Environmental Issues

A lake near a village suffered heavy mortality of fishes within a few days. Consider the following reasons for this: (i) Lots of urea and phosphate fertilizer were used in the crops in the vicinity (ii) The area was sprayed with DDT by an aircraft (iii) The lake water turned green and stinky (iv) Phytoplankton populations in the lake declined initially thereby greatly reducing photosynthesis Which two of the above were the main causes of fish mortality in the lake?

1. (i), (ii)
2. (iii), (iv)
3. (i), (iii)
4. (ii), (iii)

According to Central Pollution Control Board (CPCB), which particulate size in diameter (in micrometers) of the air pollutants is responsible for greatest harm to human health?

1. 2.5 or less
2. 1.5 or less
3. 1.0 or less
4. 5.2–2.5

Which one of the following is the correct percentage of the two (out of the total of 4) greenhouse gases that contribute to the total global warming?

1. CFCs 14%, Methane 20%
2. CO2 40%, CFCs 30%
3. N2O 6%, CO2 86%
4. Methane 20%, N2O 18%

In which one of the following the BOD (Biochemical Oxygen Demand) of sewage (S), distillery effluent (DE), paper mill effluent (PE) and sugar mill effluent (SE) have been arranged in ascending order?

1. SE < PE < S < DE
2. SE < S < PE < DE
3. PE < S < SE < DE
4. S < DE < PE < SE

In a coal fired power plant electrostatic precipitators are installed to control emission of:-

1. SPM
2. SO2
3. CO
4. NOx

Which one of the following is not a bioindicator of water pollution?

1. Blood-worms
2. Stone flies
3. Sewage fungus
4. Sludge-worms

Limit of BOD prescribed by Central Pollution Control Board for the discharge of industrial and municipal waste waters into natural surface waters, is -

1. <30 ppm
2. <3.0 ppm
3. <100 ppm
4. <10 ppm

Photochemical smog pollution does not contain-

1. Nitrogen dioxide
2. PAN (peroxy acyl nitrate)
3. Ozone
4. Carbon dioxide

Montreal Protocol which calls for appropriate action to protect the ozone layer from human activities was passed in the year-

1. 1988
2. 1986
3. 1985
4. 1987

Prolonged liberal irrigation of agricultural fields is likely to create the problem of -

1. Salinity
2. Acidity
3. Aridity
4. Metal toxicity