探花精选

Environmental physiology

The division of Environmental Physiology investigates the influence of environmental factors, such as gravity, ambient pressure and temperature, on physiological functions in humans.

Part of the:

Human performance in extreme environments

Environmental physiology is commonly associated with human performance in extreme environments, such as aviation, diving and human activities in polar and desert climates. However, the physiological functions challenged under such conditions typically play fundamental roles even in more routine and daily-life activities. Thus, interventions used in environmental physiology research include different types of physical loading as means to tease out mechanisms underlying normal physiological functions.

The Environmental Physiology Division is situated Solna where it shares personnel and laboratory facilities with the

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Gunnar Schulte

Acting group leader
+46852487933

Publications

All publications from group members

  • Doctoral thesis: 2025
    Brink A
  • Article: AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY, INTEGRATIVE AND COMPARATIVE PHYSIOLOGY. 2025
    Eiken O; Keramidas ME; Elia A; Bowes HM; K枚leg氓rd R
  • Doctoral thesis: 2025
    Moes M
  • Thesis / dissertation: KAROLINSKA INSTITUTET. 2025
    Moes M
  • Review: EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY. 2025;:1-17
    Elia A; Lemaitre F
  • Article: AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY, INTEGRATIVE AND COMPARATIVE PHYSIOLOGY. 2025;328(4):R433-R446
    Moes MI; Elia A; Eiken O; Keramidas ME
  • Preprint: BIORXIV. 2025
    Moes MI; Elia A; Eiken O; Keramidas ME
  • Article: MILITARY MEDICINE. 2025;190(1-2):e211-e220
    Norrbrand L; Johannesson B; Gronkvist M
  • Article: CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING. 2025;45(1):e12911
    Gottschalk F; Gennser M; Eiken O; Elia A
  • Article: PHYSIOLOGICAL REPORTS. 2024;12(23):e70147
    Gottschalk F; Gennser M; Gunther M; Eiken O; Elia A
  • Letter: INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH. 2024;21(11):1486
    Pollock NW; Gennser M; Blogg SL; Risberg J
  • Article: JOURNAL OF NEUROPHYSIOLOGY. 2024;132(5):1571-1576
    Keramidas ME; Kolegard R; Brink A; Eiken O
  • Article: JOURNAL OF THERMAL BIOLOGY. 2024;125:104004
    Kolegard R; Norrbrand L; Eiken O; Keramidas ME
  • Article: JOURNAL OF NEUROPHYSIOLOGY. 2024;132(3):710-721
    Brink A; Keramidas ME; Bergsten E; Eiken O
  • Article: EXPERIMENTAL PHYSIOLOGY. 2024;109(9):1517-1528
    Gottschalk F; Gennser M; Guenther M; Eiken O; Elia A
  • Article: INJURY-INTERNATIONAL JOURNAL OF THE CARE OF THE INJURED. 2024;55(8):111702
    Holtenius J; Mosfeldt M; Enocson A; Berg HE
  • Article: RESPIRATORY PHYSIOLOGY & NEUROBIOLOGY. 2024;323:104228
    Elia A; Barlow MJ; Lees MJ; Petri G; Keramidas ME
  • Article: AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY, INTEGRATIVE AND COMPARATIVE PHYSIOLOGY. 2024;326(4):R319-R329
    Elia A; Gennser M; Eiken O; Keramidas ME
  • Article: EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY. 2024;124(4):1253-1258
    Keramidas ME; Kolegard R; Elia A; Skoldefors H; Eiken O
  • Review: SPORTS MEDICINE. 2024;54(3):541-556
    Beato M; de Keijzer KL; Munoz-Lopez A; Raya-Gonzalez J; Pozzo M; Alkner BA; Dello Iacono A; Vicens-Bordas J; Coratella G; Maroto-Izquierdo S; Gonzalo-Skok O; McErlain-Naylor SA; Martin-Rivera F; Hernandez-Davo JL; Arrones LS; Sabido R; de Hoyo M; Fernandez-Gonzalo R; Norrbrand L
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Staff and contact

Group leader

All members of the group

Visiting address

Berzelius v盲g 13, Solna, 171 65 Solna

Research activities

Research at the Environmental Physiology commonly concerns 探花精选 and physiological problems that may occur in military settings, and the group is tasked to provide expert advice to the Swedish Armed Forces regarding physical load or risk for physical/探花精选 injuries in humans. Accordingly, the research is to a large extent funded by grants from the Armed Forces. The research activities may be described by three main projects, which, in turn, consist of several minor projects:

