Air Pollution
Air Pollution
Air Pollution
SHORT QUESTIONS:
Ans: The contamination of the air by pollutants like dust, smoke and harmful gases which effects
human beings, plants and the environment.
Ans: The pollutants that are released directly into the atmosphere and persist in the atmosphere in
the form in which they are emitted are called primary pollutants.
The pollutants those are formed by chemical interaction between primary pollutants and
constituents that are already present in the atmosphere are known as secondary pollutants.
Eg., ozone, sulphur trioxide, acids like sulphuric acid, nitric acid which are responsible for acid rain.
Ans: At low concentrations carbon monoxide causes fatigue in healthy people and chest pain in
people with heart disease. At higher concentrations it may impair vision and coordination,
headaches, dizziness, nausea. At higher concentrations can cause death of a person due to acute
effects of formation of carboxyhaemoglobin in blood, which inhibits oxygen intake. This is referred
as to carbon monoxide poisoning.
5. What is smog?
Ans: Smog is the conditions of atmosphere caused by the combination of smoke and fog.
From fossil fuel combustion at power plants and other industrial facilities.
Industrial processes such as extracting metal from ore and the burning of high sulphur containing
fuels by locomotives.
Ans: Oxides of nitrogen is a green house gas and contributes to global warming.
They irritates the lungs, causes respiratory infections, bronchitis, lung cancer.
8. Lead is one of the most hazardous pollutants. Explain?
Ans: Lead causes effect on the nervous, immune, renal and cardiovascular system. In early childhood
slows cognitive development, learning deficits and other effects. High amount of lead can cause
gastrointestinal symptoms, damages the brain and kidney and also causes cancer. Hence lead is
considered to be one of the most hazardous pollutants.
Ans: Thermal inversion can lead to pollution such as smog which trapped close to the ground. Areas
with heavy pollution are prone to unhealthy air and an increase in smog when an inversion is
present because they trap pollutants at ground level instead of circulating them away.
Ans: Catalytic converter in automobile helps to control smog by converting nitric oxide back to
nitrogen and oxygen.
Ans: A pH of 5 does not allow the eggs of fishes to hatch and pH lower than that even kills he fishes
affecting the biodiversity. Acid can kill the symbiotic algae on the corals resulting in the death of the
corals
LONG QUESTIONS:
Ans: *Bhopal gas tragedy was a gas leak incident considered the world’s worst industrial disaster.
* The chemicals released were methyl isocyanate (MIC) and other chemicals which spread through
the city suffocating people, breathless and blinded.
* The lungs, brain, eyes, muscles as well as gastro intestinal, neurological, and reproductive and
immune systems of those who survived were affected.
* The Government confirmed 3787deaths, other estimate were 8000 died within two weeks.
* Dead bodies of humans and animals lay on the streets, leaved turned black and smell of burning
chili peppers lingered in the air.
When primary pollutants, the oxides of nitrogen and volatile organic compounds released during
burning of fossil fuel interacts under the influence of sunlight and produce hazardous chemicals.
*Traffic increases the emission of nitrogen oxides and VOCs in the early morning.
*Later the Nox and VOCs start reacting to form nitrogen dioxide.
3. Why does California experience thermal inversion? What are its effects?
Ans: Inversion layers are a significant factor in the formation of smog in Los Angeles because they
create stable atmospheric conditions. Inversions act to prevent mixing in the lower regions of the
troposphere, so pollutants become trapped quite easily and contribute to the formation of smog.
*Domestic combustion: Burning of chulahs or stoves causes air pollution, especially in the rural areas
where fire wood is used for cooking and heating propose. It releases harmful gases like carbon
dioxide, carbon monoxides, oxides of sulphur and nitrogen, hydrocarbons etc. Burning of garbage
from the households also pollutes the atmosphere with gaseous pollutants like carbon dioxide,
sulphur dioxide, nitrogen dioxide as well as suspended particulate matter such as dust and smoke.
*Automobile: Major pollutants released from the automobiles are carbon dioxide, carbon
monoxides, oxide of nitrogen, unburnt hydrocarbons, traces of lead etc. The aircrafts release nitrous
oxide which is ozone depleting substance. Vehicles release a large quantity of suspended particulate
matter.
*Industrial pollution: Chemical industries, paper industry, textile industries, steel industry,
petroleum industry are the most polluting industries. Cement and asbestos industry produce a lot of
dust particles. Thermal power plants produce a lot of gaseous pollutants like carbon dioxide, carbon
monoxide, oxide of nitrogen and sulphur. Industries also release gases which may be toxic or
hazardous to human health.
5. What is ozone? What are its sources? What are the effects of ozone layer depletion?
Ans: Ozone is a bluish coloured gas which contains three molecules of oxygen.
Sources of ozone: Ozone is emitted from industrial facilities and electric utilities, motor vehicle
exhaust, gasoline vapours and chemical solvents.
*The ultra violet rays entering the earth add to the heat of the earth thus raising the global
temperature.
Ans: Acid rain, also called acid precipitation or acid deposition, refers to the deposition of wet and
dry acidic components, produced from the emission of sulphur dioxide (SO2) and nitrogen
oxides (NOx , the combination of NO and NO2) from human activities, mostly
the combustion of fossil fuels.
*Nitrogen oxides can be produced naturally when lightning strikes and sulphur dioxide is produce by
volcanic eruptions and wild fires.
*Human activities that lead to acid rain are combustion of fossil fuel automobile, factories, thermal
power plants, burning of garbage, etc.
*Acid rain have harmful effects on plants, aquatic life and infrastructure.
*The leaves of the plants get affected by the acid and their capacity to photosynthesize food
decreases.
5. What is smog?