Cognitive Performance During Night Work in the Cold

Objective: The objective of this study was to investigate how night work at low ambient temperatures affects cognitive performance (short-term memory and reaction time), skin- and core temperature, thermal comfort, sleepiness, and cortisol. We hypothesized that cognitive performance is reduced at night compared with daytime and worsened when exposed to low ambient temperatures. Method: Eleven male subjects were recruited to perform three tests in a climatic chamber at night and daytime: Night –2°C, Night 23°C and Day 23°C. Each test lasted 6 h. Cognitive performance (short-term memory and reaction time), skin- and core temperature, thermal sensation and comfort, cortisol levels and sleepiness were measured during the tests. Results: A lower mean skin temperature and corresponding lower thermal sensation were observed at Night –2°C compared to Day 23°C and Night 23°C. Night work caused increased sleepiness and lower cortisol levels, but was not affected by changes in ambient temperatures, thermal comfort, or skin temperatures. There was no effect of either day/night work nor ambient temperature on the short-term memory or reaction time test. Conclusion: Lower skin- and core temperature were observed at night when exposed to low ambient temperature (–2°C), but there was no effect on short-term memory or reaction time. Increased sleepiness and lower cortisol levels were observed at night compared to daytime and was not influenced by low ambient temperature at night. The result from this study suggests that cognitive performance (short-term memory and reaction time) is not adversely affected by night work when exposed to low ambient temperatures if adequate protective clothing is worn.publishedVersio

Work strain and thermophysiological responses in Norwegian fish farming — a field study

Fish farming is considered as a physical demanding occupation, including work operations with high workloads and awkward work positions for prolonged periods of time. Combined with potential challenging environmental conditions, these factors may negatively affect work performance, comfort and health. This study aimed to explore work strain and thermophysiological responses in Norwegian fish farming. Fourteen workers (age 35 ± 15 yrs) from four fish farms participated in the field studies, and measurements of heart rate (HR), core- and skin temperatures were registered continuously during a work shift. Questions about subjective thermal sensation and comfort were answered. This study has shown that workers at fish farms are periodically exposed to high or low levels of work strain, where the high workloads are manifested as increased core temperature and HR when working. The results are expected to give a better understanding of work strain and environmental challenges during fish farm operations.publishedVersio

Heat tolerance during uncompensable heat stress in men and women wearing firefighter personal protective equipment

Firefighters run a risk of heat strain during occupational tasks. The number of female firefighters has been increasing, but research relevant to this group is still scarce. We aimed to investigate whether there are any sex differences in heat tolerance or physiological responses during uncompensable heat stress while wearing firefighter personal protective equipment. Twelve female (28 ± 7 years, 66 ± 5 kg, 51.7 ± 4.7 mL kg−1 min−1) and 12 male (27 ± 7 years, 83 ± 8 kg, 58.8 ± 7.5 mL kg−1 min−1) participants performed walking (maximum of 60 min) at 6W·kg−1, 40 °C, and 14% relative humidity. No differences were observed between groups in heat tolerance, rectal temperature, heart rate, percent body mass loss, thermal sensation, and rate of perceived exertion. Thus, when personnel are selected using gender-neutral physical employment standards, sex is not an independent factor influencing heat tolerance when wearing firefighter personal protective equipment during uncompensable heat stress.publishedVersio

Sweat responses during inactive recovery after high-intensity running in hot, dry and humid conditions

This study investigated the relationship between high (85%) and low (19%) relative humidity (RH) and sweat rate during inactive recovery after high-intensity work in a hot environment (30 °C). Ten male subjects performed two 20-minute run trials at 68 ± 4 % of maximal oxygen consumption (VO2max) followed by 36 minutes of inactive recovery in standing position. Regional sweat rate (RSR) was measured on the forearm and mid-central back by technical absorbent pads, and gross sweat loss was estimated from change in body weight. Core temperature (Tc) and six skin temperatures for calculation of mean skin temperature (Ts) were measured continuously together with heart rate (HR) during running and recovery. Results show that RSR was significantly (p<0.05) higher for both arm and back during running and inactive recovery in 85% RH compared to 19% RH. The highest sweat rate was observed on the back during the last five minutes of running in 85% RH (1387 g·m-2·h-1) compared to 19% RH (886 g·m-2·h-1). Gross sweat loss (GSL) was significantly higher in 85% RH (796 ± 414 g·h-1) than 19% RH (489 ± 140 g·h-1) conditions (p=0.010). Tc continued to increase for three and seven minutes post-exercise in 19% RH and 85% RH, respectively and Ts was significantly higher in 85% RH than in 19% RH (p<0.05). HR was 11 bpm higher after running in 85% RH compared to 19% RH (p=0.001). In conclusion, RSR and GSL, as well as HR, Tc and Ts was higher during post-exercise recovery in 30°C and 85% RH than in 30°C and 19% RH. This study emphasises the importance of including the effect of relative humidity in assessment of both exercise and recovery.The study was funded by the Research Council of Norway (grant no. 227107/H20)

