Identification and characterization of quaternary ammonium compounds in Flemish indoor dust by ion-mobility high-resolution mass spectrometry.

Quaternary ammonium compounds (QACs) are a class of surfactants commonly used in disinfecting and cleaning products. Their use has substantially increased during the COVID-19 pandemic leading to increasing human exposure. QACs have been associated with hypersensitivity reactions and an increased risk of asthma. This study introduces the first identification, characterization and semi-quantification of QACs in European indoor dust using ion-mobility high-resolution mass spectrometry (IM-HRMS), including the acquisition of collision cross section values (DTCCSN2) for targeted and suspect QACs. A total of 46 indoor dust samples collected in Belgium were analyzed using target and suspect screening. Targeted QACs (n = 21) were detected with detection frequencies ranging between 4.2 and 100 %, while 15 QACs showed detection frequencies > 90 %. Semi-quantified concentrations of individual QACs showed a maximum of 32.23 µg/g with a median ∑QAC concentration of 13.05 µg/g and allowed the calculation of Estimated Daily Intakes for adults and toddlers. Most abundant QACs matched the patterns reported in indoor dust collected in the United States. Suspect screening allowed the identification of 17 additional QACs. A dialkyl dimethyl ammonium compound with mixed chain lengths (C16:C18) was characterized as a major QAC homologue with a maximum semi-quantified concentration of 24.90 µg/g. The high detection frequencies and structural variabilities observed call for more European studies on potential human exposure to these compounds. For all targeted QACs, drift tube IM-HRMS derived collision cross section values (DTCCSN2) are reported. Reference DTCCSN2 values allowed the characterization of CCS-m/z trendlines for each of the targeted QAC classes. Experimental CCS-m/z ratios of suspect QACs were compared with the CCS-m/z trendlines. The alignment between the two datasets served as an additional confirmation of the assigned suspect QACs. The use of the 4bit multiplexing acquisition mode with consecutive high-resolution demultiplexing confirmed the presence of isomers for two of the suspect QACs.

IMPORTANCE OF COMPREHENSIVE HEALTH RISK ASSESSMENT PROCEDURES FOR MODERN WASTE-TO-ENERGY FACILITIES IN COMPLEX GEOGRAPHICAL CONTEXTS ORIENTED TO CIRCULAR ECONOMY

Although circular economy (CE) principles set material circularity, resource efficiency and waste recycling as priority targets to guarantee the sustainable development of future generations, the thermochemical valorisation of municipal solid waste (MSW) still plays a fundamental role in the transition towards the final CE targets. As a matter of fact, the waste-to-energy (WtE) sector allows recovering energy from waste, reducing the pressure on MSW landfills and their related potential environmental impacts;however, recovering material for further uses is not excluded in WtE options. Significant improvements have been achieved in the air pollution control of exhaust gases from direct and indirect MSW combustion during the last decades. The efforts focussed on reducing dioxin emissions especially, and this has let other substances emerge as priority pollutants (e.g., heavy metals). In addition, the location of WtE facilities in certain geographical contexts is still potentially critical from the point of view of human exposure and the related health risk;moreover, the public acceptance of WtE plants is still limited, in spite of their recent role in fighting SARS-CoV-2 risks from waste management. The purpose of the present paper is to underline the importance of implementing correct and complete health risk assessment procedures tailored to the exposed population living in the area of influence of a WtE plant. The paper will present two case studies regarding the projects of two WtE plants in a mountainous region, highlighting the critical issues that arose during the environmental impact assessment procedures. The paper will finally suggest possible options to improve the health risk assessment procedure and alternative measures to reduce the expected impacts of the WtE sector on the environment and human exposure. © 2022 WIT Press.

A holistic review on triclosan and triclocarban exposure: Epidemiological outcomes, antibiotic resistance, and health risk assessment.

