1
|
Li H, Cui F, Wang T, Wang W, Zhang D. The impact of sunlight exposure on brain structural markers in the UK Biobank. Sci Rep 2024; 14:10313. [PMID: 38705875 PMCID: PMC11070413 DOI: 10.1038/s41598-024-59633-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Accepted: 04/12/2024] [Indexed: 05/07/2024] Open
Abstract
Sunlight is closely intertwined with daily life. It remains unclear whether there are associations between sunlight exposure and brain structural markers. General linear regression analysis was used to compare the differences in brain structural markers among different sunlight exposure time groups. Stratification analyses were performed based on sex, age, and diseases (hypertension, stroke, diabetes). Restricted cubic spline was performed to examine the dose-response relationship between natural sunlight exposure and brain structural markers, with further stratification by season. A negative association of sunlight exposure time with brain structural markers was found in the upper tertile compared to the lower tertile. Prolonged natural sunlight exposure was associated with the volumes of total brain (β: - 0.051, P < 0.001), white matter (β: - 0.031, P = 0.023), gray matter (β: - 0.067, P < 0.001), and white matter hyperintensities (β: 0.059, P < 0.001). These associations were more pronounced in males and individuals under the age of 60. The results of the restricted cubic spline analysis showed a nonlinear relationship between sunlight exposure and brain structural markers, with the direction changing around 2 h of sunlight exposure. This study demonstrates that prolonged exposure to natural sunlight is associated with brain structural markers change.
Collapse
Affiliation(s)
- Huihui Li
- Department of Epidemiology and Health Statistics, Public Health College, Qingdao University, No. 308 Ningxia Road, QingdaoShandong Province, 266071, China
| | - Fusheng Cui
- Department of Epidemiology and Health Statistics, Public Health College, Qingdao University, No. 308 Ningxia Road, QingdaoShandong Province, 266071, China
| | - Tong Wang
- Department of Epidemiology and Health Statistics, Public Health College, Qingdao University, No. 308 Ningxia Road, QingdaoShandong Province, 266071, China
| | - Weijing Wang
- Department of Epidemiology and Health Statistics, Public Health College, Qingdao University, No. 308 Ningxia Road, QingdaoShandong Province, 266071, China.
| | - Dongfeng Zhang
- Department of Epidemiology and Health Statistics, Public Health College, Qingdao University, No. 308 Ningxia Road, QingdaoShandong Province, 266071, China.
| |
Collapse
|
2
|
Deshayes TA, Hsouna H, Braham MAA, Arvisais D, Pageaux B, Ouellet C, Jay O, Maso FD, Begon M, Saidi A, Gendron P, Gagnon D. Work-rest regimens for work in hot environments: A scoping review. Am J Ind Med 2024; 67:304-320. [PMID: 38345435 DOI: 10.1002/ajim.23569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 01/08/2024] [Accepted: 01/23/2024] [Indexed: 03/16/2024]
Abstract
BACKGROUND To limit exposures to occupational heat stress, leading occupational health and safety organizations recommend work-rest regimens to prevent core temperature from exceeding 38°C or increasing by ≥1°C. This scoping review aims to map existing knowledge of the effects of work-rest regimens in hot environments and to propose recommendations for future research based on identified gaps. METHODS We performed a search of 10 databases to retrieve studies focused on work-rest regimens under hot conditions. RESULTS Forty-nine articles were included, of which 35 were experimental studies. Most studies were conducted in laboratory settings, in North America (71%), on healthy young adults, with 94% of the 642 participants being males. Most studies (66%) employed a protocol duration ≤240 min (222 ± 162 min, range: 37-660) and the time-weighted average wet-bulb globe temperature was 27 ± 4°C (range: 18-34). The work-rest regimens implemented were those proposed by the American Conference of Governmental and Industrial Hygiene (20%), National Institute of Occupational Safety and Health (11%), or the Australian Army (3%). The remaining studies (66%) did not mention how the work-rest regimens were derived. Most studies (89%) focused on physical tasks only. Most studies (94%) reported core temperature, whereas only 22% reported physical and/or mental performance outcomes, respectively. Of the 35 experimental studies included, 77% indicated that core temperature exceeded 38°C. CONCLUSIONS Although work-rest regimens are widely used, few studies have investigated their physiological effectiveness. These studies were mainly short in duration, involved mostly healthy young males, and rarely considered the effect of work-rest regimens beyond heat strain during physical exertion.
Collapse
Affiliation(s)
- Thomas A Deshayes
- Montreal Heart Institute, Montréal, Québec, Canada
- École de kinésiologie et des sciences de l'activité physique (EKSAP), Faculté de médecine, Université de Montréal, Montréal, Québec, Canada
| | - Hsen Hsouna
- Montreal Heart Institute, Montréal, Québec, Canada
- École de kinésiologie et des sciences de l'activité physique (EKSAP), Faculté de médecine, Université de Montréal, Montréal, Québec, Canada
| | - Mounir A A Braham
- Département des sciences de l'activité physique, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
- Département d'anatomie, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
| | - Denis Arvisais
- Bibliothèque des sciences de la santé, Université de Montréal, Montréal, Québec, Canada
| | - Benjamin Pageaux
- École de kinésiologie et des sciences de l'activité physique (EKSAP), Faculté de médecine, Université de Montréal, Montréal, Québec, Canada
- Centre de recherche de l'Institut universitaire de gériatrie de Montréal (CRIUGM), Montréal, Québec, Canada
- Centre interdisciplinaire de recherche sur le cerveau et l'apprentissage (CIRCA), Montréal, Québec, Canada
| | - Capucine Ouellet
- Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST), Montréal, Québec, Canada
| | - Ollie Jay
- Heat and Health Research Incubator, University of Sydney, Sydney, New South Wales, Australia
| | - Fabien D Maso
- École de kinésiologie et des sciences de l'activité physique (EKSAP), Faculté de médecine, Université de Montréal, Montréal, Québec, Canada
- Centre interdisciplinaire de recherche sur le cerveau et l'apprentissage (CIRCA), Montréal, Québec, Canada
| | - Mickael Begon
- École de kinésiologie et des sciences de l'activité physique (EKSAP), Faculté de médecine, Université de Montréal, Montréal, Québec, Canada
- Centre de recherche du CHU Sainte-Justine, Montréal, Québec, Canada
| | - Alireza Saidi
- Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST), Montréal, Québec, Canada
| | - Philippe Gendron
- Département des sciences de l'activité physique, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
| | - Daniel Gagnon
- Montreal Heart Institute, Montréal, Québec, Canada
- École de kinésiologie et des sciences de l'activité physique (EKSAP), Faculté de médecine, Université de Montréal, Montréal, Québec, Canada
| |
Collapse
|
3
|
Klous L, Reinten J, Mol D, Roijendijk L, van Beurden M, Kingma B. No large effects on cognitive performance in high versus low solar green-flag WBGT conditions. ERGONOMICS 2024; 67:194-206. [PMID: 37278045 DOI: 10.1080/00140139.2023.2218625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 05/23/2023] [Indexed: 06/07/2023]
Abstract
Excessive solar radiation negatively affects cognitive performance. Occupational guidelines typically combine environmental components into one value, such as wet-bulb globe temperature (WBGT). Here, we evaluated cognitive performance in two similar 28.6 °C WBGT-effective (WBGTeff) that were designed differently; using high or low levels of solar radiation. Eight soldiers were exposed to a virtual-reality environment in a climate chamber set to high (900 Wm-2) or low solar radiation conditions (300 Wm-2). Soldiers walked 3 x 30 min at 5 kmh-1. Cognitive performance was evaluated using a virtual-reality scenario and a computerised test battery. There was no statistically significant effect of condition on the cognitive tasks (p > 0.05). Associations were found between mean body temperature (Tb) and visual detection (P ≤ 0.01). Differences in solar radiation with similar WBGTeff (28.6 °C) do not cause large systematic differences in cognitive performance. Certain aspects of cognitive performance (i.e. response inhibition) seem to be partly associated with Tb rather than solar radiation.Practitioner summary: Cognitive performance was evaluated in two similar WBGT conditions that were designed differently; using high or low levels of solar radiation. Differences in solar radiation with similar WBGT do not cause systematic differences in cognitive performance. Certain aspects of cognition were partly associated with mean body temperature rather than solar radiation.
Collapse
Affiliation(s)
- Lisa Klous
- Department of Human Performance, Unit Defence, Safety and Security, Netherlands Organization for Applied Scientific Research (TNO), Soesterberg, The Netherlands
| | - Jikke Reinten
- Department of Human Performance, Unit Defence, Safety and Security, Netherlands Organization for Applied Scientific Research (TNO), Soesterberg, The Netherlands
| | - Douwe Mol
- Department of Human Performance, Unit Defence, Safety and Security, Netherlands Organization for Applied Scientific Research (TNO), Soesterberg, The Netherlands
| | - Linsey Roijendijk
- Department of Human Performance, Unit Defence, Safety and Security, Netherlands Organization for Applied Scientific Research (TNO), Soesterberg, The Netherlands
| | - Maurice van Beurden
- Department of Human Performance, Unit Defence, Safety and Security, Netherlands Organization for Applied Scientific Research (TNO), Soesterberg, The Netherlands
| | - Boris Kingma
- Department of Human Performance, Unit Defence, Safety and Security, Netherlands Organization for Applied Scientific Research (TNO), Soesterberg, The Netherlands
| |
Collapse
|
4
|
Morrissey-Basler MC, Brewer GJ, Anderson T, Adams WM, Navarro JS, Marcelino M, Martin DG, Casa DJ. The effect of heat mitigation strategies on thermoregulation and productivity during simulated occupational work in the heat in physically active young men. Front Sports Act Living 2024; 5:1274141. [PMID: 38274034 PMCID: PMC10808760 DOI: 10.3389/fspor.2023.1274141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 12/26/2023] [Indexed: 01/27/2024] Open
Abstract
Purpose To investigate heat stress mitigation strategies on productivity and thermoregulatory responses during simulated occupational work in the heat. Methods Thirteen physically active men (age, 25 ± 4 years; body mass,77.8 ± 14.7 kg; VO2peak, 44.5 ± 9.2 ml·kg-1·min-1) completed five randomized-controlled trials in a hot environment (40°C, 40% relative humidity). Each trial was 4.5 h in duration to simulate an outdoor occupational shift. Thermoregulatory responses (heart rate, HR; rectal temperature, Trec; mean skin temperature, Tsk), perceptual responses (rating of perceived exertion, RPE; thermal sensation; thermal comfort; fatigue) and productivity outcomes (box lifting repetitions, time to exhaustion) were examined in the following heat mitigation strategy interventions: (1) simulated solar radiation with limited fluid intake [SUN]; (2) simulated solar radiation with no fluid restrictions [SUN + H2O]; (3) shade (no simulated solar radiation during trial) with no fluid restrictions [SHADE + H2O]; (4) shade and cooling towels during rest breaks with no fluid restrictions [COOL + H2O]; and (5) shade with cooling towels, cooling vest during activity with no fluid restrictions [COOL + VEST + H2O]. Results [COOL + VEST + H2O] had lower Trec compared to [SUN] [p = 0.004, effect size(ES) = 1.48], [SUN + H2O] (p < 0.001, ES = -1.87), and [SHADE + H2O] (p = 0.001, ES = 1.62). Average Tsk was lower during the treadmill and box lifting activities in the [COOL + VEST + H2O] compared to [SUN] (p < 0.001, ES = 7.92), [SUN + H2O] (p < 0.001,7.96), [SHADE + H2O] (p < 0.001), and [COOL + H2O] (p < 0.001, ES = 3.01). There were performance differences during the [COOL + VEST + H2O] (p = 0.033) and [COOL + H2O] (p = 0.023) conditions compared to [SUN] during phases of the experimental trial, however, there were no differences in total box lifting repetitions between trials (p > 0.05). Conclusion Our results suggest that during a simulated occupational shift in a laboratory setting, additional heat mitigation strategies ([COOL + VEST + H2O] and [COOL + H2O]) reduced physiological strain and improved box lifting performance to a greater degree than [SUN]. These differences may have been attributed to a larger core to skin temperature gradient or reduction in fatigue, thermal sensation, and RPE during [COOL + H2O] and [COOL + VEST + H2O]. These data suggest that body cooling, hydration, and "shade" (removal of simulated radiant heat) as heat stress mitigation strategies should be considered as it reduces physiological strain while producing no additional harm.
