scholarly journals Concentration of Droplets from Patients during Normal Breathing and Speech and Their Importance in Protection from Coronavirus SARS-CoV-2 (COVID-19) Infection

2021 ◽  
Vol 15 (1) ◽  
pp. 103-107
Author(s):  
Tatsuya Mimura ◽  
Hidetaka Noma ◽  
Koichi Matsumoto ◽  
Makoto Kawashima ◽  
Kazuma Kitsu ◽  
...  

Purpose: Coronavirus disease (COVID-19) has been declared a pandemic and the number of infected individuals and deaths continue to increase globally. COVID-19 is transmitted through airborne droplets formed during coughing and sneezing and from the saliva of infected patients. Medical healthcare workers are often at risk of infection. This study measured the aerosol derived from the droplets of patients during the conversation. Methods: Overall, 25 patients aged 21 to 87 years were enrolled. The amount of droplets from the patient was measured under the following four conditions: 1) no conversation with the mask on; 2) conversation with the mask on; 3) conversation without the mask; and 4) no conversation without the mask. Particulate matter (PM) with an aerodynamic diameter of 2.5 μm or less (PM2.5) and PM with a diameter of 10 μm or less (PM10) were measured as representative aerosols at a position of 1 meter from the patients. Results: The concentrations of PM2.5 (µg/m3) were as follows: 22.7 ± 10.2 before the conversation with the mask, 24.2 ± 10.2 during the conversation with the mask, 32.3 ± 14.7 during the conversation without the mask, and 23.1 ± 9.9 after the conversation without the mask. The concentrations of PM10 (µg/m3) were as follows: 39.8 ± 18.2 before conversation with the mask, 41.9 ± 18.5 during conversation with the mask, 55.5 ± 27.2 during conversation without the mask, and 40.4 ± 17.8 after conversation without the mask. The variations in the PM2.5 and PM10 correlated negatively with the age of patients (PM2.5: r = -0.51, p = 0.0009 and PM10: r = -0.53, p = 0.0063). Conclusion: Wearing a mask can prevent airborne droplet formation and reduce transmission of infection.

2021 ◽  
Author(s):  
Saurabh Chandan ◽  
Shahab R. Khan ◽  
Smit Deliwala ◽  
Babu P. Mohan ◽  
Daryl Ramai ◽  
...  

INTRODUCTION: Healthcare workers (HCWs) remain on the front line of the battle against SARS-CoV-2 and COVID-19 infection, and are among the highest groups at risk of infection during this raging pandemic. We conducted a systematic review and meta-analysis to assess incidence of postvaccination SARS-CoV-2 infection among vaccinated HCWs. METHODS: We searched multiple databases from inception through August 2021 to identify studies that reported on incidence of postvaccination SARS-CoV-2 infection among HCWs. Meta-analysis was performed to determine pooled proportions of COVID-19 infection in partially and fully vaccinated individuals. RESULTS: Eighteen studies with 228,873 HCWs were included in the final analysis. Total number of partially vaccinated, fully vaccinated, and unvaccinated HCWs were 132,922, 155,673 and 17505, respectively. Overall pooled proportion of COVID-19 infections among partially/fully vaccinated and unvaccinated HCWs was 2.1% (95% CI 1.2-3.5). Among partially vaccinated, fully vaccinated and unvaccinated HCWs, pooled proportion of COVID-19 infections was 3.7% (95% CI 1.8-7.3), 1.3% (95% CI 0.6-2.9), and 10.1% (95% CI 4.5-19.5), respectively. DISCUSSION: Our analysis shows the risk of COVID-19 infection in both partially and fully vaccinated HCWs remains exceedingly low when compared to unvaccinated individuals. There remains an urgent need for all frontline HCWs to be vaccinated against SARS-CoV-2 infection.


