Dr. Muhammad Razzaq Malik

Dr. Muhammad Razzaq Malik Air The immediate environment of man comprises of air. All forms of life are dependent on it. It supplies the life giving oxygen. Air provides the atmospheric condition. Dr. Muhammad Razzaq Malik

Dr. Muhammad Razzaq Malik Functions Human body cooled by the air contact. The special senses of hearing and smell functions through air. Disease agent may by conveyed by air. Dr. Muhammad Razzaq Malik

Dr. Muhammad Razzaq Malik Air Composition Air is a mechanical mixture of gases. Nitrogen – 78.1 percent Oxygen – 20.93 Per cent Carbon dioxide – 0.03 per cent Other gas traces : Argon, neon, krypton, xenon and helium, traces of ammonia water vapour and suspended matter such as dust, bacteria, spores and vegetable debris. Dr. Muhammad Razzaq Malik

Air Changes in Occupied Room Chemical changes Increase in carbon dioxide concentration Decrease in oxygen concentration Physical changes Rise in temperature Increase of humidity Decrease in air movement Body odours Bacterial pollution Dr. Muhammad Razzaq Malik

Effective Temperature It is the temperature of still, saturated air which would induce the same sensation of warmth or cold as that experience in the given conditions. It is a single value of the effect of temperature, humidity and movement of the internal air on the sensation of warmth or cold felt by the human body. Dr. Muhammad Razzaq Malik

Dr. Muhammad Razzaq Malik Comfort Zone Defined as the range of effective temperature over which the majority of adults feel comfortable. The detail is as following: Condition E T deg C 1. Pleasant and cool 20 2. Comfortable and cool 20-25 3. Comfortable 25-27 4. Hot and uncomfortable 27-28 5. Extremely hot 28 + 6. Intolerably hot 30 + Dr. Muhammad Razzaq Malik

Dr. Muhammad Razzaq Malik Pollution of Air The dust, smoke, toxic gases and chemical vapors has resulted in sickness and death. The main sources of air pollution are, Automobiles (Traffic) Industries (Combustion of coal, gas, oil, etc and manufacturing processes which) give off dust, fumes, vapours and gases. Domestic sources (Respiration of men and animals) Miscellaneous sources. (Decomposition of organic matter) Dr. Muhammad Razzaq Malik

Dr. Muhammad Razzaq Malik Air Pollutants These are carbon dioxide, carbon monoxide, sulphur dioxide, lead, hydro carbons, Cadmium, Hydrogen sulphide, Ozone, Polynuclear aromatic hydrocarbons and particulate matter. Dr. Muhammad Razzaq Malik

Effects of air pollution The Immediate Effects Effects on the respiratory system e.g., acute bronchitis. There may be immediate death by suffocation due to intense air pollution. Dr. Muhammad Razzaq Malik

Effects of air pollution Delayed effects: Chronic bronchitis, Lung cancer, Bronchial asthma, Emphysema, Respiratory allergies. Lead poisons many systems in the body and is particularly dangerous to children developing brain and nervous system, loss of IQ. Poor school performance and Behavioural difficulties. Dr. Muhammad Razzaq Malik

Effects of air pollution Social and economic aspects: These comprise destruction of plant and animal life; corrosion of metals; repairs and aesthetic nuisance. Air pollution also reduces visibility in towns. It can coil and damage clothings. Dr. Muhammad Razzaq Malik

Air Natural - Cleansing Mechanisms Wind Sunlight Rain Plant life Dr. Muhammad Razzaq Malik

Dr. Muhammad Razzaq Malik Disinfection of Air 1. Mechanical ventilation This reduces vitiated air and bacterial density. 2.Ultravoilet Radiation. It is effective in operation theatres and infectious disease wards. Direct exposure to ultraviolet is dangerous to the eyes and skin. 3.Chemical mists. Triethyline glucol vapours have been found to be effective air bactericidal agent. 4 Dust Control. Application of oil to floors of hospital wards reduces the bacterial content. Dr. Muhammad Razzaq Malik

Dr. Muhammad Razzaq Malik VENTILATION The process and practice of keeping an enclose place supplied with fresh air for breathing. Natural Ventilation: Perflation and aspiration Difference of temperature Diffusion of gases Dr. Muhammad Razzaq Malik

Artificial and Mechanical Ventilation The extraction or vacuum system The Plenum or propulsion system The balanced system Dr. Muhammad Razzaq Malik