Triclosan (TCS) and triclocarban (TCC) are antimicrobials that are widely applied in personal care products, textiles, and plastics. TCS and TCC exposure at low doses may disturb hormone levels and even facilitate bacterial resistance to antibiotics. In the post-coronavirus disease pandemic era, chronic health effects and the spread of antibiotic resistance genes associated with TCS and TCC exposure represent an increasing concern. This study sought to screen and review the exposure levels and sources and changes after the onset of the coronavirus disease (COVID-19) pandemic, potential health outcomes, bacterial resistance and cross-resistance, and health risk assessment tools associated with TCS and TCC exposure. Daily use of antimicrobial products accounts for most observed associations between internal exposure and diseases, while secondary exposure at trace levels mainly lead to the spread of antibiotic resistance genes. The roles of altered gut microbiota in multi-system toxicities warrant further attention. Sublethal dose of TCC selects ARGs without obviously increasing tolerance to TCC. But TCS induce persistent TCS resistance and reversibly select antibiotic resistance, which highlights the benefits of minimizing its use. To derive reference doses (RfDs) for humans, more sensitive endpoints observed in populational studies need to be confirmed using toxicological tests. Additionally, the human equivalent dose is recommended to be incorporated into the health risk assessment to reduce uncertainty of extrapolation.

Highly Time-Resolved and Nontargeted Characterization of Volatile Organic Compound Emissions from Face Masks

Face covering by masks has become a lifeline for humans to prevent the airborne transmission of highly infectious SARS-CoV-2. One of the side effects, however, is the release of volatile organic compounds (VOCs), which can hardly be fully understood based on traditional offline measurements. Here, for the first time, we performed highly time-resolved and nontargeted measurements of VOCs emitted from face masks using an ultrasensitive proton transfer-reaction quadrupole-interface time-of-flight mass spectrometer. We found diverse VOC species, some of which are toxic. The chemical structures of the major VOC species were identified to be from the chemicals and processes involved in mask production. High concentrations of VOCs emitted from surgical masks (predominant mask type) were all concentrated in the initial 1 h and then dropped rapidly to an acceptable level after a process of naturally airing out. Higher emissions from a surgical mask for children are likely due to their colorful cartoon patterns. Despite the lowest emissions, the N95 respirator with an active carbon layer required 6 h to remove the toxic methanol. We support mask wearing to curtail the COVID-19 pandemic, but our results highlight the importance of naturally airing out masks to reduce zero-distance inhalation of mask-emitted VOCs.

Compendium of analytical methods for sampling, characterization and quantification of bioaerosols

Bioaerosols are suspensions of airborne particulate matter of biological origin (BioPM) which includes microorganisms and the products of these organisms. Bioaerosols are ubiquitous in indoor and outdoor environments and can become dispersed by attaching to other particles. Bioaerosols are diverse in terms of their size, composition and biological properties and are an important transmission route for infectious and sensitization agents. More recently, bioaerosols have received significant scientific and societal attention from industry, academia, government and the wider public due to the emergence and global spread of COVID-19 and the threat of bioterrorism. Yet despite their importance for human health, the microbiological components of aerosols and their species dispersal from various environments remains poorly understood. Moreover, there is a lack of understanding of the ecology and role that bioaerosols play in the environment. As a result of these knowledge gaps, health officials and regulators have been hindered in their assessment of public and occupational health exposures and risk. For example, a better understanding of the concentrations and composition of bioaerosols in a particular environment, and the transmission dynamics of pathogens and their components, can inform on the appropriate ventilation rates and hygiene procedures to maintain good air quality and reduce human health risk. However, there are currently many uncertainties still remaining with regard to exposure assessment. To better understand the impact of bioaerosol exposure on human health, comprehensive methods to detect, characterise and quantify bioaerosols are needed. Although significant advances in technologies for bioaerosol sampling and analysis have been achieved over the last two decades or so, a consensus on air sampling methods for a particular context or environment and a universal analysis method still does not exist. This makes it difficult for researchers to compare data across studies, and for regulators to set meaningful exposure limits. BioAirNet is a UKRI NERC-funded project which acts as a leading voice for the UK BioPM science community and operates around four themes: Theme (1) BioPM sources and dynamics;Theme (2) BioPM sampling and characterisation;Theme (3) Human health, behaviour and wellbeing;and Theme (4) Policy and public engagement. As part of Theme 2, researchers, regulators, and public health officials have developed this compendium and Fig. 1 presents an overview of BioAirNet Theme 2. This compendium aims to provide a comprehensive toolbox of current techniques, workflows, and technologies for bioaerosol sampling, characterisation, and monitoring across different environments for researchers, epidemiologists, regulators, public health officials and regulators involved in bioaerosols. The overall goal of this text is to support the development of useful standards to better regulate and monitor bioaerosols worldwide.

