International Journal of Environmental Research and Public Health

The SARS-CoV-2 pandemic has resulted in many live events being canceled or held without spectator participation. It is therefore necessary to develop strategies to determine the conditions under which cultural activities can be maintained. In this study the results from available literature were combined with findings, guidelines and regulations for other indoor environments and recommendations were derived. In the cultural sector, the number of experimental investigations, surveys and simulations is comparatively small. This is probably due to the complexity of the events in terms of location and visitor flow, so the respective conditions under which they take place can be very different. It is therefore practically impossible to predict the risk of infection for a specific situation with potential virus spreaders attending or to derive general rules that go beyond the known measures of vaccination, testing, masks and distance. Cultural events can be held under pandemic conditions, provided certain conditions are met. Most study results agree on this. However, any recommendations for hygiene, safety and ventilation measures in cultural institutions can only minimize the risk of infection, but cannot completely rule it out. It is also of considerable importance that visitors protect themselves individually and act responsibly. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=68 SRC="FIGDIR/small/22281932v1_ufig1.gif" ALT="Figure 1"> View larger version (10K): org.highwire.dtl.DTLVardef@13b4f8dorg.highwire.dtl.DTLVardef@e3b4a9org.highwire.dtl.DTLVardef@16a0140org.highwire.dtl.DTLVardef@78280b_HPS_FORMAT_FIGEXP M_FIG C_FIG

Children are especially vulnerable to environmental harms, thus increasing their knowledge about risk factors caused by environmental exposures, in addition to epidemiology by providing practical experiences through a non-computer based educational game in environmental epidemiology may lead to more promising behavioral outcomes. Because no educational game exists in environmental epidemiology, we augmented an existing epidemiology game by adding an environmental health theme, involving practical decision-making and problem solving in environmental epidemiology. A cross-sectional survey assessed the games impact, on childrens knowledge, experience, and attitudes regarding environmental health, and experience and attitudes toward epidemiology following game exposure in 2016. Participants from Croatia had a median age of 11.5 years with interquartile range (IQR) 11-13. The majority of children indicated they had learned a lot about the environmental health concepts newly added to an existing epidemiology game. Our modified game offers interactive and practical examples, which may facilitate teaching environmental epidemiology to elementary school students.

Contaminated aerosols in room air are one of the transmission routes of the coronavirus. The amount of contaminated aerosols in the room seems to play an important role for the infection risk. In rooms without technical air refreshing systems, the aerosol concentration can be reduced with simple natural ventilation activity. Instrumental and vocal lessons and rehearsals take place in closed indoor rooms. Therefore it is important to optimize the necessary ventilation activity in order to keep the infection risk for musicians low. Therefore, knowledge about the maximum duration of the lesson or rehearsal for ventilation intervals are necessary. In this study, carbon dioxide concentration (CO2) as an indicator of the indoor air quality (IAQ) was measured during 47 music lessons and rehearsals at a university of music including 141 persons. From these measurements, the air exchange rates of the rooms and the CO2 emission rates per person were extracted. The results show that the CO2 emission in musical activities can be assigned to light and moderate activities between 28 l/h and 39 l/h. Wind instruments had the highest CO2 emissions. Singers showed low CO2 emission rates comparable to the control group which only spoke and listened. Recommendations for the frequency of ventilation breaks were derived from empirical data and allow for an individual risk assessment of instrumental and vocal lessons and rehearsals depending on room size and number of musicians.

