Personal Exposure Levels Research Articles

Estimating elemental constituents of personal PM2.5: A modeling approach of older individuals of the China BAPE study

Most previous studies on air pollution have used mass concentrations and elemental constituents of fine particulate matter (PM 2.5 ) from monitoring stations as dose metrics when determining health risks associated with PM 2.5 exposure, which may result in error in their estimations. Herein we conducted an exploratory panel study in Jinan, China, to investigate potential determinants and estimation of personal PM 2.5 elemental constituents using a modeling approach. For 76 old individuals aged 60–69 years, 5 repeated measurements of personal PM 2.5 were taken from September 2018 to January 2019. The average concentrations of personal PM 2.5 was 57.1 ± 46 . 3 μ g/m 3 , which was lower than ambient levels. The concentrations of Zn, Fe, and Ti in personal PM 2.5 were lower than those in ambient PM 2.5 . Personal PM 2.5 , Zn, Fe, Ti, and Ca were significantly correlated with their corresponding ambient concentrations. Ambient measurements, the demographic characteristics and lifestyles of subjects, and meteorological factors were crucial factors influencing personal exposure. The final predictive models based on ambient measurements and accessible variables explained 70% of the variance of personal PM 2.5 , and 52%–64% of the variance of personal Zn, Fe, Ti, and Ca. The average ratios of ambient to personal measurements and of modeling predictions to personal measurements of PM 2.5 , Zn, Fe, Ti, and Ca were 1.23 ± 0.47 and 1.08 ± 0.41, 1.85 ± 0.57 and 1.09 ± 0.30, 1.25 ± 0.42 and 1.04 ± 0.26, 2.20 ± 0.97 and 1.07 ± 0.41, and 1.08 ± 0.39 and 1.09 ± 0.34, respectively. The results suggest that models integrating ambient measurements and related variables can be a reliable candidate for estimating the levels of personal exposure to elemental constituents of PM 2.5 . • A panel of 76 old healthy individuals aged 60–69 years were enrolled in Jinan, China. • Using ambient elements in PM 2.5 as the proxy of personal exposure may increase exposure misclassification. • Ambient measurement and accessible variables were critical influencing factors for personal elements. • The predictive models increased the accuracy of personal exposure assessment.

Air pollution exposure in relation to guard duty at Tidworth Camp: A cross-sectional study

BackgroundAir pollution is the largest environmental health risk in the United Kingdom, and an issue of concern amongst outdoor workers. Road transport is a major source producing the largest amount of nitrogen dioxide (NO2) and ozone (O3) (as a secondary pollutant). Hundreds of vehicles enter and exit the Tidworth Camp’s main gate daily, potentially producing these pollutants. However, the air pollution exposure experienced by personnel on guard duty is unknown. This study aimed to determine and compare background NO2 and O3 levels experienced by personnel on guard duty.MethodsCross-sectional data was collected using a static sampling technic on randomly selected days of the week. Data analysis was done using IBM-SPSS-26 and a p-value of <0.05 was considered statistically significant.ResultsThe background concentration of NO2 and O3 pollutants were within recommended limits. There was no significant difference between mean morning and afternoon exposure levels for both pollutants. However, NO2 and O3 levels were significantly higher during weekdays compared to weekends (M = -0.022, SD = 0.007, t(6) = -8.672, p <0.0001 and M = -0.016, SD = 0.008, t(6) = -5.040, p = 0.002 respectively). Both pollutants showed no significant differences in exposure levels when only weekdays were compared. NO2 levels showed a weak positive correlation during weekdays (r = 0.04) and a strong positive correlation during weekends (r = 0.96). O3 levels had a positive correlation on both weekdays and weekends; however, levels on Monday showed a negative correlation (r = -0.55). Linear regression analysis showed that outside temperature was a significant predictor of O3 levels (p = 0.026).ConclusionPersonnel on guard duty experienced higher pollution levels during weekdays compared to weekends; however, air pollution levels for both pollutants were within recommended limits. Further studies are recommended over hotter months using a personal sampling technic to measure personal air pollution exposure levels in order to minimise any health and safety risks.