Occurrence of phthalates in facemasks used in India and its implications for human exposure.

Synthetic polymers with additives are used in the manufacturing of face masks (FMs); hence, FMs could be a potential source of exposure to phthalic acid esters (PAEs). India stands second in the world in terms of the FMs usage since the beginning of Covid-19 pandemic. However, little is known about the PAEs content of FMs used in India. Some PAEs, such as DEHP and DBP are suspected endocrine disrupting chemicals (EDCs); hence, wearing FM may increase the risk of exposure to these EDCs. In this study, we collected 91 samples of FMs from eight Indian cities and analyzed for five PAEs viz. DMP, DEP, DBP, BBP, and DEHP. The PAEs contents in FMs ranged from 101.79 to 27,948.64 ng/g. The carcinogenic risk of N 95 with filter, N-95, and cloth masks was higher than the threshold levels. The findings indicate the need to control PAEs in FMs through regulatory actions.

Polycyclic aromatic hydrocarbons (PAHs) exposure through cooking environment and assessment strategies for human health implications

The polycyclic aromatic hydrocarbons' (PAHs) exposure through day to day cooking activities has been a serious concern for human health due to their carcinogenic nature. Given the Covid-19 conditions, where people are spending extended time indoors, the likely exposure to these compounds will increase for the members involved/not involved in cooking. In this context, this review summarizes different studies undertaken worldwide on PAHs from cooking activities, the sources of exposure (fumes/emissions, dust/depositions), effect of scale (households/restaurants/neighborhoods) of cooking, monitoring process, risk assessment (air sampling and urinary metabolites), global distribution pattern. Proportionately higher number of studies was focused on cooking fumes and emissions while very limited studies aimed at kitchen depositions and dust. Most of the studies have not reported the size of particulate matter considered for determining PAHs exposure from cooking fumes and emissions. The evaluation of reported data becomes more complicated due to difference in sampling and expression units, the number and types of PAHs (parent, oxygenated-PAHs, i.e., o-PAHs, nitro-PAHs, i.e., n-PAHs) studied/found, lack of other intrinsic information (site and control parameters), lack of specific regulations etc. Therefore, such studies require method standardization for future policy development. This review also highlights the gaps and challenges in existing knowledge and future prospects.

Modeling Clothing as a Vector for Transporting Airborne Particles and Pathogens across Indoor Microenvironments.

Evidence suggests that human exposure to airborne particles and associated contaminants, including respiratory pathogens, can persist beyond a single microenvironment. By accumulating such contaminants from air, clothing may function as a transport vector and source of "secondary exposure". To investigate this function, a novel microenvironmental exposure modeling framework (ABICAM) was developed. This framework was applied to a para-occupational exposure scenario involving the deposition of viable SARS-CoV-2 in respiratory particles (0.5-20 µm) from a primary source onto clothing in a nonhealthcare setting and subsequent resuspension and secondary exposure in a car and home. Variability was assessed through Monte Carlo simulations. The total volume of infectious particles on the occupant's clothing immediately after work was 4800 µm3 (5th-95th percentiles: 870-32 000 µm3). This value was 61% (5-95%: 17-300%) of the occupant's primary inhalation exposure in the workplace while unmasked. By arrival at the occupant's home after a car commute, relatively rapid viral inactivation on cotton clothing had reduced the infectious volume on clothing by 80% (5-95%: 26-99%). Secondary inhalation exposure (after work) was low in the absence of close proximity and physical contact with contaminated clothing. In comparison, the average primary inhalation exposure in the workplace was higher by about 2-3 orders of magnitude. It remains theoretically possible that resuspension and physical contact with contaminated clothing can occasionally transmit SARS-CoV-2 between humans.

On the Flip Side of Mask Wearing: Increased Exposure to Volatile Organic Compounds and a Risk-Reducing Solution.

