Pollutions - class-VIII

The world is facing accelerated rates of species extinction, largely due to human interference. There are four major causes collectively called as the evil quarter.

Itai-itai is the disease which was caused by the cadmium poisioning due to mining in Toyama Prefecture, Japan. This term was given by the locals for the severe pain the victims felt in the spine and the joints. It can also cause softening of bones and kidney failure. The disease was first described in the menopausal Japanese woman exposed to excessive levels of cadmium over their lifetimes. 

Due to the increase in the temperature, there can be incidental forests fires. The fires result in the burning of the vegetation and animals. This results in the formation of ash which contains the carbon particles. The fumes of the fire are released in the atmosphere causing air pollution. This is the natural source of air pollution.

MIC stands for methyl-isocyanate which is a gas and was leaked accidently in the Union Carbide subsidiary pesticide plant of Bhopal on 3rd dec, 1984 and led to the world's worst industrial disaster.

NO2 (55) + Hydrocarbons (90) = 145. SO2 = 200. Since 145 < 200, statement C is correct. Statement A is incorrect because 200 + 55 = 255, not 145.

Burning of fossil fuels is a man-made source of air pollution. The various fossil fuels like coal, natural gas, fuel oil are burned by humans for obtaining heat which is used in the generation of electric power. This leads to increase in the concentration of gas emissions like carbon dioxide and sulphur dioxide which enters the atmosphere and leads to air pollution. The increase in the concentration of carbon dioxide causes global warming and sulphur dioxide leads to breathing problem and the major cause of acid rain.

Green plants are the producers through which inorganic elements first enter the food chain. Green plants take in elements from the atmosphere, soil and water and manufacture food on which all the other animals either directly or indirectly feed on. Since plants are directly exposed to pollutants, the effect of pollution is first visible in natural flora of a place, then it will be visible on organisms that are dependent on the plants.

Pollution is any change in physical, chemical, or biological characteristics of the environment, that has the potentiality to harm human life, life of other desirable species, natural resources, cultural assets and industries. Pollution affects the atmosphere, hydrosphere and lithosphere by disturbing the delicate balance between abiotic and biotic components and the interaction between various organisms. Thus, the correct answer is option B.

TCDD stands for 2,3,7,8-Tetrachlorodibenzo-p-dioxin, which is a highly toxic dioxin.

Water pollution and land contamination, it's the quantity (or concentration) of a chemical in the air that makes the difference between "harmless" and "pollution." Carbon dioxide (CO2), is present in the air around you at a typical concentration of less than 0.05 per cent and breathing it in usually does no harm (you breathe it out all day long); but air with an extremely high concentration of carbon dioxide is toxic and could kill you in a matter of minutes. Since Earth's atmosphere is very turbulent many of us live in windy countries air pollution will often disperse relatively quickly.

Haze refers to the accumulation of smoke, dust, particulate matter and other dry particulates in the atmosphere. The formation of haze reduced visibility and it generally occurs in an area which is farther from the source of smoke and dust. 

• Environmental pollution is the release of chemical waste that causes detrimental (causing harm) effects on the environment. Environmental pollution is often divided into water pollution, air pollution, and soil pollution.
• Environmental pollution can be controlled by Least use of fossil fuel, The effluent of factories should be treated before discharge into the surrounding environment and By using more biodegradable products.
• So, the correct answer is 'All the above'.

Leaded petrol poisons the catalyst in a catalytic converter, rendering it ineffective. Therefore, leaded petrol should not be used in vehicles equipped with catalytic converters.

Large amounts of DDT are released into the air and on soil or water, when sprayed on crops and forests to control mosquitoes and other insects. Also, DDT may enter the atmosphere when it is evaporated from contaminated water and soil. DDT in the air may then be deposited on land or surface waters. This cycle of evaporation and deposition may be repeated many times. As a result, DDT causes an undesirable change in the atmosphere. 

There are many contaminants that contaminate the natural ecosystem. This leads to destruction of natural environment. This is called as pollution which disturbs the natural ecosystem.