VPE 511: Environment and Environmental Hygiene (2+1)

CAUSES OF AIR POLLUTION

• Causes of Indoor Air pollution: Improper ventilation and exhaustive use of synthetic waxes, paints fumigants etc are the causes

Control of Indoor Air pollution

• Source Removal
• Sources other than human such as motor vehicles, wastes, appliances that are not in use etc to be moved out. Smoking must be practically prohibited in indoor.
• Improved Building Design
• Better consideration to instantaneously remove combustion production during cooking and related enjoyment activities. Preferably use low fuming heating agents, attached with chimney in the kitchen. Better exhaust in the toilet in favourably placed position ion the house for better aeration and lighting.
• Tobacco smoke
• Cigarette smoking is injurious to others health too and hence many legislations to prevent it with due license to manufacture and distribute the same. Typically about 500 ppm carbon monoxide is inhaled in each smoke which inactivate about 5% of hemoglobin . Other pollutants of cigarette smoke inclues carcinogens such as aldehydes, tar, hydrogen cyanide, nicotine, lead etc.
• The effects of cigarette smoking include lung cancer to smokers and also others living in the environment. Smokers recover slowly from acute virus infections. Cigarette significantly causes air pollution.
• Air Pollution from Cement Industry
• Cement is manufactured by crushing two types of stones, argillaceous and calcareous, brought from the quarry. The fine powders are blended in right proportion and slurry is prepared by adding water. The slurry slides down an inclined klin kept rotating on its axis, as very hot air blows through the klin. Due to the heat and rolling action clinker balls are formed and they roll out of the kiln. The clinker is pulverized to fine powder, which is the final product, cement. The above process in called a dry process. In an alternative wet process the raw material stones are crushed in a wet state and the slurries are blended in proportion.
• The air pollution from cement factories comprises mainly of
• Dust, cement , crushed stone power and ash content of coal fuel burning for power and
• So₂, NOX, CO and CO₂ , as combustion products of coal.
• Silica dust causes a lung disorder known as ‘silicosis’. Vegetation is affected by cement dust clogging the process of the leaves there by affecting the gas exchange process of the plant. The cement dust settling on the soil will adversely alter the soil composition affecting the land productivity. Noise and heat pollution also add to the nuisance in the victinity.
• To control air pollution in cement factories the following measures are to be recommended:
• Wet process of cement manufacturing should be encouraged. Since the dry process has more pollution potentials.
• Pulverization of clinker and transport of materials in the process flow should be enclosed to prevent dust spillage.
• Superior grade coal should be used, if coal firing is the source of energy.
• Air pollution control equipments like bag filters and electrostatic precipitators should be used. Unlike in other industries cement dust pollution control in the cement industry is rewarding to the management, since pollution means loss of the product itself.
• Green belt should be developed around the industry to reduce the dispersion of dust, noise and heat, which are efficiently absorbed by plantations.