Surgical masks have been worn by the public worldwide during the COVID-19 pandemic, yet hazardous chemicals in the petroleum-derived polymer layer of masks are currently ignored and unregulated. These organic compounds pose potential health risks to the mask wearer through dermal contact or inhalation. Here, we show that surgical masks from around the world are loaded with semivolatile and volatile organic compounds (VOCs), including alkanes, polycyclic aromatic hydrocarbons (PAHs), phthalate esters, and reactive carbonyls at ng to µg/mask levels. Naphthalene was the most abundant mask-borne PAH, accounting for over 80% of total PAH levels; acrolein, a mutagenic carbonyl, was detected in most of the mask samples, and di(2-ethylhexyl) phthalate, an androgen antagonist, was detected in one-third of the samples. Furthermore, there is large mask-to-mask variability of the residue VOCs, revealing the uneven quality of masks. We confirm that masks containing more residue VOCs lead to significantly higher exposure levels and associated disease risks to the wearer, which should warrant the attention of the general public and regulatory agencies. We find that heating the masks at 50 °C for as short as 60 min lowers the total VOC content by up to 80%, providing a simple method to limit our exposure to mask-borne VOCs.

Risk of Environmental Exposure to H7N9 Influenza Virus via Airborne and Surface Routes in a Live Poultry Market in Hebei, China.

Environmental transmission of viruses to humans has become an early warning for potential epidemic outbreaks, such as SARS-CoV-2 and influenza virus outbreaks. Recently, an H7N9 virus, A/environment/Hebei/621/2019 (H7N9), was isolated by environmental swabs from a live poultry market in Hebei, China. We found that this isolate could be transmitted by direct contact and aerosol in mammals. More importantly, after 5 passages in mice, the virus acquired two adaptive mutations, PB1-H115Q and B2-E627K, exhibiting increased virulence and aerosol transmissibility. These results suggest that this H7N9 virus might potentially be transmitted between humans through environmental or airborne routes.

Genotoxic effect of microplastics and COVID-19: The hidden threat.

Microplastics (MPs) are ubiquitous anthropogenic contaminants, and their abundance in the entire ecosystem raises the question of how far is the impact of these MPs on the biota, humans, and the environment. Recent research has overemphasized the occurrence, characterization, and direct toxicity of MPs; however, determining and understanding their genotoxic effect is still limited. Thus, the present review addresses the genotoxic potential of these emerging contaminants in aquatic organisms and in human peripheral lymphocytes and identified the research gaps in this area. Several genotoxic endpoints were implicated, including the frequency of micronuclei (MN), nucleoplasmic bridge (NPB), nuclear buds (NBUD), DNA strand breaks, and the percentage of DNA in the tail (%Tail DNA). In addition, the mechanism of MPs-induced genotoxicity seems to be closely associated with reactive oxygen species (ROS) production, inflammatory responses, and DNA repair interference. However, the gathered information urges the need for more studies that present environmentally relevant conditions. Taken into consideration, the lifestyle changes within the COVID-19 pandemic, we discussed the impact of the pandemic on enhancing the genotoxic potential of MPs whether through increasing human exposure to MPs via inappropriate disposal and overconsumption of plastic-based products or by disrupting the defense system owing to unhealthy food and sleep deprivation as well as stress. Overall, this review provided a reference for the genotoxic effect of MPs, their mechanism of action, as well as the contribution of COVID-19 to increase the genotoxic risk of MPs.

COVID-19 face masks: A new source of human and environmental exposure to organophosphate esters.

For the first time, organophosphate ester (OPE) content was studied in different types of surgical, self-filtering (KN95, FFP2, and FFP3) and reusable face masks used for COVID-19 prevention. OPEs were detected in all mask samples, although in highly variable amounts which ranged from 0.02 to a maximum of 27.7 µg/mask, with the highest mean concentrations obtained for KN95 masks (11.6 µg/mask) and the lowest for surgical masks (0.24 µg/mask). Twelve out of 16 tested analytes were detected, with TEP, TPHP, TNBP, TEHP and TClPP being the most common OPEs as well as present at the highest concentrations. The non-carcinogenic and carcinogenic risks of OPE inhalation were calculated as being always several orders of magnitude lower than threshold levels, indicating that the use of face masks is safe with regard to OPE contamination. However, given the wide range of OPEs observed in different masks, it can be concluded that some masks (e.g. reusable) are less OPE-contaminated than others (e.g. KN95). With regard to environmental pollution, the disposal of billions of face masks is adding to the already substantial levels of microplastics and associated toxic additives worldwide, an impact that is lessened by use of reusable masks, which also have the lowest economic cost per user. However, in situations of relatively high risk of viral inhalation, such as poorly ventilated indoor public spaces, we recommend the use of FFP2 masks.