Human Physiological Adaptations to the Arctic Climate

This review deals with thermal, metabolic and hormonal responses of various human populations to natural or experimental acclimation. Modern people react to cold with shivering, increased metabolism and cutaneous vasoconstriction (metabolic response). Native people, such as Australian aborigines, Eskimos, arctic Indians and Lapps, who were regularly exposed to cold in their natural habitat, have been reported to exhibit less pronounced shivering during experimental cold exposure and experience a greater fall in body temperature (hypometabolic and hypothermic type of adaptation). Australian aborigines and traditional Korean divers have been shown to have low body heat conductivity (insulative type of adaptation). Modern Caucasians intensively exposed to prolonged cold may also develop hypothermic and insulative types of adaptation. Exposure to cold climate increases blood pressure, which may be a factor contributing to the greater mortality due to cardiovascular diseases and stroke observed in the winter. The secretion of the pineal hormone melatonin, which is believed to inhibit the secretion of a pituitary luteinizing hormone, is elevated during winter and decreased in summer. This leads to the higher conception rate observed during spring and summer.Key words: acclimatization, birth rate, blood pressure, body temperature, cold exposure, conceptions, hormones, light, metabolic rate, mortality, native people, seasonMots clés: acclimatation, taux de natalité, pression sanguine, température du corps, exposition au froid, conception, hormones, lumière, taux de métabolisme, mortalité, autochtones, saiso

Frostbites in circumpolar areas

Circumpolar areas are associated with prolonged cold exposure where wind, precipitation, and darkness further aggravate the environmental conditions and the associated risks. Despite the climate warming, cold climatic conditions will prevail in circumpolar areas and contribute to adverse health effects. Frostbite is a freezing injury where localized damage affects the skin and other tissues. It occurs during occupational or leisure-time activities and is common in the general population among men and women of various ages. Industries of the circumpolar areas where frostbite occurs frequently include transportation, mining, oil, and gas industry, construction, agriculture, and military operations. Cold injuries may also occur during leisure-time activities involving substantial cold exposure, such as mountaineering, skiing, and snowmobiling. Accidental situations (occupational, leisure time) often contribute to adverse cooling and cold injuries. Several environmental (temperature, wind, wetness, cold objects, and altitude) and individual (behavior, health, and physiology) predisposing factors are connected with frostbite injuries. Vulnerable populations include those having a chronic disease (cardiovascular, diabetes, and depression), children and the elderly, or homeless people. Frostbite results in sequelae causing different types of discomfort and functional limitations that may persist for years. A frostbite injury is preventable, and hence, unacceptable from a public health perspective. Appropriate cold risk management includes awareness of the adverse effects of cold, individual adjustment of cold exposure and clothing, or in occupational context different organizational and technical measures. In addition, vulnerable population groups need customized information and care for proper prevention of frostbites

Climate warming and health adaptation in Finland. FINADAPT Working Paper 7

Heat-related mortality and morbidity will be increased slightly; respectively wintertime mortality and morbidity will decrease under a warming environmental temperature. Short-term extreme weather events will probably cause most of additional burden of climate induced adverse health outcomes in Finland. In increased risks are elderly and children, and those with poor health. A risk of some infectious diseases may increase. There is a consensus that population would adjust successfully, with little increase in heat related mortality, to climate warming predicted to occur in the next half century. However, the physiologic adaptation responses are not developed to short-term hazardous or extreme weather events. The adaptive capacity of Finnish society is fairly good as we are able to maintain the public health infrastructure and achieve sustainable political and economical development. Ageing population together with threats posed by climate has to be underlined. Urbanization may decrease the adaptive capacity as urban population is considered to cope less well with harsh climatic conditions as their counterparts in rural areas do. This means threats for especially teenagers and old people. Spontaneous adjustments to extreme heat might not compensate fully for effects of future heat waves in Finland. The future adaptive capacity is also a function of population health status and pre-existing disease burdens

Habituation of thermal sensations, skin temperatures and norepinephrine in men exposed to cold air

6 sujets masculins ont été exposés à l'intérieur d'une salle climatisée, à une température de 11° C pendant 2 heures. Les sujets ont suivi ce protocole pendant 11 jours durant lesquels plusieurs mesures ont été relevées (évolution métabolique, température corporelle et sensations thermiques notamment au niveau des extrémités (pieds et mains)

Alcohol consumption among male reindeer herders of lappish and finnish origin

Ethnic differences in alcohol intake among male reindeer herders were studied, since historical evidence suggests that Lapps drink more than Finns and since the considerable freedom of the herding occupation may imply a high risk for alcohol problems. In 1988, 2001 men answered a mail questionnaire including questions on alcohol intake over the past 12 months. The mean alcohol intake was 22.3 g/day among the Lapps and 13.2 g/day among the Finns (Palcohol ethnic groups occupational groups