A better air quality has led to a significant reduction of premature deaths over the past decade in Europe, as emissions of many pollutants declined considerably in the EU-27 Member States: SOx emissions by 76%, NOx by 42%, NMVOCs by 29% and PM2.5 by 29%. The present paper reports an in-depth analysis of the reasons why the regions of the Po valley, Northern Italy, still have difficulties to comply with EU air quality standards, in particular for PM10 and NO2, in spite of strong emission reductions carried out through careful Air Quality Plans put in practice during the last 2 decades. The analysis includes a consistent comparison of emission inventories for different European regions in Italy, Germany and Poland, the measured air quality trends and PM source apportionment in these areas, and, most of all, a thorough investigation of meteorological parameters influencing atmospheric pollutant dispersion and transport. The study reports that in the colder seasons, wind speed, PBL height and atmospheric pressure occurring in the Po basin are three to five times less efficient in diluting and dispersing pollutant if compared to regions north of the Alps. Due to the extremely disadvantageous orographic and climatic configuration of the Po Valley, only radical emission reductions could bring air quality into EU limit values with a questionable cost-benefit ratio of due policies. Provided that air quality standards (particularly for PM10 and PM2.5) aim at protecting people from adverse health effects arising from air pollution, it is however necessary to also consider the toxicity of atmospheric particulate in addition to PM10/PM2.5 mass concentration as a limit value. Based on existing toxicological studies and reports, a discussion is reported about PM toxicity factor depending on toxicity scores for source-specific aerosols and PM composition determined by Source Apportionment. Provided that PM components profiles are strongly different across Europe, the obtained PM toxicity factors range from 0.3 (for areas where the main PM contribution is referable to sea salts or inorganic matter) to 3.5 (where Elemental and Organic Carbon prevail), suggesting that, even at the same mass concentration, the effects of PM10/2.5 on human health are significantly variable and limit values should take into account differential toxicity. Modern PM Source Apportionment techniques, along with reliable toxicity and epidemiological analyses, represent the right tools to overcome the shortcomings of the current regulation standard and build a new consistent health metric for ambient PM in the future, helping policy makers impose effective air quality measures to protect people health.

PurposeIt is questioned whether the exposure-response relation for the onset of vibration-induced white finger (VWF) in ISO 5349-1:2001 needs to be revised based on the epidemiologic studies identified by Nilsson et al., (2017) (https://doi.org/10.1371/journal.pone.0180795), and whether the relation they derive improves the prediction of VWF in vibrationexposed populations. MethodsA pooled analysis has been performed using pidemiologic studies that complied with selection rules and reported a VWF prevalence of 10% or more, and exposure constructed according to the provisions of ISO 5349-1:2001. The lifetime exposure at 10% prevalence was calculated for various data sets using linear interpolation. They were then compared to both the model from the standard and that developed by Nilsson et al. ResultsRegression analyses reveal excluding extrapolation to adjust group prevalences to 10% produce models with 95-percentile confidence intervals that include the ISO exposure-response relation but not that in Nilsson et al. (2017). Different curve fits are obtained for studies involving daily exposure to single or multiple power tools and machines. Studies with similar exposure magnitudes and lifetime exposure durations but markedly different prevalences are observed to cluster. ConclusionsA range of exposures and A(8)-values is predicted within which the onset of VWF is most likely to occur. The exposure-response relation in ISO 5349-1:2001, but not that proposed by Nilsson et al., falls within this range and provides a conservative estimate for the development of VWF. Additionally, the analyses demonstrate that the method for evaluating vibration exposure contained in ISO 5349-1:2001 needs revision.

IntroductionMilitary exposure summarization is critical for Veterans with complex environmental, occupational, or toxic exposures. Existing methods are limited by technical language, incompatible data formats, and difficulty in prioritizing information. Clinicians require concise, standardized, and easily interpretable exposure summaries to facilitate rapid assessment. This report is part of a broader programmatic effort to collate military exposure information from established, as well as new sources of data to improve VA exposure-informed healthcare. MethodsIn a collaborative effort, VA clinicians from multiple specialties participated in a structured clinical needs assessment interview to identify the most clinically useful information to be included in the Health Exposure Records and Occupations (HERO) summary. The interviews covered summary length, exposure prioritization, demographics, military occupational history, features characterizing exposure, resilience factors, health outcomes, and impact on clinical practice. ResultsConsensus recommendations prescribed a concise summary with clear language, basic military demographics, and critical military exposures that prioritize exposures that require further investigation. Based on recommendations, the HERO summary also includes types of exposure, proximity, route, symptoms at the time of exposure, exposure period, duration, frequency, and protective controls used. ConclusionThis perspective piece not only assesses the clinical need for exposure summarization and the optimal format for the HERO summary, but also highlights its potential impact. The HERO summary, as a tool, offers improved time efficiency, consistency in exposure-informed care across the VA, enhances communication between Veterans and providers, and improves understanding of the association between military exposures and health outcomes, potentially transforming the VA healthcare system.

