Limit of BOD prescribed by Central Pollution Control Board for the discharge of industrial

and municipal waste water into natural surface water, is

1. < 3.0 ppm

2. < 10 ppm

3. < 100 ppm

4. < 30 ppm

Checking of re-radiating heat by atmospheric CO₂ methane, ozone, dust is known as 

1. green house effect

2. radioactive effect

3. ozone layer

4. solar effect.

Chronic exposure to arsenic causes ?

1. blue-baby syndrome

2. foot and mouth disease

3. dropsy

4. itai-itai disease

Green muffler is used against which type of pollution ?

1. Air

2. Water

3. Soil

4. Noise

Biochemical Oxygen Demand (BOD) is a measure of

1. industrial wastes poured into water bodies

2. extent to which water is polluted with organic compounds 

3. amount of carbon monoxide inseparably

4. amount of oxygen needed by green plants during night.

Drinking of mineral water with very low level of pesticides (about 0.02 ppm) for long

periods may :-

1. produce immunity against mosquito

2. cause leukemia (blood cancer) in most people

3. cause cancer of the intestine

4. lead to accumulation of pesticide residues in body fat

Photochemical smog formed in congested metropolitan cities mainly consists of

1. ozone, peroxyacetyl nitrate and NO_x

2. smoke, peroxyacetyl nitrate and SO₂

3. hydrocarbons, SO₂ and CO₂

4. hydrocarbons, ozone and SO_x.

In almost all Indian metropolitan citiies like Delhi, the major atmospheric pollutant(s)

is/are:

1. suspended particular matter (SPM)

2. oxides of suplhur

3. carbon dioxide and carbon monoxide

4. oxides of nitrogen.

A lake with an inflow of domestic sewage rich in organic waste may result in 

1. drying of the lake very soon due to algal bloom

2. an increased production of fish due to lot of nutreients

3. death of fish due to lack of oxygen

4. increased population of aquatic food web organisms.

Minamata disease was caused due to the consumption of

1. sea food containing lot of cadmium

2. fish contaminated with mercury

3. oysters with lot of pesticide

4. sea food contaminated with selenium.