Personal exposure levels to O3, NOx and PM10 and the association to ambient levels in two Swedish cities

Exposure to air pollution is of great concern for public health although studies on the associations between exposure estimates and personal exposure are limited and somewhat inconsistent. The aim of this study was to quantify the associations between personal nitrogen oxides (NOx), ozone (O3) and particulate matter (PM10) exposure levels and ambient levels, and the impact of climate and time spent outdoors in two cities in Sweden. Subjects (n = 65) from two Swedish cities participated in the study. The study protocol included personal exposure measurements at three occasions, or waves. Personal exposure measurements were performed for NOx and O3 for 24 h and PM10 for 24 h, and the participants kept an activity diary. Stationary monitoring stations provided hourly data of NOx, O3 and PM, as well as data on air temperature and relative humidity. Data were analysed using mixed linear models with the subject-id as a random effect and stationary exposure and covariates as fixed effects. Personal exposure levels of NOx, O3 and PM10 were significantly associated with levels measured at air pollution monitoring stations. The associations persisted after adjusting for temperature, relative humidity, city and wave, but the modelled estimates were slightly attenuated from 2.4% (95% CI 1.8–2.9) to 2.0% (0.97–2.94%) for NOx, from 3.7% (95% CI 3.1–4.4) to 2.1% (95% CI 1.1–2.9%) for O3 and from 2.6% (95% 0.9–4.2%) to 1.3% (95% CI − 1.5–4.0) for PM10. After adding covariates, the degree of explanation offered by the model (coefficient of determination, or R2) did not change for NOx (0.64 to 0.63) but increased from 0.46 to 0.63 for O3, and from 0.38 to 0.43 for PM10. Personal exposure to NOx, O3 and PM has moderate to good association with levels measured at urban background sites. The results indicate that stationary measurements are valid as measure of exposure in environmental health risk assessments, especially if they can be refined using activity diaries and meteorological data. Approximately 50–70% of the variation of the personal exposure was explained by the stationary measurement, implying occurrence of misclassification in studies using more crude exposure metrics, potentially leading to underestimates of the effects of exposure to ambient air pollution.

Dynamic molecular choreography induced by traffic exposure: A randomized, crossover trial using multi-omics profiling

The biological mechanism of adverse health outcomes related to exposure to traffic-related air pollution (TRAP) needs elucidation. We conducted a randomized, crossover trial among healthy young students in Shanghai, China. Participants wore earplugs and were randomly assigned to a 4-hour walking treatment either along a traffic-polluted road or through a traffic-free park. We conducted untargeted analyses of plasma exosome transcriptomics, serum mass spectrometry-based proteomics, and serum metabolomics to evaluate changes in genome-wide transcription, protein, and metabolite profiles in 35 randomly selected participants. Mean personal exposure levels of ultrafine particles, black carbon, nitrogen dioxide, and carbon monoxide in the road were 2–3 times higher than that in the park. We observed 3449 exosome mRNAs, 58 serum proteins, and 128 serum metabolites that were significantly associated with TRAP. The multi-omics analysis showed dozens of regulatory pathways altered in response to TRAP, such as inflammation, oxidative stress, coagulation, endothelin-1 signaling, and renin-angiotensin signaling. We found that several novel pathways activated in response to TRAP exposure: growth hormone signaling, adrenomedullin signaling, and arachidonic acid metabolism. Our study served as a demonstration and proof of concept on the evidence that associated TRAP exposure with global molecular changes based on the multi-omics level.

Personal Passive Air Samplers for Chlorinated Gases Generated from the Use of Consumer Products.

Various chlorine-based disinfectants are being used during the COVID-19 pandemic; however, only a few studies on exposure to harmful gases resulting from the use of these disinfectants exist. Previously, we developed a personal passive air sampler (PPAS) to estimate the exposure level to chlorine gas while using chlorinated disinfectants. Herein, we investigated the color development of the passive sampler corresponding to chlorine exposure concentration and time, which allows the general population to easily estimate their gas exposure levels. The uptake and reaction rate of PPAS are also explained, and the maximum capacity of the sampler was determined as 1.8 mol of chlorine per unit volume (m3) of the passive sampler. Additionally, the effects of disinfectant types on the gas exposure level were successfully assessed using passive samplers deployed in a closed chamber. It is noteworthy that the same level of chlorine gas is generated from liquid household bleach regardless of dilution ratios, and we confirmed that the chlorine gas can diffuse out from a gel-type disinfectant. Considering that this PPAS reflects reactive gas removal, individual working patterns, and environmental conditions, this sampler can be successfully used to estimate personal exposure levels of chlorinated gases generated from disinfectants.