As electret technology can drastically improve the filtration efficiency of disposable procedure masks and portable air purifiers, it is widely used to prevent the airborne transmission of SARS-CoV-2. Furthermore, alcohol disinfectants are now widely used in offices, hospitals, and homes to prevent contact infection; hence, there is a concern that alcohol exposure may inactivate electret. In this study, 5 types of high-efficiency particulate air filter (HEPA) air purifiers--of which, one was made of fiberglass HEPA filter--14 types of cubical masks, and 11 types of pleated masks available to Japanese citizens were subjected to discharge according to the alcohol exposure protocol based on ISO (International Organization for Standardization) 16890, and changes in filtration efficiency and pressure drop were measured before and after the discharge. The results revealed that 17 (68%) of the 25 masks exhibited a significant decrease in filtration efficiency; this decrease due to discharge depended on the filter material. However, masks of polypropylene, polyethylene, and poly-vinylidene-difluoride composite fiber materials exhibited no significant decrease in filtration efficiency. In addition, 4 (80%) of the 5 HEPA filters showed a 40-64% decrease in filtration efficiency, while no decrease in filtration efficiency was observed for the fiberglass HEPA filter. Our survey (n = 500 Japanese adults, including 30 healthcare professionals) revealed that approximately 90% of the general public was unaware that the performance of masks and air purifiers could be degraded by direct spraying of alcohol--for disinfection purposes--or vapor exposure. Furthermore, 36% of the surveyed healthcare professionals indicated that they had sprayed alcohol directly on their masks. Therefore, based on the results of this experiment, we examined effective consumer warnings that could be utilized on the product labels and in the instructions. The results showed that it would be more effective to detail the extent and duration of the adverse effects of disregarding the precautions.

The 2019 health crisis has underscored the imperative role of information and communications technology (ICT) in bolstering employees health, well-being, and ameliorating health risks associated with artificial intelligence (AI) errors. Digital health technology facilitates remote healthcare delivery, employee health monitoring, and enhanced communication channels between workers and healthcare professionals. This paper conducts a comprehensive analysis of global trends in digital occupational health research over the past decade, with a specific focus on prolific authors, countries, academic institutions, and publications. Leveraging the PRISMA framework and VOSviewer software, relevant documents are extracted from the Scopus database. The findings underscore the significance of digital technology in the realm of occupational health and highlight the pressing need for further investigation, particularly encompassing emerging economies and employing robust methodologies to ensure the reliability of results. This study offers a valuable assessment of advancements in digital occupational health, serving as a foundation for future research endeavors aimed at optimizing workplace health and well-being on a global scale.

During the COVID-19 pandemics, several outbreaks have been recorded all other the world in industrial slaughterhouses and meat processing plants. Occupational preventive medicine in such non-healthcare frontline essential services accounts for combined different environmental, social, and economic factors, to reduce the burden of COVID-19 in the workplaces and in the connected residential settings. In Italy, during the first year of the pandemics, an advocacy action has been activated, targeted on meat plant managers and related food business operators. A risk-oriented control plan was agreed by competent Italian Health Authorities at Region/Province level. A questionnaire focused on the inventoried risk factors reported in the literature in such working places have been developped as supporting tool, and administered on voluntary basis to the interested stakeholders. In addition, an outbreak questionnaire was proposed to the Prevention Depts of the Local Health Units. In the 2021 - 2022 years timeframe, we collected 333 advocacy and 24 outbreak questionnaires, respectively, on 4,765 inventoried plants at national level. Responses came mainly from those districts that locally activated the risk-oriented control plan. The lack of awareness to update the Risk Assessment Document of the meat plant for COVID-19, non instrumental body Temperature checks of workers at the entrance, working force from different subcontractors, poor hygiene in the shared places and insufficient ventilation represented the main critical points recorded. The cross-checks between the results from the advocacy and from the outbreak questionnaires are feeding an after-action review for such food-chain related essential work settings within a One Health approach.

Aim and MethodsA coronavirus disease 2019 (COVID-19) cluster emerged in a manufacturing factory in early August 2021. In November 2021, a ventilation survey using tracer gas and data analysis was performed to reproduce the situation at the time of cluster emergence and verify that ventilation in the office increased the risk of aerosol transmission; verify the effectiveness of measures implemented immediately in August; and verify the effectiveness of additional measures when previously enforced measures proved inadequate. ResultsAt the time of cluster emergence, the average ventilation frequency was 0.73 times/h, less than the 2 times/h recommended by the Ministry of Health, Labour, and Welfare; as such, the factorys situation was deemed to have increased the risk of aerosol transmission. Due to the measures already taken at the time of the survey, the ventilation frequency increased to 3.41 times/h on average. It was confirmed that ventilation frequency increased to 8.33 times/h on average, when additional measures were taken. ConclusionTo prevent the re-emergence of COVID-19 clusters, it is necessary to continue the measures that have already been implemented. Additionally, introduction of real-time monitoring that visualizes CO2 concentrations is recommended. Furthermore, we believe it is helpful that external researchers in multiple fields and internal personnel in charge of health and safety department and occupational health work together to confirm the effectiveness of conducted measures, such as this case.