Collapse
Affiliation(s)
- Margaret C. Morrissey-Basler
- Department of Kinesiology, Korey Stringer Institute, University of Connecticut, Storrs, CT, United States
- Department of Health Sciences, Providence College, Providence, RI, United States
| | - Gabrielle J. Brewer
- Department of Kinesiology, Korey Stringer Institute, University of Connecticut, Storrs, CT, United States
| | - Travis Anderson
- Department of Sports Medicine, UnitedStates Olympic & Paralympic Committee, Colorado Springs, CO, United States
- UnitedStates Coalition for the Prevention of Illness and Injury in Sport, Colorado Springs, CO, United States
| | - William M. Adams
- Department of Sports Medicine, UnitedStates Olympic & Paralympic Committee, Colorado Springs, CO, United States
- UnitedStates Coalition for the Prevention of Illness and Injury in Sport, Colorado Springs, CO, United States
- School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, United Kingdom
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, NC, United States
| | - John S. Navarro
- Department of Kinesiology, Korey Stringer Institute, University of Connecticut, Storrs, CT, United States
| | - Monique Marcelino
- Department of Kinesiology, Korey Stringer Institute, University of Connecticut, Storrs, CT, United States
| | - David G. Martin
- Department of Kinesiology, Korey Stringer Institute, University of Connecticut, Storrs, CT, United States
| | - Douglas J. Casa
- Department of Kinesiology, Korey Stringer Institute, University of Connecticut, Storrs, CT, United States
| |
Collapse
|
5
|
Ioannou LG, Tsoutsoubi L, Gkiata P, Brown HA, Periard JD, Mekjavic IB, Kenny GP, Nybo L, Flouris AD. Effect of sportswear on performance and physiological heat strain during prolonged running in moderately hot conditions. Scand J Med Sci Sports 2024; 34:e14520. [PMID: 37839051 DOI: 10.1111/sms.14520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 09/01/2023] [Accepted: 10/01/2023] [Indexed: 10/17/2023]
Abstract
INTRODUCTION This study examined the impact of different upper-torso sportswear technologies on the performance and physiological heat strain of well-trained and national-level athletes during prolonged running in moderately hot conditions. METHODS A randomized crossover design was employed in which 20 well-trained (n = 16) and national-level (n = 4) athletes completed four experimental trials in moderately hot conditions (35°C, 30% relative humidity). In each trial, participants ran at 70% of their peak oxygen uptake (70% V̇O2peak ) for 60 min, while wearing a different upper-body garment: cotton t-shirt, t-shirt with sweat-wicking fabric, compression t-shirt, and t-shirt with aluminum dots lining the inside of the upper back of the garment. Running speed was adjusted to elicit the predetermined oxygen consumption associated with 70% V̇O2peak . Physiological (core and skin temperatures, total body water loss, and urine specific gravity) and perceptual (thermal comfort and sensation, ratings of perceived exertion, and garment cooling functionality) parameters along with running speed at 70% V̇O2peak were continuously recorded. RESULTS No significant differences were observed between the four garments for running speed at 70% V̇O2peak , physiological heat strain, and perceptual responses (all p > 0.05). The tested athletes reported larger areas of perceived suboptimal cooling functionality in the cotton t-shirt and the t-shirt with aluminum dots relative to the sweat-wicking and compression t-shirts (d: 0.43-0.52). CONCLUSION There were not differences among the tested garments regarding running speed at 70% V̇O2peak , physiological heat strain, and perceptual responses in well-trained and national-level endurance athletes exercising in moderate heat.
Collapse
Affiliation(s)
- Leonidas G Ioannou
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
| | - Lydia Tsoutsoubi
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
| | - Paraskevi Gkiata
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
| | - Harry A Brown
- Research Institute for Sport and Exercise (UCRISE), University of Canberra, Bruce, Australian Capital Territory, Australia
| | - Julien D Periard
- Research Institute for Sport and Exercise (UCRISE), University of Canberra, Bruce, Australian Capital Territory, Australia
| | - Igor B Mekjavic
- Department of Automatics, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Lars Nybo
- Department of Nutrition, Exercise and Sports, August Krogh Building, University of Copenhagen, Copenhagen, Denmark
| | - Andreas D Flouris
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
| |
Collapse
|
6
|
Rony MKK, Alamgir HM. High temperatures on mental health: Recognizing the association and the need for proactive strategies-A perspective. Health Sci Rep 2023; 6:e1729. [PMID: 38059052 PMCID: PMC10696165 DOI: 10.1002/hsr2.1729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 09/28/2023] [Accepted: 11/05/2023] [Indexed: 12/08/2023] Open
Abstract
Background and Aims The influence of temperature on various aspects of daily life is often underestimated, and its effects on mental health are not widely recognized. Understanding and addressing the relationship between temperature and mental well-being is crucial in the context of climate change and rising global temperatures. This perspective aimed to investigate the effects of high temperatures on mental health and identify proactive strategies to mitigate these effects. Methods This perspective adopted a twofold approach, including a comprehensive literature review and socioecological framework. The literature review involved extensive searches across Google Scholar, PubMed, and Scopus to identify relevant, peer-reviewed articles, and reports from diverse disciplines. Results The perspective emphasized the significance of recognizing heat stress and its consequences on mental well-being. Chronic heat stress can lead to increased stress, anxiety, and cognitive impairment. Vulnerable populations include, the very young, older adults, and individuals with pre-existing mental health conditions. Socioeconomic factors can further exacerbate vulnerability, highlighting the need for tailored strategies to manage mental health challenges during high temperatures. Additionally, the article identified and discussed proactive coping strategies to minimize both the psychological and physical impacts of heat stress. Mindfulness, stress management techniques, and therapy are suggested as effective means for individuals to manage psychological distress. Conclusion Implementing preventive measures are essential steps in promoting mental wellness in high temperatures. Proactive strategies by addressing the physiological and psychological effects of heat and considering the specific needs of vulnerable populations can help individuals and communities navigate the challenges posed by rising temperatures and promote resilience and preserve their mental well-being.
Collapse
Affiliation(s)
- Moustaq Karim Khan Rony
- Department of Public HealthBangladesh Open UniversityGazipurBangladesh
- Department of Institute of Social Welfare and ResearchUniversity of DhakaDhakaBangladesh
| | - Hasnat M. Alamgir
- Department of Career & Professional Development Services (CPDS)Southeast UniversityDhakaBangladesh
| |
Collapse
|
7
|
Carrillo AE, Akerman AP, Notley SR, Herry CL, Seely AJE, Ruzicka M, Boulay P, Kenny GP. Cardiac autonomic modulation in individuals with controlled and uncomplicated hypertension during exercise-heat stress. Appl Physiol Nutr Metab 2023; 48:863-869. [PMID: 37556854 DOI: 10.1139/apnm-2023-0173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
TAKE-HOME MESSAGE During short bouts of light-to-vigorous exercise in the heat, controlled and uncomplicated hypertension did not significantly modulate HRV in physically active individuals. These findings can be used to refine guidance on use of exercise for hypertension management in the heat.
Collapse
Affiliation(s)
- Andres E Carrillo
- Department of Exercise Science, School of Health Sciences, Chatham University, Pittsburgh, PA 15232, USA
| | - Ashley P Akerman
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, ON, Canada
| | - Sean R Notley
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, ON, Canada
| | - Christophe L Herry
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Andrew J E Seely
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
- Division of Thoracic Surgery and Department of Critical Care Medicine, Ottawa Hospital, Ottawa, ON, Canada
| | - Marcel Ruzicka
- Hypertension Program, Division of Nephrology, University of Ottawa, Ottawa, ON, Canada
| | - Pierre Boulay
- Faculté des sciences de l'activité physique, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, ON, Canada
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| |
Collapse
|
8
|
Notley SR, Mitchell D, Taylor NAS. A century of exercise physiology: concepts that ignited the study of human thermoregulation. Part 1: Foundational principles and theories of regulation. Eur J Appl Physiol 2023; 123:2379-2459. [PMID: 37702789 DOI: 10.1007/s00421-023-05272-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 06/30/2023] [Indexed: 09/14/2023]
Abstract
This contribution is the first of a four-part, historical series encompassing foundational principles, mechanistic hypotheses and supported facts concerning human thermoregulation during athletic and occupational pursuits, as understood 100 years ago and now. Herein, the emphasis is upon the physical and physiological principles underlying thermoregulation, the goal of which is thermal homeostasis (homeothermy). As one of many homeostatic processes affected by exercise, thermoregulation shares, and competes for, physiological resources. The impact of that sharing is revealed through the physiological measurements that we take (Part 2), in the physiological responses to the thermal stresses to which we are exposed (Part 3) and in the adaptations that increase our tolerance to those stresses (Part 4). Exercising muscles impose our most-powerful heat stress, and the physiological avenues for redistributing heat, and for balancing heat exchange with the environment, must adhere to the laws of physics. The first principles of internal and external heat exchange were established before 1900, yet their full significance is not always recognised. Those physiological processes are governed by a thermoregulatory centre, which employs feedback and feedforward control, and which functions as far more than a thermostat with a set-point, as once was thought. The hypothalamus, today established firmly as the neural seat of thermoregulation, does not regulate deep-body temperature alone, but an integrated temperature to which thermoreceptors from all over the body contribute, including the skin and probably the muscles. No work factor needs to be invoked to explain how body temperature is stabilised during exercise.
