Health Hygiene & Sanitation

Lesson 29 : Air

Prevention And Control Of Air Pollution

The WHO has recommended the following procedures for the prevention and control of air pollution:

1. Containment: prevention of escape of toxic substances into the ambient air.


2. Replacement: replacing the technological process causing air pollution, by a new process that does not. For example use of electricity, natural gas and central heating in place of coal.


3. Dilution: dilution is valid so long as it is within the self ­cleansing capacity of the environment. The establishment of "green belts" between industrial and residential areas is an attempt at dilution.


4. Legislation: legislation like Clean Air Acts, Legislation on height of chimneys, powers to local authorities to investigate, for research and education, creation of smokeless zones and enforcement of standard for air quality. The Govt. of India has enacted "The Air (Prevention and Control of Pollution) Act" in 1981.


5. International Action: The WHO has established an international network of laboratories for the monitoring and study of air pollution.

Disinfection of AIR

The methods employed for disinfection of air are

• Mechanical Ventilation: reduces vitiated air and bacterial density


• Ultraviolet Radiation: effective in special situations like operation theatres and infectious disease wards.


• Chemical Mists: Triethylene glucol vapours are effective air bactericides against droplet nuclei and dust.


• Dust Control: Application of oil to floors of hospital words reduces the bacterial content of the air.