Humans are potentially exposed to microplastics through food, drink, and air. The first two pathways have received quite some scientific attention, while little is known about the latter. We address the exposure of humans to indoor airborne microplastics using a Breathing Thermal Manikin. Three apartments were investigated, and samples analysed through FPA-µFTIR-Imaging spectroscopy followed by automatic analyses down to 11 µm particle size. All samples were contaminated with microplastics, with concentrations between 1.7 and 16.2 particles m⁻³. Synthetic fragments and fibres accounted, on average, for 4% of the total identified particles, while nonsynthetic particles of protein and cellulose constituted 91% and 4%, respectively. Polyester was the predominant synthetic polymer in all samples (81%), followed by polyethylene (5%), and nylon (3%). Microplastics were typically of smaller size than nonsynthetic particles. As the identified microplastics can be inhaled, these results highlight the potential direct human exposure to microplastic contamination via indoor air.

It is essential to understand where and howsevere acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2)is transmitted.Case reports were extracted from the local Municipal Health Commissions of 320prefecturalmunicipalities in China (not including Hubei province). We identified alloutbreaks involving three or more cases and reviewed the major characteristics of the enclosed spaces in which the outbreakswere reported and their associated indoor environmental aspects.Three hundred and eighteen outbreaks with three or more cases were identified,comprising a total of 1245 confirmed cases in 120prefectural cities. Amongst the identified outbreaks, 53.8% involved three cases, 26.4%involved four cases, and only 1.6%involved ten or more cases. Home‐based outbreakswere the dominant category (254 of 318 outbreaks;79.9%), followed by transport‐based outbreaks (108;34.0%), and many outbreaks occurred in more than one categoryof venue. All identified outbreaksof three or more cases occurred in indoor environments, which confirmsthat sharing indoor spaceswith one or more infected persons isa major SARS‐CoV‐2 infection risk.

Hand hygiene (HH) is a cost-effective measure to reduce health care-associated infections. The overall characteristics and changes of hand hygiene compliance (HHC) among health care providers during the COVID-19 pandemic provided evidence for targeted HH intervention measures. To systematically review the literature and conduct a meta-analysis of studies investigating the rate of HHC and the characteristics of HH during the COVID-19 pandemic. The PubMed, Embase, Cochrane Library, Web of Science, CNKI, WanFang Data, VIP, and CBM databases were searched. All the original articles with valid HHC data among health care providers during the COVID-19 pandemic (from January 1, 2020 to October 1, 2021) were included. Meta-analysis was performed using a DerSimonian and Laird model to yield a point estimate and a 95% CI for the HHC rate. The heterogeneity of the studies was evaluated using the Cochrane Q test and I² statistics and a random-effects model was used to contrast between different occupations, the WHO 5-moments of HH and different observation methods. Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines were followed. Seven studies with 2,377 health care providers reporting HHC were identified. The estimated overall HHC was 74%, which was higher than that reported in previous studies (5%-89%). Fever clinic has become a new key place for HHC observation. Nurses had the highest HHC (80%; 95% CI:74%-87%) while auxiliary workers (70%; 95%CI:62%-77%) had the lowest. For the WHO 5-moments, the health care providers had the highest HHC after contact with the body fluids of the patients (91%; 95% CI:88%-94%), while before contact with patient's health care providers had the lowest HHC (68%; 95% CI:62%-74%) which was consistent with before the pandemic. There existed great HHC differences among different monitoring methods (automatic monitoring system:53%; 95% CI:44%-63% versus openly and secretly observation: 91%; 95% CI: 90%-91%). During the COVID-19 pandemic, the compliance of health care providers’ HH showed a great improvement. The fever clinics have become the focused departments for HH monitoring. The HHC of auxiliary workers and the HH opportunity for “before contact with patients” should be strengthened. In the future, it will be necessary to develop standardized HH monitoring tools for practical work.

Background: The role of aerosols in the transmission of SARS-CoV-2 remains debated. We analysed an outbreak involving three non-associated families in Restaurant X in Guangzhou, China, and assessed the possibility of aerosol transmission of SARS-CoV-2 and characterize the associated environmental conditions. Methods: We collected epidemiological data, obtained a video record and a patron seating-arrangement from the restaurant, and measured the dispersion of a warm tracer gas as a surrogate for exhaled droplets from the suspected index patient. Computer simulations were performed to simulate the spread of fine exhaled droplets. We compared the in-room location of subsequently infected cases and spread of the simulated virus-laden aerosol tracer. The ventilation rate was measured using the tracer decay method. Results: Three families (A, B, C), 10 members of which were subsequently found to have been infected with SARS-CoV-2 at this time, or previously, ate lunch at Restaurant X on Chinese New Year’s Eve (January 24, 2020) at three neighboring tables. Subsequently, three members of family B and two members of family C became infected with SARS-CoV-2, whereas none of the waiters or 68 patrons at the remaining 15 tables became infected. During this occasion, the ventilation rate was 0.75–1.04 L/s per person. No close contact or fomite contact was observed, aside from back-to-back sitting by some patrons. Our results show that the infection distribution is consistent with a spread pattern representative of exhaled virus-laden aerosols. Conclusions: Aerosol transmission of SARS-CoV-2 due to poor ventilation may explain the community spread of COVID-19.