What is pollution according to environmental science?

Undesirable change in physical, chemical and biological characteristics of air, water, land and soil.

True or False: The Environment Protection Act was passed in 1986.

True. This act was passed to protect and improve environmental quality.

Which gas causes giddiness, headache and cardiovascular malfunction?
A) Hydrogen sulphide
B) Carbon monoxide
C) Sulphur dioxide
D) Nitrogen oxide

B) Carbon monoxide causes these health effects including asphyxia.

Fill in the blank: ESP can remove about _____ of particulate matter from thermal power plants.

99% of particulate matter can be removed by Electrostatic Precipitator.

What happens when exhaust passes through a catalytic convertor?

Nitric oxide splits into nitrogen and oxygen, carbon monoxide oxidises to carbon dioxide.

Why should unleaded petrol be used with catalytic convertors?

Because leaded petrol inactivates the catalyst, making the convertor ineffective.

Riddle: I burn efficiently, leave no remains, and cannot be stolen easily. What fuel am I?

Compressed Natural Gas (CNG) used in Delhi buses.

True or False: Sound above 115 dB is harmful to ears.

True. Prolonged exposure above 80 dB leads to permanent hearing loss.

Which act includes noise as an air pollutant?
A) Water Pollution Act 1974
B) Environment Protection Act 1986
C) Air Pollution Act amended 1987
D) Noise Control Act 1981

C) Air (Prevention and Control of Pollution) Act amended in 1987.

What percentage of impurities makes domestic sewage unfit for humans?

A mere 0.1% impurities make domestic sewage unfit for human use.

Fill in the blank: _____ is the increase in toxicant concentration at successive trophic levels.

Biological magnification is the increase in toxicant concentration at successive trophic levels.

How does DDT affect bird populations specifically?

DDT disturbs calcium metabolism, causing egg shell thinning and declining bird populations.

What does BOD measure in water bodies?

Biochemical Oxygen Demand measures oxygen required for microbial breakdown of organic matter.

True or False: Higher BOD indicates cleaner water.

False. Higher BOD indicates more polluted water; clean water has lower BOD.

Which aquatic plant is called 'Terror of Bengal'?
A) Water lily
B) