scholarly journals 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

2021 ◽  
Author(s):  
Josh Foster ◽  
James W. Smallcombe ◽  
Simon Hodder ◽  
Ollie Jay ◽  
Andreas D. Flouris ◽  
...  
Keyword(s):  
Heat Stress ◽  
Solar Radiation ◽  
Air Temperature ◽  
Work Capacity ◽  
Stress Index ◽  
Physical Work ◽  
Physical Work Capacity ◽  
Heat Effects ◽  
Heat Stress Index ◽  
The Impact

AbstractHeat 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.

scholarly journals The impact of heat on human physical work capacity; Part III: the impact of solar radiation varies with air temperature, humidity, and clothing coverage.

2021 ◽  
Author(s):  
Josh Foster ◽  
James W Smallcombe ◽  
Simon G Hodder ◽  
Andreas D Flouris ◽  
Lars Nybo ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Air Temperature ◽  
Work Productivity ◽  
Work Capacity ◽  
Physical Work ◽  
Physical Work Capacity ◽  
Adult Males ◽  
Cumulative Energy ◽  
Heat Effects ◽  
The Impact

It is well-known that heat impacts human labour/physical work capacity (PWC), but systematic evaluations of solar radiation (SOLAR) effects and the interaction with air temperature and humidity levels and clothing are lacking, as most lab-studies are conducted in semi-nude subjects without radiation or only in a single climatic condition. Due to the high relevance of SOLAR in various occupations, this study quantified how SOLAR interacts with clothing and other primary environmental factors (air temperature/humidity) of importance to determine PWC in the heat. The data allowed the development of a SOLAR correction factor for predicting PWC in major outdoor industries. Fourteen young adult males (7 wearing a standardised work coverall (0.9 Clo), 7 with shorts and trainers (0.3 Clo) walked for 1-hour at a fixed heart rate of 130 b∙min-1, in seven combinations of air temperature (25 to 45 Celsius) 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. WBGT and UTCI based prediction equations of PWC represented SOLAR correctly. For heat indices not intrinsically accounting for SOLAR, correction factors are provided enabling forecasting of heat effects on work productivity.

scholarly journals Deforestation and climate change are projected to increase heat stress risk in the Brazilian Amazon

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Beatriz Fátima Alves de Oliveira ◽  
Marcus J. Bottino ◽  
Paulo Nobre ◽  
Carlos A. Nobre
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Amazon Basin ◽  
Stress Index ◽  
Climate Change Scenarios ◽  
Stress Exposure ◽  
Extreme Risk ◽  
High Emission ◽  
Heat Stress Index ◽  
The Impact

AbstractLand use change and deforestation can influence local temperature and climate. Here we use a coupled ocean-atmosphere model to assess the impact of savannization of the Amazon Basin on the wet-bulb globe temperature heat stress index under two climate change scenarios (RCP4.5 and RCP8.5). We find that heat stress exposure due to deforestation was comparable to the effect of climate change under RCP8.5. Our findings suggest that heat stress index could exceed the human adaptation limit by 2100 under the combined effects of Amazon savannization and climate change. Moreover, we find that risk of heat stress exposure was highest in Northern Brazil and among the most socially vulnerable. We suggest that by 2100, savannization of the Amazon will lead to more than 11 million people will be exposed heat stress that poses an extreme risk to human health under a high emission scenario.

scholarly journals The Influence of Microclimatic Ammonia Changes in Closed House on Broiler’s Performance in Dry Season

2019 ◽  
Vol 20 (2) ◽  
pp. 125
Author(s):  
Ica Putri Angkeke ◽  
Teysar Adi Sarjana ◽  
Edjeng Suprijatna
Keyword(s):  
Body Weight ◽  
Heat Stress ◽  
Body Weight Gain ◽  
Dry Season ◽  
Feed Consumption ◽  
Stress Index ◽  
Initial Weight ◽  
Feed Cost ◽  
Heat Stress Index ◽  
The Impact

