Impact of the COVID-19 pandemic on household disinfectant consumption behaviors and related environmental concerns: A questionnaire-based survey in China

Analysis of key circRNA events in the AOP framework of TCS acting on zebrafish based on the data-driven

Triclosan (TCS) is a broad-spectrum antibiotic widely used in various personal care products. Research has found that exposure to TCS can cause toxic effects on organisms including neurotoxicity, cardiotoxicity, disorders of lipid metabolism, and abnormal vascular development, and the corresponding toxic mechanisms are gradually delving into the level of abnormal expression of miRNA regulating gene expression. Although the downstream mechanism of TCS targeting miRNA abnormal expression to induce toxicity is gradually improving, its upstream mechanism is still in a fog. Starting from the abnormal expression data of circRNA in zebrafish larvae induced by TCS, this study conducted a hierarchical analysis of the expression levels of all circRNAs, differential circRNAs, and trend circRNAs, and identified 29 key circRNA events regulating miRNA abnormal expression. In combination with GO and KEGG, the effects of TCS exposure were analyzed from the function and signaling pathway of the corresponding circRNA host gene. Furthermore, based on existing literature evidence about the biological toxicity induced by TCS targeting miRNA as data support, a competing endogenous RNAs (ceRNA) network characterizing the regulatory relationship between circRNA and miRNA was constructed and optimized. Finally, a comprehensive Adverse Outcome Pathway (AOP) framework of multiple levels of events including circRNA, miRNA, mRNA, pathway, and toxicity endpoints was established to systematically elucidate the toxic mechanism of TCS. Moreover, the rationality of the AOP framework was verified from the expression level of miRNA and adverse outcomes such as neurotoxicity, cardiotoxicity, oxidative stress, and inflammatory response by knockdown of circRNA48. This paper not only provides the key circRNA events for exploring the upstream mechanism of miRNA regulating gene expression but also provides an AOP framework for comprehensively demonstrating the toxicity mechanism of TCS on zebrafish, which is a theoretical basis for subsequent hazard assessment and prevention and control of TCS.

Synergistic interaction of co-exposure to humidifier disinfectant chemicals CMIT/MIT and PHMG in lung injury

A number of biocidal disinfectant chemicals are used as household products to prevent spread of pathogens. People are commonly exposed to multiple chemicals through those disinfectants. However, effects of interactions (e.g., synergism) between disinfectants on human health outcomes have been rarely studied. In this study, we aimed to investigate associations of a mixture of chloromethylisothiazolinone/methylisothiazolinone (CMIT/MIT) and polyhexamethylene guanidine (PHMG), which had been used as humidifier disinfectants (HDs) in South Korea, with HD-associated lung injury (HDLI) in a Korean population (n = 4058) with HD exposure through use of HD products. Exposure to HD was retrospectively assessed by an interview-based standardized survey, and HDLI was determined by clinical assessment. After adjusting for covariates, PHMG-specific exposure indices (e.g., amount of use, indoor air concentration, and weekly exposure level) were dose-dependently associated with HDLI (their odds ratios for the comparison of third tertile versus first tertile were 1.95, 1.77, and 2.16, respectively). CMIT/MIT exposure was not observed to have a significant association with HDLI in a single chemical exposure model; however, associations between PHMG exposure and HDLI were strengthened by co-exposure to CMIT/MIT in combined chemical exposure models, where synergistic interactions between CMIT/MIT use and PHMG indices (amount of use and weekly exposure level) were observed (p-interaction in additive scale: 0.02 and 0.03, respectively). Our findings imply that adverse effects of PHMG exposure on lung injury among HD users might be worsened by co-exposure to CMIT/MIT. Given that plenty of household products contain disinfectants on global markets, epidemiological and toxicological investigations are warranted on interaction effects of co-exposure to disinfectants.

Effects of intensive chlorine disinfection on nitrogen and phosphorus removal in WWTPs

The increased use of disinfection since the pandemic has led to increased effective chlorine concentration in municipal wastewater. Whereas, the specific impacts of active chlorine on nitrogen and phosphorus removal, the mediating communities, and the related metabolic activities in wastewater treatment plants (WWTPs) lack systematic investigation. We systematically analyzed the influences of chlorine disinfection on nitrogen and phosphorus removal activities using activated sludge from five full-scale WWTPs. Results showed that at an active chlorine concentration of 1.0 mg/g-SS, the nitrogen and phosphorus removal systems were not significantly affected. Major effects were observed at 5.0 mg/g-SS, where the nitrogen and phosphorus removal efficiency decreased by 38.9 % and 44.1 %, respectively. At an active chlorine concentration of 10.0 mg/g-SS, the nitrification, denitrification, phosphorus release and uptake activities decreased by 15.1 %, 69.5-95.9 %, 49.6 % and 100 %, respectively. The proportion of dead cells increased by 6.1 folds. Reverse transcriptional quantitative polymerase chain reaction (RT-qPCR) analysis showed remarkable inhibitions on transcriptions of the nitrite oxidoreductase gene (nxrB), the nitrite reductase genes (nirS and nirK), and the nitrite reductase genes (narG). The nitrogen and phosphorus removal activities completely disappeared with an active chlorine concentration of 25.0 mg/g-SS. Results also showed distinct sensitivities of different functional bacteria in the activated sludge. Even different species within the same functional group differ in their susceptibility. This study provides a reference for the understanding of the threshold active chlorine concentration values which may potentially affect biological nitrogen and phosphorus removal in full-scale WWTPs, which are expected to be beneficial for decision-making in WWTPs to counteract the potential impacts of increased active chlorine concentrations in the influent wastewater.

