The highest DDT concentration in aquatic food chain shall occur in
1. Eel
2. phytoplankton
3. seagull
4. crab

Which one of the following statements in not valid for aerosols
1. They are harmful to human health
2. They alter rainfall and monsoon patterns
3. They cause increased agricultural productivity
4. They have negative impact on agricultural land

Match the items given in Column I with those given in Column II and select the correct option given below:

Which of the following is a secondary pollutant?
1. CO
2. ${\mathrm{O}}_3$
3. ${\mathrm{SO}}_2$
4. ${\mathrm{CO}}_2$

World Ozone Day is celebrated on
1. 5th June
2. 22nd April
3. 16th September
4. 21st April

In stratosphere, which of the following elements acts as a catalyst in degradation of ozone and releaseof molecular oxygen?
1. Carbon
2. Oxygen
3. Fe
4. CI

Drinking mineral water with low levels ( ~ 0.02 ppm) of pesticide for long period would
1. Cause cancer of intestine
2. Pesticide accumulation in the body
3. Cause leukaemia
4. Produce immunity against mosquito

Nitrogen oxides formed during emission from automobiles and power plants are a source of fine airparticles which lead to
1. Dry acid deposition
2. Photochemical smog
3. Wet acid deposition
4. Industrial smog

Which one of the following statements pertaining to pollutant is correct?
1. DDT is nonbiodegradable pollutant
2. Excess fluoride in drinking water causes osteoporosis
3. Excess cadmium in drinking water may cause black foot disease
4. Methyl mercury in water may cause ‘’itaiitai’’ disease.

Formation of non functional methaemoglobin causes blue baby syndrome. This is due to
1. Excess of arsenic in drinking water
2. Excess of nitrate in drinking water
3. Deficiency of iron in food
4. Increased methane content in atmosphere