This research aims at investigating the impact of microclimatic ammonia change on Broiler’s  performance in closed house during dry season. Seven hundred and twenty broiler’s with their initial weight of 49.29 ± 1.13 grams are kept in a 60 x 12 m2 cage.The research consists of 4 treatments and 6 experiment units. The microclimatic ammonia change is measured at a distance of 0, ¼, ½, and ¾ of closed house’s length from the inlet. The parameters observed are feed consumption, body weight gain (BWG), feed convertion ratio (FCR), performance index (PI) and Income Over Feed Cost (IOFC). The obtained data are subjected to analysis of variance and several data related to microclimatic ammonia and heat stress index (HSI) are also calculted for their correlation to find out their correlation with the broiler’s’s performance. The research results indicate that the microclimatic ammonia change significantly reduces Broiler’s performance. This is shown by the significant increase of FCR value, decrease of feed consumption, BWG, PI and IOFC (P≤0.05) starting from a distance of ¼ of cage length from the inlet. The correlation analysis result shows a negative, significant correlation between performance with ammonia, while HSI does not show any correlation with the observed parameters. The conclusion of this research is that the increase in microclimatic ammonia at increasingly further distance from the inlet decreases Broiler’s  performance in dry season.

scholarly journals Individual Responses to Heat Stress: Implications for Hyperthermia and Physical Work Capacity

2020 ◽  
Vol 11 ◽  
Author(s):  
Josh Foster ◽  
Simon G. Hodder ◽  
Alex B. Lloyd ◽  
George Havenith
Keyword(s):  
Heat Stress ◽  
Work Capacity ◽  
Physical Work ◽  
Physical Work Capacity

scholarly journals Physical Work Capacity of Young Greco-Roman Wrestlers on the Background of their Somatic Development

2018 ◽  
Vol 3 (57) ◽  
Author(s):  
Wladyslaw Jagiello ◽  
Wlodzimierz Tkaczuk
Keyword(s):  
Body Mass ◽  
Work Capacity ◽  
High Rate ◽  
Physical Work ◽  
Physical Work Capacity ◽  
Mean Values ◽  
Functional Changes ◽  
Somatic Development ◽  
Greco Roman ◽  
The Impact

On the basis of studies of 210 Greco-Roman wrestlers aged 11—18 the impact of training loads and sports selectionin the above sports event upon physical development and general work capacity of young athletes have beendetermined.Besides, age dynamics of changes of the major somatic indices (body length and mass) as well as physical workcapacity at the stage of initial and basic sports preparation has been determined.The studies have resulted in the determination of specific for Greco-Roman wrestlers changes in the examined indicesand development of evaluation scale of general physical work capacity.On the basis of findings we may conclude that Greco-Roman wrestling has a positive influence on developing body.In most cases mean values of examined somatic indices exceed those of children not engaged in sports as well aschildren practising other sports events. This sports event may be considered as a good means stimulating physicaldevelopment of children and youth.The age of 11—15 has turned to be the period of the greatest structural and functional changes in their ontogenesis.During this period the greatest rate of development is peculiar for body mass and height (11—12 years — mass 16%,length 6%; 14—15 years — mass 25%, length 6%), whereas development of work capacity occurs evenly. Along withrelative stabilization of the rate of body mass and height development beginning from the age of 16 high rate of workcapacity development is observed.Keywords: Greco-Roman wrestling, somatic development, performance abilities.

scholarly journals Quantifying the impact of heat on human physical work capacity; part II: the observed interaction of air velocity with temperature, humidity, sweat rate, and clothing is not captured by most heat stress indices

2021 ◽  
Author(s):  
Josh Foster ◽  
James W. Smallcombe ◽  
Simon Hodder ◽  
Ollie Jay ◽  
Andreas D. Flouris ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Empirical Study ◽  
Air Temperature ◽  
Physical Work ◽  
Climate Index ◽  
Physical Work Capacity ◽  
Air Movement ◽  
Wide Range ◽  
Temperature And Humidity ◽  
The Impact

