Osha breathing zone radius5/9/2023 ![]() The checklist included questions on the presence or absence of controls such as physical barriers, social distancing markers, required masking of customers, cleaning of check-out stands, closures of store areas. Sixteen stores between Seattle, WA (n = 9) and Portland, OR (n = 7) were visited monthly by the study team from May 2020 to January 2021, and observations of controls were recorded using a standardized checklist in REDCap. Utilizing a longitudinal, observational study, grocery store health and safety controls implemented during the COVID-19 pandemic across stores in two cities were characterized. Aggressive and continuous testing would reveal more cases especially asymptomatic cohorts in the population. Early epidemiological patterning occurred along population density and outdoor exposure lines. Conclusion: Causation and spread are attributed to travel and contact risk factors. Additionally, 17% (circa) of the tested population were confirmed positive. Transmission via contact with infected persons accounted for 23% of a confirmed case. It further showed an increased number of confirmed cases in densely populated states. CJAST, 39(26): 9-19, 2020 Article no.CJAST.60total active cases, a mortality rate of 0.12 per 100,000 population, and a Case Fatality Rate (CFR) of 3. ![]() Findings: Retrospective analysis revealed 8344 confirmed cases in 35 of the 36 states (with the federal capital territory inclusive), 249 fatalities, 2385 discharged cases, 48544 laboratory testing, Original Research Article Osakwe et al. Methods: A descriptive epidemiological study involving a review of the first three-month Covid-19 situation reports and updates in Nigeria using primary data was analyzed by Spatio-temporal analysis with categorical variables reported in percentages and numbers. Objective: To characterize and present epidemiological trends of Covid-19 pandemic in the first three months of index confirmation in Nigeria. The exposure level of the mannequin was about 5.5-9.3 times higher than that of the human subject.īackground: Since the confirmation of the index case of Covid-19 on the 27th of February in Nigeria, the spread from Lagos to other parts of the country has been on the climb without a plateau in sight. The ratios of nose concentration to chest concentration for the human subject and the mannequin were 0-0.2 and 0.12, respectively. Then, the effects of the sampling location and the body temperature on the exposure were observed. In experiment, ethanol vapor was released in front of a model worker (human subject and mockup mannequin) and the vapor concentrations were measured at two different sampling points, at the nose and at the chest, in the breathing zone. In order to examine the spatial variability of contaminant concentrations in a worker's breathing zone, comparative measurements of personal exposure were carried out in a laboratory. However, several studies have mentioned that the concentration is not uniform in the breathing zone when a worker is close to the contaminant source. ![]() Conventionally, the "breathing zone" is defined as the zone within a 0.3 m (or 10 inches) radius of a worker's nose and mouth, and it has been generally assumed that a contaminant in the breathing zone is homogeneous and its concentration is equivalent to the concentration inhaled by the worker.
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