Air Pollution & its Gaseous Pollutants!

[Nethra K Putti]

AIR POLLUTION

- the change in the composition of air i.e. the presence of materials in the air harmful to human & environment is called air pollution.

TWO TYPES OF POLLUTANTS:
1) Gaseous
2) Particulate

1) Gaseous Pollutant :
a) Sulphur oxides, Hydrogen Sulphides :
- Sources :biological decomposition, volcanic erruption smelting of sulphide containing ores, combustion of sulphur containing fuels such as coal & oil, petroleum refining & geothermal energy.
- Harmful effects : suppress the growth, low reproductive capacity & low yield , defoliation & cellular collapse.
- On human :constricts bronchi, damages lungs, lower resistance to pneumonia & influenza, bronchitis & emphysema.

b) Hydrogen Fluride :
- Sources : volcanoes, aluminium, steel & electro chemical reduction plant, blast furnaces, brick, tile & superphosphate fertilizer industries from combustion of coal.
- Harmful effects : impair plant growth, excessive dropping of bloom & young fruits , small & seedless fruit.
- On human : --

c) Nitrogen Oxides :
- Sources : anaerobic breakdown of nitrogenous compounds by bacteria, forest fires & lightening . Anthropogenic but major sources are power generators, motor vehicles, burning of organic waste, explosives & nitrogenous fertilizers.
- Harmful effects : collapse of leaves, enhancement of green colour followed by chlorosis, increase in fruit drop & low fruit yield.
- On human :general & pulmonary edema & hemorrhage .

d) Hydrogen Chloride :
- Sources : accidental spills from chemical manufacturing plants, combustion of coal paper, plastics, chlorinated hydrocarbon & ignition of solid fuel rocket engines.
- Harmful effects : abaxial glazing of leaves caused by collapse of cellulose.
- On human : plasmolysis of epidermal cells.

e) Hydro Carbons : (methane, tarpenes, ethylene, aniline)
- Sources :biological decomposition of organic matter, seepage from natural gas & oilfield & volatile emissions from plants, incomplete combustion of fuels , motor vehicle exhaust, petroleum refinary, agriculture burning.
- Ethylene causes : yellowing & necrosis of leaves, chlorosis of flora buds, thickening of stems, reduced growth, low content of chlorophyles.
- Aniline : appearence of bands on leaves, necrotic spots & abscission of leaves.
- On human : irritation of mucous membrane, bronchial constriction & eye irritation.

f) Ammonia :
- Sources :refrigerator, precoolar system , ammonium fertilizers & nitric acids, domestic incinerations.
- Harmful effects :bleaching of leaves & flower reduction of root & shoot growth.

g) Carbon Mono-oxides :
- Sources :cheifly from automobile engines & furnaces.
- Harmful effects :headaches, dizziness, inability to distinguish time intervals, cardiac & pulmonary change. prolong exposure leads to death due to formation of carboxy-hemoglobin in RBC, decreasing oxygen carrying capacity. it is a poisonous gas.

h) Photochemical oxidents :
- Sources :secondary pollutants formed by photo chemical reactions among primary polutants nitrogen oxides are ozone & peroxy acetyl nitrate also called brown air.
- Harmful effects : ozone : defoliation, suppression of growth & low yield , cause of several diseases such as weather fleck of tobacco, leaftip burn of carnations , tip burn of onions.
- PAN : bronzing & glazing of abaxial leaf.
- On human :stringing of eyes, coughing headaches, severe tired feeling, oedema narmorrhage, dry throat disorientation & altered breathing.

2) PARTICULATE POLLUTANT :
a) Florides :
- Sources : increase in floride contents of leaves, intake of which cause calcification of bones & teeth called flurosis in cattle.

b) Lead :
- Sources : tetra ehtyl lead used as anti knocking additive in fuels of motor vehicles, also from smeltig complexes, ceramic paints, pesticides & solar.
- Harmful effects : interferes with development & maturation of RBC.chronic exposure leads to striped red cells, damaged liver, kidney, gastro-intestine & includes adnormalitites in fertility.

c) Cement kilu :
- particulates emitted from cement.
- causes : premature fall of needles, formation of more stomata, increase in number ofinfertile seeds.

[chanda_s]

AIR POLLUTION

- the change in the composition of air

if for whatever reason, the proportion of oxygen increases in the air, will it still be called air pollution?

[Nethra K Putti]

if for whatever reason, the proportion of oxygen increases in the air, will it still be called air pollution?

some how you are not getting proper or clean air to breath. if proportion of oxygen increases / decreases in the air why not you call it still as air pollution? so many of them who don't know about this is still thinking it as air pollution only.

[chanda_s]

you haven't answered my question.

[vishaw]

I think Sir,

If level of O2 is decreased it will lead to increase in other components of the air like CO2, N2, etc that may harm the organisms.
But if we look at increase in O, then it may lead to improper photosynthesis as plant will be getting less of CO2, and thus will harm plant life.

So may be term pollution signifies addition of unwanted components but you have asked very good question. Pollution is defined as the introduction of pollutants (whether chemical substances, or energy such as noise, heat, or light) into the environment to such a point that its effects become harmful to human health, other living organisms, or the environment. Hence it is pollution.

Regards