An evaluation of personal cooling systems for reducing thermal strain whilst working in chemical/biological protective clothing

© 2019 The Authors. Published by Frontiers Media. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3389/fphys.2019.00424© 2019 Bach, Maley, Minett, Zietek, Stewart and Stewart. Objective: The use of personal cooling systems to mitigate heat strain on first-responders achieves two potential performance benefits relative to the absence of such cooling: (1) the completion of a workload with less effort; and/or (2) the completion of a greater workload for the same effort. Currently, claims made by manufacturers regarding the capability of their products for use in conjunction with chemical/biological protective clothing remain largely unsubstantiated. The purpose of this investigation was to evaluate the means by which heat strain can be alleviated during uncompensable heat stress in chemical/biological clothing, using the ASTM F2300-10 methodology. Methods: Eight healthy males completed five trials of continuous walking (4.5 km h-1; 35°C; 49% RH) for up to 120 min while wearing one of four cooling systems and/or a National Fire and Protection Association 1994 Class-3 chemical/biological ensemble. The four cooling methods (ice vest [IV], phase-change vest [PCM], water-perfused suit [WS], and combination ice slurry/ice vest [SLIV]) and no cooling (CON). Results: We observed significant improvements in trial times for IV (18 ± 10 min), PCM (20 ± 10 min) and SLIV (22 ± 10 min), but no differences for WS (4 ± 7 min). Heart rate, rectal, mean skin, and body temperatures were significantly lower in all cooling conditions relative to control at various matched time points in the first 60 min of exercise. Thermal sensation, comfort and perceived exertion all had significant main effects for condition, and time, there were no differences in their respective interactions. Conclusion: The IV, PCM, and SLIV produced lower heart rate, mean skin, rectal and mean body temperatures in addition to improved work times compared to control. The WS did not improve work times possibly as a result of the cooling capacity of the suit abating, and magnifying thermal insulation. Considering the added time and resources required to implement combination cooling in the form of ice slurry and ice vest (SLIV), there was no significant additive effect for perception, cardiovascular strain, rectal temperature and total trial time relative to the phase change vest or ice vest alone. This may be a product of a "ceiling" effect for work limit set to 120 min as part of ASTM F2300-10.This project is financially supported by the United States Government through the United States Department of Defense (DOD).Published versio

Babesiosis in Immunocompetent Patients, Europe

We report 2 cases of babesiosis in immunocompetent patients in France. A severe influenza-like disease developed in both patients 2 weeks after they had been bitten by ticks. Diagnosis was obtained from blood smears, and Babesia divergens was identified by PCR in 1 case. Babesiosis in Europe occurs in healthy patients, not only in splenectomized patients

A Hidden Markov Model for Analysis of Frontline Veterinary Data for Emerging Zoonotic Disease Surveillance

Surveillance systems tracking health patterns in animals have potential for early warning of infectious disease in humans, yet there are many challenges that remain before this can be realized. Specifically, there remains the challenge of detecting early warning signals for diseases that are not known or are not part of routine surveillance for named diseases. This paper reports on the development of a hidden Markov model for analysis of frontline veterinary sentinel surveillance data from Sri Lanka. Field veterinarians collected data on syndromes and diagnoses using mobile phones. A model for submission patterns accounts for both sentinel-related and disease-related variability. Models for commonly reported cattle diagnoses were estimated separately. Region-specific weekly average prevalence was estimated for each diagnoses and partitioned into normal and abnormal periods. Visualization of state probabilities was used to indicate areas and times of unusual disease prevalence. The analysis suggests that hidden Markov modelling is a useful approach for surveillance datasets from novel populations and/or having little historical baselines

Ensuring the Right to Rest

OBJECTIVE: The aim of this study was to evaluate the effectiveness of city Rest Break Ordinance (RBO) policies in expanding access to rest at work. METHODS: We use data from surveys of construction workers in Austin and Dallas, Texas, in 2009, 2012, and 2015 (n = 557) to calculate the odds of receiving a rest break in pre- versus post-RBO Austin and in post-RBO Austin versus pre-RBO Dallas, controlling for demographic and employment characteristics. RESULTS: Construction workers were 35% more likely to report receiving a rest break in Austin post-RBO and 16% less likely in Dallas without a RBO as compared to Austin with a RBO. CONCLUSION: The increased likelihood of receiving rest breaks at work in a RBO city suggests that, in the absence of enforceable national standards, city-level RBOs can be an important first step to effective prevention of heat-related illnesses (HRIs) and heat-related fatalities at work