BackgroundEcosyndemic research focuses on the role of environmental contextual factors in syndemics. However, there is no consensus on the difference between syndemics and ecosyndemics, as the physical environment is often also included in syndemic studies. This review aims to describe the definitions used, environmental aspects included, and methods employed in ecosyndemic and syndemic studies with an environmental contextual focus. MethodsWe conducted a literature search across five databases. We screened articles in two phases: software-assisted screening and manual full-text screening. To distinguish common elements, ecosyndemic and syndemics definitions were coded. Information regarding methods, factors related to the physical environment, and study results were extracted from the empirical articles. ResultsA total of 169 publications were included, 16 used an ecosyndemic definition, 137 a syndemic one, and 16 a global syndemic definition. Most articles were nonempirical (n=112). Two types of ecosyndemic conceptualizations were distinguished: the extension conceptualization (n=10), which emphasizes the role of the physical environmental context in combination with other contextual factors, and the trigger conceptualization (n=6), which focuses on how environmental factors can trigger a syndemic. The built environment was studied most frequently (n=48), the food environment the least (n=18). ConclusionThe ecosyndemic framework highlights the role of the physical and social environment in worsened population-level health outcomes, which could inform health policies. Ecosyndemic research should focus on a multidisciplinary understanding of it through knowledge triangulation derived from different scientific disciplines to ensure that all aspects of ecosyndemics--clustering, interaction, and social and environmental contextual drivers--are included.

BACKGROUNDWhen the lockdowns are relaxed, the responsibility of mitigating the COVID-19 spread shifts from the governments to the individuals. To know how to conduct one-self, it is important for everyone to know the risks of transmission during the quotidian activities - meetings, meals, etc, from individuals who are known to them and looking healthy. METHODSThe detailed case-studies corresponding to 425 infections upon point-exposures over a specified duration are curated. The data from the case studies is summarized and reorganized to reflect different situations from the daily life. A meta-analysis of the attack rates of transmission and the number of infections per infected person are performed. RESULTSThe attack rates are very high in family dinners (66.7% (48.8-80.8%)) compared to sit-down dinners with lesser mixing among people eating at different tables (15.7% (12.1-20.1%)), both lasting a couple of hours. In an open workspace office floor organized in a two-half structure with shared elevators and restrooms and the employees speaking continuously, the average attack rate over the course of a few days was much higher in one half (78.7% (70.3-85.3%)) than the one for the entire floor (43.5% (37.0-50.1%)). Inferred data suggests that the transmission in elevators and trains may be lower under the conditions of using masks. In most of the instances we studied, the infected individuals spreading (35/44) and even super-spreading (3/6) were mostly without symptoms of coughing, sneezing or a fever. CONCLUSIONSAlthough the basic reproduction number R0 is around 3.0, the number of infections caused, including the super-spreading events, seem to be limited by the number of personal interactions in a group and their proximity. By acknowledging the risks in daily life, from healthy-looking persons, one may be able to organize their interactions better to reduce the chances of spreading or super-spreading infections.