In certain conditions, humans are requested to perform hard physical work in extreme climates or at high altitudes. The project investigates physiological responses during exercise in hot climates, particulary in individuals wearing airtight clothing and carrying heavy equipment, for instance military soldiers or fire fighters. In addition, the project investigates physiological responses to cooling of the body core (hypothermia) and peripheral regions. A current focus of the project is on the interaction between factors that per se increase the risk of central or peripheral cooling during cold exposure. Examples of such factors are hypoxia, physical fatigue and sleep depravation.

Barophysiology concerns effects on healthy humans as exerted by changes in the ambient pressure. Substantial changes in ambient pressure are induced upon ascent to high altitude or during diving. All living organisms are affected by hydrostatic pressure changes but, save for during extreme deep diving, effects induced by hydrostatic pressure changes per se are minute in comparison with effects induced by changes in the partial pressures of the breathing-gas components, either secondary to the changed ambient pressure or caused by introducing artificial breathing-gas mixtures. Thus, to a large extent, barophysiology concerns the effects of different gases on physiological responses in humans. Since humans cannot remain immersed more than a few minutes without breathing gas supply, a large portion of the research is focused on the interplay between the human and his/her breathing apparatus.

Gas mixtures and decompression tables

Within this project we develop and test decompression tables for breathing gases other than air (nitrox, trimix), to meet requests from the Swedish Navy. In addition, we conduct experiments aimed at increasing our understanding of the mechanisms underlying decompression sickness. The work includes both computer simulations and tests on healthy human subjects.

Physiology-based adjustments of breathing apparatuses

This project concerns investigations on the effects of breathing apparatuses on human respiratory functions, as well as techniques for surveillance and testing of oxygen dosage whilst using closed-circuit breathing apparatuses.

High-altitude physiology and hypoxia

Within this project we conduct investigations of the effects on physiological and cognitive functions of reduced partial pressures of oxygen and of high-altitude exposures. The project also investigates factors affecting decompression sickness in conjunction with flying aircraft with low cabin pressures.

Research in Aerospace Physiology comprises three projects: Spatial disorientation, Increased gravitoinertial load, Weightlessness.

Spatial disorientation

Spatial disorientation is the single most common cause of serious aircraft mishaps. Spatial disorientation develops during flying because visual references are commonly lacking and because the vestibular system is incapable of correctly detecting certain movements under conditions where the gravitoinertial force vector deviates from normal (1 G). We investigate how complex stimulation of the vestibular system in a centrifuge and/or aircraft affects an individual鈥檚 spatial orientation.

Increased gravitoinertial load

Pilots flying high-performance aircraft may be exposed to gravitoinertial loads as high as 9 times the gravity vector (9 G), which results in considerable strain on several organ systems. For instance, to maintain adequate arterial pressure at the level of the head while exposed to 9G in the head-to-foot direction, arterial pressure at heart level must be increased threefold from normal values. This can be achieved by pressurizing both the pilot鈥檚 anti-G suit and his/her breathing gas, but also by means of blood-pressure increasing muscular straining maneuvers performed by the pilot. The project investigates physiological responses to increased G load and develops G-protective garments/techniques.

Weightlessness

Several of the physiological adaptations to weightlessness may be induced by means of ground-based (1 G) simulation models, of which prolonged, sustained recumbency (bed rest), in the horizontal or slightly head-down position, is the most common. The project investigates physiological responses - cardiovascular, musculoskeletal, metabolic - to sustained bed rest. Such experiments are typically conducted within the frame of a multinational collaboration. Brief exposures to weightlessness can be induced by controlled free fall in aircraft, commonly termed parabolic flight. The environmental physiology group uses also this technique to study physiological responses to weightlessness.

Military personnel perform many physically demanding tasks in their daily work. Within this project, the physical and physiological demands of different wartime positions are evaluated by studying their work in the field. One aim of the project is to describe the physical capacities needed for military personnel in different wartime positions, i.e. to set the required physical standard.

Experimental facilities

To a large extent, the equipment/facilities used at the Division of Environmental Physiology has been developed to cope with physiological problems that humans encounter during flying or diving.

