ABSTRACT
Background: Coronavirus disease 2019 (COVID-19) began in 2019 with several unknown factors. The World Health Organization (WHO) subsequently developed COVID-19 occupational safety and health (OSH) guidelines to reduce occupational COVID-19 transmission. Many countries also developed their own COVID-19 OSH guidelines, but whether these guidelines included WHO's guidelines and whether including WHO's guidelines in countries' COVID-19 OSH guidelines reduced COVID-19 transmission is unknown. Objectives: The objectives of our study were to (1) compare the COVID-19 OSH guidelines of several countries to WHO's OSH guidelines, (2) estimate associations between characteristics of countries and their OSH guidelines and the number of WHO's OSH guidelines included in countries' OSH guidelines, and (3) estimate associations between WHO's OSH guidelines included in countries' OSH guidelines and COVID-19 risk, death risk, and case-fatality proportion. Methods: This study represents international, ecological research of 36 countries from all six world health regions. Countries' COVID-19 OSH guidelines were compared with WHO's OSH guidelines. Linear regression models adjusted for potential confounders were used to estimate associations of interest. Results: The median number of WHO's 15 COVID-19 OSH guidelines included in countries' COVID-19 OSH guidelines was eight. Countries' COVID-19 OSH guidelines focused on workers included significantly more of WHO's COVID-19 OSH guidelines than countries' COVID-19 OSH guidelines focused on general populations. Including "provide personal protective equipment for workers" and "create workplace policy for wearing personal protective equipment" in countries' COVID-19 OSH guidelines were significantly related to decreased COVID-19 risk, death risk, and/or case-fatality proportion. Conclusions: Countries' COVID-19 OSH guidelines should include WHO's guidelines, focus on workers, and include "provide personal protective equipment for workers" and "create workplace policy for wearing personal protective equipment."
ABSTRACT
The objectives of this work were to explore a methodology that combines static and dynamic finite element (FE) analysis, linear elastic fracture mechanics (LEFM) and experimental methods to investigate a worst-case scenario in which a previously damaged bone plate system is subjected to an impact load. Cadaver ulnas with and without midshaft dynamic compression plates are subjected to a static three-point bend test and loaded such that subcritical crack growth occurs as predicted by a hybrid method that couples LEFM and static FE. The plated and unplated bones are then unloaded and subsequently subjected to a midshaft transverse impact test. A dynamic strain-based FE model is also developed to model the midshaft transverse impact test. The average value of the impact energy required for failure was observed to be 10.53% greater for the plated set. There appears to be a trade-off between impact damage and impact resistance when ulnas are supported by fixation devices. Predictions from the dynamic FE model are shown to corroborate inferences from the experimental approach.
