irradiated by ultraviolet (UV) light. After 28 days of ultraviolet radiation, part of the main chain of the mask was broken and a large number of transparent MPs fell off. The longer the UV irradiation time, the larger the proportion of small particle MPs. The middle layer of surgical mask is the most difficult to release MPs due to charge treatment, and N95 mask is the most difficult to degrade the inner material. © 2022, HARD Publishing Company. All rights reserved.
ABSTRACT
A large amount of disposable plastic face masks (DPFs) is produced and used during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, which results in an inevitable consequence of the dramatic increase of DPFs waste. However, the impact of DPFs exposure to the environment on their toxicity is rarely considered. In this study, a range of 76-276 items/L microplastics (MPs) was detected in the DPFs leachates, and fibrous (> 80.3%) and polypropylene (PP, > 89.2%) MPs were dominant. Co, Cu, Ni, Sr, Ti and Zn, were commonly detected in all leachates of the tested DPFs. Organics, such as acetophenone, 2,4-Di-tert-butylphenol, benzothiazole, bisphenol-A and phthalide, were found in the DPFs leachate, which were including organic solvents and plasticizer. Besides, we first found an emerging environmental risk substance, namely environmentally persistent free radicals (EPFRs), was generated in the DPFs leachates. The characteristic g-factors of the EPFRs was in a range of 2.003-2.004, identified as mixture of carbon- and oxygen-centered radicals. By means of in vitro toxicity assay, the DPFs leachate were confirmed to cause cytotoxicity and oxidative stress. Significantly, it is found that the formed EPFRs could contribute more toxic effects. Furthermore, when compared to N95 respirators, the tested surgical masks tend to release more MPs, leach more metals and organics, and generate more EPFRs. Surgical masks were thus showed higher risk than N95 respirators after exposure to water. This work highlights the importance of understanding the chemical complexity and possible toxicity of DPFs for their risk assessment.
Subject(s)
COVID-19 , Masks , Free Radicals , Humans , Pandemics , Plastics , SARS-CoV-2ABSTRACT
During the COVID-19 pandemic, the extensive use of face masks and protective personal equipment (PPE) kits has led to increasing degree of microplastic pollution (MP) because they are typically discarded into the seas, rivers, streets, and other parts of the environment. Currently, microplastic (MP) pollution has a negative impact on the environment because of high-level fragmentation. Typically, MP pollution can be detected by various techniques, such as microscopic analysis, density separation, and Fourier transform infrared spectrometry. However, there are limited studies on disposable face masks and PPE kits. A wide range of marine species ingest MPs in the form of fibers and fragments, which directly affect the environment and human health; thus, more research and development are needed on the effect of MP pollution on human health. This article provides a perspective on the origin and distribution of MP pollution in waterbodies (e.g., rivers, ponds, lakes, and seas) and wastewater treatment plants, and reviews the possible remediation of MP pollution related to the excessive disposal of face masks and PPE kits to aquatic environments.
ABSTRACT
Due to the characteristics of rapid transmission of COVID-19 and extended survival time on the plastic surface, resulting in a sharp increase in the number of microplastics (MPs) in sludge. In this paper, different amounts of terephthalate (PET) were added to four earthworm-assisted sludge treatment wetland (ESTW) reactors to investigate the effect of MPs on the operation process of ESTW. The results show that the addition of a small number of MPs had little effect on the ESTW reactor, and the negative impact was evident when a large number of MPs. The ESTW4 reactor with 200000 particles/kg the worst organic matter removal and sludge stability. The plant height, root length and chlorophyll growth of the ESTW4 reactor were significantly inhibited, and the yield of catalase (CAT) increased significantly, which proved that a large number of MPs had noticeable side effects on plants. The number of MPs (35.21particles/kg) and small size MPs (62.6%) in earthworm casts reached maximum, CAT (38.1U/mg prot) and acetylcholine esterase (AChE) (14.3U/mg prot) have the same trend in ESTW4. A large number of MPs during the ESTW reactor lead to an obvious oxidative stress reactions and lasting neurotoxicity of earthworm. Additionally, the type and quantity of bacteria in the ESTW reactor could reduce when the MPs adding too much. © 2021 Elsevier Ltd