Collapse
Affiliation(s)
- Sean R Notley
- Defence Science and Technology Group, Department of Defence, Melbourne, Australia
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Duncan Mitchell
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
- School of Human Sciences, University of Western Australia, Crawley, Australia
| | - Nigel A S Taylor
- Research Institute of Human Ecology, College of Human Ecology, Seoul National University, Seoul, Republic of Korea.
| |
Collapse
|
9
|
Buller MJ, Atkinson E, Driver K, Tharion WJ, Ely BR, Cheuvront SN, Charkoudian N. Individualized monitoring of heat illness risk: novel adaptive physiological strain index to assess exercise-heat strain from athletes to fully encapsulated workers. Physiol Meas 2023; 44:10NT01. [PMID: 37703905 DOI: 10.1088/1361-6579/acf991] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 09/13/2023] [Indexed: 09/15/2023]
Abstract
Objective. Exercise-heat strain estimation approaches often involve combinations of body core temperature (Tcore), skin temperature (Tsk) and heart rate (HR). A successful existing measure is the 'Physiological Strain Index' (PSI), which combines HR and Tcore values to estimate strain. However, depending on variables such as aerobic fitness and clothing, the equation's 'maximal/critical' Tcore must be changed to accurately represent the strain, in part because high Tsk (small Tcore-Tsk) can increase cardiovascular strain and thereby negatively affect performance. Here, an 'adaptive PSI' (aPSI) is presented where the original PSI Tcorecriticalvalue is 'adapted' dynamically by the delta between Tcore and Tsk.Approach. PSI and aPSI were computed for athletes (ELITE,N= 11 male and 8 female, 8 km time-trial) and soldiers in fully encapsulating personal protective equipment (PPE,N= 8 male, 2 km approach-march). While these were dissimilar events, it was anticipated given that the clothing and work rates would elicit similar very-high exercise-heat strain values.Main results. Mean end HR values were similar (∼180 beats min-1) with higher Tcore = 40.1 ± 0.4 °C for ELITE versus PPE 38.4 ± 0.6 °C (P< 0.05). PSI end values were different between groups (P< 0.01) and appeared 'too-high' for ELITE (11.4 ± 0.8) and 'too-low' for PPE (7.6 ± 2.0). However, aPSI values were not different (9.9 ± 1.4 versus 9.0 ± 2.5 versus;p> 0.05) indicating a 'very high' level of exercise-heat strain for both conditions.Significance. A simple adaptation of the PSI equation, which accounts for differences in Tcore-to-Tsk gradients, provides a physiological approach to dynamically adapt PSI to provide a more accurate index of exercise-heat strain under very different working conditions.
Collapse
Affiliation(s)
- Mark J Buller
- US Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Natick, MA 01760, United States of America
| | - Emma Atkinson
- US Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Natick, MA 01760, United States of America
| | - Kyla Driver
- US Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Natick, MA 01760, United States of America
| | - William J Tharion
- US Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Natick, MA 01760, United States of America
| | - Brett R Ely
- Department of Health Sciences, Providence College, Providence, RI 02918, United States of America
| | - Samuel N Cheuvront
- Sports Science Synergy, LLC, Franklin, MA 02038, United States of America
| | - Nisha Charkoudian
- US Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Natick, MA 01760, United States of America
| |
Collapse
|
10
|
Taggart SM, Girard O, Landers GJ, Ecker UKH, Wallman KE. Comparing thermal strain in outdoor maintenance and indoor service workers in the mining industry during summer. PLoS One 2023; 18:e0292436. [PMID: 37796853 PMCID: PMC10553273 DOI: 10.1371/journal.pone.0292436] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 09/20/2023] [Indexed: 10/07/2023] Open
Abstract
While working in the heat is a common practice within the Australian mining industry, it can lead to adverse effects on cognitive function, productivity, and physical health. This study aimed to compare the thermal strain experienced by maintenance workers and service workers in the mining industry during summer. Psycho-physiological parameters, manual dexterity, and cognitive function were assessed in maintenance workers (n = 12) and service workers (n = 12) employed at mine site villages in north-west Australia. Maintenance workers had the freedom to self-select their work intensity and predominantly worked outdoors (33.9±4.2°C, 38±18% RH), whereas service workers had to work to a fixed schedule and worked intermittently indoors (∼64% of work shift; 29.5±3.4°C, 48±8% RH) and outdoors (∼36%; 35.4±4.6°C, 47±21% RH). All workers underwent assessment at the beginning (day 2/3), middle (day 7/8), and end of their swing (day 13/14), at various time points throughout their 11-12 h shift. Service workers completed more steps (11282±1794 vs. 7774±2821; p<0.001), experienced a higher heart rate (p = 0.049) and reported higher ratings of perceived exertion (p<0.001), thermal discomfort (p<0.001), thermal sensation (p<0.001), and fatigue (p<0.012) compared to maintenance workers. Urinary specific gravity values were higher (less hydrated) in service workers (1.024±0.007) compared to maintenance workers (1.018±0.006; p = 0.007), with USG being overall higher post- compared to pre-shift (1.022±0.008 vs. 1.020±0.006; p<0.05). Core temperature, working memory capacity, processing speed and manual dexterity did not differ between occupations. Workers in hot environments who cannot self-select their work intensity should be educated about the importance of hydration before, during, and after their work-shifts and provided with more scheduled rest breaks during their shift. Employers should closely monitor workers for symptoms of heat illness, discomfort, and fatigue to ensure the health and safety of the workers.
Collapse
Affiliation(s)
- Sarah M. Taggart
- School of Human Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Olivier Girard
- School of Human Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Grant J. Landers
- School of Human Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Ullrich K. H. Ecker
- School of Psychological Science, The University of Western Australia, Crawley, WA, Australia
| | - Karen E. Wallman
- School of Human Sciences, The University of Western Australia, Crawley, WA, Australia
| |
Collapse
|
11
|
Veríssimo TNS, Saraiva EP, Sant’Anna AC, Loureiro BA, do Nascimento PV, Lima LADA, Maia MIL, Morais LKDC, dos Santos SGCG, de Lima EHS, Fonseca VDFC. Heat Tolerance of Siberian Husky Dogs Living in Brazil: A Case Study on the Perceptions and Attitudes of Their Owners. Animals (Basel) 2023; 13:2774. [PMID: 37685038 PMCID: PMC10486465 DOI: 10.3390/ani13172774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 08/21/2023] [Accepted: 08/24/2023] [Indexed: 09/10/2023] Open
Abstract
The management of the thermal environment to which dogs are exposed should be included in strategies to improve their welfare. An online questionnaire was administered to 624 owners of Siberian Husky dogs residing in Brazil, with the objective of assessing their perceptions regarding their dogs' capacity to adapt to heat, and its association with the owners' routine care. Owners who believed that dogs are low-heat-tolerant animals were more likely to report heat response behaviors from their dogs. Overall, owners reported walk with their dogs during early morning, late afternoon and nighttime. They also reported solar radiation as the primary criteria for determining the time to walk with their dogs. However, owners who reported walking with their dogs at noon mentioned time availability as their primary criteria. In conclusion, owners perceive Siberian Husky dogs living in Brazil as being poorly adapted to heat, and this perception appeared to influence their positive attitudes towards protecting their dogs from heat stress by choosing to walk them during times with less solar exposure. However, the lack of time for owners to walk with their dogs during cooler periods can still be a risk factor in exposing the animals to extreme hot conditions.
Collapse
Affiliation(s)
- Tarsys Noan Silva Veríssimo
- Research Group in Bioclimatology, Ethology and Animal Welfare (BioEt), Department of Animal Science, Federal University of Paraíba, Areia 58397-000, Brazil; (T.N.S.V.); (E.P.S.); (P.V.d.N.); (L.A.d.A.L.); (M.I.L.M.); (L.K.d.C.M.); (E.H.S.d.L.); (V.d.F.C.F.)
| | - Edilson Paes Saraiva
- Research Group in Bioclimatology, Ethology and Animal Welfare (BioEt), Department of Animal Science, Federal University of Paraíba, Areia 58397-000, Brazil; (T.N.S.V.); (E.P.S.); (P.V.d.N.); (L.A.d.A.L.); (M.I.L.M.); (L.K.d.C.M.); (E.H.S.d.L.); (V.d.F.C.F.)
| | - Aline Cristina Sant’Anna
- Nucleus of Studies in Ethology and Animal Welfare, Departament of Zoology, Federal University of Juiz de Fora, Juiz de Fora 36036-900, Brazil
| | - Bruna Agy Loureiro
- Veterinarian Medicine and Animal Science School, Federal University of Bahia, Salvador 40170-110, Brazil;
| | - Pavlos Vinicius do Nascimento
- Research Group in Bioclimatology, Ethology and Animal Welfare (BioEt), Department of Animal Science, Federal University of Paraíba, Areia 58397-000, Brazil; (T.N.S.V.); (E.P.S.); (P.V.d.N.); (L.A.d.A.L.); (M.I.L.M.); (L.K.d.C.M.); (E.H.S.d.L.); (V.d.F.C.F.)
| | - Luiz Arthur dos Anjos Lima
- Research Group in Bioclimatology, Ethology and Animal Welfare (BioEt), Department of Animal Science, Federal University of Paraíba, Areia 58397-000, Brazil; (T.N.S.V.); (E.P.S.); (P.V.d.N.); (L.A.d.A.L.); (M.I.L.M.); (L.K.d.C.M.); (E.H.S.d.L.); (V.d.F.C.F.)
| | - Maria Isabelly Leite Maia
- Research Group in Bioclimatology, Ethology and Animal Welfare (BioEt), Department of Animal Science, Federal University of Paraíba, Areia 58397-000, Brazil; (T.N.S.V.); (E.P.S.); (P.V.d.N.); (L.A.d.A.L.); (M.I.L.M.); (L.K.d.C.M.); (E.H.S.d.L.); (V.d.F.C.F.)
| | - Larissa Kellen da Cunha Morais
- Research Group in Bioclimatology, Ethology and Animal Welfare (BioEt), Department of Animal Science, Federal University of Paraíba, Areia 58397-000, Brazil; (T.N.S.V.); (E.P.S.); (P.V.d.N.); (L.A.d.A.L.); (M.I.L.M.); (L.K.d.C.M.); (E.H.S.d.L.); (V.d.F.C.F.)
| | | | - Eduardo Henrique Santos de Lima
- Research Group in Bioclimatology, Ethology and Animal Welfare (BioEt), Department of Animal Science, Federal University of Paraíba, Areia 58397-000, Brazil; (T.N.S.V.); (E.P.S.); (P.V.d.N.); (L.A.d.A.L.); (M.I.L.M.); (L.K.d.C.M.); (E.H.S.d.L.); (V.d.F.C.F.)
| | - Vinícius de França Carvalho Fonseca
- Research Group in Bioclimatology, Ethology and Animal Welfare (BioEt), Department of Animal Science, Federal University of Paraíba, Areia 58397-000, Brazil; (T.N.S.V.); (E.P.S.); (P.V.d.N.); (L.A.d.A.L.); (M.I.L.M.); (L.K.d.C.M.); (E.H.S.d.L.); (V.d.F.C.F.)
| |
Collapse
|
12
|
Ioannou LG, Testa DJ, Tsoutsoubi L, Mantzios K, Gkikas G, Agaliotis G, Nybo L, Babar Z, Flouris AD. Migrants from Low-Income Countries have Higher Heat-Health Risk Profiles Compared to Native Workers in Agriculture. J Immigr Minor Health 2023:10.1007/s10903-023-01493-2. [PMID: 37208495 DOI: 10.1007/s10903-023-01493-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/30/2023] [Indexed: 05/21/2023]
Abstract
The present observational study was conducted to uncover potential differences in the risk of experiencing high occupational heat strain during agriculture work between migrants and their native coworkers, as well as to elucidate the factors that may contribute to such differences. The study took place over the period from 2016 through 2019 and involved monitoring 124 experienced and acclimatized individuals from high-income (HICs), upper-middle-income (UMICs), as well as lower-middle- and low-income (LMICs) countries. Baseline self-reported data for age, body stature, and body mass were collected at the start of the study. Second-by-second video recordings throughout the work shifts were captured using a video camera and were used to estimate workers' clothing insulation, covered body surface area, and body posture, as well as to calculate their walking speed, the amount of time they spent on different activities (and their intensity) and unplanned breaks throughout their work shifts. All information derived from the video data was used to calculate the physiological heat strain experienced by the workers. The core temperature of migrant workers from LMICs (37.81 ± 0.38 °C) and UMICs (37.71 ± 0.35 °C) was estimated to be significantly higher compared to the core temperature of native workers from HICs (37.60 ± 0.29 °C) (p < 0.001). Moreover, migrant workers from LMICs faced a 52% and 80% higher risk for experiencing core body temperature above the safety threshold of 38 °C compared to migrant workers from UMICs and native workers from HICs, respectively. Our findings show that migrant workers originating from LMICs experience higher levels of occupational heat strain, as compared to migrant workers from UMICs and native workers from HICs, because they take fewer unplanned breaks during work, they work at a higher intensity, they wear more clothing, and they have a smaller body size.