Microplastic pollution interaction with disinfectant resistance genes: research progress, environmental impacts, and potential threats

The consumption of disposable plastic products and disinfectants has surged during the global COVID-19 pandemic, as they play a vital role in effectively preventing and controlling the spread of the virus. However, microplastic pollution and the excessive or improper use of disinfectants contribute to the increased environmental tolerance of microorganisms. Microplastics play a crucial role as vectors for microorganisms and plankton, facilitating energy transfer and horizontal gene exchange. The increase in the use of disinfectants has become a driving force for the growth of disinfectant resistant bacteria (DRB). A large number of microorganisms can have intense gene exchange, such as plasmid loss and capture, phage transduction, and cell fusion. The reproduction and diffusion rate of DRB in the environment is significantly higher than that of ordinary microorganisms, which will greatly increase the environmental tolerance of DRB. Unfortunately, there is still a huge knowledge gap in the interaction between microplastics and disinfectant resistance genes (DRGs). Accordingly, it is critical to comprehensively summarize the formation and transmission routes of DRGs on microplastics to address the problem. This paper systematically analyzed the process and mechanisms of DRGs formed by microbes. The interaction between microplastics and DRGs and the contribution of microplastic on the diffusion and spread of DRGs were expounded. The potential threats to the ecological environment and human health were also discussed. Additionally, some challenges and future priorities were also proposed with a view to providing useful basis for further research.

High-Resolution Mass Spectrometry Screening of Quaternary Ammonium Compounds (QACs) in Dust from Homes and Various Microenvironments in South China

Despite their ubiquitous use, information regarding the presence of quaternary ammonium compounds (QACs) in various microenvironments remains scarce and only a small subset of QACs has been monitored using targeted chemical analysis. In this study, a total of 111 dust samples were collected from homes and various public settings in South China during the COVID-19 pandemic and were analyzed for traditional and emerging QACs using high-resolution mass spectrometry. The total traditional QAC concentrations in residential dust (∑traditional QAC, sum of 18 traditional QACs) ranged from 13.8 to 150 μg/g with a median concentration of 42.2 μg/g. Twenty-eight emerging QACs were identified in these samples, and the composition of ∑emerging QAC (sum of emerging QACs) to ∑QAC (sum of traditional and emerging QACs) ranged from 19 to 42% across various microenvironments, indicating the widespread existence of emerging QACs in indoor environments. Additionally, dust samples from cinemas exhibited higher ∑QAC concentrations compared to homes (medians 65.9 μg/g vs 58.3 μg/g, respectively), indicating heavier emission sources of QACs in these places. Interestingly, significantly higher ∑QAC concentrations were observed in dust from the rooms with carpets than those without (medians 65.6 μg/g vs 32.6 μg/g, p < 0.05, respectively). Overall, this study sheds light on the ubiquitous occurrence of QACs in indoor environments in South China.

Man-made reactive oxygen species as green disinfectants

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A review on in silico prediction of the environmental risks posed by pharmaceutical emerging contaminants

Computer-aided (in silico) prediction has shown good potential to support the environmental risk assessment (ERA) of pharmaceutical emerging contaminants (PECs), allowing low-cost, animal-free, high-throughput screening of multiple potential risks posed by a wide variety of pharmaceuticals in the environment based on insufficient toxicity data. This review provided recent insights regarding the application of in silico approaches in prediction for environmental risks of PECs. Based on the review of 20 included articles from 8 countries published since 2018, we found that the researchers' interest and concern in this research topic were sharply aroused since 2021. Recently, in silico approaches have been widely used for the prediction of bioaccumulation and biodegradability, lethal endpoints, developmental toxicity, mutagenicity, other eco-toxicological effects such as ototoxicity and hematological toxicity, and human health hazards of exposure to PECs. Particular attention has been given to the simultaneous discernment of multiple environmental risks and health effects of PECs based on mechanistic data of pharmaceuticals using advanced bioinformatic methods such as transcriptomic analysis and network pharmacology prediction. In silico software platforms and databases used in the included studies were diversified, and there is currently no standardized and accepted in silico model for ERA of PECs. Date suggested that in silico prediction of the environmental risks posed by PECs is still in its infancy. Considerable critical challenges need to be addressed, including consideration of environmental exposure concentration for PECs, interactions among mixtures of PECs and other contaminants coexisting in environments, and development of in silico models specific to ERA of PECs.

Risks of benzalkonium chlorides as emerging contaminants in the environment and possible control strategies from the perspective of ecopharmacovigilance

An unprecedented increase in the use of disinfection products triggered by the coronavirus disease 2019 (COVID-19) pandemic is resulting in aggravating environmental loads of disinfectants as emerging contaminants, which has been considered a cause for worldwide secondary disasters. This review analyzed the literature published in the last decade about occurrence, bioaccumulation, and possible environmental risks of benzalkonium chlorides (BKCs) as emerging contaminants. Results indicated that BKCs globally occurred in municipal wastewater, surface water, groundwater, reclaimed water, sludge, sediment, soil, roof runoff, and residential dust samples across 13 countries. The maximum residual levels of 30 mg/L and 421 μg/g were reported in water and solid environmental samples, respectively. Emerging evidences suggested possible bioaccumulation of BKCs in plants, even perhaps humans. Environmentally relevant concentrations of BKCs exert potential adverse impacts on aquatic and terrestrial species, including genotoxicity, respiratory toxicity, behavioural effects and neurotoxicity, endocrine disruption and reproductive impairment, phytotoxicity, etc. Given the intrinsic biocidal and preservative properties of disinfectants, the inductive effects of residual BKCs in environment in terms of resistance and imbalance of microorganisms have been paid special attention. Considering the similarities of disinfectants to pharmaceuticals, from the perspective of ecopharmacovigilance (EPV), a well-established strategy for pharmaceutical emerging contaminants, we use the control of BKC pollution as a case, and provide some recommendations for employing the EPV measures to manage environmental risks posed by disinfectant emerging contaminants.

