1. Dr. Muhammad Razzaq Malik

2. 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

3. 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

4. Dr. Muhammad Razzaq Malik
Air Composition
Air is a mechanical mixture of gases.
Nitrogen – 78.1 percent
Oxygen – 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

5. 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

6. 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

7. 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
2. Comfortable and cool
3. Comfortable
4. Hot and uncomfortable
5. Extremely hot
6. Intolerably hot
Dr. Muhammad Razzaq Malik

8. 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

9. 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

10. 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

11. 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

12. 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

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

14. 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

15. 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

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