Collapse
Affiliation(s)
- Leonidas G Ioannou
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Karies, 42100, Trikala, Greece
| | - Davide J Testa
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Karies, 42100, Trikala, Greece
| | - Lydia Tsoutsoubi
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Karies, 42100, Trikala, Greece
| | - Konstantinos Mantzios
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Karies, 42100, Trikala, Greece
| | - Giorgos Gkikas
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Karies, 42100, Trikala, Greece
| | - Gerasimos Agaliotis
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Karies, 42100, Trikala, Greece
| | - Lars Nybo
- Department of Nutrition, Exercise and Sports, August Krogh Building, University of Copenhagen, Copenhagen, Denmark
| | - Zahra Babar
- Center for International and Regional Studies, Georgetown University, Doha, Qatar
| | - Andreas D Flouris
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Karies, 42100, Trikala, Greece.
| |
Collapse
|
13
|
Taggart SM, Girard O, Landers GJ, Ecker UKH, Wallman KE. Seasonal influence on cognitive and psycho-physiological responses to a single 11-h day of work in outdoor mine industry workers. Temperature (Austin) 2023; 10:465-478. [PMID: 38130661 PMCID: PMC10732613 DOI: 10.1080/23328940.2023.2208516] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 04/25/2023] [Indexed: 12/23/2023] Open
Abstract
This study investigated the seasonal effects that working outdoors had on various parameters in mining industry workers over the course of a work-shift. Workers (n = 27) were assessed in summer (33.3 ± 4.2°C, 38 ± 18% RH; n = 13, age = 46 ± 14 y, BMI = 29.1 ± 5.7 kg/m2) and winter (23.6 ± 5.1°C, 39 ± 20% RH; n = 14, age = 44 ± 12 y, BMI = 31.2 ± 4.1 kg/m2). Core temperature and heart-rate were measured continuously (analyzed at five time points), while perceptual measures, cognitive and manual dexterity performance were assessed at various times over an 11-h shift at the start of a 14-day swing. Hydration was assessed (urine specific gravity) pre- and post-shift. Working memory was impaired in summer compared to winter (-10%; p = 0.039), however did not change throughout the shift. Processing efficiency was significantly reduced at 12 pm (-12%; p = 0.005) and 5 pm (-21%; p < 0.001) compared to 9 am, irrespective of season (p > 0.05). Manual dexterity (dominant-hand) improved over the shift (+13%, p = 0.002), but was not different between seasons. Perceived fatigue had no main effect of season or shift. Core temperature, heart-rate, thermal sensation and rating of perceived exertion increased throughout the shift, with only core temperature and thermal sensation showing a seasonal effect (summer: +0.33°C, +18%, respectively; p < 0.002). Notably, 23% of workers in summer and 64% in winter started work significantly dehydrated, with 54% and 64% in summer and winter, respectively, finishing work with significant to serious dehydration. Impairment in working memory in summer combined with high levels of dehydration over the work-shift reinforces the need for workplace education on the importance of hydration and risk of occupation heat stress. Abbreviations: Core temperature: Tc; Fly-in fly-out: FIFO; Ratings of perceived exertion: RPE; Relative humidity: RH; Urinary specific gravity: USG; Wet bulb globe temperature: WBGT.
Collapse
Affiliation(s)
- Sarah M. Taggart
- School of Human Sciences (Sport Science, Exercise and Health), The University of Western Australia, Crawley, WA, Australia
| | - Olivier Girard
- School of Human Sciences (Sport Science, Exercise and Health), The University of Western Australia, Crawley, WA, Australia
| | - Grant J. Landers
- School of Human Sciences (Sport Science, Exercise and Health), The University of Western Australia, Crawley, WA, Australia
| | - Ullrich K. H. Ecker
- School of Psychological Science, The University of Western Australia, Crawley, WA, Australia
| | - Karen E. Wallman
- School of Human Sciences (Sport Science, Exercise and Health), The University of Western Australia, Crawley, WA, Australia
| |
Collapse
|
14
|
Hamidi Shishavan H, Garza J, Henning R, Cherniack M, Hirabayashi L, Scott E, Kim I. Continuous physiological signal measurement over 24-hour periods to assess the impact of work-related stress and workplace violence. APPLIED ERGONOMICS 2023; 108:103937. [PMID: 36462453 DOI: 10.1016/j.apergo.2022.103937] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 10/30/2022] [Accepted: 11/11/2022] [Indexed: 06/17/2023]
Abstract
Work-related stress has long been recognized as an essential factor affecting employees' health and wellbeing. Repeated exposure to acute occupational stressors puts workers at high risk for depression, obesity, hypertension, and early death. Assessment of the effects of acute stress on workers' wellbeing usually relies on subjective self-reports, questionnaires, or measuring biometric and biochemical markers in long-cycle time intervals. This study aimed to develop and validate the use of a multiparameter wearable armband for continuous non-invasive monitoring of physiological states. Two worker populations were monitored 24 h/day: six loggers for one day and six ICU nurses working 12-hr shifts for one week. Stress responses in nurses were highly correlated with changes in heart rate variability (HRV) and pulse transit time (PTT). A rise in the low-to high-frequency (LF/LH) ratio in HRV was also coincident with stress responses. HRV on workdays decreased compared to non-work days, and PTT also exhibited a persistent decrease reflecting increased blood pressure. Compared to loggers, nurses were involved in high-intensity work activities 45% more often but were less active on non-work days. The wearable technology was well accepted by all worker participants and yielded high signal quality, critical factors for long-term non-invasive occupational health monitoring.
Collapse
Affiliation(s)
- Hossein Hamidi Shishavan
- Department of Medicine, University of Connecticut School of Medicine, Farmington, CT, 06030, USA; Department of Biomedical Engineering, University of Connecticut, Storrs, CT, 06269, USA.
| | - Jennifer Garza
- Department of Medicine, University of Connecticut School of Medicine, Farmington, CT, 06030, USA.
| | - Robert Henning
- Department of Psychological Sciences, University of Connecticut, Storrs, CT, 06269, USA.
| | - Martin Cherniack
- Center for the Promotion of Health in the New England Workplace, University of Connecticut, USA.
| | - Liane Hirabayashi
- Northeast Center for Occupational Health and Safety in Agriculture, Forestry, and Fishing, Bassett Medical Center, NY, 13326, USA.
| | - Erika Scott
- Northeast Center for Occupational Health and Safety in Agriculture, Forestry, and Fishing, Bassett Medical Center, NY, 13326, USA.
| | - Insoo Kim
- Department of Medicine, University of Connecticut School of Medicine, Farmington, CT, 06030, USA; Department of Biomedical Engineering, University of Connecticut, Storrs, CT, 06269, USA.
| |
Collapse
|
15
|
Di Blasi C, Marinaccio A, Gariazzo C, Taiano L, Bonafede M, Leva A, Morabito M, Michelozzi P, de’ Donato FK. Effects of Temperatures and Heatwaves on Occupational Injuries in the Agricultural Sector in Italy. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:2781. [PMID: 36833478 PMCID: PMC9957348 DOI: 10.3390/ijerph20042781] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/30/2023] [Accepted: 02/02/2023] [Indexed: 05/12/2023]
Abstract
The effects of heat on health have been well documented, while less is known about the effects among agricultural workers. Our aim is to estimate the effects and impacts of heat on occupational injuries in the agricultural sector in Italy. Occupational injuries in the agricultural sector from the Italian national workers' compensation authority (INAIL) and daily mean air temperatures from Copernicus ERA5-land for a five-year period (2014-2018) were considered. Distributed lag non-linear models (DLNM) were used to estimate the relative risk and attributable injuries for increases in daily mean air temperatures between the 75th and 99th percentile and during heatwaves. Analyses were stratified by age, professional qualification, and severity of injury. A total of 150,422 agricultural injuries were considered and the overall relative risk of injury for exposure to high temperatures was 1.13 (95% CI: 1.08; 1.18). A higher risk was observed among younger workers (15-34 years) (1.23 95% CI: 1.14; 1.34) and occasional workers (1.25 95% CI: 1.03; 1.52). A total of 2050 heat-attributable injuries were estimated in the study period. Workers engaged in outdoor and labour-intensive activities in the agricultural sector are at greater risk of injury and these results can help target prevention actions for climate change adaptation.
Collapse
Affiliation(s)
- Chiara Di Blasi
- Department of Epidemiology Lazio Regional Health Service, ASL ROMA 1, 00147 Rome, Italy
| | - Alessandro Marinaccio
- Occupational and Environmental Medicine, Epidemiology and Hygiene Department, Italian Workers’ Compensation Authority (INAIL), 00143 Rome, Italy
| | - Claudio Gariazzo
- Occupational and Environmental Medicine, Epidemiology and Hygiene Department, Italian Workers’ Compensation Authority (INAIL), 00143 Rome, Italy
| | - Luca Taiano
- Occupational and Environmental Medicine, Epidemiology and Hygiene Department, Italian Workers’ Compensation Authority (INAIL), 00143 Rome, Italy
| | - Michela Bonafede
- Occupational and Environmental Medicine, Epidemiology and Hygiene Department, Italian Workers’ Compensation Authority (INAIL), 00143 Rome, Italy
| | - Antonio Leva
- Occupational and Environmental Medicine, Epidemiology and Hygiene Department, Italian Workers’ Compensation Authority (INAIL), 00143 Rome, Italy
| | - Marco Morabito
- Institute of Bioeconomy, National Research Council (IBE-CNR), 50019 Florence, Italy
| | - Paola Michelozzi
- Department of Epidemiology Lazio Regional Health Service, ASL ROMA 1, 00147 Rome, Italy
| | | | | |
Collapse
|
16
|
Ciuha U, Valenčič T, Ioannou LG, Mekjavic IB. Efficacy of cooling vests based on different heat-extraction concepts: The HEAT-SHIELD project. J Therm Biol 2023; 112:103442. [PMID: 36796897 DOI: 10.1016/j.jtherbio.2022.103442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 12/15/2022] [Accepted: 12/22/2022] [Indexed: 01/26/2023]
Abstract
INTRODUCTION A wide range of cooling vests for heat-strain mitigation purposes during physical work are available on the market. The decision regarding the optimal cooling vest/concept for a specific environment can be challenging by relying solely on the information provided by the manufacturers. The aim of this study was to investigate how different types of cooling vests would manifest/perform in a simulated industrial setting, in a warm and moderately humid environment with low air velocity. METHODS Ten young males completed six experimental trials, including a control trial (no vest) and five trials with vests of different cooling concepts. Once entering the climatic chamber (ambient temperature: 35 °C, relative humidity: 50 %), participants remained seated for 30 min to induce passive heating, after which they donned a cooling vest and started a 2.5-h of walk at 4.5 km·h-1. During the trial, torso skin temperature (Tsk), microclimate temperature (Tmicro) and relative humidity (RHmicro), as well as core temperature (rectal and gastrointestinal; Tc) and heart rate (HR) were measured. Before and after the walk, participants conducted different cognitive tests and provided subjective ratings throughout the walk. RESULTS The use of the vests attenuated the increase in HR (103 ± 12 bpm) when compared to control trial (116 ± 17 bpm, p < 0.05). Four vests maintained a lower torso Tsk (31.7 ± 1.5 °C) compared to control trial (36.1 ± 0.5 °C, p < 0.05). Two vests using PCM inserts attenuated the increase in Tc between 0.2 and 0.5 °C in relation to control trial (p < 0.05). Cognitive performance remained unchanged between the trials. Physiological responses were also well reflected in subjective reports. CONCLUSION Most vests could be considered as an adequate mitigation strategy for workers in industry under the conditions simulated in the present study.