Protecting the children -a virtual reality experiment on consumers' risk perceptions of household chemicals

Warnings on the labels of hazardous household chemicals (e.g. warning pictograms and use instructions) should create risk awareness and thus encourage safe storage, handling and disposal. However, scientific findings have called into question the effectiveness of warnings to prevent accidents, albeit mostly based on consumers' self-reports. This study aimed to contribute to existing data on household chemicals and consumer safety by applying a novel observational method using virtual reality (VR). The study participants (N = 119) were observed after receiving a task to childproof a virtual apartment from various interactable neutral and hazardous objects (i.e. knives, lighters and household chemicals with and without warnings) that were placed in the virtual apartment. For the analysis, the object placement (i.e. accessible or inaccessible to the children) and the level of interaction with the objects were coded, and the observational data were supplemented with data gathered through a questionnaire. The results showed that most hazardous household chemicals were moved to spots that were inaccessible to the children without any interactions of the participants with the warnings. Instead, they used their pre-existing knowledge and intuitive strategies to judge the objects' risks. These potentially misleading intuitive strategies should be increasingly considered in the regulation of hazardous household chemicals. This study also discussed the use and limitations of VR for the observation of human behaviour and decision making under uncertainty.

Effect of Graphene Oxide and Silver Nanoparticle Hybrid Composite on Acinetobacter baumannii Strains, Regarding Antibiotic Resistance and Prevalence of AMP-C Production

Background and Objectives: Growing antibiotic resistance among bacteria is a global issue that is becoming harder and more expensive to solve. Traditional treatment options are becoming less effective, causing more fatal outcomes of nosocomial infections. Since the development of new antibiotics has stagnated in the last decade, a novel approach is needed. Materials and Methods: Graphene-based materials are being developed and tested for various applications, and the medical field is no exception. We tested 98 clinical A. baumannii strains for antibiotic resistance, AMP-C production and the effectiveness of a graphene oxide and silver nanoparticle hybrid nanocomposite. The disc diffusion method was used to determine antibiotic susceptibility results. Antibiotic discs containing cefotaxime, cloxacillin and clavulanate were used to detect AMP-C production. The effectiveness of the GO-Ag hybrid nanocomposite was determined by counting colony forming units (CFUs) after a suspension of A. baumannii and the GO-Ag hybrid nanocomposite was plated on MH agar and incubated overnight to grow colonies. Results: In our research, we found that A. baumannii strains are resistant to the majority of commonly used antibiotics. Antibiotic resistance levels and AMP-C production can be factors, indicating the better effectiveness of the graphene oxide and silver nanoparticle hybrid nanocomposite. Conclusions: In this study, a GO-Ag hybrid nanocomposite was shown to have the potential to fight even the most problematic bacteria like A. baumannii.

Psychological and psychosocial determinants of COVID Health Related Behaviours (COHeRe): An evidence and gap map

Background

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has resulted in illness, deaths and societal disruption on a global scale. Societies have implemented various control measures to reduce transmission of the virus and mitigate its impact. Individual behavioural changes are crucial to the successful implementation of these measures. Common recommended measures to limit risk of infection include frequent handwashing, reducing the frequency of social interactions and the use of face coverings. It is important to identify those factors that can predict the uptake and maintenance of these protective behaviours.

Objectives

We aimed to identify and map the existing evidence (published and unpublished) on psychological and psychosocial factors that determine uptake and adherence to behaviours aimed at reducing the risk of infection or transmission of COVID-19.

Search Methods

Our extensive search included electronic databases (n = 12), web searches, conference proceedings, government reports, other repositories including both published peer reviewed, pre-prints and grey literature. The search strategy was built around three concepts of interest including (1) context (terms relating to COVID-19), (2) behaviours of interest and (3) terms related to psychological and psychosocial determinants of COVID Health-Related Behaviours and adherence or compliance with recommended behaviours, to capture both malleable and non-malleable determinants (i.e. determinants that could be changed and those that could not).

Selection Criteria

This Evidence and Gap Map (EGM) includes all types of studies examining determinants of common recommended behaviours aimed at mitigating human-to-human spread of COVID-19. All potential malleable and non-malleable determinants of one or more behaviours are included in the map. As part of the mapping process, categories are used to group determinants. The mapping categories were based on a previous rapid review by Hanratty 2021. These include: 'behaviour', 'cognition', 'demographics', 'disease', 'emotions', 'health status', 'information', 'intervention', and 'knowledge'. Those not suitable for categorisation in any of these groups are included in the map as 'other' determinants.

Data Collection and Analysis

Results were imported to a bibliographic reference manager where duplications of identical studies gathered from multiple sources were removed. Data extraction procedures were managed in EPPI-Reviewer software. Information on study type, population, behaviours measured and determinants measured were extracted. We appraised the methodological quality of systematic reviews with AMSTAR-2. We did not appraise the quality of primary studies in this map.

Main Results

As of 1 June 2022 the EGM includes 1034 records reporting on 860 cross-sectional, 68 longitudinal, 78 qualitative, 25 reviews, 62 interventional, and 39 other studies (e.g., mixed-methods approaches). The map includes studies that measured social distancing (n = 487), masks and face coverings (n = 382), handwashing (n = 308), physical distancing (n = 177), isolation/quarantine (n = 157), respiratory hygiene/etiquette (n = 75), cleaning surfaces (n = 59), and avoiding touching the T-zone (n = 48). There were 333 studies that assessed composite measures of two or more behaviours. The largest cluster of determinants was 'demographics' (n = 730 studies), followed by 'cognition' (n = 496 studies) and determinants categorised as 'other' (n = 447). These included factors such as 'beliefs', 'culture' and 'access to resources'. Less evidence is available for some determinants such as 'interventions' (n = 99 studies), 'information' (n = 101 studies), and 'behaviour' (149 studies).

Authors' Conclusions

This EGM provides a valuable resource for researchers, policy-makers and the public to access the available evidence on the determinants of various COVID-19 health-related behaviours. The map can also be used to help guide research commissioning, by evidence synthesis teams and evidence intermediaries to inform policy during the ongoing pandemic and potential future outbreaks of COVID-19 or other respiratory infections. Evidence included in the map will be explored further through a series of systematic reviews examining the strength of the associations between malleable determinants and the uptake and maintenance of individual protective behaviours.