Assessment of Noise Level Pollution from Powered Generators – A Case Study of UTC Commercial Business Area Abuja, Nigeria

BACKGROUND AND AIM: This environmental pollution research work was carried out to ascertain the level of exposure of noise an average worker is exposed to during the working hour in the Abuja Commercial Business Area. METHODS: The study was conducted between June and August 2019. A handheld digital sound level meter (BENETECH GM 1356 Digital Sound Level Meter 30dB-130dB) was used in obtaining the noise level at the study area (UTC Area 11 Commercial Business District). Two different measurement were taken simultaneously. First, inside the offices (personal exposure) and outside the offices (environmental exposure). RESULTS:The results shows that on the average, the overall mean value for personal assessment i.e. the noise level which an individual worker was exposed to was 74.7 dB(A) and for the environmental assessment i.e. the noise level of the commercial district was 71.9 dB(A). The comparative analysis between mean personal and environment exposure level values were all above the commercial area maximum permissible noise limit of Nigeria, Unites State of America, Japan, India, Australia and World health Organization (WHO) values of 60 dB(A), 65 dB(A), and 55 dB(A) respectively except for the Occupational Safety and Health Administration (OSHA) which has a maximum limit of 85 dB(A). CONCLUSIONS:From the data obtained and analysis carried out, it revealed that the noise level at the commercial business district, Abuja, Nigeria was way above the permissible noise limit for a commercial area in Nigeria according to the National Environmental (Noise Standards and Control) Regulations 2009. This should be a source of concern to responsible stakeholders because of the danger this possesses to the health and wellbeing of workers and residents. It was also recommended that tress should be planted within the business hub to tackle noise pollution. KEYWORDS: Noise, Pollution, Environment, Noise level, Generators, Abuja Nigeria.

Evaluating the Theoretical Background of STOFFENMANAGER® and the Advanced REACH Tool.

STOFFENMANAGER® and the Advanced REACH Tool (ART) are recommended tools by the European Chemical Agency for regulatory chemical safety assessment. The models are widely used and accepted within the scientific community. STOFFENMANAGER® alone has more than 37 000 users globally and more than 310 000 risk assessment have been carried out by 2020. Regardless of their widespread use, this is the first study evaluating the theoretical backgrounds of each model. STOFFENMANAGER® and ART are based on a modified multiplicative model where an exposure base level (mg m−3) is replaced with a dimensionless intrinsic emission score and the exposure modifying factors are replaced with multipliers that are mainly based on subjective categories that are selected by using exposure taxonomy. The intrinsic emission is a unit of concentration to the substance emission potential that represents the concentration generated in a standardized task without local ventilation. Further information or scientific justification for this selection is not provided. The multipliers have mainly discrete values given in natural logarithm steps (…, 0.3, 1, 3, …) that are allocated by expert judgements. The multipliers scientific reasoning or link to physical quantities is not reported. The models calculate a subjective exposure score, which is then translated to an exposure level (mg m−3) by using a calibration factor. The calibration factor is assigned by comparing the measured personal exposure levels with the exposure score that is calculated for the respective exposure scenarios. A mixed effect regression model was used to calculate correlation factors for four exposure group [e.g. dusts, vapors, mists (low-volatiles), and solid object/abrasion] by using ~1000 measurements for STOFFENMANAGER® and 3000 measurements for ART. The measurement data for calibration are collected from different exposure groups. For example, for dusts the calibration data were pooled from exposure measurements sampled from pharmacies, bakeries, construction industry, and so on, which violates the empirical model basic principles. The calibration databases are not publicly available and thus their quality or subjective selections cannot be evaluated. STOFFENMANAGER® and ART can be classified as subjective categorization tools providing qualitative values as their outputs. By definition, STOFFENMANAGER® and ART cannot be classified as mechanistic models or empirical models. This modeling algorithm does not reflect the physical concept originally presented for the STOFFENMANAGER® and ART. A literature review showed that the models have been validated only at the ‘operational analysis’ level that describes the model usability. This review revealed that the accuracy of STOFFENMANAGER® is in the range of 100 000 and for ART 100. Calibration and validation studies have shown that typical log-transformed predicted exposure concentration and measured exposure levels often exhibit weak Pearson’s correlations (r is <0.6) for both STOFFENMANAGER® and ART. Based on these limitations and performance departure from regulatory criteria for risk assessment models, it is recommended that STOFFENMANAGER® and ART regulatory acceptance for chemical safety decision making should be explicitly qualified as to their current deficiencies.