Collapse
Affiliation(s)
- Urša Ciuha
- Jozef Stefan Institute, Department of Automatics, Biocybernetics and Robotics, Ljubljana, Slovenia.
| | - Tamara Valenčič
- Jozef Stefan Institute, Department of Automatics, Biocybernetics and Robotics, Ljubljana, Slovenia
| | - Leonidas G Ioannou
- Jozef Stefan Institute, Department of Automatics, Biocybernetics and Robotics, Ljubljana, Slovenia
| | - Igor B Mekjavic
- Jozef Stefan Institute, Department of Automatics, Biocybernetics and Robotics, Ljubljana, Slovenia
| |
Collapse
|
17
|
Guzman-Echavarria G, Middel A, Vanos J. Beyond heat exposure - new methods to quantify and link personal heat exposure, stress, and strain in diverse populations and climates: The journal Temperature toolbox. Temperature (Austin) 2022; 10:358-378. [PMID: 37554380 PMCID: PMC10405775 DOI: 10.1080/23328940.2022.2149024] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 10/31/2022] [Accepted: 11/12/2022] [Indexed: 11/21/2022] Open
Abstract
Fine-scale personal heat exposure (PHE) information can help prevent or minimize weather-related deaths, illnesses, and reduced work productivity. Common methods to estimate heat risk do not simultaneously account for the intensity, frequency, and duration of thermal exposures, nor do they include inter-individual factors that modify physiological response. This study demonstrates new whole-body net thermal load estimations to link PHE to heat stress and strain over time. We apply a human-environment heat exchange model to examine how time-varying net thermal loads differ across climate contexts, personal attributes, and spatiotemporal scales. First, we investigate summertime climatic PHE impacts for three US cities: Phoenix, Miami, and New York. Second, we model body morphology and acclimatization for three profiles (middle-aged male/female; female >65 years). Finally, we quantify model sensitivity using representative data at synoptic and micro-scales. For all cases, we compare required and potential evaporative heat losses that can lead to dangerous thermal exposures based on (un)compensable heat stress. Results reveal misclassifications in heat stress or strain due to incomplete environmental data and assumed equivalent physiology and activities between people. Heat strain is most poorly represented by PHE alone for the elderly, non-acclimatized, those engaged in strenuous activities, and when negating solar radiation. Moreover, humid versus dry heat across climates elicits distinct thermal responses from the body. We outline criteria for inclusive PHE evaluations connecting heat exposure, stress, and strain while using physiological-based methods to avoid misclassifications. This work underlines the value of moving from "one-size-fits-all" thermal indices to "fit-for-purpose" approaches using personalized information.
Collapse
Affiliation(s)
- Gisel Guzman-Echavarria
- School of Geographical Sciences and Urban Planning, Arizona State University, Tempe, AZ, USA
| | - Ariane Middel
- School of Arts, Media and Engineering, Arizona State University, Tempe, AZ, USA
- School of Computing and Augmented Intelligence, Arizona State University,Tempe, AZ, USA
| | - Jennifer Vanos
- School of Sustainability, Arizona State University, Tempe, AZ, USA
| |
Collapse
|
18
|
Long-term residential sunlight exposure associated with cognitive function among adults residing in Finland. Sci Rep 2022; 12:20818. [PMID: 36460719 PMCID: PMC9718732 DOI: 10.1038/s41598-022-25336-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 11/28/2022] [Indexed: 12/03/2022] Open
Abstract
While sunlight may influence cognitive function through several pathways, associations of residential sunlight exposure with cognitive function are not well known. We evaluated associations of long-term residential sunlight exposure with cognitive function among a representative cohort of 1838 Finnish adults residing in Finland who underwent comprehensive cognitive assessment in midlife. We linked daily recordings of global solar radiation to study participants using residential information and calculated the average daily residential exposure to sunlight for four exposure time intervals: 2 months, 1 year, 2 years and 5 years prior to the date of the cognition assessment. Associations of the residential sunlight exposure with cognitive function were assessed using linear regression analyses adjusting for season, sex, age, and individual- and neighborhood-level socioeconomic characteristics. Greater average residential sunlight exposure over 2 and 5 years prior to the cognitive function assessment was associated with better global cognitive function (b = 0.13, 95% CI = 0.01, 0.25; b = 0.17, 95% CI = 0.05, 0.29, per 1 MJ/m2 difference in sunlight exposure), while no associations with global cognitive function were observed at shorter exposure time intervals. In domain-specific analyses, greater residential exposure to sunlight over 1, 2 and 5 years prior to the cognitive function assessment was associated with better performance on new learning and visual memory (b = 0.10, 95% CI = 0.00, 0.20; b = 0.16, 95% CI = 0.04, 0.28; b = 0.19, 95% CI = 0.08, 0.31) and sustained attention (b = 0.15, 95% CI = 0.05, 0.25; b = 0.18, 95% CI = 0.06, 0.30; b = 0.17, 95% CI = 0.05, 0.29), but worse performance on reaction time (b = - 0.12, 95% CI = - 0.22, - 0.02; b = -0.15, 95% CI = - 0.28, - 0.02; b = - 0.18, 95% CI = - 0.30, - 0.05). Residential sunlight exposure was not associated with executive function. These findings suggest long-term residential sunlight exposure may be an environmental factor influencing cognitive function among a cognitively healthy cohort residing in Northern Europe. Further studies in populations residing in different geographical locations are needed.
Collapse
|
19
|
Sánchez-Jiménez JL, Tejero-Pastor R, Calzadillas-Valles MDC, Jimenez-Perez I, Cibrián Ortiz de Anda RM, Salvador-Palmer R, Priego-Quesada JI. Chronic and Acute Effects on Skin Temperature from a Sport Consisting of Repetitive Impacts from Hitting a Ball with the Hands. SENSORS (BASEL, SWITZERLAND) 2022; 22:8572. [PMID: 36366270 PMCID: PMC9655514 DOI: 10.3390/s22218572] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 10/30/2022] [Accepted: 11/05/2022] [Indexed: 06/16/2023]
Abstract
Valencian handball consists in hitting the ball with the hands and it may contribute to injury development on the hands. This study aimed to analyze skin temperature asymmetries and recovery after a cold stress test (CST) in professional players of Valencian handball before and after a competition. Thirteen professional athletes and a control group of ten physically active participants were measured. For both groups, infrared images were taken at the baseline condition; later they underwent a thermal stress test (pressing for 2 min with the palm of the hand on a metal plate) and then recovery images were taken. In athletes, the images were also taken after their competition. Athletes at baseline condition presented lower temperatures (p < 0.05) in the dominant hand compared with the non-dominant hand. There were asymmetries in all regions after their match (p < 0.05). After CST, a higher recovery rate was found after the game. The regions with the most significant differences in variation, asymmetries and recovery patterns were the index, middle and ring fingers, and the palm of the dominant hand. Taking into account that lower temperatures and the absence of temperature variation may be the consequence of a vascular adaptation, thermography could be used as a method to prevent injuries in athletes from Valencian handball.
Collapse
Affiliation(s)
- Jose Luis Sánchez-Jiménez
- Research Group in Sports Biomechanics (GIBD), Department of Physical Education and Sports, University of Valencia, 46010 Valencia, Spain
| | - Robert Tejero-Pastor
- Department of Physical Education and Sports, University of Valencia, 46010 Valencia, Spain
| | | | - Irene Jimenez-Perez
- Research Group in Sports Biomechanics (GIBD), Department of Physical Education and Sports, University of Valencia, 46010 Valencia, Spain
- Research Group in Medical Physics (GIFIME), Department of Physiology, University of Valencia, 46010 Valencia, Spain
| | | | - Rosario Salvador-Palmer
- Research Group in Medical Physics (GIFIME), Department of Physiology, University of Valencia, 46010 Valencia, Spain
| | - Jose Ignacio Priego-Quesada
- Research Group in Sports Biomechanics (GIBD), Department of Physical Education and Sports, University of Valencia, 46010 Valencia, Spain
- Research Group in Medical Physics (GIFIME), Department of Physiology, University of Valencia, 46010 Valencia, Spain
| |
Collapse
|
20
|
Rykaczewski K, Bartels L, Martinez DM, Viswanathan SH. Human body radiation area factors for diverse adult population. INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 2022; 66:2357-2367. [PMID: 36074273 DOI: 10.1007/s00484-022-02362-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 08/30/2022] [Indexed: 06/15/2023]
Abstract
Radiation accounts for a significant fraction of the human body and environment heat exchange and strongly impacts thermal comfort and safety. The direct radiative exchange between an individual and a source or sink can be quantified using the effective (feff) and projected radiation area factors (fp). However, these factors have not been quantified for half of the population of the USA with an above-average body mass index (BMI). Here, we address this gap by developing thirty male and thirty female computational manikin models that cover the 1 to 99 percentile variation in height and BMI of adults in the USA. The radiative simulations reveal that the feff and the fp angular distributions are nearly independent of gender, height, and BMI. Appreciable relative differences from the average models only emerge for manikins with BMI above 80th percentile. However, these differences only occur at low zenith angles and, in absolute terms, are small as compared to variations induced by, for example, the zenith angle increase. We also use the manikin set to evaluate whether the body shape impacts the quality of human representation with several levels of geometrical simplification. We find that the "box/peg" body representation, which is based on the hemispherical fp average, is independent of the body shape. In turn, the fp distributions averaged over the azimuth angle range, representing the rotationally symmetric humans, are only impacted to the same degree as for the anatomical manikins. We also show that the anatomical manikins can be closely approximated by the multi-cylinder and sphere representation, at least from a radiation perspective. The developed anatomical manikin set is freely available and can be used to compute how body shape impacts a variety of external heat transport processes.
Collapse
Affiliation(s)
- Konrad Rykaczewski
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, 85287, USA.