2019 ◽  
Vol 65 (No. 8) ◽  
pp. 375-384 ◽  
Author(s):  
Monika Roman ◽  
Michał Roman ◽  
Kamil Krzysztof Roman

The article presents the spatial differentiation of particulates emission resulting from agricultural production in Poland. Some indicators of emission have been verified and adjusted to the Polish conditions. The paper estimates PM2.5 (particulate matter, aerodynamic diameter less than 2.5 µm) and PM10 (particulate matter, aerodynamic diameter less than 10 µm) emission resulting from agricultural production and agricultural soil. The findings of the research conducted by the Institute of Ecology of Industrial Areas in Katowice in cooperation with the Institute for Chemical Processing of Coal in Zabrze were the main source of those alterations. Data concerning particular sources of emission also come from the information provided by the Central Statistical Office in Warsaw, the Bank of Local Data 2017. The estimation of PM2.5 and PM10 emission was conducted based on the structure of sources of emission resulting from agriculture contained in “EMEP/EEA Emission Inventory Guidebook” in accordance with the Tier 2 method.


2020 ◽  
Vol 4 (1) ◽  
pp. 9
Author(s):  
Martina Habulan ◽  
Bojan Đurin ◽  
Anita Ptiček Siročić ◽  
Nikola Sakač

Particulate matter (PM) comprises a mixture of chemical compounds and water particles found in the air. The size of suspended particles is directly related to the negative impact on human health and the environment. In this paper, we present an analysis of the PM pollution in urban areas of Croatia. Data on PM10 and PM2.5 concentrations were measured with nine instruments at seven stationary measuring units located in three continental cities, namely Zagreb (the capital), Slavonski Brod, and Osijek, and two cities on the Adriatic coast, namely Rijeka and Dubrovnik. We analyzed an hourly course of PM2.5 and PM10 concentrations and average seasonal PM2.5 and PM10 concentrations from 2017 to 2019. At most measuring stations, maximum concentrations were recorded during autumn and winter, which can be explained by the intensive use of fossil fuels and traffic. Increases in PM concentrations during the summer months at measuring stations in Rijeka and Dubrovnik may be associated with the intensive arrival of tourists by air during the tourist season, and lower PM concentrations during the winter periods may be caused by a milder climate consequently resulting in lower consumption of fossil fuels and use of electric energy for heating.


Author(s):  
Adrianna Bella ◽  
Mochamad Thoriq Akbar ◽  
Gita Kusnadi ◽  
Olivia Herlinda ◽  
Putri Aprilia Regita ◽  
...  

(1) Background: because of close contacts with COVID-19 patients, hospital workers are among the highest risk groups for infection. This study examined the socioeconomic and behavioral correlates of COVID-19 infection among hospital workers in Indonesia, the country hardest-hit by the disease in the Southeast Asia region. (2) Methods: we conducted a cross-sectional study, which collected data from 1397 hospital staff from eight hospitals in the Greater Jakarta area during April–July 2020. The data was collected using an online self-administered questionnaire and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) tests. We employed descriptive statistics and adjusted and unadjusted logistic regressions to analyze the data of hospital workers as well as the subgroups of healthcare and non-healthcare workers. (3) Results: from a total of 1397 hospital staff in the study, 22 (1.6%) were infected. In terms of correlates, being a healthcare worker (adjusted odds ratio (AOR) = 8.31, 95% CI 1.27–54.54) and having a household size of more than five (AOR = 4.09, 1.02–16.43) were significantly associated with a higher risk of infection. On the other hand, those with middle- and upper-expenditure levels were shown to have a lower risk of infection (AOR = 0.06, 0.01–0.66). Behavioral factors associated with COVID-19 infection among healthcare and non-healthcare workers included knowledge of standard personal protective equipment (PPE) (AOR = 0.08, 0.01–0.54) and application of the six-step handwashing technique (AOR = 0.32, 0.12–0.83). (4) Conclusion: among hospital staff, correlates of COVID-19 infection included being a healthcare worker, household size, expenditure level, knowledge and use of PPE, and application of appropriate hand washing techniques.