Could Electromagnetic Field Exposure Contribute to “Zoom Fatigue”?

The article discusses potential exposure sources to workers during remote teleconferencing and discusses measures to reduce exposure and prevent potential harms. Topics discussed include demonstrated that electric and magnetic field (EMF) from RF sources results in electric, magnetic, and associated currents that permeate into tissues of the body from the surrounding areas;and Regarding personal exposure levels, there are two primary factors that determine the magnitude of current.

Particulate Matter Exposures under Five Different Transportation Modes during Spring Festival Travel Rush in China

Serious traffic-related pollution and high population density during the spring festival (Chinese new year) travel rush (SFTR) increases the travelers’ exposure risk to pollutants and biohazards. This study investigates personal exposure to particulate matter (PM) mass concentration when commuting in five transportation modes during and after the 2020 SFTR: China railway high-speed train (CRH train), subway, bus, car, and walking. The routes are selected between Nanjing and Xuzhou, two major transportation hubs in the Yangtze Delta. The results indicate that personal exposure levels to PM on the CRH train are the lowest and relatively stable, and so it is recommended to take the CRH train back home during the SFTR to reduce the personal PM exposure. The exposure level to PM2.5 during SFTR is twice as high as the average level of Asia, and it is higher than the WHO air quality guideline (AQG).

Assessment of Home-Based and Mobility-Based Exposure to Black Carbon in an Urban Environment: A Pilot Study.

The combustion of fossil fuels is a significant source of particulate-bound black carbon (BC) in urban environments. The personal exposure (PE) of urban dwellers to BC and subsequent health impacts remain poorly understood due to a lack of observational data. In this study, we assessed and quantified the levels of PE to BC under two exposure scenarios (home-based and mobility-based exposure) in the city of Trivandrum in India. In the home-based scenario, the PE to BC was assessed in a naturally ventilated building over 24 h each day during the study period while in the mobility-based scenario, the PE to BC was monitored across diverse microenvironments (MEs) during the day using the same study protocol for consistency. Elevated BC concentrations were observed during the transport by motorcycle (26.23 ± 2.33 µg/m3) and car (17.49 ± 2.37 µg/m3). The BC concentrations observed in the MEs decreased in the following order: 16.58 ± 1.38 µg/m3 (temple), 13.78 ± 2.07 µg/m3 (restaurant), 11.44 ± 1.37 µg/m3 (bus stop), and 8.27 ± 1.88 µg/m3 (home); the standard deviations represent the temporal and spatial variations of BC concentrations. Overall, a relatively larger inhaled dose of BC in the range of 148.98–163.87 µg/day was observed for the mobility-based scenario compared to the home-based one (118.10–137.03 µg/day). This work highlights the importance of reducing PE to fossil fuel-related particulate emissions in cities for which BC is a good indicator. The study outcome could be used to formulate effective strategies to improve the urban air quality as well as public health.

Noise Exposure Levels in Black Tea Processing Factories and Its Effects on Employees

The aim of this study was to determine the daily noise exposure levels in black tea processing factories and to evaluate its effects on employees' occupational health and safety. In the study, the sound pressure level dBA values were measured at the ear levels of the employees in each production unit in three tea factories operating in Artvin Province. These factories where the measurements were made consist of withering, curling, oxidation, drying (boiler and stove) and classification units. These units include various systems and mechanisms formed by conveyors, fans, steam heaters, boilers, reducers, pallets, hoods, screens, gears, and drums. In the measurements performed considering the ISO 9612:2009 (Acoustics Determination of Occupational Noise Exposure Engineering Method) standard, a sound pressure level meter in Type-2 class complying with the requirements of the IEC 61672-1: 2002 was used. A weighted equivalent sound pressure levels were determined using the measured values. Considering these values and working times, personal daily noise exposure levels were calculated. It was determined that the equivalent sound pressure levels and daily personal noise exposure levels at the employee ear level were in the range of 77-87 dBA and 74-83 dBA, respectively. Curling units have the highest equivalent sound pressure level (86.81 dBA) and daily personal noise exposure level value (83.10 dBA) compared to other units, while boilers have the lowest equivalent sound pressure level (76.75 dBA) and daily personal noise exposure level value (73.55 dBA). Considering the regulation on protection of employees from noise related risks, it was concluded that the daily noise exposure level reached the lower exposure action value (80 dBA) in these factories. The study showed that the health and work efficiency of the employees could be adversely affected by noise in tea factories, considering various research results and Regulations on noise.

