INFLUENCE OF CLIMATE ON HUMAN HEALTH AND WELL-BEING

INTRODUCTION

The beneficial effects on the health and well-being and progress of mankind is from the adaptation. Even after acclimatization the physical, physiological, psychological and functional abilities of human being are maximum with in a certain range of atmosphere and climatic conditions. Climate decides the energy level of man in a given environment. In a tropical climate to counter act the difficulty of in heat loss. Man has adopted a lower rate of heat production. The main capacity of young healthy adults living near the equator is only a little more than half of the vital capacity in similar individuals living in a temperate climate. Sub tropical and temperate climate are more suited to the fullest efficiency of man as moderate variations maintain the vigour of developmental progression.

THE METEOROLOGY

This is recently developed branch of science which studies the effects of climate living organisms. the branch of biology which deals with the inter-relation ship of organisms with their complete environs, inclusive of earth, water, atmosphere, radiation, plants and other living organisms is called ecology. The science concerned with atmosphere, weather, climate and inter relation between the components of atmosphere is called meteorology. Bio meteorology consists of the ecology of living things; plants animals and man. It joins biology, ecology, and meteorology in the study of system in which organisms and atmospheric component of the total environment interact. It has got 3 sub divisions namely, the plant, animal and the human bio meteorology. The favorable reactions maintain the internal normality and lead to adaptation and biological success of the organisms; unfavorable reactions lead to internal imbalance, non adaptation of living things and its biological defeat and disease process.

THE ADVERSE EFFECTS

Climate adversely effect on human health directly of its whimsical and extremes; indirectly by influencing mans metabolism or defensive mechanisms and remotely by modifying his complete environs. The direct adverse effects are caused when exposed to climatic extremes and if the homeostatic mechanisms fail, either due to severity or rapidity of or prolonged exposure or non-adaptability, or  due to physiological dysfunction. This conditions produce like heat stroke, cold injuries, heat exhaustion and high altitude hypoxia, etc. Incidence of infection and illness, functional deficiency or inefficiency due to them are commoner than due to the direct influences. The remote mode of causation of disease is by adversely changing the external environments so that it affects human physiology hurtfully. Thus prolonged shortage of water in areas with low rain fall may be associated with higher malnutrition. Meteorological changes also bring about the evolution and devolution of disease on the pathogenic organisms either by direct influence or indirectly through change in the socio-economic and cultural patterns of the community. There are three types of reactions occur in response to exposure to climatic extremes. The first type occurs when the homeostatic mechanisms inadequately meet the challenge of climatic vagaries and extremes in an inadequately acclimatized person and the second type happens when the homeostatic mechanisms are quite adequate but the external conditions are excessively severe or prolonged and the third type occurs when the homeostatic mechanisms completely surrender because of stretched beyond normal tolerable critical limits and the failure of general adaptation mechanisms and general collapse results.

A knowledge of the principles of bio meteorology is necessary for health staff from the point of view of promoting health, prevention of ill effects and prevention of and control of diseases and maintaining of high physical and mental efficiency.

EFFECTS OF POWERFUL SOLAR RADIATION

Solar radiation affects the health directly or indirectly. The direct effects occurs directly to eyes and skin. Various wave lengths of the component rays in the solar spectrum which penetrate the atmosphere cause biochemical, luminous and thermal effects rays are Ultra-violet and violet, Blue are biochemical rays. luminous rays are Green, Yellow, orange and heat rays are Red infra red. The combined effect of solar radiation is to provide radiant thermal energy to warm the skin and stimulate metabolism to produce a biochemical effect on the living organisms and plants. In temperate climates sunshine promotes a feeling of comfort, cheerfulness and physical well-being. Moderate exposure to sun rays is beneficial even during hot weather when it promotes adaptive mechanisms. Forty percent of the solar radiation is reflected away from the unclad skin reducing the thermal heat load to a great extent. And also clothing reduces the penetration of solar radiation. Very little of ultra-violet and longer infra-red rays are reflected from the skin surface, and there fore they are absorbed in the upper horny layer of skin. The infra red which penetrates beyond the epidermis causes heating in the dermis and the deeper layer which produce vitamin d and destroy micro organisms.

