Transcript Air - Dr Muhammad Razaq 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
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
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
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Increase in carbon dioxide concentration
Decrease in oxygen concentration
Physical changes
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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
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
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
Air Pollutants
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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
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Wind
Sunlight
Rain
Plant life
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
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