- Julie Ann Wrigley Global Futures Laboratory, Arizona State University, Tempe, AZ, 85287, USA.
| | - Lyle Bartels
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, 85287, USA
| | - Daniel M Martinez
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, 85287, USA
| | - Shri H Viswanathan
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, 85287, USA
| |
Collapse
|
21
|
Chavez Santos E, Spector JT, Egbert J, Krenz J, Sampson PD, Palmández P, Torres E, Blancas M, Carmona J, Jung J, Flunker JC. The effect of the participatory heat education and awareness tools (HEAT) intervention on agricultural worker physiological heat strain: results from a parallel, comparison, group randomized study. BMC Public Health 2022; 22:1746. [PMID: 36104813 PMCID: PMC9476265 DOI: 10.1186/s12889-022-14144-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 09/06/2022] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Farmworkers are at risk of heat-related illness (HRI). We sought to: 1) evaluate the effectiveness of farmworker Spanish/English participatory heat education and a supervisor decision-support mobile application (HEAT intervention) on physiological heat strain; and 2) describe factors associated with HRI symptoms reporting. METHODS We conducted a parallel, comparison group intervention study from May-September of 2019 in Central/Eastern Washington State, USA. We used convenience sampling to recruit adult outdoor farmworkers and allocated participating crews to intervention (n = 37 participants) and alternative-training comparison (n = 38 participants) groups. We measured heat strain monthly using heart rate and estimated core body temperature to compute the maximum work-shift physiological strain index (PSImax) and assessed self-reported HRI symptoms using a weekly survey. Multivariable linear mixed effects models were used to assess associations of the HEAT intervention with PSImax, and bivariate mixed models were used to describe factors associated with HRI symptoms reported (0, 1, 2+ symptoms), with random effects for workers. RESULTS We observed larger decreases in PSImax in the intervention versus comparison group for higher work exertion levels (categorized as low, low/medium-low, and high effort), after adjustment for maximum work-shift ambient Heat Index (HImax), but this was not statistically significant (interaction - 0.91 for high versus low/medium-low effort, t = - 1.60, p = 0.11). We observed a higher PSImax with high versus low/medium-low effort (main effect 1.96, t = 3.81, p < 0.001) and a lower PSImax with older age (- 0.03, t = - 2.95, p = 0.004), after covariate adjustment. There was no clear relationship between PSImax and the number of HRI symptoms reported. Reporting more symptoms was associated with older age, higher HImax, 10+ years agricultural work, not being an H-2A guest worker, and walking > 3 min to get to the toilet at work. CONCLUSIONS Effort level should be addressed in heat management plans, for example through work/rest cycles, rotation, and pacing, in addition to education and other factors that influence heat stress. Both symptoms and indicators of physiological heat strain should be monitored, if possible, during periods of high heat stress to increase the sensitivity of early HRI detection and prevention. Structural barriers to HRI prevention must also be addressed. TRIAL REGISTRATION ClinicalTrials.gov Registration Number: NCT04234802 , date first posted 21/01/2020.
Collapse
Affiliation(s)
- Erica Chavez Santos
- grid.34477.330000000122986657Department of Health Systems and Population Health, University of Washington, Seattle, WA USA
| | - June T. Spector
- grid.34477.330000000122986657Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way NE, Seattle, WA 98105 USA ,grid.34477.330000000122986657Department of Medicine, University of Washington, 4225 Roosevelt Way NE, Seattle, WA 98105 USA
| | - Jared Egbert
- grid.34477.330000000122986657Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way NE, Seattle, WA 98105 USA ,grid.416237.50000 0004 0418 9357Department of Preventive Medicine, Madigan Army Medical Center, Joint Base Lewis-McChord, Seattle, WA USA
| | - Jennifer Krenz
- grid.34477.330000000122986657Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way NE, Seattle, WA 98105 USA
| | - Paul D. Sampson
- grid.34477.330000000122986657Department of Statistics, University of Washington, Seattle, WA USA
| | - Pablo Palmández
- grid.34477.330000000122986657Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way NE, Seattle, WA 98105 USA
| | - Elizabeth Torres
- Northwest Communities Education Center/Radio KDNA, Granger, WA USA
| | - Maria Blancas
- grid.34477.330000000122986657Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way NE, Seattle, WA 98105 USA
| | - Jose Carmona
- grid.34477.330000000122986657Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way NE, Seattle, WA 98105 USA
| | - Jihoon Jung
- grid.34477.330000000122986657Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way NE, Seattle, WA 98105 USA
| | - John C. Flunker
- grid.34477.330000000122986657Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way NE, Seattle, WA 98105 USA
| |
Collapse
|
22
|
Tokizawa K, Shimuta T, Tsuchimoto H. Validity of a wearable core temperature estimation system in heat using patch-type sensors on the chest. J Therm Biol 2022; 108:103294. [DOI: 10.1016/j.jtherbio.2022.103294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 01/14/2022] [Accepted: 07/19/2022] [Indexed: 10/17/2022]
|
23
|
Ioannou LG, Mantzios K, Tsoutsoubi L, Notley SR, Dinas PC, Brearley M, Epstein Y, Havenith G, Sawka MN, Bröde P, Mekjavic IB, Kenny GP, Bernard TE, Nybo L, Flouris AD. Indicators to assess physiological heat strain – Part 1: Systematic review. Temperature (Austin) 2022; 9:227-262. [PMID: 36211945 PMCID: PMC9542768 DOI: 10.1080/23328940.2022.2037376] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
In a series of three companion papers published in this Journal, we identify and validate the available thermal stress indicators (TSIs). In this first paper of the series, we conducted a systematic review (registration: INPLASY202090088) to identify all TSIs and provide reliable information regarding their use (funded by EU Horizon 2020; HEAT-SHIELD). Eight databases (PubMed, Agricultural and Environmental Science Collection, Web of Science, Scopus, Embase, Russian Science Citation Index, MEDLINE, and Google Scholar) were searched from database inception to 15 April 2020. No restrictions on language or study design were applied. Of the 879 publications identified, 232 records were considered for further analysis. This search identified 340 instruments and indicators developed between 200 BC and 2019 AD. Of these, 153 are nomograms, instruments, and/or require detailed non-meteorological information, while 187 can be mathematically calculated utilizing only meteorological data. Of these meteorology-based TSIs, 127 were developed for people who are physically active, and 61 of those are eligible for use in occupational settings. Information regarding the equation, operating range, interpretation categories, required input data, as well as a free software to calculate all 187 meteorology-based TSIs is provided. The information presented in this systematic review should be adopted by those interested in performing on-site monitoring and/or big data analytics for climate services to ensure appropriate use of the meteorology-based TSIs. Studies two and three in this series of companion papers present guidance on the application and validation of these TSIs, to guide end users of these indicators for more effective use.
Collapse
Affiliation(s)
- Leonidas G. Ioannou
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
- Department of Nutrition, Exercise and Sports, August Krogh Building, University of Copenhagen, Denmark
| | - Konstantinos Mantzios
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
| | - Lydia Tsoutsoubi
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
| | - Sean R. Notley
- Human and Environmental Physiology Research Unit, Faculty of Health Sciences, University of Ottawa, Ontario, Canada
| | - Petros C. Dinas
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
| | - Matt Brearley
- National Critical Care and Trauma Response Centre, Royal Darwin Hospital, Darwin, Northern Territory, Australia
- Thermal Hyperformance, Pty Ltd, Takura, QLD, Australia
| | - Yoram Epstein
- Heller Institute of Medical Research, Sheba Medical Center, Ramat Gan and the Sackler Faculty of Medicine, Tel Aviv University, Israel
| | - George Havenith
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, UK
| | - Michael N. Sawka
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Peter Bröde
- Department of Immunology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | - Igor B. Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Glen P. Kenny
- Human and Environmental Physiology Research Unit, Faculty of Health Sciences, University of Ottawa, Ontario, Canada
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Canada
| | - Thomas E. Bernard
- College of Public Health, University of South Florida, 13201 Bruce B Downs Boulevard, Tampa, FL 33612, USA
| | - Lars Nybo
- Department of Nutrition, Exercise and Sports, August Krogh Building, University of Copenhagen, Denmark
| | - Andreas D. Flouris
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
- Human and Environmental Physiology Research Unit, Faculty of Health Sciences, University of Ottawa, Ontario, Canada
| |
Collapse
|
24
|
Ioannou LG, Tsoutsoubi L, Mantzios K, Vliora M, Nintou E, Piil JF, Notley SR, Dinas PC, Gourzoulidis GA, Havenith G, Brearley M, Mekjavic IB, Kenny GP, Nybo L, Flouris AD. Indicators to assess physiological heat strain – Part 3: Multi-country field evaluation and consensus recommendations. Temperature (Austin) 2022; 9:274-291. [PMID: 36249710 PMCID: PMC9559325 DOI: 10.1080/23328940.2022.2044739] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In a series of three companion papers published in this Journal, we identify and validate the available thermal stress indicators (TSIs). In this third paper, we conducted field experiments across nine countries to evaluate the efficacy of 61 meteorology-based TSIs for assessing the physiological strain experienced by individuals working in the heat. We monitored 372 experi-enced and acclimatized workers during 893 full work shifts. We continuously assessed core body temperature, mean skin temperature, and heart rate data together with pre/post urine specific gravity and color. The TSIs were evaluated against 17 published criteria covering physiological parameters, practicality, cost effectiveness, and health guidance issues. Simple meteorological parameters explained only a fraction of the variance in physiological heat strain (R2 = 0.016 to 0.427; p < 0.001), reflecting the importance of adopting more sophisticated TSIs. Nearly all TSIs correlated with mean skin temperature (98%), mean body temperature (97%), and heart rate (92%), while 66% of TSIs correlated with the magnitude of dehydration and 59% correlated with core body temperature (r = 0.031 to 0.602; p < 0.05). When evaluated against the 17 published criteria, the TSIs scored from 4.7 to 55.4% (max score = 100%). The indoor (55.4%) and outdoor (55.1%) Wet-Bulb Globe Temperature and the Universal Thermal Climate Index (51.7%) scored higher compared to other TSIs (4.7 to 42.0%). Therefore, these three TSIs have the highest potential to assess the physiological strain experienced by individuals working in the heat.
Collapse
Affiliation(s)
- Leonidas G. Ioannou
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
- Department of Nutrition, Exercise and Sports, August Krogh Building, University of Copenhagen, Denmark
| | - Lydia Tsoutsoubi
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
| | - Konstantinos Mantzios
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
| | - Maria Vliora
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
| | - Eleni Nintou
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
| | - Jacob F. Piil
- Department of Nutrition, Exercise and Sports, August Krogh Building, University of Copenhagen, Denmark
| | | | - Petros C. Dinas
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
| | | | - George Havenith
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, UK
| | - Matt Brearley
- National Critical Care and Trauma Response Centre, Royal Darwin Hospital, Darwin, Northern Territory, Australia
- Thermal Hyperformance, Pty Ltd, Takura, Qld, Australia
| | - Igor B. Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Slovenia
| | - Glen P. Kenny
- Human and Environmental Physiology Research Unit, Faculty of Health Sciences, University of Ottawa, ON, Canada
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Lars Nybo
- Department of Nutrition, Exercise and Sports, August Krogh Building, University of Copenhagen, Denmark
| | - Andreas D. Flouris
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
- Human and Environmental Physiology Research Unit, Faculty of Health Sciences, University of Ottawa, ON, Canada
| |
Collapse
|
25
|
Ioannou LG, Dinas PC, Notley SR, Gofa F, Gourzoulidis GA, Brearley M, Epstein Y, Havenith G, Sawka MN, Bröde P, Mekjavic IB, Kenny GP, Bernard TE, Nybo L, Flouris AD. Indicators to assess physiological heat strain – Part 2: Delphi exercise. Temperature (Austin) 2022; 9:263-273. [PMID: 36211947 PMCID: PMC9542877 DOI: 10.1080/23328940.2022.2044738] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
In a series of three companion papers published in this Journal, we identify and validate the available thermal stress indicators (TSIs). In this second paper of the series, we identified the criteria to consider when adopting a TSI to protect individuals who work in the heat, and we weighed their relative importance using a Delphi exercise with 20 experts. Two Delphi iterations were adequate to reach consensus within the expert panel (Cronbach's α = 0.86) for a set of 17 criteria with varying weights that should be considered when adopting a TSI to protect individuals who work in the heat. These criteria considered physiological parameters such as core/skin/mean body temperature, heart rate, and hydration status, as well as practicality, cost effectiveness, and health guidance issues. The 17 criteria were distributed across three occupational health-and-safety pillars: (i) contribution to improving occupational health (55% of total importance), (ii) mitigation of worker physiological strain (35.5% of total importance), and (iii) cost-effectiveness (9.5% of total importance). Three criteria [(i) relationship of a TSI with core temperature, (ii) having categories indicating the level of heat stress experienced by workers, and (iii) using its heat stress categories to provide recommendations for occupational safety and health] were considered significantly more important when selecting a TSI for protecting individuals who work in the heat, accumulating 37.2 percentage points. These 17 criteria allow the validation and comparison of TSIs that presently exist as well as those that may be developed in the coming years.