In the tropics so much sunshine is uncomfortable, irritating and enervating and dangerous to health. Constant exposure to the intense glare from the sun is irritating to the point of causing distress, head ache, mental irritation and exhaustion. There are heat effects but are the radiation effects may occur in the tropics, sub tropics and high altitude or even in the arctic zone. The long term effects of exposure to intense unfiltered sunshine as at high altitude or in tropical or sub tropical regions are ageing of skin with wrinkling and loss of elasticity and in the long run even the rodent ulcers and skin cancers. The rays at high altitude are unfiltered of its short ultra-violet portion and causing harmful effects. Similar effects are seen in those parts of the world where sun rays are mostly unfiltered due to paucity of terrestrial dust and water vapour. for example in Australia and Newzealand where rodent ulcers are common.

PROPHYLAXIS AND FIRST AID

Clothing removes a larger portion of the  ultra-violet rays. It should be based on the fact that skin pigmentation is increased by rays of wave lengths different from those which produce sun burn and dermatitis. Protective s should be the applications which filter out the shorter sun burn portion but allow longer pigment-forming portion of ultra-violet rays to pass through. Application of calamine lotion is the first measure for sun burn and solar dermatitis. The best preventive measures for eye is wearing of glasses as advised by ophthalmologist or by an authorized person. The symptoms are intense pain, photo phobia(fear of looking to light), etc. Coloured glasses and plastic filters can absorb most of the ultra violet components of actnic rays. In advising sun glasses all the three regions of the spectrum have to be considered. The best glasses are ordinarily green or rose smoke colour. Infra-red transmission through them is slight and also they completely filter out the harmful portion of ultra-violet spectrum and transmit fifteen to twenty percent of visible radiation.

PREVENTION OF DISEASES LIABLE TO BE IMPORTED BY AIRCRAFT

INTRODUCTION

Journeys by air from countries where the major ineffective diseases are present like cholera, yellow fever, plague and typhus, etc are endemic to non-infected countries are so soon that are normally transmitted with in the incubation period of these diseases. the administrative authority for the health control of air traffic is based on the international sanitary regulations by the world health assembly in 1951. 

RESPONSIBILITY OF THE COMMANDER OF THE AIRCRAFT

The commander of the aircraft should see that he is not carrying any passenger suffering from an infectious disease. He should see that the passengers and aircrew are fully protected by inoculation and vaccination against diseases that are prevalent in his own country and country of passenger en route and against which protection is available. He should ensure that similarly they are protected against diseases that are to be likely present in the country of destination, and in other countries through which the aircraft is routed. This is essential for the safety of air crew and passengers and also for complying with the convention of international aerial navigation. For this purpose the diseases considered to be ineffective are as mentioned above, and no animal or plant product likely to convey diseases and no living animal or plant should be carried across national boundaries with out special permission of from all concerned. this is very essential to prevent the spread of diseases such as hydrophobia(rabies) etc. to avoid importation and exportation of animals that might become pests.

IMPORTANCE OF PROPER AND TIMELY NOTIFICATION

The effectiveness of the international sanitary regulations depend primarily on the rapid exchange of notification. This is the responsibility of health administrative authority and world health organisation. The health administrations are bound to notify world health organisation(WHO) by means of telegram/signal with in 24 hours. that a local area become an infected local area. Similar information must be sent when evidence is found of yellow fever virus in an area where it was not found previously. First information by the health administration of local infected area must be supplemented by detailed information afterwards and then follow up reports. Deaths and quarantinable diseases must be reported to WHO by the health administration.

CONTROL OF SANITATION IN AERODROMES

The commander of aircraft arriving from abroad must notify any case of death other than accidental. Any case of death suspected quaratinable diseases that has occurred on board to the aerodrome officer by wireless message. On receiving such message the aerodrome officer must notify the medical officer concerned immediately. Infected planes which are coming from infected local areas or those with rodent dying abroad. On such infected aircraft on landing air crew and passengers must not be allowed to go out until the medical officer examines them and declares the plane and crew/passengers free from infection. If there is any case on board showing evidence of infection. must be hospitalized under proper supervision. For yellow fever cases a mosquito proofed ambulance must be used to avoid mosquito bite while transferring, sucking of infected blood with yellow fever virus by the aedes mosquitoes.Yellow fever virus is not imported to India so far.