Abstract Increasing air movement can alleviate or exacerbate occupational heat strain, but the impact is not well defined across a wide range of hot environments, with different clothing levels. Therefore, we combined a large empirical study with a physical model of human heat transfer to determine the climates where increased air movement (with electric fans) provides effective body cooling. The model allowed us to generate practical advice using a high-resolution matrix of temperature and humidity. The empirical study involved a total of 300 1-h work trials in a variety of environments (35, 40, 45, and 50 °C, with 20 up to 80% relative humidity) with and without simulated wind (3.5 vs 0.2 m∙s−1), and wearing either minimal clothing or a full body work coverall. Our data provides compelling evidence that the impact of fans is strongly determined by air temperature and humidity. When air temperature is ≥ 35 °C, fans are ineffective and potentially harmful when relative humidity is below 50%. Our simulated data also show the climates where high wind/fans are beneficial or harmful, considering heat acclimation, age, and wind speed. Using unified weather indices, the impact of air movement is well captured by the universal thermal climate index, but not by wet-bulb globe temperature and aspirated wet-bulb temperature. Overall, the data from this study can inform new guidance for major public and occupational health agencies, potentially maintaining health and productivity in a warming climate.

Relationship Between Physical Activity and the Objective Indicators of Physical Capital for Women in Fitness

2015 ◽  
Vol 6 (2) ◽  
pp. 21-35
Author(s):  
Aleksandra Čuprika ◽  
Andra Fernāte ◽  
Leonīds Čupriks
Keyword(s):  
Physical Activity ◽  
Body Composition ◽  
Physical Fitness ◽  
Functional State ◽  
Physical Capital ◽  
Work Capacity ◽  
Physical Work ◽  
Physical Work Capacity ◽  
The Impact ◽  
Objective Indicators

Abstract As it is mentioned in the action direction Healthy and Workable Individual of the National Development Plan of Latvia 2012 –2020: 30% of all the dead in Latvia have lost their life at the age of being able to work. The main causes of death rate are different diseases (cardio-vascular a.o.), as well as outer death causes (injuries) (Pudule et al, 2012; Štale et al, 2013). Only 8% of the EU and 6% of the Latvian population regularly perform moderate and very difficult physical activity (PA) (Eurobarometer, 2013). Therefore it is necessary to implement purposeful and effective health promoting and risk limiting events to develop the physical capital of one. The understanding of the impact of physical activity on one’s physical capital is not well explored in the previous studies (Hutson, 2012; Maguire, 2008; Goldenberg, 2003; Hedblom, 2009). Therefore, the aim of the study is to determine the relationship between PA and the objective indicators of physical capital for women in fitness. In the study voluntarily participated 33 women (30±4.1 years) from 2 fitness clubs in Riga. In order to determine the respondents’ objective indicators of physical capital were applied: bioimpedance method (TANITA SC330, Japan, 89/336/EC), heart rate variability analysis data processing software ‘Omega’, complex load test with expiratory gas analysis (VIASYS Healthcare GMBH, Germany) and Eirofit tests for adults. In order to determine the level of PA the IPAQ (Craig et al, 2003) short version in Latvian (Kaupuzs & Larins, 2010) was used. Descriptive and inferential statistics were made (SPSS ver.18.0). Several moderately close (0.5<|rs|<0.69; p<0.01) and close correlations (0.7<|rs|<0.99; p<0.01) are determined between the level of PA and indicators of body composition, physical work capacity, physical fitness and functional state of the body. The level of PA has a positive impact on the objective indicators of physical capital. The more physically active the respondent is, the better physical fitness, higher work capacity, better the indicators of his body composition are and better functional state.

scholarly journals Tailored WBGT as a heat stress index to assess the direct solar radiation effect on indoor thermal comfort