BackgroundVentilation plays an important role in controlling aerosol transmission of coronavirus disease (COVID-19), and mass transmission of COVID- 19 has been reported in poorly ventilated areas. ObjectiveA real-world mass infection outbreak which occurred in an elderly nursing home, in Miyagi Prefecture, Japan, was simulated experimentally and numerically to investigate the controlling factors and quantify the effectiveness of various natural ventilation settings by means of air change rate (ACR). MethodsUsing the CO2 tracer gas method, the ACR values at the time of the outbreak were estimated to be 2.0-6.2 h-1 in rooms in the facility. Furthermore, a low-cost intervention of opening windows improved the ventilation frequency by a factor of 1.48-5.74. This implies that advective fluid flows are the key in the spread of high CO2 concentration zones. A numerical simulation was performed to obtain spatio-temporal evolution on such high CO2 concentration zones under similar conditions to the present experiment. ResultsThe results showed that ventilation was significantly dependent on the window opening conditions in all rooms (p-values ranging from 0.001 to 0.03 for all the rooms). In contrast, there was no significant dependence on the location of the sensor in any of the areas. Development of high CO2 concentration zones occurs in the first few minutes. Furthermore, the leading edge of such zones towards the common room yields a relatively high fluid velocity, suggesting that the large-scale advective flow dictates the spread of such high CO2 concentration zones. ConclusionsThe present results suggest that secondary infections could occur due to the aerosol advection driven by such large-scale flows, even when the building design adheres the ventilation guidelines. In elderly care facilities, open architectural spaces are recommended to realize quality of life and monitor residents. However, management is required to reduce the downwind infection risk from aerosols and ACR.

Effective communication about the health effects of wildfire smoke is important to protect the public, especially those most vulnerable to the effects of exposure: people with chronic respiratory conditions, children, and older adults. The objective of this paper is to examine the clarity and accessibility of materials intended to provide education about the health effects of wildfire. The Centers for Disease Controls Clear Communications Index (CCI) is used to evaluate whether materials adhere to the main principles of health literacy: clarity and accessibility. This analysis found that only 32% of the materials received a passing score on the Clear Communications Index. Most materials were successful at clearly presenting specific behavioral recommendations, particularly that people should avoid exposure to air polluted by wildfire smoke by staying indoors, reducing activity levels, and using air purifiers or approved dust masks. However, materials often failed to acknowledge any uncertainty around these recommendations. Creators of these materials may want to incorporate more relevant illustrations to support the main message, and consider how information about the risks and benefits of the recommended behaviors can most clearly be presented.

BackgroundAbout 3 million people die every year in USA. In order to provide a general direction and background for subsequent research and development in this field, we reviewed the studies about impact of potential factors associated with the main causes of mortality and all-cause mortality. MethodResearches are selected by PubMed website for last 15 years with published language of English. The leading cause of death were published by CDC in 2020 (excluded COVID-19) including the ten natural mortalities and unnatural mortality. We summarized the potential factors associated with the mortality and sorted them by "positive/negative effect" and "long-term/short-term effect". ResultAmong risk factors, the factors of depression, unhealthy diet, overweight and obesity and other similar factors increase the mortality of main leading natural causes. Among protective factors, the factors of physical activity, nut intake, chocolate consumption were associated with the reduced mortality of multiple diseases. We also found that some factors possess bidirectional influence on different diseases or even one disease. The gender of female negatively affects mortality of diabetes, but positively affects cardiovascular diseases. The majority of air pollutants are risk factors for respiratory diseases while ozone possibly reduce the mortality. ConclusionOur review summarized various factors which have positive/negative and long-term/short-term effects on the main mortality of cause-specific and all-caused mortality. Further study is required to investigate the contribution of different variable on mortality.

The droplet has a limited travel distance. Nonetheless, especially in the indoor public space the air flow can propagate the droplet to travel long distance. Based on this situation, this paper aims to study the relationships of seat configuration-social distance-air flow-droplet dispersions. The analysis was based on the computational fluid dynamic (CFD) using lattice-Boltzmann model (LBM). The result confirms that by modifying public space configuration in this case by providing more space and increasing seating distance can reduce the vulnerability towards droplet dispersions. Whereas, providing shield including adding protection is far more effective in avoiding dispersions. The public space reconfiguration including increasing seat distance and reducing seating capacity also has an effect in reducing the indoor CO2. Capacity reduction from full capacity to 30% can decrease the CO2 from 5722 to 2144 ppm.