In vitro evaluation for estrogenic mechanisms of the disinfectant benzalkonium chloride as an emerging contaminant

This study aimed to evaluate in vitro the possible mechanisms underlying the estrogenic potential of benzalkonium chloride (BAC) as a disinfectant emerging contaminant. Effects of BAC at the environmentally-relevant concentrations on estrogen synthesis and estrogen receptor (ER) signaling were assessed using the H295R steroidogenesis assay and the MCF-7 proliferation assay, respectively. Results showed that exposure to BAC at concentrations of 1.0-1.5 mg/L for 48 h significantly increased estradiol production of H295R cells in a concentration-dependent manner. Transcription of steroidogenic genes 3β-HSD2, 17β-HSD1, 17β-HSD4, and CYP19A were significantly enhanced by BAC. In ER-positive MCF-7 cells, exposure to 0.5-1.5 mg/L BAC for 48 h significantly promoted cell proliferation and increased the expressions of ERα and G-protein coupled estrogen receptor 1. Flow cytometry analysis showed that 0.5-1.5 mg/L BAC significantly decreased the percentage of cells in G0/G1 phase, increased the percentage in S phase, and BAC at concentrations of 1.0 and 1.5 mg/L increased the G2/M phase cells. Findings of the study suggested that BAC at environmentally-relevant concentrations might act as a xenoestrogen through its inhibitory effect on steroidogenesis and ER-mediated mechanism.

Toxicity effects of disinfection byproduct chloroacetic acid to Microcystis aeruginosa: Cytotoxicity and mechanisms

Chlorine-based disinfectants are widely used for disinfection in wastewater treatment. The mechanism of the effects of chlorinated disinfection by-products on cyanobacteria was unclear. Herein, the physiological effects of chloroacetic acid (CAA) on Microcystis aeruginosa (M. aeruginosa), including acute toxicity, oxidative stress, apoptosis, production of microcystin-LR (MC-LR), and the microcystin transportation-related gene mcyH transcript abundance have been investigated. CAA exposure resulted in a significant change in the cell ultrastructure, including thylakoid damage, disappearance of nucleoid, production of gas vacuoles, increase in starch granule, accumulation of lipid droplets, and disruption of cytoplasm membranes. Meanwhile, the apoptosis rate of M. aeruginosa increased with CAA concentration. The production of MC-LR was affected by CAA, and the transcript abundance of mcyH decreased. Our results suggested that CAA poses acute toxicity to M. aeruginosa, and it could cause oxidative damage, stimulate MC-LR production, and damage cell ultrastructure. This study may provide information about the minimum concentration of CAA in the water environment, which is safe for aquatic organisms, especially during the global coronavirus disease 2019 pandemic period.

Toxicity of microplastics and triclosan, alone and in combination, to the fertilisation success of a broadcast spawning bivalve Tegillarca granosa

Since most marine invertebrates adopted external fertilisation, their fertilisation process is particularly vulnerable to aquatic pollutants. Both antimicrobial ingredients and microplastics (MPs) are ubiquitous in aquatic environments; however, their synergistic effects on the fertilisation of marine invertebrates remain unclear. Therefore, in this study, the fertilisation toxicity of MPs and triclosan (TCS), alone and in combination, was investigated in the broadcast spawning bivalve Tegillarca granosa. Results showed that MPs and TCS significantly suppressed the fertilisation success of T. granosa. As the fertilisation success of broadcast spawning invertebrates depends on successful gamete collisions, gamete fusion, and egg activation, sperm swimming velocity, viability, gamete collision probability, ATP status, and ion-transport enzyme activities were also analysed to further ascertain the underlying toxicity mechanisms. In summary, our findings indicate that the presence of MPs may enhance the fertilisation toxicity of TCS by hampering sperm-egg collision probability, reducing gamete fusion efficiency, and restricting Ca²⁺ oscillation formation.

Embryonic exposure to chloroxylenol induces developmental defects and cardiovascular toxicity via oxidative stress, inflammation, and apoptosis in zebrafish

Chloroxylenol is an extensively consumed anti-microbial compound. Since its usage is on the rise due to the coronavirus pandemic and ban on other antimicrobial ingredients, recent studies have suggested the necessity of estimating its potential for ecotoxicity. The detrimental effect of chloroxylenol on zebrafish (Danio rerio) viability has been reported; however, research on the mechanisms underlying its toxicity is quite limited. Therefore, we applied the zebrafish model for elucidating responses against chloroxylenol to predict its toxicity toward human health and ecology. Zebrafish exposed to chloroxylenol (0, 0.5, 1, 2.5, 5, and 10 mg/L) at the embryonic stage (from 6 h post-fertilization (hpf) to 96 hpf) showed impaired viability and hatchability, and pathological phenotypes. To address these abnormalities, cellular responses such as oxidative stress, inflammation, and apoptosis were confirmed via in vivo imaging of a fluorescent dye or measurement of the transcriptional changes related to each response. In particular, developmental defects in the cardiovascular system of zebrafish exposed to 0, 0.5, 1, and 2.5 mg/L of chloroxylenol from 6 to 96 hpf were identified by structural analyses of the system in the flk1:eGFP transgenic line. Additional experiments were conducted using human umbilical vein endothelial cells (HUVECs) to predict the adverse impacts of chloroxylenol on the human vascular system. Chloroxylenol impairs the viability and tube formation ability of HUVECs by modulating ERK signaling. The findings obtained using the zebrafish model provide evidence of the possible risks of chloroxylenol exposure and suggest the importance of more in-depth ecotoxicological studies.

