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The Effects of Living in a Moderate Altitude

Moderate altitude is defined as around 2,200 meters (7,216 feet) to 2,500 meters (8,200 feet) above sea level. Cities such as Vail, Colorado; Cooke City, Montana; and Clovis, New Mexico are at moderate altitudes. Some of the stresses people living at higher altitudes are exposed to are reduced available oxygen (i.e., hypoxia), low humidity, more solar radiation, cold, and wind.

  1. Red Blood Cells

    • Because of the lowered barometric pressure at moderate altitudes, oxygen is less concentrated in a given volume of air. Human physiology adjusts to lowered oxygen availability by increasing the number of circulating red blood cells, which transport oxygen throughout the body. John Hawley in "Running" cites studies showing that runners who trained at moderate altitudes had an improved red blood cell mass of 12 percent and a hemoglobin content with 9 percent improvement.

    Maximal Oxygen Uptake

    • In a study conducted by Benjamin Levine and James Stray-Gunderson, athletes who trained at moderate elevations showed a significant 5 percent increase in maximal oxygen uptake.

    Elderly People

    • Elderly people with pre-existing medical conditions such as high blood pressure, coronary artery disease and lung disease were studied during a stay at moderate elevation in Vail, Colorado. Researchers led by R. C. Roach reported a 16 percent occurrence of acute mountain sickness, slightly below that experienced by younger people. No adverse signs or symptoms occurred in chronic disease states while the participants were at moderate elevations, indicating that unacclimatized elderly people can safely visit moderate altitudes.

    Low Humidity

    • Effects of low humidity, especially in winter, can be alleviated indoors by the use of air humidifiers and vaporizers. This helps the health of mucous membranes and helps prevent susceptibility to infectious airborne agents.

    Solar Radiation

    • More solar energy reaches organisms living at moderate altitudes because there are fewer layers of atmosphere and clouds to absorb and filter it out. Molecules of oxygen and ozone absorb some of the ultraviolet (UV) radiation that would otherwise reach the earth's surface, but at higher altitudes the thinner atmosphere absorbs less UV energy. In particular, UV-B exposure is more intense at higher altitudes. Research led by Darrell Rigel, MD, in Vail, Colorado, showed UV-B levels 60 percent higher there than in New York City. The average person with unprotected skin would sunburn in 6 minutes as opposed to after 25 minutes in New York.

    Skin Cancer

    • UV-B is also a factor in the development of skin cancer. For year-round residents living at 8,500 feet elevation, the risk of developing nonmelanoma skin cancer is about 115 percent greater than for people living at a similar latitude at sea level. The American Academy of Dermatologists recommends the use of protective clothing, sunscreen, and the practice of avoiding the strongest solar energy levels around noon.

    Food Preparation

    • Cooking and baking is affected by the lower atmospheric pressure and lower humidity at moderate elevations. Boiling water evaporates more quickly in the lower humidity, and ingredients dry out faster in storage. Water boils at a lower temperature, and leavening agents act more quickly because of the lowered pressure.

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