CASES RELATING TO YELLOW FEVER 

 If an aeroplane shall be regarded as infected with yellow fever, and if it has a case of yellow fever on board, or if there has been on board a case of yellow fever and subsequent to the occurrence of that case, all measures of sanitation have not been taken to the satisfaction of the health officer before arriving in India or live mosquitoes are found on board. Aircraft and cargo shall be disinfected and all infected persons shall be disembarked and isolated to such periods as the health officer may consider necessary. All persons on board shall be medically examined before getting out or under such arrangements may be made by health officer to reduce to a minimum the risk of spread of infection. and any passenger or crew who disembarks and is not in possession of a valid certificate of vaccination against yellow fever shall be segregated until his certificate becomes valid or until a period of not more than 9 days reckoned from the date of last possible exposure to infection has elapsed, whichever occur first.

HYGIENE AND SANITATION IN FLIGHT

Water supply, food, emergency ration, disposal of wastes and ventilation problems of air craft are to be checked and proper action to be done before take off the aeroplane. Disinfection of aircraft is carried out as per the international regulations laid down. These are given in Govt, of India, Indian aircraft manual, 1964. Disinfection of aircraft when considered necessary can be carried out with formalin spray. For the purpose of 5% formalin solution with 5 ml of formalin to a liter of water should be used. The spraying can be done with a hand pump or stirrup pump. The size of  nozzle tip should be capable of producing a flat fan spray of a uniform pattern with a spray angle of 60 degree, and the size the nozzle should be 0.4 mm. All removable articles should be disinfected as usual.

HEAT STROKE AND HEAT EXAUSTION AND ITS PREVENTION AND FIRST AID TREATMENT

 HEAT STROKE AND HEAT EXHAUSTION

Introduction

The effects of heat are spread out in the subtropics in the hot season. But hey are less happened in the tropics than generally, expected mainly the heat stroke. The epicenters for effects of heat are the shores of the Persian gulf and the central and western plains of India like Punjab, Hariyana, etc. The incidence of effects of heat in India is commonest in an area drawn horizontally through Nagpur with its western limit marked by drawn vertically along the western border of Bengal Asansol, excluding the coastal areas. The great majority of cases occur in Punjab, but there is hardly a place in the plains of northern and central India. Most cases occur during the week or two prior to the on set of the south west monsoon and during the breaks of monsoons, when atmospheric temperature and humidity are very high. In the north and west dangerous period is in the end of the June or later. In central India it is in mid-June. While in the south and eastern India, May and early June are critical periods. But the cases occur at any time during the hot weather in any part of India. The incidence in Kerala in recent years with sun burns starts from March to May before onset of monsoon.

Primary environmental factors

High atmospheric temperature is the most main important primary cause. Final effect is determined by the period of exposure to the hot temperature to 43 degree centigrade in dry atmosphere. As the temperature increases high 46 degree or more in the presence of wind velocity of more than 32 km per hour the danger point approaches and the heat stroke may occur. Direct exposure to sun rays increases the body heat load further and may occur the attack. Constant exposure to the sun glare is irritating to the causing point of distress, head ache, mental irritability and exhaustion. High atmospheric humidity is an important factor as high atmospheric temperature in the causation of heat effects, since upon it depends the evaporating power of the atmosphere and hence the body heat loss. Air movement is the important atmospheric factor which decides the human thermal comfort.

Heat stroke.

Onset is sudden. This condition occurs a result of an excessive rise in the body temperature. When sweating and its evaporation are adequate the thermal loss maintain the the thermal balance of the body and continue to do so until the replenishment of water is maintained. The regulatory mechanism may fail if the conditions are adverse such as any deficiency of any water in the body or the internal requirement is excessive or the external conditions are unbearable under intense solar radiation, high temperature or  very hot winds. The heat load imposed upon the body by such severe conditions may be about 200 kilo-calories per sq.meter of the body surface per hour, which is equivalent to the metabolic out put of any Strenuous work. It occurs due to lack of sweating and beak down of heat regulating centre in the brain. Under all such conditions, when the heat regulating mechanism fails to keep body temperature below the critical level, high fever develops. There may be sign of lack of sweating, giddiness, feeling vomiting, exhaustion and frequency of difficult pass urine. The individual in good health may suddenly become unconscious and get rapid  rise in temperature above 40 degree Centigrade.The main causes are very high fever, stop sweating, head ache, restlessness,  thirsty, anxiety, dry tongue, and in later stage unconsciousness with circulatory failure. the face is congested or in bluish colour, eyes are suffused, and the skin is dry and burning. abnormal and loss of consciousness occur in about one third cases. Mental confusion is seen in two third cases. Mortality varies with the degree of high fever/pyrexia

Heat exhaustion.