2017 ◽  
Author(s):  
Carlo Bozzetti ◽  
Imad El Haddad ◽  
Dalia Salameh ◽  
Kaspar Rudolf Daellenbach ◽  
Paola Fermo ◽  
...  

Abstract. We investigated the seasonal trends of OA sources affecting the air quality of Marseille (France) which is the largest harbor of the Mediterranean Sea. This was achieved by measurements of nebulized filter extracts using an aerosol mass spectrometer (offline-AMS). PM2.5 (particulate matter with an aerodynamic diameter


Author(s):  
Chao Zhang ◽  
Zhenyu Quan ◽  
Qincheng Wu ◽  
Zhezhen Jin ◽  
Joseph Lee ◽  
...  

Background: Air pollution in large Chinese cities has led to recent studies that highlighted the relationship between particulate matters (PM) and elevated risk of cardio-cerebrovascular mortality. However, it is unclear as to whether: (1) The same adverse relations exist in cities with relatively low levels of air pollution; and (2) the relationship between the two are similar across ethnic groups. Methods: We collected data of PM2.5 (PM with an aerodynamic diameter ≤ 2.5 µm) and PM10 (aerodynamic diameter ≤ 10 µm) in the Yanbian Korean Autonomous Prefecture between 1 January 2015 and 31 December 2016. Using a time-stratified case-crossover design, we investigated whether levels of particulate pollutants influence the risk of cardio-cerebrovascular disease mortality among ethnic Korean vs. ethnic Han residents residing in the Yanbian Korean Autonomous Prefecture. Results: Under the single air pollutant model, the odds ratios (ORs) of cardio-cerebrovascular disease were 1.025 (1.024–1.026) for each 10 μg/m3 increase in PM2.5 at lag0 day, 1.012 (1.011–1.013) for each 10 μg/m3 increase in PM10 at lag1 day. In the multi-pollutant model adjusted by PM10, SO2, and NO2, the ORs of cardio-cerebrovascular disease were 1.150 (1.145–1.155) for ethnic Koreans and 1.154 (1.149–1.158) for ethnic Hans for each 10 μg/m3 increase in PM2.5. In the multi-pollutant model adjusted by PM2.5, SO2, and NO2, the ORs of cardio-cerebrovascular disease were 1.050 (1.047–1.053) for ethnic Koreans and 1.041 (1.039–1.043) for ethnic Hans for each 10 μg/m3 increase in PM10. Conclusion: This study showed that PM2.5 and PM10 were associated with increased risks of acute death events in residential cardio-cerebrovascular disease in Yanbian, China.


Author(s):  
F Kemta Lekpa ◽  
MS Doualla ◽  
HB Ngahane Mbatchou ◽  
AS Mkoh ◽  
H Namme Luma

Atmosphere ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 120
Author(s):  
Haoran Zhai ◽  
Jiaqi Yao ◽  
Guanghui Wang ◽  
Xinming Tang

Based on measurement data from air quality monitoring stations, the spatio-temporal characteristics of the concentrations of particles with aerodynamic equivalent diameters smaller than 2.5 and 10 μm (PM2.5 and PM10, respectively) in the Beijing–Tianjin–Hebei (BTH) region from 2015 to 2018 were analysed at yearly, seasonal, monthly, daily and hourly scales. The results indicated that (1) from 2015 to 2018, the annual average values of PM2.5 and PM10 concentrations and the PM2.5/PM10 ratio in the study area decreased each year; (2) the particulate matter (PM) concentration in winter was significantly higher than that in summer, and the PM2.5/PM10 ratio was highest in winter and lowest in spring; (3) the PM2.5 and PM10 concentrations exhibited a pattern of double peaks and valleys throughout the day, reaching peak values at night and in the morning and valleys in the morning and afternoon; and (4) with the use of an improved sine function to simulate the change trend of the monthly mean PM concentration, the fitting R2 values for PM2.5 and PM10 in the whole study area were 0.74 and 0.58, respectively. Moreover, the high-value duration was shorter, the low-value duration was longer, and the concentration decrease rate was slower than the increase rate.


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