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CLIMATE AND HEALTH

CLIMATE AND HEALTH. There is often confusion between climate and weather. CLIMATE: Climate is an average weather condition throughout a year at a place. OR. Climate refers to a weather pattern of a place over a long period, may be 30 years

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CLIMATE AND HEALTH

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  1. CLIMATE AND HEALTH

  2. There is often confusion between climate and weather. CLIMATE: Climate is an average weather condition throughout a year at a place. OR

  3. Climate refers to a weather pattern of a place over a long period, may be 30 years or more, long enough to yield meaningful averages. For example, although the weather in pakistan may be cool and dry today, but Pakistan’s climate is hot most of the time.

  4. WEATHER: A single event in a series of conditions that make up the climate. OR Weather is the day to day condition of the atmosphere at a particular place over a short period of time.

  5. EFFECT OF CLIMATE ON HEALTH

  6. EFFECT OF CLIMATE ON HEALTH

  7. METEOROLOGY: It is a branch of atmospheric science concerned with phenomena occurring in the environment. It studies weather, while CLIMATOLOGY studies climate.

  8. ELEMENTS OF METEOROLOGY: Elements of meteorology are: 1. Atmospheric pressure. 2. Air temperature. 3. Humidity. 4. Air velocity. 5. Rainfalls. 6. Clouds & Sunshine.

  9. 1. ATMOSPHERIC PRESSURE: Atmospheric pressure at earth's surface close to sea level is 760 mmHg. It falls as altitude increases and rises as altitude decreases. It is determined with the help of a barometer.

  10. EFFECTS OF ATMOSPHERIC PRESSURE ON HEALTH: • HIGH ALTITUDE: Air is less dense at high altitude so partial pressure of oxygen is less. Man cannot survive at an altitude of 25000 ft without assisted breathing. PHYSIOLOGICAL CHANGES: • Decrease in alveolar and arterial PO2 • Increase in ventilation i.e respiratory rate • Increase in Hb concentration.

  11. Increase in cardiac output SUDDEN EXPOSURE TO HIGH ALTITUDE: It causes: • ACUTE MOUNTAIN SICKNESS: characterized by headache, insomnia, breathlessness, nausea, vomiting, impaired vision, tinnitus, palpitation & nose bleed.

  12. HIGH ALTITUDE PULMONARY OEDEMA: Initially symptoms are of acute mountain sickness,but gradually patient develops cough, cheyne stokes breathing, confusion, hallucinations, stupor, seizures and coma. TREATMENT is to bring the patient to lower altitude as soon as possible.

  13. b. LOW ALTITUDE: Atmospheric pressure increases by 1 atm for each 33 feet depth below sea level. This effect is seen in persons working in compressed air chambers or mines. CAISSON DISEASE: When a man is exposed to high pressure, gases in air i.e O2, CO2 and N2 are dissolved in the blood and tissues proportionately to the partial pressure of these gases.

  14. Excess concentration of N2 exerts a narcotic action leading to loss of mental functions & consciousness. Excess of CO2 increases the narcotic action of N2. Excess of O2 leads to convulsions and death.

  15. When a person comes up to the surface, the gases which are dissolved in blood under pressure are released and cause air embolism, which is a fatal condition and can lead to death. 2. AIR TEMPERATURE: The temperature of air varies in different parts of the day and also in different seasons.

  16. The temperature of ground surface is always higher than that of air. MEASUREMENT: Thermometers are instruments that are used to measure temperature.

  17. HEAT STRESS: Heat stress is the burden of heat that must be dissipated from the body in order have thermal equilibrium.

  18. FACTORS: Factors which influence the heat stress are • metabolic rate • air temperature • humidity • air movement • radiant temperature

  19. EFFECTS OF HEAT STRESS: They include: a. HEAT STROKE: Failure of heat regulating mechanism. It is characterised by very high temperature which may rise to 110 degree F and disturbances include: - delirium - convulsions - partial or complete loss of consciousness.

  20. Skin is dry and hot. Death is often sudden may be due to hyperkalemia (increased potassium level), which may be due to release of potassium from RBC’s which have been injured by the heat.