Collapse
Affiliation(s)
- Leonidas G. Ioannou
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
- Department of Nutrition, Exercise and Sports, August Krogh Building, University of Copenhagen, Copenhagen, Denmark
| | - Petros C. Dinas
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
| | - Sean R. Notley
- Human and Environmental Physiology Research Unit, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Flora Gofa
- Hellenic National Meteorological Service, Athens, Greece
| | | | - Matt Brearley
- National Critical Care and Trauma Response Centre, Royal Darwin Hospital, Darwin, Northern Territory, Australia
- Thermal Hyperformance, Pty Ltd, Takura, Australia
| | - Yoram Epstein
- Heller Institute of Medical Research, Sheba Medical Center, Ramat Gan and the Sackler Faculty of Medicine, Tel Aviv University, Israel
| | - George Havenith
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, UK
| | - Michael N. Sawka
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Peter Bröde
- Department of Immunology, Leibniz Research Centre for Working Environment and Human Factors (IfADO), Dortmund, Germany
| | - Igor B. Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Glen P. Kenny
- Human and Environmental Physiology Research Unit, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Thomas E. Bernard
- College of Public Health, University of South Florida, Tampa, FL, USA
| | - Lars Nybo
- Department of Nutrition, Exercise and Sports, August Krogh Building, University of Copenhagen, Copenhagen, Denmark
| | - Andreas D. Flouris
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
- Human and Environmental Physiology Research Unit, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| |
Collapse
|
26
|
Effects of Unilateral Muscle Fatigue on Thermographic Skin Surface Temperature of Back and Abdominal Muscles—A Pilot Study. Sports (Basel) 2022; 10:sports10030041. [PMID: 35324650 PMCID: PMC8951321 DOI: 10.3390/sports10030041] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 02/15/2022] [Accepted: 03/02/2022] [Indexed: 01/25/2023] Open
Abstract
The present study aimed to assess the effects of asymmetric muscle fatigue on the skin surface temperature of abdominal and back muscles. The study was based on a pre-post/follow-up design with one group and included a total of 41 subjects (22 male, 19 female; age, 22.63 ± 3.91; weight, 71.89 ± 12.97 kg; height, 173.36 ± 9.95). All the participants were asked to perform side bends in sets of 20 repetitions on a Roman chair until complete exhaustion. The pre-, post- and follow-up test (24 h after) skin surface temperatures were recorded with infrared thermography. Subjective muscle soreness and muscle fatigue were analyzed using two questionnaires. The results of the post hoc tests showed that skin temperature was statistically significantly lower in the post-tests than in the pre- and follow-up tests, but no meaningful differences existed between the pre- and follow-up tests. Asymmetric side differences were found in the post-test for the upper and lower areas of the back. Differences were also noted for the front in both the upper and lower areas. No thermographic side asymmetries were found at the pre- or follow-up measurement for either the back or the front. Our results support the potential of using thermographic skin surface temperature to monitor exercise and recovery in athletes, as well as its use in rehabilitational exercise selection.
Collapse
|
27
|
Koh D, Park J, Lee S, Kim H, Jung H, Kim I, Choi S, Park D. Assessment of sunlight exposure across industries and occupations using blood vitamin D as a biomarker. J Occup Health 2022; 64:e12318. [PMID: 35152501 PMCID: PMC8841173 DOI: 10.1002/1348-9585.12318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/18/2022] [Accepted: 02/03/2022] [Indexed: 11/12/2022] Open
Abstract
Objective Exposure to ultraviolet (UV) radiation from sunlight induces the production of essential vitamin D, whereas overexposure to sunlight leads to skin cancer. Sunlight exposure has been measured using questionnaires, dosimeters, and vitamin D levels. Several studies have measured vitamin D in the working population; however, these studies were limited to certain occupations such as farmers and construction workers. In the present study, we evaluated sunlight exposure using blood vitamin D as an exposure surrogate across industries and occupations. Methods The Korea National Health and Nutrition Examination Survey (KNHANES) is a nationwide study representing the Korean population. We analyzed data from KNHANES between 2008 and 2009. We examined the association between vitamin D levels and pertinent personal, seasonal, residential, and occupational factors. Furthermore, we developed a multiple regression model with factors other than occupational factors (industry and occupation) and obtained residual values. We computed the third quartile (Q3) of the residuals and then calculated the fractions exceeding the Q3 level for each combination of industry and occupation. Results Age, sex, body mass index, year, season, latitude, living area, living in an apartment, industry, and occupation were significantly associated with vitamin D levels. Based on the exceeding fraction, the armed forces showed the highest exceeding fraction level of 0.71. Conclusions Our results present the high exposure groups to sunlight across industries and occupations. Our results may provide a source for prioritizing occupational groups with a high risk of adverse health effects from sunlight exposure.
Collapse
Affiliation(s)
- Dong‐Hee Koh
- Department of Occupational and Environmental Medicine International St. Mary’s Hospital Catholic Kwandong University Incheon Korea
| | - Ju‐Hyun Park
- Department of Statistics Dongguk University Seoul Korea
| | - Sang‐Gil Lee
- Occupational Safety and Health Research Institute Korea Occupational Safety and Health Agency Ulsan Korea
| | - Hwan‐Cheol Kim
- Department of Occupational and Environmental Medicine Inha University Incheon Korea
| | - Hyejung Jung
- Department of Occupational and Environmental Medicine International St. Mary’s Hospital Catholic Kwandong University Incheon Korea
| | - Inah Kim
- Department of Occupational and Environmental Medicine College of Medicine Hanyang University Seoul Korea
| | - Sangjun Choi
- Department of Preventive Medicine College of Medicine The Catholic University of Korea Seoul Korea
| | - Donguk Park
- Department of Environmental Health Korea National Open University Seoul Korea
| |
Collapse
|
28
|
Spencer S, Samateh T, Wabnitz K, Mayhew S, Allen H, Bonell A. The Challenges of Working in the Heat Whilst Pregnant: Insights From Gambian Women Farmers in the Face of Climate Change. Front Public Health 2022; 10:785254. [PMID: 35237548 PMCID: PMC8883819 DOI: 10.3389/fpubh.2022.785254] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 01/17/2022] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND The expected increase in heat in The Gambia is one of the most significant health threats caused by climate change. However, little is known about the gendered dynamics of exposure and response to heat stress, including women's perceived health risks, their adaptation strategies to heat, and their perceptions of climate change. This research project aims to answer the question of whether and how pregnant farmers in The Gambia perceive and act upon occupational heat stress and its health impacts on both themselves and their unborn children, against the backdrop of current and expected climatic changes. METHOD In-depth semi-structured interviews were conducted with 12 women who practice subsistence farming and were either pregnant or had delivered within the past month in West Kiang, The Gambia. Participants were selected using purposive sampling. Translated interview transcripts were coded and qualitative thematic content analysis with an intersectional lens was used to arrive at the results. RESULTS All women who participated in the study experience significant heat stress while working outdoors during pregnancy, with symptoms often including headache, dizziness, nausea, and chills. The most common adaptive techniques included resting in the shade while working, completing their work in multiple shorter time increments, taking medicine to reduce symptoms like headache, using water to cool down, and reducing the amount of area they cultivate. Layered identities, experiences, and household power structures related to age, migration, marital situation, socioeconomic status, and supportive social relationships shaped the extent to which women were able to prevent and reduce the effects of heat exposure during their work whilst pregnant. Women who participated in this study demonstrated high awareness of climate change and offered important insights into potential values, priorities, and mechanisms to enable effective adaptation. CONCLUSION Our findings reveal many intersecting social and economic factors that shape the space within which women can make decisions and take adaptive action to reduce the impact of heat during their pregnancy. To improve the health of pregnant working women exposed to heat, these intersectionalities must be considered when supporting women to adapt their working practices and cope with heat stress.
Collapse
Affiliation(s)
- Shantelle Spencer
- Medical Research Council Unit, The Gambia at London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Tida Samateh
- Medical Research Council Unit, The Gambia at London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Katharina Wabnitz
- Chair for Public Health and Health Services Research, Institute for Medical Information Processing, Biometry and Epidemiology (IBE), Ludwig-Maximilians-Universität München, Munich, Germany
| | - Susannah Mayhew
- London School of Hygiene and Tropical Medicine, Faculty of Public Health and Policy, University of London, London, United Kingdom
| | - Haddijatou Allen
- Medical Research Council Unit, The Gambia at London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Ana Bonell
- Medical Research Council Unit, The Gambia at London School of Hygiene and Tropical Medicine, Banjul, Gambia
- Centre on Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, University of London, London, United Kingdom
| |
Collapse
|
29
|
Flouris AD, Ioannou LG, Notley SR, Kenny GP. Determinants of heat stress and strain in electrical utilities workers across North America as assessed by means of an exploratory questionnaire. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2022; 19:12-22. [PMID: 34731074 DOI: 10.1080/15459624.2021.2001475] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Previous field studies monitoring small groups of participants showed that heat stress in the electrical utilities industry may be detrimental to worker health and safety. Our aim in this study was to characterize heat stress and strain in electrical utilities workers across North America. A total of 428 workers in the power generation, transmission, and distribution industry across 16 U.S. states and 3 Canadian Provinces completed a two-part on-line questionnaire anonymously. The first part comprised 13 general questions on the employee's workplace location, role in the organization, years of experience, general duties, average work shift duration, and other job-related information. It also included two questions on self-reported heat stress. The second part consisted of the "Heat Strain Score Index" (HSSI), a validated questionnaire which evaluates heat stress at the workplace as "safe level" (score ≤13.5: worker experiences no/low heat strain), "caution level" (score 13.6 to 18.0: moderate risk for heat strain), and "danger level" (score >18.0: high risk for heat strain). In addition to the survey, we obtained meteorological data from weather stations in proximity (12.3 ± 12.2 km) to the work locations. Based on the HSSI, 32.9%, 22.3%, and 44.4% of the responders' workplaces were diagnosed as "safe level," "caution level," and "danger level," respectively. The HSSI varied significantly depending on the occupation from 4.9 ± 3.2 in contact center workforce to 19.1 ± 5.4 in mechanics (p < 0.001), and demonstrated moderate linear relationships with summertime (June, July, August) midday air temperature (r = 0.317, p < 0.001) and outdoor midday Wet-Bulb Globe Temperature (r = 0.322, p < 0.001). The highest HSSI was observed in mechanics, machine operators in line installations, line workers, electricians, and meter-readers. We conclude that electrical utilities workers experience instances of severe environmental heat stress resulting in elevated levels of heat strain, particularly when performing physically demanding tasks (e.g., manually climbing utility poles, installing lines).
