Ultraviolet Exposure, Antioxidant Use and Skin Erythema at Extreme High Altitude

This study has been completed.
Ontario Centres of Excellence
Information provided by:
Sunnybrook Health Sciences Centre
ClinicalTrials.gov Identifier:
First received: May 22, 2008
Last updated: May 27, 2008
Last verified: May 2008

With the increasing tourism and adventure travel into extreme environments comes the need to reassess the required protection against ultraviolet (UV) radiation and possible other oxidative stresses. This is an observational study of UV radiation exposure and skin erythema while at extreme altitude (Mt. Everest). In addition to UV exposure, skin erythema, antioxidant use (such as vitamins C and E) will be measured.


  1. UV radiation at extreme altitude has larger effects on the skin than at sea level; therefore requiring an adjustment of the antioxidant use for adequate protection.
  2. The skin is an accurate reflection of UV and oxidative stress exposure
  3. The efficacy of oxidatives stress is reflective of the ethnicity of the individual.

Ultraviolet Rays
Oxidative Stress

Study Type: Observational
Study Design: Observational Model: Ecologic or Community
Time Perspective: Prospective
Official Title: Observational Study of Skin Erythema by Spectrophotometer, and UV Exposure With Viospore Ultraviolet Monitors at Extreme Altitude (Mt. Everest, North Side)

Resource links provided by NLM:

Further study details as provided by Sunnybrook Health Sciences Centre:

Enrollment: 25
Study Start Date: April 2007
Study Completion Date: June 2007
Detailed Description:

The literature widely acknowledges the deleterious effects of UV radiation on skin health, via production of oxidative free radicals. Consequently, there have been numerous studies on the potential dermatological/anti-carcinogenic benefits of anti-oxidants, such as vitamins C and E, melatonin, green tea, zinc, and selenium. There is, however, a limited amount of literature on the quantity of UV exposure in high-risk settings, such as extreme altitude and equatorial zones. Currently, there is no literature on UV exposure on Mount Everest. Additionally, the efficacy of antioxidants (topical or systemic) has not yet been established in this environment.

This will be an observational study where the principal investigator will collect accumulated ultraviolet exposure at different extreme altitudes during a 6 week period of a summit expedition on the north side of Mt. Everest. Included in the data collection will be patient demographics, time, altitude, temperature, use of anti-oxidants, sunscreen (weighed), and skin erythema (spectophotometer).


Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
9 Mountaineers with intention to summit Everest (1 American, 1 British, 1 German, 5 Australians, 1 Asian-Australian) 4 Trekkers with intention to go to 7000m (2 Americans, 1 Asian, 1 British) 12 climbing sherpas (11 Nepali and 1 Tibetan)

Inclusion Criteria:

  • Participants part of the expedition who are willing to wear the monitor, and disclose information of diet/antioxidant supplements and topical sunblock.

Exclusion Criteria:

  • Participants who are unwilling to carry the UV monitor or disclose their demographics
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00685438

Mount Everest, North side
Kathmandu, Nepal
Sponsors and Collaborators
Sunnybrook Health Sciences Centre
Ontario Centres of Excellence
Principal Investigator: Ivy S Cheng, MD Sunnybrook Hospital Emergency Department
Principal Investigator: Lothar D Lilge, PhD Ontario Cancer Institute
  More Information

Additional Information:
Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Ivy Cheng, Sunnybrook Health Sciences Center
ClinicalTrials.gov Identifier: NCT00685438     History of Changes
Other Study ID Numbers: 005-2007
Study First Received: May 22, 2008
Last Updated: May 27, 2008
Health Authority: Canada: Ethics Review Committee

Keywords provided by Sunnybrook Health Sciences Centre:
Environmental Medicine
Ultraviolet Rays
Oxidative Stress

Additional relevant MeSH terms:
Skin Diseases
Molecular Mechanisms of Pharmacological Action
Pharmacologic Actions
Physiological Effects of Drugs
Protective Agents

ClinicalTrials.gov processed this record on November 30, 2015