This occurs commonly more than heatstroke. Onset is gradual and body temperature does not rise as high as in the case of heat stroke. Those are not so much due to excessive temperature, but are rather the result of water and salt shortage due to excessive sweating. The reasons are depletion of salts in the body due to more sweating, and very high humidity and lack of cooling body. Water necessity in the body in hot climate is higher than in cold climate or a temperate climate. If water intake also reduced its exertion is reduced, but normal water loss necessary to remove the toxic nitrogenous metabolites has to continue in concentrated  urine. Excessive sweating also reduces salt balance in the body. Normally 15 gm salts intake is adequate. Any salt consumed in excess over daily requirement is exerted in urine. If the intake is reduced or exertion in sweat is increased, salt is conserved by diminishing its excretion in the urine.

Water constitutes 70 percent of the body weight and maintenance of  the fluid  balance and its distribution in the 3 compartments is importance for the health of cells and tissues and its constant by the relative osmotic pressures.

Sign and symptoms of heat stroke

Temperature of body becomes above 104 degree F, dry skin, mental irritability, head ache, muscular cramps, fits, slow respiration and unconsciousness

The prevention of effects of heat.

The fluid intake must be enough to produce sweat and compensate for loss of water. Supply of cool water should be ensured. water consumption is likely to be inadequate and if it is not cool enough to quench thirst. Moderate work in hot climate may need upto 7 to 10 liters of water per day per and men for man on long time doing strenuous physical work even upto 15 liters a day may be needed.

Salt intake must compensate for its excessive loss in sweating. Rest and sleep should be adequate as the recovery must compensate for the activity. he best period for the best satisfactory and result restful sleep is during the coolest 3 to 4 hrs before dawn.

Bathing should be done every day. Improved shower  baths are also of great important and valuable. An active , healthy and clean skin is an important factor dissipation of heat through radiation and evaporation and convection.

Clothing should be normally light and loose and permeable to water vapour and air. Food must be wholesome and well cooked and must be consumed with good amount of fluid. Dining hall should be cool and comfortable as no one can be expected to take full meals under hot and humid conditions.

Living rooms must be well ventilated and cool. A large numbers of heat stroke cases occurs in congested and ill ventilated and crowded rooms and huts, etc. In an area if possible, fans made be available to workers in their tents and quarters and no one should be allowed to sleep out side.

Medical inspection should be regular and through to detect early symptoms of the heat effect or any other diseases which may aggravate the effects of heat. Cases detected early can be often placed in rest in a cool place.

Avoid working in sun when it is too hot from 1 p m to 3 pm(IST) and drink plenty of pure water and use umber la while walking in sun, also avoid tea,coffee and alcohol,etc. during extreme summer and take rest or avoid doing strenuous work during peak hours.

First aid and early treatment

Keep the patient in bed or on the floor and fan on to reduce temperature. Raise the foot end and keep wet cloths on the body to reduce temperature and give plenty of fluid diet. This is necessary to stop the progress of illness, avoid permanent neurological injury and save life. Temperature must be reduced rapidly by spraying cool water and fanning. Ice-cool water is not to be used. Give plenty of cool water to drink, not too much. The temperature is checked every 10 minutes when cooling is reduced when it comes to 39 degree centigrade, patient is to be removed to the heat stroke centre. Dehydration is treated by administration of fluids and electrolytes. Cases of pure water loss is treated with water only. In severe cases with considerable impairment of mental and physical capacity there may be a deficit of 5 to 10 liters. In salt deficiency, if there is any giddiness and fainting on standing, there may be an approximate deficit of 4liters isotonic saline and if urinary chlorides are absent and if there is any feeling of vomiting/anorexia, nausea and vomiting with systolic blood pressure above 90mm of mercury, there may be a deficit of 5 liters, and if systolic blood pressure is less than 90mm of mercury, there is an approximate deficit of 8 liters.