Centrifuges

The gondola centrifuge in Solna, which at a peripheral speed of 117 km/h generates a centrifugal force fifteen times higher than the gravity force vector (15 G), was constructed because of the great number of military aircraft accidents induced by pilot loosing consciousness during advanced flying. In the centrifuge pilots could practice techniques to maintain adequate arterial pressure in the brain during exposure to high G loads. The centrifuge is, however, mainly used for research and development, for instance for development of G-protective equipment and for studies concerning basic physiology, e.g. circulatory, respiratory and vestibular functions.

The Division of Environmental Physiology conducts experimental studies also in the human-use centrifuge at Malmsl盲tt close to Link枚ping. With a radius of 9.1 m (from the center of rotation to the center of the gondola) and a main engine weighing 90,000 kg this centrifuge has a capacity to accelerate to a peripheral speed of 150 km/h within a second. The gondola is equipped with one of the worlds most advanced flight simulators, termed 鈥淒ynamic Flight Simulator, DFS鈥, allowing the pilot/test subject to "fly" high-performance aircraft in a virtual surrounding whilst controling the G-force in the head-seat-direction by simulating turns with varying radius and at different velocities. The research conducted in this facility predominantly deals with risk factors encountered during military operations in high-performance aircraft and in helicopters, for instance G-induced loss of consciousness and spatial disorientation. Equipped with separate gimbal engines, the gondola can move (roll and pitch) irrespective of the resulting gravitoinertial vector, offering unique possibilities of investigating how human spatial orientation is governed by the different components of the vestibular system.

Pressure chambers and immersion pools

The predominant tools used to investigate the effects of changed ambient pressure are hyper- and hypobaric chambers. At the laboratory in Solna, the Environmental Physiology group has both a hypobaric chamber, in which high-altitude exposures (up to >20 000 masl) are simulated, and a hyperbaric chamber, in which diving is simulated (150 m Sea water). The Environmental Physiology group has a close collaboration with the Swedish Navy and hence has access to a swim flume, indoor pools and a free-escape tower located at the Diving and Naval Medicine Center (DNC) in Karlskrona as well as the large hyperbaric facility.