Assessment of dust exposure and chronic respiratory symptoms among workers in medium scale woodwork factories in Ethiopia; a cross sectional study

BackgroundWood dust in a form of inhalable particulates can penetrate the lung tissues and affect respiratory health. Woodwork factory workers are at a greater risk of developing respiratory health problems because of exposure in their working environment, but existing data were few. The aim of this study was to assess the prevalence of chronic respiratory symptoms, associated factors, and concentration of personal total wood dust level among medium-scale woodwork factory workers.MethodsAn institutional based cross-sectional study was conducted among 506 woodwork factory workers. We selected study participants using a simple random sampling technique. We assessed chronic respiratory symptoms using the British Medical Research Council respiratory symptoms questionnaire with a few modifications. A multivariate logistic regression model was used to identify the factors. Forty dust measurements were collected from 20 randomly selected workers using a closed-face cassette (CFC) personal sampler. We analyzed the dust samples gravimetrically using a standard microbalance scale.ResultsWe recruited a random sample of 506 workers in the study with a response rate of 98%. The prevalence of chronic respiratory health symptoms among woodworkers was 69.8% with a prevalence of cough (54.6%), phlegm (52.2%), wheezing (44.6%), breathlessness (42.1%), and chest pain (42.9%). Past occupational dust exposure history (AOR = 2.09, 95% CI; 1.09–4.01), work experience > 5 years (AOR = 9.18, 95% CI; 5.27–16.00), using bio-fuel as energy for cooking (AOR = 2.42, 95% CI; 1.44–4.07), and having no occupational safety and health training (AOR = 3.38, 95% CI; 1.20–9.49) were factors that significantly associated with chronic respiratory symptoms among woodwork workers. The geometric mean (GM) of dust exposure level among woodworkers was 10.27 mg/m3, which exceeded the limit of 10 mg/m3 set by the ACGIH.ConclusionsHigh prevalence of chronic respiratory symptoms was reported from woodwork factory workers. Increased work- experience, using bio-fuel as an energy source for cooking, past occupational dust exposure history, and having no occupational safety and health training were identified risk factors. The measured average personal wood dust exposure level was above the recommended occupational threshold limit value. Therefore, workers’ wood dust exposure reduction and control methods and respiratory health awareness programs should be implemented.

Opportunities and challenges in reducing personal inhalation exposure to air pollution among electronic waste recovery workers in Ghana.

Informal sector electronic waste (e-waste) recovery produces toxic emissions resulting from burning e-waste to recover valuable metals. To identify high-risk worker groups by measuring relative levels of personal inhalation exposure to particulate matter (PM) of fine (≤2.5 µm) and coarse (2.5-10 µm) fractions (PM2.5 and PM2.5-10, respectively) across work activities among e-waste workers, and to assess how wind conditions modify levels of PM by activity and site location. At the Agbogbloshie e-waste site, 170 partial-shift PM samples and time-activity data were collected from participants (N = 105) enrolled in the GeoHealth cohort study. Personal sampling included continuous measures of size-specific PM from the worker's breathing zone and time-activity derived from wearable cameras. Linear mixed models were used to estimate changes in personal PM2.5 and PM2.5-10 associated with activities and evaluate effect modification by wind conditions. Mean (±standard deviation) personal PM2.5 and PM2.5-10 concentrations were 80 (± 81) and 123 (± 139) µg m-3 , respectively. The adjusted mean PM2.5 concentration for burning e-waste was 88 µg m-3 , a 28% increase above concentrations during non-recovery activities (such as eating). Transportation-related and burning activities were associated with the highest PM2.5-10 concentrations. Frequent changes in wind direction were associated with higher PM2.5 concentrations when burning, and high wind speeds with higher PM2.5-10 concentrations when dismantling e-waste downwind of the burning zone.