IntroductionMost adolescents do not meet physical activity (PA) recommendations, especially girls. Physical inactivity has major physical and psychosocial deleterious effects on adolescents. Little is known about the effect of girl-only, extra-curricular PA programs designed for adolescents on physical and psychosocial outcomes. Hence, this systematic review assessed quantitative and qualitative studies evaluating the effects of such interventions. It also aimed at identifying recommendations to improve their implementation and efficacy. MethodsLiterature published until June 4, 2018, was searched in three electronic databases. Two reviewers independently assessed the methodological quality of studies presenting results on physical and psychosocial outcomes, not those presenting solely implementation recommendations. ResultsSeventeen quantitative and qualitative studies describing 10 different PA programs were included. Six of these studies provided recommendations for implementation only. The overall quality of the studies assessing the effects on physical and psychosocial outcomes was moderate, with an average score of 58%. The PA programs assessed did not lead to clear improvements in PA levels or other physical outcomes. Concerning psychosocial results, there is some evidence that the programs could improve dimensions of the self-esteem construct. ConclusionFuture studies should assess the effect of girl-only, extra-curricular PA programs on the health-related habits, such as reduction of sedentary time among adolescents and sleep duration. More studies evaluating the psychosocial effects as a primary outcome are recommended to obtain a clearer understanding of the benefits. This review gathers recommendations to improve the efficacy of future extra-curricular PA programs designed to increase PA levels in girls.

Military pilots are exposed to severe physiological challenges during their missions that may affect cognitive and physical performance. Therefore, continuous monitoring potentially provides critical insights about the impact of extreme condition exposure on the fitness for duty of military pilots. We applied a textile-based monitoring system during training sessions with pilot aspirants to investigate the impact of hypobaric hypoxia and high G-force exposures on the signal quality obtained for a 1-lead electrocardiogram (ECG) and chest excursions. The physiological variables considered were heart rate, heart rate variability, as well as respiratory frequency and respiratory amplitude. In general, 92% and 82% of the recorded ECG time segments during hypoxia and G-force exposure, respectively, were classified as plausible for further analysis. For respiratory data, 72% and 76% were classified as accurate for further data analysis and interpretation. Detailed information about signal quality was found to be critical for the assessment of physiological variables recorded in extreme conditions. Furthermore, the combination of various physiological signals allows for a more holistic interpretation of body responses, for the assessment of body tolerances and an early detection of possible physical and cognitive impairments.

BackgroundGlobally nearly 20% of cardiovascular disease deaths were attributable to air pollution. Out-of-hospital cardiac arrest (OHCA) represents a major public health problem, therefore, the identification of novel OHCA triggers is of crucial relevance. The aim of the study was to evaluate the association between air pollution (short-, mid-and long-term exposure) and out-of-hospital cardiac arrest (OHCA) risk, during a 7 years-period from a highly polluted urban area with a high density of automated external defibrillators (AEDs). Methods and resultsOHCA were prospectively collected from the "Progetto Vita Database" between 01/01/2010 to 31/12/2017; day-by-day air pollution levels were extracted from the Environmental Protection Agency (ARPA) stations. Electrocardiograms of OHCA interventions were collected from the AEDs data cards. Day-by-day particulate matter (PM) 2.5 and 10, ozone (O3), carbon monoxide (CO) and nitrogen dioxide (NO2) levels were measured. A total of 880 OHCAs occurred in 748 days. A significantly increased in OHCA risk with the progressive increase in PM 2.5, PM 10, CO and NO2 levels was found. After adjustment for temperature and seasons, a 9% and 12% increase of OHCA risk for each 10 g/m3 increase of PM 10 (p< 0.0001) and PM 2.5 (p< 0.0001) levels was found. Air pollutants levels were associated with both asystole and shockable rhythm risk while no correlation was found with pulseless electrical activity. ConclusionsShort-term and mid-term exposure to PM 2.5 and PM 10 is independently associated with the risk of OHCA due to asystole or shockable rhythm.

We measured the compartmental air change per hour (ACH) using a CO2 sensor network in an office space where a cluster of COVID-19 infections attributed to aerosol transmission occurred. Generalized linear mixed models and dynamic time warping were used for a time series data analysis, and the results indicated that the ventilation conditions were poor at the time of the cluster outbreak, and that the low ACH in the room likely contributed to the outbreak. In addition, the adverse effects of inappropriate partitions and the effectiveness of ventilation improvements were investigated in detail. ACH of less than 2 /h was considered a main contributor for the formation of the COVID-19 cluster in the studied facility. Practical ImplicationsA systematic method for measuring and evaluating indoor ventilation to prevent the spread of infectious diseases caused by aerosols is presented. Ventilation bias caused by ventilation pathways and inappropriate use of plastic sheeting can be detected by a CO2 sensor network and time series data analysis. Estimated ventilation rate will be a good index to suppress the formation of the COVID-19 cluster.