Excessive disinfection aggravated the environmental prevalence of antimicrobial resistance during COVID-19 pandemic

During COVID-19 pandemic, chemicals from excessive consumption of pharmaceuticals and disinfectants i.e., antibiotics, quaternary ammonium compounds (QACs), and trihalomethanes (THMs), flowed into the urban environment, imposing unprecedented selective pressure to antimicrobial resistance (AMR). To decipher the obscure character pandemic-related chemicals portrayed in altering environmental AMR, 40 environmental samples covering water and soil matrix from surroundings of Wuhan designated hospitals were collected on March 2020 and June 2020. Chemical concentrations and antibiotic resistance gene (ARG) profiles were revealed by ultra-high-performance liquid chromatography-tandem mass spectrometry and metagenomics. Selective pressure from pandemic-related chemicals ascended by 1.4-5.8 times in March 2020 and then declined to normal level of pre-pandemic period in June 2020. Correspondingly, the relative abundance of ARGs under increasing selective pressure was 20.1 times that under normal selective pressure. Moreover, effect from QACs and THMs in aggravating the prevalence of AMR was elaborated by null model, variation partition and co-occurrence network analyses. Pandemic-related chemicals, of which QACs and THMs respectively displayed close interaction with efflux pump genes and mobile genetic elements, contributed >50 % in shaping ARG profile. QACs bolstered the cross resistance effectuated by qacEΔ1 and cmeB to 3.0 times higher while THMs boosted horizon ARG transfer by 7.9 times for initiating microbial response to oxidative stress. Under ascending selective pressure, qepA encoding quinolone efflux pump and oxa-20 encoding β-lactamases were identified as priority ARGs with potential human health risk. Collectively, this research validated the synergistic effect of QACs and THMs in exacerbating environmental AMR, appealing for the rational usage of disinfectants and the attention for environmental microbes in one-health perspective.

Triclosan and triclocarban weaken the olfactory capacity of goldfish by constraining odorant recognition, disrupting olfactory signal transduction, and disturbing olfactory information processing

Recently, increased production and consumption of disinfectants such as triclosan (TCS) and triclocarban (TCC) have led to massive pollution of the environment, which draws global concern over the potential risk to aquatic organisms. However, the olfactory toxicity of disinfectants in fish remains elusive to date. In the present study, the impact of TCS and TCC on the olfactory capacity of goldfish was assessed by neurophysiological and behavioral approaches. As shown by the reduced distribution shifts toward amino acid stimuli and hampered electro-olfactogram responses, our results demonstrated that TCS/TCC treatment would cause deterioration of the olfactory ability of goldfish. Our further analysis found that TCS/TCC exposure suppressed the expression of olfactory G protein-coupled receptors in the olfactory epithelium, restricted the transformation of odorant stimulation into electrical responses by disturbing the cAMP signaling pathway and ion transportation, and induced apoptosis and inflammation in the olfactory bulb. In conclusion, our results demonstrated that an environmentally realistic level of TCS/TCC would weaken the olfactory capacity of goldfish by constraining odorant recognition efficiency, disrupting olfactory signal generation and transduction, and disturbing olfactory information processing.

Mobile Phones: Reservoirs of Resistant Bacteria during the COVID-19 Pandemic in Abu Dhabi, United Arab Emirates

BACKGROUND

Mobile phones are excessively used even though microbes' ability to survive on phone surfaces was confirmed. During the COVID-19 pandemic, heavy hygiene practices have been applied to mobile surfaces. Therefore, it is interesting to evaluate the emergence of antimicrobial-resistant bacteria on mobile phone surfaces.

METHODS

A random sampling technique was utilized on residents in Abu Dhabi, UAE between May and June 2021. A swab sample from each participant's mobile phone was collected and transported to the microbiology laboratory for bacterial culture and antimicrobial susceptibility tests. Furthermore, a cross-sectional study was conducted via a self-administered questionnaire filled by participants. The questionnaire was used to collect sociodemographic data, phone frequency usage and cleaning methods.

RESULTS

One hundred two-sample swabs and data have been included in the study. The majority of participants (91.1%) reported cleaning their mobile phones with wipes and alcohol. However, 100% of participants had a mobile phone contaminated by bacteria such as S. aureus, E. coli, Coagulase-negative staphylococci, Micrococcus, Bacillus, Streptococcus, Citrobacter, Proteus, Enterococcus, klebsiella, Pseudomonas and Actinobacteria. Interestingly, most of these potentially pathogenic bacteria were found to be resistant to ampicillin, ceftazidime and cefotaxime.

CONCLUSION

The continuous hand and mobile disinfectant have contributed to the emergence of resistant bacteria.

Composition of Culturable Microorganisms in Dusts Collected from Sport Facilities in Finland during the COVID-19 Pandemic

Sport facilities represent extreme indoor environments due to intense cleaning and disinfection. The aim of this study was to describe the composition of the cultivated microbiota in dust samples collected in sport facilities during the COVID-19 pandemic. A dust sample is defined as the airborne dust sedimented on 0.02 m² within 28 d. The results show that the microbial viable counts in samples of airborne dust (n = 9) collected from seven Finnish sport facilities during the pandemic contained a high proportion of pathogenic filamentous fungi and a low proportion of bacteria. The microbial viable counts were between 14 CFU and 189 CFU per dust sample. In seven samples from sport facilities, 20-85% of the microbial viable counts were fungi. Out of 123 fungal colonies, 47 colonies belonged to the potentially pathogenic sections of Aspergillus (Sections Fumigati, Nigri, and Flavi). Representatives of each section were identified as Aspergillus fumigatus, A. flavus, A. niger and A. tubingensis. Six colonies belonged to the genus Paecilomyces. In six samples of dust, a high proportion (50-100%) of the total fungal viable counts consisted of these potentially pathogenic fungi. A total of 70 isolates were considered less likely to be pathogenic, and were identified as Aspergillus section Nidulantes, Chaetomium cochliodes and Penicillium sp. In the rural (n = 2) and urban (n = 7) control dust samples, the microbial viable counts were >2000 CFU and between 44 CFU and 215 CFU, respectively, and consisted mainly of bacteria. The low proportion of bacteria and the high proportion of stress tolerant, potentially pathogenic fungi in the dust samples from sport facilities may reflect the influence of disinfection on microbial communities.