  • M. I. Moes et al., American Journal of Physiology. Regulatory Integrative and Comparative Physiology, vol. 326, no. 3, pp. R197-R209, 2024.
  • M. Beato et al., Sports Medicine, vol. 54, no. 3, pp. 541-556, 2024.
  • M. Beato et al., in European College of Sport Science 2024, Glasgow, UK, 2-5 July 2024, 2024.
  • A. Elia et al., American Journal of Physiology. Regulatory Integrative and Comparative Physiology, vol. 326, pp. R319-R329, 2024.
  • A. Brink et al., Perception, vol. 53, no. 2, pp. 75-92, 2024.
  • L. Norrbrand, B. Johannesson and M. Gr枚nkvist, Military medicine, 2024.
  • M. E. Keramidas et al., European Journal of Applied Physiology, vol. 124, no. 4, pp. 1253-1258, 2024.
  • A. Elia et al., Respiratory Physiology & Neurobiology, vol. 323, 2024.
  • P. Ferentinos et al., Aging Clinical and Experimental Research, vol. 35, pp. S558-S558, 2023.
  • O. Eiken et al., European Journal of Applied Physiology, 2023.
  • F. Gottschalk et al., European Journal of Applied Physiology, vol. 123, no. 9, pp. 2001-2011, 2023.
  • L. Norrbrand et al., in The 6th International Congress on Soldiers Physical Performance, London, UK, 12 鈥 14 September 2023, 2023.
  • T. Ispoglou et al., Clinical Case Reports, vol. 11, no. 6, 2023.
  • M. E. Keramidas et al., American Journal of Physiology. Regulatory Integrative and Comparative Physiology, vol. 325, no. 1, pp. R21-R30, 2023.
  • L. Norrbrand et al., Military medicine, vol. 188, no. 9-10, pp. e3118-e3126, 2023.
  • M. Sj枚berg et al., Sports Biomechanics, vol. 22, no. 6, pp. 767-783, 2023.
  • M. Sj枚berg et al., Journal of Strength and Conditioning Research, vol. 37, no. 1, pp. 27-34, 2023.
  • L. Norrbrand, in Cold Weather Operation Conference 2023, Hamar, Norway, 14鈥16 November 2023, 2023.
  • M. Moes et al., Journal of applied physiology, vol. 135, no. 3, pp. 631-641, 2023.
  • M. D. Koskolou et al., Physiologia, vol. 3, no. 2, pp. 247-258, 2023.
  • A. Tribukait et al., Journal of Vestibular Research-Equilibrium & Orientation, vol. 33, no. 1, pp. 1-19, 2023.
  • M. E. Keramidas et al., American Journal of Physiology. Regulatory Integrative and Comparative Physiology, vol. 323, no. 1, pp. R1-R15, 2022.
  • J. Van Cutsem et al., Frontiers in Neuroscience, vol. 16, 2022.
  • L. Norrbrand, in Swedish Society of Biomechanics meeting 2022, 2022.
  • A. Elia et al., Scandinavian Journal of Medicine and Science in Sports, vol. 32, no. 1, pp. 233-241, 2022.
  • M. J. Lees et al., American Journal of Physiology. Endocrinology and Metabolism, vol. 322, no. 6, pp. E551-E555, 2022.
  • E. Rosa et al., Military Psychology, vol. 34, no. 2, pp. 224-236, 2022.
  • O. Eiken et al., European Journal of Applied Physiology, 2022.
  • I. B. Mekjavic et al., Frontiers in Physiology, vol. 12, 2022.
  • O. Eiken et al., American Journal of Physiology. Regulatory Integrative and Comparative Physiology, vol. 322, no. 6, pp. R597-R608, 2022.
  • A. Elia et al., Aerospace Medicine and Human Performance, vol. 93, no. 1, pp. 54-57, 2022.
  • R. 脜nell et al., Aerospace Medicine and Human Performance, vol. 93, no. 1, pp. 46-49, 2022.
  • L. Norrbrand et al., Military medicine, vol. 188, no. 7-8, pp. e2010-e2017, 2022.
  • L. Norrbrand, in European College of Sport Science ECSS 2022, Sevilla, Spain, 30 Aug - 02 Sep 2022, 2022.
  • P. Lindholm et al., Undersea & Hyperbaric Medicine, vol. 49, no. 3, pp. 367-372, 2022.
  • A. Ros茅n et al., European Journal of Applied Physiology, vol. 122, no. 4, pp. 993-1005, 2022.
  • A. Ros茅n et al., European Journal of Applied Physiology, vol. 122, no. 10, pp. 2317-2318, 2022.
  • A. Elia et al., American Journal of Physiology. Regulatory Integrative and Comparative Physiology, vol. 323, no. 6, pp. R839-R848, 2022.
  • F. von Walden et al., Journal of applied physiology, vol. 131, no. 3, pp. 1035-1042, 2021.
  • O. Eiken et al., American Journal of Physiology. Heart and Circulatory Physiology, vol. 320, no. 4, pp. H1303-H1312, 2021.
  • E. Rosa et al., Aerospace Medicine and Human Performance, 2021.
  • M. Sj枚berg et al., Frontiers in Sports and Active Living, vol. 3, 2021.
  • R. 脜nell, Doctoral thesis Solna : Kungliga Tekniska h枚gskolan, TRITA-CBH-FOU, 2021:28, 2021.
  • M. E. Keramidas et al., American Journal of Physiology. Regulatory Integrative and Comparative Physiology, vol. 321, no. 5, pp. R742-R750, 2021.
  • R. J. Croft et al., Aerospace Medicine and Human Performance, vol. 92, no. 2, pp. 75-82, 2021.
  • S. N. Kounalakis et al., Experimental Physiology, vol. 106, no. 7, pp. 1498-1507, 2021.
  • E. Rosa et al., Aerospace Medicine and Human Performance, vol. 92, no. 9, pp. 710-719, 2021.
  • M. E. Keramidas et al., Microvascular Research, 2021.
  • U. Ciuha et al., European Journal of Applied Physiology, vol. 121, no. 11, pp. 3005-3015, 2021.
  • M. Gr枚nkvist et al., Aerospace Medicine and Human Performance, vol. 92, no. 4, pp. 248-256, 2021.
Keywords:
Gravity, Altered Physiology Physiology and Anatomy Space Research
Content reviewer:
Gunnar Schulte
14-05-2025