2021 ◽  
Vol 242 ◽  
pp. 110974
Author(s):  
Shayan Mirzabeigi ◽  
Behrooz Khalili Nasr ◽  
Andrea Giovanni Mainini ◽  
Juan Diego Blanco Cadena ◽  
Gabriele Lobaccaro
Keyword(s):  
Heat Stress ◽  
Solar Radiation ◽  
Thermal Comfort ◽  
Radiation Effect ◽  
Direct Solar Radiation ◽  
Stress Index ◽  
Indoor Thermal Comfort ◽  
Heat Stress Index

scholarly journals An advanced empirical model for quantifying the impact of heat and climate change on human physical work capacity

2021 ◽  
Author(s):  
Josh Foster ◽  
James W. Smallcombe ◽  
Simon Hodder ◽  
Ollie Jay ◽  
Andreas D. Flouris ◽  
...  
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Skin Temperature ◽  
Work Capacity ◽  
Extreme Heat ◽  
Future Climate Change ◽  
Physical Work ◽  
Climate Change Scenarios ◽  
Physical Work Capacity ◽  
Mild Heat

AbstractOccupational heat stress directly hampers physical work capacity (PWC), with large economic consequences for industries and regions vulnerable to global warming. Accurately quantifying PWC is essential for forecasting impacts of different climate change scenarios, but the current state of knowledge is limited, leading to potential underestimations in mild heat, and overestimations in extreme heat. We therefore developed advanced empirical equations for PWC based on 338 work sessions in climatic chambers (low air movement, no solar radiation) spanning mild to extreme heat stress. Equations for PWC are available based on air temperature and humidity, for a suite of heat stress assessment metrics, and mean skin temperature. Our models are highly sensitive to mild heat and to our knowledge are the first to include empirical data across the full range of warm and hot environments possible with future climate change across the world. Using wet bulb globe temperature (WBGT) as an example, we noted 10% reductions in PWC at mild heat stress (WBGT = 18°C) and reductions of 78% in the most extreme conditions (WBGT = 40°C). Of the different heat stress indices available, the heat index was the best predictor of group level PWC (R2 = 0.96) but can only be applied in shaded conditions. The skin temperature, but not internal/core temperature, was a strong predictor of PWC (R2 = 0.88), thermal sensation (R2 = 0.84), and thermal comfort (R2 = 0.73). The models presented apply to occupational workloads and can be used in climate projection models to predict economic and social consequences of climate change.

scholarly journals Analysis of Mental and Physical Fatigue Risk Factors in Utility Unit of Petrochemical Company

2020 ◽  
Vol 9 (1) ◽  
pp. 21
Author(s):  
Bian Shabri Putri Irwanto
Keyword(s):  
Risk Factors ◽  
Heat Stress ◽  
Mental Fatigue ◽  
Stress Index ◽  
Physical Work ◽  
Physical Fatigue ◽  
Mental Work ◽  
Cross Sectional ◽  
Work Duration ◽  
Heat Stress Index

Introduction: Work exhaustion defined as a tired feeling felt by workers with different symptoms in each individual. In this study work fatigue was divided into two types, namely physical work fatigue and mental work fatigue. This study aims to determine risk factors of physical and mental fatigue on utility unit PT. Trans Pacific Petrochemical Indotama (TPPI) which produces petroleum or gas, as well as the chemical BTX. Methods: This research was an observational study with a cross-sectional method. Based on the problem characteristic and data analysis, this study belongs to analytical research. Data were collected by interview, questionnaires, measurement, and observations. The population is 36 workers and the sample size of this study is 33 respondents from utility unit workers. The sampling technique used simple random sampling. The variables in this study were age, years of service, work duration, workload, heat stress index, responsibility, and support from company’s head. Results: Showed that factors associated with physical and mental fatigue are the age, workloads, work duration, and heat stress index. Conclusion: Physical fatigue and mental fatigue had correlation with age, workloads, work time, and heat stress index. The higher age, workload, work duration, and heat stress index, it will increasingly cause physical and mental fatigue faster and harder.Keywords: fatigue risk factors, mental fatigue work, physical fatigue work

Sign in / Sign up

Export Citation Format

Share Document