Molecular interactions between bovine serum albumin (BSA) and trihalophenol: Insights from spectroscopic, calorimetric and molecular modeling studies

The issue of disinfection byproducts (DBPs) in the water has received critical attention due to the health effects on humans. In the water environment, interactions between bovine serum albumins (BSA), the most abundant water-soluble protein, and DBPs unavoidably occur. In this study, comparative binding interactions of two aromatic DBPs - 2,4,6-trichlorophenol (TCP) and 2,4,6-tribromophenol (TBP) with BSA were investigated systematically utilizing fluorescence spectrometry, UV absorption spectrometry, isothermal titration calorimetry and molecular docking approach. The fluorescence quenching results indicated that TCP/TBP could quench the endogenous fluorescence of BSA through static quenching mechanisms, and TBP showed a more substantial quenching effect. The binding constants were determined for TCP-BSA (3.638 × 10⁵ L/mol, 303 K) and TBP-BSA (6.394 × 10⁵ L/mol, 303 K) complexes, with TBP showing higher binding affinity than TCP. The thermodynamic study and docking analysis suggested that hydrogen bonding and van der Waals forces were the primary interaction forces. Both of TCP and TBP were located in the subdomain IIIA of BSA, and TBP could form more stable complex than TCP. The results of the present study contributed valuable information on the environmental behaviors of halophenols in water environment from perspectives of binding with BSA.

Environmental challenges of COVID-19 pandemic: resilience and sustainability - A review

The emergence of novel respiratory disease (COVID-19) caused by SARS-CoV-2 has become a public health emergency worldwide and perturbed the global economy and ecosystem services. Many studies have reported the presence of SARS-CoV-2 in different environmental compartments, its transmission via environmental routes, and potential environmental challenges posed by the COVID-19 pandemic. None of these studies have comprehensively reviewed the bidirectional relationship between the COVID-19 pandemic and the environment. For the first time, we explored the relationship between the environment and the SARS-CoV-2 virus/COVID-19 and how they affect each other. Supporting evidence presented here clearly demonstrates the presence of SARS-CoV-2 in soil and water, denoting the role of the environment in the COVID-19 transmission process. However, most studies fail to determine if the viral genomes they have discovered are infectious, which could be affected by the environmental factors in which they are found.The potential environmental impact of the pandemic, including water pollution, chemical contamination, increased generation of non-biodegradable waste, and single-use plastics have received the most attention. For the most part, efficient measures have been used to address the current environmental challenges from COVID-19, including using environmentally friendly disinfection technologies and employing measures to reduce the production of plastic wastes, such as the reuse and recycling of plastics. Developing sustainable solutions to counter the environmental challenges posed by the COVID-19 pandemic should be included in national preparedness strategies. In conclusion, combating the pandemic and accomplishing public health goals should be balanced with environmentally sustainable measures, as the two are closely intertwined.

Knowledge, attitudes and practice regarding environmental friendly disinfectants for household use among residents of China in the post-pandemic period

Background

A sharp rise in household consumption of disinfectants triggered by COVID-19 pandemic has generated tremendous environmental burden and risks of disinfectant emissions in the post-pandemic period. To address this emerging challenge, replacing highly hazardous disinfectants with more environmental friendly alternatives has been accepted as an inherently effective solution to environment issues posed by disinfectant emerging contaminants. However, no study has yet been done to explore the potential customers' attitudes and the market prospect of environmental friendly disinfectants until now.

Methods

This cross-sectional questionnaire-based survey was conducted from January to March, 2022, among resident volunteers in China, to explore the practices, knowledge and attitudes of the public regarding environmental friendly disinfectants for household use.

Results

Among a total of 1,861 Chinese residents finally included in the analyses, 18% agreed or strongly agreed that they paid special attention to the environmental certification label on the product, and only bought the environmental certified disinfectant products; 16% and 10% were using environmental friendly disinfectants for hand sanitization and environmental disinfection, respectively. The mean self-assessed and actual knowledge scores were 2.42 ± 1.74 and 2.12 ± 1.97, respectively, out of a total of 5. Participants having good practices of consuming environmental friendly disinfectants achieved higher knowledge scores. Residents' overall attitudes toward the development, consumption and application of environmental friendly disinfectants were very positive. "Possible conflict between disinfection effectiveness and environmental factor of disinfectants in a context of severe COVID-19 pandemic" was considered as the most important barrier jeopardizing the participants' usage intention for environmental friendly disinfectants.

Conclusions

These data suggested most residents of China had a positive attitude, poor knowledge and practices toward environmental friendly disinfectants. More should be done to enhance the residents' environmental knowledge levels about disinfectants, and to further develop and promote disinfectant products with both excellent disinfection activity and environmentally friendly attributes.

Environmental impacts of the widespread use of chlorine-based disinfectants during the COVID-19 pandemic

Chlorinated disinfectants are widely used in hospitals, COVID-19 quarantine facilities, households, institutes, and public areas to combat the spread of the novel coronavirus as they are effective against viruses on various surfaces. Medical facilities have enhanced their routine disinfection of indoors, premises, and in-house sewage. Besides questioning the efficiency of these compounds in combating coronavirus, the impacts of these excessive disinfection efforts have not been discussed anywhere. The impacts of chlorine-based disinfectants on both environment and human health are reviewed in this paper. Chlorine in molecular and in compound forms is known to pose many health hazards. Hypochlorite addition to soil can increase chlorine/chloride concentration, which can be fatal to plant species if exposed. When chlorine compounds reach the sewer/drainage system and are exposed to aqueous media such as wastewater, many disinfection by-products (DBPs) can be formed depending on the concentrations of natural organic matter, inorganics, and anthropogenic pollutants present. Chlorination of hospital wastewater can also produce toxic drug-derived disinfection by-products. Many DBPs are carcinogenic to humans, and some of them are cytotoxic, genotoxic, and mutagenic. DBPs can be harmful to the flora and fauna of the receiving water body and may have adverse effects on microorganisms and plankton present in these ecosystems.