On optimal enforcement in international crime setting

National and international criminal courts often choose to focus prosecutions on the heads of organizations that commit international crimes. In this article we consider a game between a law enforcement authority and a head of a criminal organization who decides on his level of personal exposure to crime and the number of individual criminals he recruits. Our results highlight that, depending on the level of social harm and detection costs, optimal enforcement does not always imply concentrating enforcement resources on the head of the organization and may involve investing resources in detecting and sanctioning individual criminals who execute the crime for the head.

Effects of roadside green infrastructure on particle exposure: A focus on cyclists and pedestrians on pathways between urban roads and vegetative barriers

Roadside green infrastructure (GI) has attracted worldwide attention for its potentials to alleviate local air pollution. However, previous studies have not clearly characterized the effects of roadside GI on personal exposure levels to vehicular emissions, particularly for cyclists and pedestrians on the pathways between urban roads and vegetative barriers. In this study, field experiments were implemented to measure and compare the concentration levels of particulate matter (PM) and black carbon (BC) on pathways (e.g., bike lanes and sidewalks) and near residential buildings with and without roadside GI. Results show that the presence of GI significantly elevated the particle concentrations over bike lanes and sidewalks. Compared with the GI-free case, an increase of up to 20% and 28% was separately observed for BC and PM on the pathways before GI. This is strongly associated with the impact of GI on local wind fields that impedes the dispersion of traffic-emitted particles on the roadways. However, roadside GI brought a significant reduction of particle concentrations near residential buildings, separately decreasing by about 8% for BC and 6% for PM. Then Computational Fluid Dynamics software was adopted to simulate the diffusion process of traffic-emitted particles in the typical urban scenarios of roadways, pathways, GI, and residential buildings, and further analyze the particle distribution patterns under six roadside GI configurations. Simulation results suggest that tall vegetative barriers can lead to the accumulation of particles on the pathways and increase cyclists' and pedestrians’ exposure to local particulate pollution. The GI case of “tree canopy only” can be a potentially viable choice to reduce particle concentrations on the pathways due to the fact that its better ventilation conditions are more favorable for particle diffusion than other GI configurations. However, compared with the complex GI configurations, the scenario with no roadside GI exhibits more positive effects on decreasing particulate exposure on the pathways. These findings could provide practical insights into roadside GI design and important implications in near-road air quality improvements.

Risk assessment of farmers handling pelleted seeds containing crystalline silica and attapulgite.

ObjectivesThis study aimed to assess the risk to farmers from handling pelleted seeds that include crystalline silica and attapulgite.MethodsWe measured personal exposure levels to respirable crystalline silica and attapulgite in the experimenter representing a farmer in a simulated workplace. From these values, the annual occupational exposure levels were estimated and compared with the established occupational exposure limits. To assess the toxicity of respirable crystalline silica and attapulgite, digital chest images of workers in a factory producing pelleted seeds were examined.ResultsThe personal exposure measurement results showed that the concentrations of total dust, respirable dust, and respirable crystalline silica generated during work handling of pelleted seeds were 0.27, 0.06, and 0.00043 mg/m3, respectively. The estimated annual occupational exposure level to total dust, respirable dust, and respirable crystalline silica in farmers was 103 to 104 times lower than established occupational exposure limits. Attapulgite was not detected by analysis of the pelleted seeds themselves or dust collected during the personal exposure measurements. No pulmonary parenchymal or pleural lesions were detected in the digital chest images of the factory workers.ConclusionWe found that farmers handling pelleted seeds would not be exposed to levels of total dust, respirable dust, respirable crystalline silica, and attapulgite derived from pelleted seeds exceeding occupational exposure limits. These results suggest that the risk to farmers of handling pelleted seeds is negligible.

Occupational Dust Hazards and Risk Assessment of Coal-Fired Thermal Power Plants of Different Capacities - China, 2017-2019.

What is already known about this topic?Silica dust and coal dust are the main occupational hazards in coal-fired thermal power plants, which mainly exist in coal transportation workplaces, combustion milling workplaces, and ash removal workplaces.What is added by this report?The overall environmental and personal dust exposure levels decrease with an increase in the capacity of coal-fired thermal power plants, the overall dust hazard risk level of the workforce in coal-fired is Medium.What are the implications for public health practice?Dust management should be conducted in the coal-fired thermal power plant in 300 million watt units because it has the highest dust exposure level, and ash removal workplaces and combustion milling workplaces are key control points for dust hazards.