Collapse
Affiliation(s)
- Andreas D Flouris
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
- Human and Environmental Physiology Research Unit, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Leonidas G Ioannou
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
| | - Sean R Notley
- Human and Environmental Physiology Research Unit, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, Canada
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| |
Collapse
|
30
|
Foster J, Smallcombe JW, Hodder S, Jay O, Flouris AD, Nybo L, Havenith G. Quantifying the impact of heat on human physical work capacity; part III: the impact of solar radiation varies with air temperature, humidity, and clothing coverage. INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 2022; 66:175-188. [PMID: 34709466 PMCID: PMC8727397 DOI: 10.1007/s00484-021-02205-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 10/05/2021] [Accepted: 10/07/2021] [Indexed: 05/03/2023]
Abstract
Heat stress decreases human physical work capacity (PWC), but the extent to which solar radiation (SOLAR) compounds this response is not well understood. This study empirically quantified how SOLAR impacts PWC in the heat, considering wide, but controlled, variations in air temperature, humidity, and clothing coverage. We also provide correction equations so PWC can be quantified outdoors using heat stress indices that do not ordinarily account for SOLAR (including the Heat Stress Index, Humidex, and Wet-Bulb Temperature). Fourteen young adult males (7 donning a work coverall, 7 with shorts and trainers) walked for 1 h at a fixed heart rate of 130 beats∙min-1, in seven combinations of air temperature (25 to 45°C) and relative humidity (20 or 80%), with and without SOLAR (800 W/m2 from solar lamps). Cumulative energy expenditure in the heat, relative to the work achieved in a cool reference condition, was used to determine PWC%. Skin temperature was the primary determinant of PWC in the heat. In dry climates with exposed skin (0.3 Clo), SOLAR caused PWC to decrease exponentially with rising air temperature, whereas work coveralls (0.9 Clo) negated this effect. In humid conditions, the SOLAR-induced reduction in PWC was consistent and linear across all levels of air temperature and clothing conditions. Wet-Bulb Globe Temperature and the Universal Thermal Climate Index represented SOLAR correctly and did not require a correction factor. For the Heat Stress Index, Humidex, and Wet-Bulb Temperature, correction factors are provided enabling forecasting of heat effects on work productivity.
Collapse
Affiliation(s)
- Josh Foster
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, LE11 3TU, UK
| | - James W Smallcombe
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, LE11 3TU, UK
- Thermal Ergonomics Laboratory, University of Sydney, Sydney, NSW, Australia
| | - Simon Hodder
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, LE11 3TU, UK
| | - Ollie Jay
- Thermal Ergonomics Laboratory, University of Sydney, Sydney, NSW, Australia
| | | | - Lars Nybo
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - George Havenith
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, LE11 3TU, UK.
| |
Collapse
|
31
|
Moyen NE, Bapat RC, Tan B, Hunt LA, Jay O, Mündel T. Accuracy of Algorithm to Non-Invasively Predict Core Body Temperature Using the Kenzen Wearable Device. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph182413126. [PMID: 34948736 PMCID: PMC8701050 DOI: 10.3390/ijerph182413126] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/30/2021] [Accepted: 12/09/2021] [Indexed: 11/16/2022]
Abstract
With climate change increasing global temperatures, more workers are exposed to hotter ambient temperatures that exacerbate risk for heat injury and illness. Continuously monitoring core body temperature (TC) can help workers avoid reaching unsafe TC. However, continuous TC measurements are currently cost-prohibitive or invasive for daily use. Here, we show that Kenzen's wearable device can accurately predict TC compared to gold standard TC measurements (rectal probe or gastrointestinal pill). Data from four different studies (n = 52 trials; 27 unique subjects; >4000 min data) were used to develop and validate Kenzen's machine learning TC algorithm, which uses subject's real-time physiological data combined with baseline anthropometric data. We show Kenzen's TC algorithm meets pre-established accuracy criteria compared to gold standard TC: mean absolute error = 0.25 °C, root mean squared error = 0.30 °C, Pearson r correlation = 0.94, standard error of the measurement = 0.18 °C, and mean bias = 0.07 °C. Overall, the Kenzen TC algorithm is accurate for a wide range of TC, environmental temperatures (13-43 °C), light to vigorous heart rate zones, and both biological sexes. To our knowledge, this is the first study demonstrating a wearable device can accurately predict TC in real-time, thus offering workers protection from heat injuries and illnesses.
Collapse
Affiliation(s)
| | | | - Beverly Tan
- Human Potential Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore;
- School of Sport, Exercise and Nutrition, Massey University, Palmerston North 4472, New Zealand;
| | - Lindsey A. Hunt
- Thermal Ergonomics Laboratory, School of Health and Science, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia; (L.A.H.); (O.J.)
| | - Ollie Jay
- Thermal Ergonomics Laboratory, School of Health and Science, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia; (L.A.H.); (O.J.)
| | - Toby Mündel
- School of Sport, Exercise and Nutrition, Massey University, Palmerston North 4472, New Zealand;
| |
Collapse
|
32
|
Morrissey MC, Brewer GJ, Williams WJ, Quinn T, Casa DJ. Impact of occupational heat stress on worker productivity and economic cost. Am J Ind Med 2021; 64:981-988. [PMID: 34590324 DOI: 10.1002/ajim.23297] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 09/12/2021] [Accepted: 09/13/2021] [Indexed: 12/16/2022]
Abstract
Heat stress is a growing concern in the occupational setting as it endangers worker health, safety, and productivity. Heat-related reductions in physical work capacity and missed workdays directly and indirectly cause productivity losses and may substantially affect the economic wellbeing of the organization. This review highlights the physiological, physical, psychological, and financial harms of heat stress on worker productivity and proposes strategies to quantify heat-related productivity losses. Heat stress produces a vicious-cycle feedback loop that result in adverse outcomes on worker health, safety, and productivity. We propose a theoretical model for implementing an occupational heat safety plan that disrupts this loop, preventing heat-related productivity losses while improving worker health and safety.
Collapse
Affiliation(s)
- Margaret C. Morrissey
- Department of Kinesiology, Korey Stringer Institute University of Connecticut Storrs Connecticut USA
| | - Gabrielle J. Brewer
- Department of Kinesiology, Korey Stringer Institute University of Connecticut Storrs Connecticut USA
| | - Warren Jon Williams
- Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH) National Personal Protective Technology Laboratory (NPPTL) Pittsburgh Pennsylvania USA
| | - Tyler Quinn
- Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH) National Personal Protective Technology Laboratory (NPPTL) Pittsburgh Pennsylvania USA
| | - Douglas J. Casa
- Department of Kinesiology, Korey Stringer Institute University of Connecticut Storrs Connecticut USA
| |
Collapse
|
33
|
Impact of a Cold Environment on the Performance of Professional Cyclists: A Pilot Study. Life (Basel) 2021; 11:life11121326. [PMID: 34947857 PMCID: PMC8704244 DOI: 10.3390/life11121326] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/22/2021] [Accepted: 11/29/2021] [Indexed: 11/29/2022] Open
Abstract
The practice of physical activity in a variable climate during the same competition is becoming more and more common due to climate change and increasingly frequent climate disturbances. The main aim of this pilot study was to understand the impact of cold ambient temperature on performance factors during a professional cycling race. Six professional athletes (age = 27 ± 2.7 years; height = 180.86 ± 5.81 cm; weight = 74.09 ± 9.11 kg; % fat mass = 8.01 ± 2.47%; maximum aerobic power (MAP) = 473 ± 26.28 W, undertook ~20 h training each week at the time of the study) participated in the Tour de la Provence under cold environmental conditions (the ambient temperature was 15.6 ± 1.4 °C with a relative humidity of 41 ± 8.5% and the normalized ambient temperature (Tawc) was 7.77 ± 2.04 °C). Body core temperature (Tco) was measured with an ingestible capsule. Heart rate (HR), power, speed, cadence and the elevation gradient were read from the cyclists’ onboard performance monitors. The interaction (multivariate analysis of variance) of the Tawc and the elevation gradient has a significant impact (F(1.5) = 32.2; p < 0.001) on the variables (cadence, power, velocity, core temperature, heart rate) and on each individual. Thus, this pilot study shows that in cold environmental conditions, the athlete’s performance was limited by weather parameters (ambient temperature associated with air velocity) and race characteristics. The interaction of Tawc and elevation gradient significantly influences thermal (Tco), physiological (HR) and performance (power, speed and cadence) factors. Therefore, it is advisable to develop warm-up, hydration and clothing strategies for competitive cycling under cold ambient conditions and to acclimatize to the cold by training in the same conditions to those that may be encountered in competition.
Collapse
|
34
|
Bonell A, Nadjm B, Samateh T, Badjie J, Perry-Thomas R, Forrest K, Prentice AM, Maxwell NS. Impact of Personal Cooling on Performance, Comfort and Heat Strain of Healthcare Workers in PPE, a Study From West Africa. Front Public Health 2021; 9:712481. [PMID: 34540787 PMCID: PMC8440920 DOI: 10.3389/fpubh.2021.712481] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 08/10/2021] [Indexed: 01/25/2023] Open
Abstract
Background: Personal protective equipment (PPE) is an essential component of safely treating suspected or confirmed SARS-CoV-2 patients. PPE acts as a barrier to heat loss, therefore increasing the risk of thermal strain which may impact on cognitive function. Healthcare workers (HCWs) need to be able to prioritize and execute complex tasks effectively to ensure patient safety. This study evaluated pre-cooling and per-cooling methods on thermal strain, thermal comfort and cognitive function during simulated emergency management of an acutely unwell patient. Methods: This randomized controlled crossover trial was run at the Clinical Services Department of the Medical Research Unit The Gambia. Each participant attended two sessions (Cool and Control) in standard PPE. Cool involved pre-cooling with an ice slurry ingestion and per-cooling by wearing an ice-vest external to PPE. Results: Twelve participants completed both sessions. There was a significant increase in tympanic temperature in Control sessions at both 1 and 2 h in PPE (p = 0.01). No significant increase was seen during Cool. Effect estimate of Cool was -0.2°C (95% CI -0.43; 0.01, p = 0.06) post 1 h and -0.28°C (95% CI -0.57; 0.02, p = 0.06) post 2 h on tympanic temperature. Cool improved thermal comfort (p < 0.001), thermal sensation (p < 0.001), and thirst (p = 0.04). No difference on cognitive function was demonstrated using multilevel modeling. Discussion: Thermal strain in HCWs wearing PPE can be safely reduced using pre- and per-cooling methods external to PPE.
Collapse
Affiliation(s)
- Ana Bonell
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, Gambia
- Centre on Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Behzad Nadjm
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Tida Samateh
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Jainaba Badjie
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Robyn Perry-Thomas
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Karen Forrest
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Andrew M. Prentice
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Neil S. Maxwell
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, United Kingdom
| |
Collapse
|