Physical activity levels among offshore fleet seafarers

Advanced technology has rationalized and simplified operations at sea; however, this development has resulted in higher demands being made of the operator. Good health has become an important safety factor: a good state of health is crucial both to preventing strain injuries and to ensuring alertness and optimal performance at work. Physical activity is a powerful preventive &#8220;medicine&#8221; for the maintenance of good health and the prevention of overweight and musculoskeletal disorders. The aim of this paper is to analyse the habits and preferences of seafarers with regard to physical activity. Individual health factors, physical activity levels and work-related problems were surveyed on board vessels in a Norwegian shipping company. A questionnaire was completed by 577 seafarers. The results demonstrated that 70% of the respondents exercised twice or more times per week when at home, whereas only 39% exercised on board. Twenty per cent never exercised on board, and 5% never exercised at home. Walking is preferred by 70% of seafarers at home, as well as cycling and doing manual work. On board, walking, cycling and manual work are the most common types of exercise. Strength training is more often preferred on board than at home. Preventing illness and injury, a pleasant and inviting gym on board, and keeping weight under control are the three most important motivational factors. The results show that there is significant potential for improving and organising exercise-related activities on board as a means of maintaining good health and improving the performance of seafarers

Physiological and perceptual strain of firefighters during graded exercise to exhaustion at 40 and 10°C

Purpose. To study whether perceptual identification should be included as a measure to evaluate physiological stress. Methods. Physiological variables oxygen uptake (VO2), ventilation, heart rate, blood lactate concentration, rectal temperature (Trec) and mean skin temperature, and perceptual variables rate of perceived exertion, thermal sensation and time to exhaustion, were measured at submaximal and maximal intensities during graded exercise on a treadmill to exhaustion in 12 firefighters wearing protective clothing and extra mass at 40 and 10 °C. Physiological strain index (PhSI) and perceptual strain index (PeSI) were calculated. Results. Apart from Trec, all physiological and perceptual variables were higher at submaximal intensities of 40 °C. Time to exhaustion was 16% shorter and the corresponding VO2 was reduced by 7% in the heat. A high correlation (r = 89) between PhSI and PeSI was found at both temperatures. PeSI scores were equal to PhSI at both ambient temperatures, except at the two highest intensities in the heat, where PeSI was higher. Conclusions. These findings support use of perceptual identification to evaluate physiological stress. However, at very high intensities under hot conditions the perceptual strain was estimated higher than the physiological strain. More precise indexes are needed to include perceptual measures in safety standard.publishedVersio

Thermophysiological responses and work strain in fishermen on deep-sea fishing vessels

Background: Fishermen working on deep-sea vessels in the Barents and Norwegian Sea are exposed to low air temperatures, strong winds, high humidity, rain, snow and work at different intensities. Few studies have investigated the effect of environmental work factors on the physiology of this occupational group. The aim of the study was to investigate work strain and thermophysiological responses of fishermen on the trawl and factory decks of deep-sea vessels. Materials and methods: Twenty-five professional male fishermen (age 39 ± 13 years) were recruited to the study which was performed on three trawlers in the Norwegian Sea in April, June and August 2014. During a six-hour shift, heart rate (HR), core (Tc) and mean skin (Ts) temperatures were recorded, and questions about subjective thermal sensation and comfort were answered. Results: Short periods of hard (above 86% of HRmax) work raised Tc by 0.8°C to 37.8°C and decreased Ts by 2.3°C to 29.8°C during work on the trawl deck, and subjects reported being warm and sweaty. On the factory deck long periods of fairly light (between 52% and 66% HRmax) work, Tc of 37.4°C and Ts of 30.9°C were measured. Conclusions: Fishermen experience intermittent periods of heavy work on the trawl deck shown with elevated core temperature and HR. Work on the factory deck includes long periods of repetitive work with light to moderate work strain. A better understanding of work strain and environmental challenges during work on Norwegian deep-sea vessels will help identify exposure risks during work in the cold and heat.

Safer work clothing for fishermen

The fisherman&#8217;s work environment consists of many potential risks. A study of occupational accidents in the Norwegian fishing industry in the nine-year period from 1998 to 2006 shows that more than 3/4 of the deaths were caused by loss of fishing vessel or man-overboard accidents. Furthermore, the greatest risk of drowning is found in the smallest fleet. The aim of our project was to develop safer work clothing and through this contribute to a reduction in work accidents and injuries in the fishing fleet. We considered that it is possible to produce protective work clothing that satisfies a specification of requirements covering the fishermen&#8217;s needs for protection and comfort during work. An end user-centred process including twenty-three personal interviews and a questionnaire was used to clarify the fishermen&#8217;s needs and wishes before detailed design and product development. We identified an overview of all the fishermen&#8217;s needs for protection during work, and produced a prioritised list of functional requirements for the clothing. The results show that the clothing previously preferred by fishermen does not satisfy all the users&#8217; demands for safety, functionality and comfort. These demands have been taken into consideration when designing improved work clothing for the fishing fleet. A selected number of prototypes were developed on the basis of the established specification of requirements. The prototypes were evaluated according to the users&#8217; requirements through tests in SINTEF&#8217;s Work Physiology Laboratory and on board fishing vessels. The results demonstrate that the new protective clothing satisfies the fishermen&#8217;s requirements

Velferdsteknologi for økt fysisk aktivitet. Forebygging av sykdom og økt livskvalitet hos personer med kols. Kvalifiseringsprosjekt.

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