Comparison of personal exposures to gaseous pollutants under public transportation modes during and after the SFTR

During the Spring Festival Travel Rush (SFTR) in China, many people travel and public vehicles are always full. This research studies the air pollutant exposure of commuters under five transportation modes: China railway high-speed train (CRH train), subway, bus, car, and walk. The routes are selected between Nanjing and Xuzhou. The volatile organic compounds (VOCs), carbon dioxide (CO2), and formaldehyde (HCHO) levels are compared in five different transportation modes. The results indicate that personal exposure level to VOC and HCHO in CRH train is the lowest and relatively stable. So taking the CRH train during the SFTR may be the best choice. During the Corona Virus Disease 2019 (COVID-19) outbreak, spraying 70% alcohol for disinfection in public spaces significantly increased the personal exposure level to VOCs.

Indoor Formaldehyde Concentration, Personal Formaldehyde Exposure and Clinical Symptoms during Anatomy Dissection Sessions, University of Medicine 1, Yangon.

The formaldehyde (FA) embalming method, the world’s most common protocol for the fixation of cadavers, has been consistently used in medical universities in Myanmar. This study was designed to examine the indoor FA concentrations in anatomy dissection rooms, an exposed site, and lecture theater, an unexposed control site, and to access personal exposure levels of FA and clinical symptoms of medical students and instructors. In total, 208 second year medical students (1/2019 batch) and 18 instructors from Department of Anatomy, University of Medicine 1, participated. Thirteen dissection sessions were investigated from February 2019 to January 2020. Diffusive sampling devices were used as air samplers and high-performance liquid chromatography was used for measurement of FA. Average indoor FA concentration of four dissection rooms was 0.43 (0.09–1.22) ppm and all dissection rooms showed indoor concentrations above the occupational exposure limits and short-term exposure limit for general population. Personal FA exposure values were higher than indoor FA concentrations and the instructors (0.68, 0.04–2.11 ppm) had higher exposure than the students (0.44, 0.06–1.72 ppm). Unpleasant odor, eye and nose irritations and inability to concentrate were frequently reported FA-related symptoms, and the students were found to have significantly higher risks (p < 0.05) of having these symptoms during the dissection sessions than during lecture.

Investigating the Potential for Ultraviolet Light to Modulate Morbidity and Mortality From COVID-19: A Narrative Review and Update.

During the COVID-19 (coronavirus disease of 2019) pandemic, researchers have been seeking low-cost and accessible means of providing protection from its harms, particularly for at-risk individuals such as those with cardiovascular disease, diabetes and obesity. One possible way is via safe sun exposure, and/or dietary supplementation with induced beneficial mediators (e.g., vitamin D). In this narrative review, we provide rationale and updated evidence on the potential benefits and harms of sun exposure and ultraviolet (UV) light that may impact COVID-19. We review recent studies that provide new evidence for any benefits (or otherwise) of UV light, sun exposure, and the induced mediators, vitamin D and nitric oxide, and their potential to modulate morbidity and mortality induced by infection with SARS-CoV-2 (severe acute respiratory disease coronavirus-2). We identified substantial interest in this research area, with many commentaries and reviews already published; however, most of these have focused on vitamin D, with less consideration of UV light (or sun exposure) or other mediators such as nitric oxide. Data collected to-date suggest that ambient levels of both UVA and UVB may be beneficial for reducing severity or mortality due to COVID-19, with some inconsistent findings. Currently unresolved are the nature of the associations between blood 25-hydroxyvitamin D and COVID-19 measures, with more prospective data needed that better consider lifestyle factors, such as physical activity and personal sun exposure levels. Another short-coming has been a lack of measurement of sun exposure, and its potential to influence COVID-19 outcomes. We also discuss possible mechanisms by which sun exposure, UV light and induced mediators could affect COVID-19 morbidity and mortality, by focusing on likely effects on viral pathogenesis, immunity and inflammation, and potential cardiometabolic protective mechanisms. Finally, we explore potential issues including the impacts of exposure to high dose UV radiation on COVID-19 and vaccination, and effective and safe doses for vitamin D supplementation.