  21. TREATMENT: - Rapid cooling of body in ice water baths till the rectal temperature falls below 103 degree F. It is measured after every 10 minutes. - Patient should be kept in bed for several days until the temperature control becomes stable. - Chlorpromazine is recommended along with rest.

  22. b. HYPERPYREXIA: It is defined as temperature above 106 degree F. This is also due to impaired functioning of heat regulating mechanism but without features of heat stroke but it may proceed to heat stroke. c. HEAT EXHAUSTION: It is a severe form of heat illness. It is a medical emergency.

  23. SYMPTOMS OF HEAT EXHAUSTION

  24. FEATURES: It is characterized by - excessive sweating - rapid pulse - decrease urine output - headache - thirst - dizziness - nausea - irritability

  25. DIFFERENCE BETWEEN HEAT STROKE & EXHAUSTION

  26. d. HEAT CRAMPS: These are painful & spasmodic contraction of skeletal muscles. It occurs in those persons who are doing heavy muscular work in high temperature & humidity. CAUSE: Due to loss of sodium and chlorides in the blood.

  27. e. HEAT SYNCOPE: This is the common effect of heat. In its milder form, person standing in the sun becomes pale, his blood pressure falls and he collapses suddenly. There is no rise in body temperature. MECHANISM: It is due to pooling of blood in lower limbs due to dilation of blood vessels, venous return to the heart decreases, causing decrease in blood pressure hence

  28. lack of blood supply to brain. TREATMENT: - very simple Patient should made to lie in a shade with the head slightly down or elevate the foot end to increase the blood flow to brain. Recovery usually occurs in 5 to 10 minutes, may be earlier.

  29. HEAT SYNCOPE

  30. PREVENTIVE MEASURES OF HEAT STRESS: 1. REPLACEMENT OF WATER: People working under hot environment should be encouraged to drink cool water. 2. REGULATION OF WORK: Duration of exposure to hot environment should be cut down. There should be period of rest in between intense work.

  31. 3. CLOTHING: Clothing should be light, loose and of light colours. 4. PROTECTIVE DEVICES: Protective goggles, shields and helmets should be used. 5. WORK ENVIRONMENT: Proper ventilation and air conditioning system should be there.

  32. EFFECTS OF COLD STRESS: Injury to cold may be local or systemic. - SYSTEMIC: It is characterised by numbness, loss of sensation, muscular weakness, desire for sleep, coma and death. - LOCAL: * Frost Bite => at temp below freezing (dry-cold condition),the tissues freeze and ice crystals form in between cells.

  33. Frostbite is common at high altitudes. • Treatment: a. The affected part should be warmed using water at 44 degree F. Warming should be last about 20 minutes at a time. b. Intake of hot fluids promote general rewarming.

  34. * Trench Foot => It is caused by prolonged exposure of feet to damp, unsanitary and cold conditions. Unlike frost bite, it does not require freezing temperature. • Prevention: It can be prevented by keeping the feet clean, warm and dry.

  35. 3. HUMIDITY: It is the amount of water vapour in the air. TYPES: There are three types of humidity: - absolute - relative - specific

  36. a. Absolute humidity, It is water content of air at a given temperature expressed in gram per cubic meter. b. Relative humidity, It measures the current absolute humidity relative to the maximum (highest point) for that temperature. It is expressed in percentage.

  37. c. Specific humidity, It is a ratio of the water vapour content of the mixture to the total air content on a mass basis. MEASUREMENT: It is measured by hygrometer or psychrometer.

  38. 4. AIR VELOCITY It is a parameter that often is referenced in thermal design. MEASUREMENT: It is measured in meters per second. EXAMPLES: • when it is about 0.5 m/s - complete calm • when it is about 3.3 m/s - slight breeze with leaves rustling • when it is about 10 m/s - strong wind

  39. when it is about 15-20 m/s - storm • when it is about 25-30 m/s - gale • and when it is over 30-50 m/s it is called hurricane. 5. RAINFALL: It is the form of water precipitated by atmosphere. It is measured in millimeters per unit time.

  40. 6. CLOUDS & SUNSHINE: Clouds are observed for their form, amount, direction and height. Such observations give an insight into the sequence of weather in a particular locality. Similarly, amount of sunshine also give information about the weather.

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