Experimental Research on the Treatment of Stormwater Contaminated by Disinfectants Using Recycled Materials-Hemp Fiber and Ceramzite

Pollution caused by the use of disinfectants in public spaces is a relatively new form of environmental contamination. During the COVID-19 pandemic of 2020-2021, early research showed a sevenfold increase in the use of disinfectants to clean outdoor spaces and a corresponding increase in environmental pollution. Typically, after entering stormwater systems, disinfectants are carried to surface waters (e.g., rivers, seas and lakes) where they react with various elements to form harmful compounds. In the absence of data, it is not possible to determine accurate levels of pollution according to the latest scientific information. Our enquiry demonstrates that stormwater pollution indicators (pH, conductivity, turbidity and color intensity) change depending on the amounts of disinfectants present. Laboratory tests were conducted using hemp fiber and ceramzite, in which filtered stormwater samples contaminated with different amounts of disinfectants showed decreases in the amounts of active chlorine from 2.93 ppm to 1.0 ppm. Changes in pH levels, conductivity, turbidity and color intensity were monitored before and after filtration; pH indicators changed slightly (from 7.81 to 7.85), turbidity changes varied in the range of 0.070-0.145 NTU and the highest value of color intensity (1.932 AV) was obtained when 50 mL of disinfectant was added to the investigated sample water. This article presents the results of our research into the impact of disinfectants on stormwater. Further investigation is needed in order to determine the impacts of chemical substances on our water ecosystem.

Evaluating knowledge, awareness and associated water usage towards hand hygiene practices influenced by the current COVID-19 pandemic in Bangladesh

Hand hygiene is considered as one of the most effective ways for preventing transmissible diseases, especially for preventing virus-borne diseases. The study has been conducted to evaluate changes in knowledge, awareness and practices of hand hygiene due to the outbreak of the coronavirus disease (COVID-19) in Bangladesh. The potential factors influencing human behaviours for maintaining hand hygiene have also been explored. Moreover, a probable increase in daily water demand associated with the changed situation has been assessed. An online survey was performed among a total of 367 Bangladeshi residents about their practices of hand hygiene during pre-corona, corona, and of their perceived future practices at post-corona period. It has been observed that a significant percentage (62.1%) of the respondents have received basic hygiene education at any level of their academic education. Nevertheless, their hygiene practices were very poor before the COVID-19 pandemic. The outbreak of the COVID-19 has reinforced their previous knowledge and greatly influenced their behavioural changes towards practicing hand hygiene as per World Health Organization guidelines for preventing the virus outbreak. The changes, however, have created increased water demand. The estimated water usage is found to be 2.68 times (9.15 L/c/d) and 2.52 times (8.59 L/c/d) higher in the corona and post-corona period respectively than that of the pre-corona situation (3.41 L/c/d). The principal component analysis (PCA) elucidated that an individual's practice of hand hygiene was associated with income, level of academic and hygiene education, and the COVID-19 outbreak itself. Moreover, the influence of hygiene education and COVID-19 outbreak affecting the duration of handwashing are found highly significant (p-value < 0.001) from the regression analysis. Raising awareness towards behavioural change of an individual about water usage, improvement of academic curriculum regarding hand hygiene and provision of water pricing are recommended to attain sustainable development goals of the country.

The knowledge, attitudes and practices of hand, foot, and mouth disease prevention strategies amongst parents and educators of children under 5 years amidst COVID-19 pandemic: A cross-sectional study

Background

Hand, foot, and mouth disease (HFMD) is endemic in Singapore. Prevention efforts have been ramped up since major outbreaks in the early 2000's. This study aims to assess the current knowledge, and attitudes towards and practise (KAP) levels of HFMD prevention strategies (HFMD-PS) amongst parents and teachers of children under 5 years amidst the COVID-19 pandemic.

Methods and results

A convenience sample of 240 teachers and 404 parents responded to a self-administered standardised questionnaire between mid-October and December 2020. A scoring framework was used to assess responses in the 'knowledge', 'attitude', and 'practice' domains. A multivariable analysis was adjusted for ethnicity and attitudes towards getting children to follow proper handwashing steps and regularly disinfecting children's toys amongst parents, knowledge about HFMD's infectious period, and the responses to a child turning symptomatic in the childcare centre amongst teachers. Existing levels of knowledge and attitudes of parents and teachers were not high, and only a small proportion practised high levels of prevention measures (99 parents and 28 teachers). Key facilitators for a higher practise level in parents include the following: (1) awareness of regular liquid soap's efficacy as a disinfectant, (2) toy cleaning before and after playtime, and (3) the cleaning agent used for this practise. Teachers had no significant factors associated with higher practise levels.

Conclusion

This study suggested potential gaps between positive knowledge and attitudes towards prevention strategies and their actual adoption levels in homes and childcare centres during COVID-19 pandemic. These evidences suggest the importance of continuous promotion of HFMD prevention practise in homes and childcare centres, even amidst pandemics.

The Lesson Learned from the COVID-19 Pandemic: Can an Active Chemical Be Effective, Safe, Harmless-for-Humans and Low-Cost at a Time? Evidence on Aerosolized Hypochlorous Acid

The COVID-19 pandemic has underlined the importance of disinfectants as tools to prevent and fight against coronavirus spreading. An ideal disinfectant and sanitizer must be nontoxic to surface contact, noncorrosive, effective, and relatively inexpensive as it is hypochlorous acid (HOCl). The present work intended to evaluate, on different surfaces, the bactericidal and virucidal effectiveness of nebulized HOCl and test its safety usage in 2D and 3D skin and lung models. Our data showed that HOCl at the dose of 300 ppm did not affect cellular and tissue viability, not their morphology. The HOCl bactericidal properties varies with the surface analyzed: 69% for semi-porous, 96-99.9% for flat and porous. This discrepancy was not noticed for the virucidal properties. Overall, this study showed that nebulized HOCl can prevent virus and bacteria growth without affecting lung and skin tissues, making this compound a perfect candidate to sanitize indoor environments.