Occupational Heat-Related Mortality in the United States, 2000-2010: Epidemiology and Policy Recommendations

Heat stress due to ambient outdoor temperatures is a workplace hazard that has not been well studied or characterized. The incidence of occupational heat-related illness is unknown. Heat-related morbidity and mortality have been well-studied at the population level, however it cannot be determined if these findings extend systematically to workers exposed to high heat conditions. Remarkably, there is no U.S. federal standard to protect workers from the peril of elevated environmental temperatures and few states have protective regulations. This dissertation research will add to the limited knowledge base of occupational heat-related illnesses, by characterizing worker fatalities due to environmental heat stress. Three independent, but related, research strategies were designed, executed, and completed to evaluate the current research, as well as knowledge gaps, and to thoroughly describe these fatalities based on available information. This work was initiated with a thorough literature review to summarize research findings that characterize U.S. occupational heat-related morbidity and mortality and identify gaps in the existing research literature. This review of science, health, and medical databases found that few studies examine ambient heat stress or characterize the incidence of occupational heat-related illnesses and outcomes. Significantly more research examining the heterogeneity of worker and environmental risk factors to heat exposure is needed to identify unsafe working conditions and implement practical, evidence-based heat-stress policies and interventions. The subsequent study describes the epidemiological characteristics of heat-related deaths among workers in the U.S. from 2000 to 2010. Fatality data were obtained at the Bureau of Labor Statistics from the confidential on-site Census of Fatal Occupational Injuries database. Fatality rates and risk ratios with 95% confidence intervals were calculated by year, sex, age group, ethnicity, race, state, and industry. Between 2000 and 2010, 359 occupational heat-related deaths were identified in the U.S., for a yearly average fatality rate of 0.22 per 1 million workers. Highest rates were found among Hispanics, men, the agriculture and construction industries, the states of Mississippi and Arkansas, and very small establishments. This study provides the first comprehensive national profile of heat-related deaths in the U.S. workplace. Prevention efforts should be directed at small businesses, states, industries and individuals who may be at increased risk of heat stress. Lastly, to further characterize these fatalities, research was performed to: 1) determine the ranges of heat index and temperature at which workers fatally succumb to environmental heat; 2) identify risk factors that may influence heat-related deaths; and 3) translate these findings to policy recommendations. The Census of Fatal Occupational Injuries and the National Climate Data Center were used to identify worker heat-related deaths in the U.S., 2000- 2010, and to assign a maximum daily temperature and heat index to each case. Demographic, meteorological, and geographical variables were analyzed to evaluate any differences in fatal heat exposure. The National Weather Service temperature alert tools, the Excessive Heat Event warning and the heat index category chart, were utilized to assess community threshold suitability for workers subjected to exertional heat stress. Of the 327 cases that qualified for the analysis, there were no differences found in mean temperatures and heat indexes between the sexes, races, age groups, ethnic groups, and industries. Southern workers died at significantly higher temperatures than workers in the North. This study supports the use of heat index and temperature as a guide when evaluating environmental conditions for workers. Population-level heat index threshold alerts are unsuitable for preventing exertional heat stress and new warning systems should be developed. Since heat-related health hazards at work can be anticipated before they manifest, preventive measures can be implemented before illness occurs. With no federal regulatory standards to protect workers from environmental heat exposure, and with climate change as a driver for adaptation and prevention of heat disorders, it is increasing sensible and imperative for the Occupational Safety and Health Administration to take action. National leadership is needed to promulgate regulations, develop new heat alert tools using the heat index as a metric, and promote state-specific occupational heat stress prevention policies

Animals as Early Detectors of Bioevents: Veterinary Tools and a Framework for Animal-Human Integrated Zoonotic Disease Surveillance

The threat of bioterrorism and emerging infectious diseases has prompted various public health agencies to recommend enhanced surveillance activities to supplement existing surveillance plans. The majority of emerging infectious diseases and bioterrorist agents are zoonotic. Animals are more sensitive to certain biological agents, and their use as clinical sentinels, as a means of early detection, is warranted