Antarctica blues
HAD Dante been to Antarctica, he might have painted a different picture of hell. Fire and brimstone, the symbols of torture, may have given way to blistering blizzards, long periods of uninterrupted blinding sunlight or netherworld darkness -- and almost complete isolation. While Dante's hell was reserved for the dead, Antarctica offers a hellish experience to the living.
But what is this experience like? To find out the effect of the Antarctic climate on humans, scientists from Delhi's All India Institute of Medical Sciences (AIIMS) visited Indians stationed in Antarctica. After analysing the data gathered, the scientists found that the freezing, alien Antarctic climate alters the way the bodies and minds of Indians normally behave.
Scientists Usha Sachdeva, Meenakshi Naidu and B Chhajer found that after a week's stay in the icy continent, the skin cooled down markedly from a normal of about 32.13 degree C to 24.13 degree C, to prevent heat loss from the body. Because heat loss is more through body's extremities, such as fingers, toes, and nose, the body rations blood supply to these organs.
The Indian geologists in Antarctica were found to have gained weight. But, unlike in the tropics, the weight gain wasn't reflected in a paunch; instead the mid-arm region grew flabbier. The icy continent experiences 6-month long continuous period of light and this affects the psychology of the geologists stationed there. Says M K Kaul, director (Antarctica Division), Geological Survey of India, who led the 5th Indian Antarctic Expedition, "Due to the endless days, one feels like working for longer periods and is unable to sleep well. Eventually the exertion catches up, leading to fatigue." He says that for geologists working out in the field, housed in tents, the situation is worse, as the light penetrates through the tent fabric.
The AIIMS scientists say that behind this altered physiology is the body's inbuilt biological clock, whose natural timing is upset by the 6-month long periods of continuous light and then darkness. Scientists believe that this biological clock is located in the brain and controls the secretion of several hormones from the pituitary gland -- the master hormone-secreting gland located at the base of the brain. Among the hormones secreted by the pituitary is the thyroid-stimulating hormone, which in turn triggers the thyroid gland responsible for regulating the pace of the body's activity.
The secretion of hormones follows a 24-hourly regularity called the circadian rhythm. But the circadian rhythm is influenced by factors such as the length of day and night, temperature, food habits, and sleep cycles. The extreme Antarctic climate disrupts this rhythm in the Indian geologists examined, leading to the unusual psychosomatic behaviour observed, the AIIMS scientists conclude.