The Effects of Social Network and Institutional Embeddedness on Household Consumption: Evidence from China Household Finance Survey

Consumer behavior is embedded in a certain social structure and social networks, and the scale and density of household social networks will be likely to affect consumption expenditure. To explore the impact of social networks and institutional embeddedness on household consumption, this study constructs a model of consumption influencing factors, and devises an empirical study using the data of China Household Finance Survey (CHFS). The results show some innovation. (1) The impact of household social networks on total household consumption is significant. A 1% increase in social networks spending boosts household consumption spending by 0.364%. (2) The institutional embeddedness will affect household consumption. Every 1% increase of social security account balance (the proxy variable of institutional embeddedness) can boost household consumption by 0.196%. This proves that the social insurance institution can enhance consumer confidence and promote current consumption growth. (3) The results of the robustness test confirmed that even after replacing the dependent variable with “the proportion of developmental consumption in total household consumption,” the influence of social networks and institutional embeddedness on consumption is still significant. Using the variable “communication expenses” instead of “gift income and expenditure” as the proxy variable of social networks, the estimation result is still robust. (4) Social networks have a significant influence on all types of household consumption except medical care consumption, but the degree of influence is different. Further discussion revealed that the estimation results are different for different regions in China, but the coefficients of core independent variables are not significantly different. This conclusion is different from people’s intuition, which holds that people in regions with low economic development rely more on social communication and spend more on social communication to maintain a certain social status. The conclusion of this paper is of great significance for formulating policies and institutions affecting residents’ consumption.

Clostridium perfringens Spores in Urology Hospitals

Background: Clostridium spp. spores are resistant to many factors, including alcohol-based disinfectants. The presence of clostridial spores in a hospital environment may lead to infection outbreaks among patients and health care workers. Objective: This study aimed to detect clostridial spores in aurology hospital using C diff Banana Broth™ and assess the antibiotic sensitivity and toxinotypes of isolates. Methods: After diagnosing COVID-19 in medical staff and closing an 86-bed urology hospital in 2020 for H2O2 fogging, 58 swabs from the hospital environment were inoculated to C diff Banana Broth™, incubated at 37°C for 14 days, checked daily, and positive broths were sub-cultured anaerobically for 48 h at 37°C. After identification, multiplex PCR (mPCR) was performed for Clostridium perfringens, C. difficile toxin genes, and MIC determination. Results: In this study, 16.58 (~ 28%) strains of Clostridium spp. were cultured: 11 - C. perfringens, 2 - C. baratii, and 1 each of C. paraputrificum, C. difficile, and C. clostridioforme. Moreover, C. difficile produced all toxins, and 11 C. perfringens consisted of 1 cpa, 7 cpb2, 2 cpiA, and 1 cpb gene-positive. All isolates were sensitive to metronidazole, vancomycin, moxifloxacin, penicillin/tazobactam, and rifampicin. Two out of the 11 C. perfringens strains were resistant to erythromycin and clindamycin. Conclusions: Regardless of the performed H2O2 fogging, antibiotic-resistant, toxigenic strains of C. perfringens (69%) obtained from the urology hospital environment were cultured using C diff Banana Broth™, indicating the need to develop the necessary sanitary and epidemiological procedures in this hospital.

Occurrence and Transport of Isothiazolinone-Type Biocides from Commercial Products to Aquatic Environment and Environmental Risk Assessment

This study investigated the occurrence and transport of four isothiazolinone-type biocides from commercial products to wastewater treatment plants (influents, sludges, and effluents) and to natural emissaries (upstream and downstream the wastewater treatment plants) in Romania. All four biocides were determined in personal care and household products, with the highest concentration of 76.4 µg/L OIT (2-octyl-4-isothiazolin-3-one). For environmental samples, three of the four isothiazolinones were determined, CMI (5-chloro-2-methyl-4-isothiazolin-3-one) being the prominent compound for water samples. The maximum concentration of 84.0 µg/L in influent, 122 µg/L upstream, and 144 µg/L downstream the wastewater treatment plants were obtained for CMI. Unlike water samples, in the sewage sludge samples, OIT proved to be the dominant compound, with concentration up to 5.80 µg/g d.w. The extremely high levels of isothiazolinone determined in different WWTPs from Romania may be due to the COVID-19 pandemic situation, during which a much larger amount of cleaning, hygiene, and personal care products was used. The isothiazolinone-type biocides were readily removed from the influents of the five WWTPs, with the mean removal rate up to 67.5%. The mean mass loading value for the targeted biocides based on influent was 20.4 μg/day/1000 people, while the average environmental emissions were 6.93 μg/day/1000 people for effluents. The results obtained for riverine water combine with statistical analysis showed that the anthropogenic activities are the major contamination sources of the surface waters. Preliminary ecological risk evaluation showed that BIT (1,2-benzisothiazol-3(2H)-one), OIT, and CMI could pose a very high risks to different aquatic species living in the receiving aquatic environments.

Insights into the spatiotemporal occurrence and mixture risk assessment of household and personal care products in the waters from rivers to Laizhou Bay, southern Bohai Sea

Household and personal care products (HPCPs) are a kind of contaminants closely related to daily life, capturing worldwide concern. To our knowledge, this is the first attempt focusing on the spatiotemporal occurrence and mixture risk of HPCPs in the waters from rivers to Laizhou Bay. Nine HPCPs were quantitated in 216 water samples gathered from Laizhou Bay and its adjacent rivers in 2018, 2019, and 2021 to reveal the spatiotemporal occurrence and mixture ecological risks in Laizhou Bay. Eight HPCPs were detected with detection frequencies ranging from 74% to 100%. The total concentrations were in the ranges 105-721 ng L^-1 in river water and 51.3-332 ng L^-1 in seawater. The HPCPs were dominated by p-hydroxybenzoic and triclosan, which together contributed over 75% of the total HPCPs. The average level of the total HPCP concentration in the summer of 2018 (96.1 ng L^-1) was slightly exceed that in the spring of 2019 (91.6 ng L^-1), which is associated with the higher usage of HPCPs and enhanced tourism during summer. However, the highest total concentrations were found in spring of 2021 (124 ng L^-1 in average), which was attribute to a higher level of methylparaben, a predominant paraben used as preservatives in commercial pharmaceuticals of China. Influenced by riverine inputs and ocean currents, higher HPCP concentrations in Laizhou Bay were found nearby the estuary of Yellow River and the southern part of the bay. Triclosan should be given constant concern considering its medium to high risks (RQ > 0.1) in nearly 80% of the water samples. The cumulative risk assessment in two approaches revealed that HPCP mixtures generally elicit medium or high risk to three main aquatic taxa. Considering the worldwide outbreak of COVID-19, the levels and risks of multiple HPCPs in natural waters requires constant attention in future studies.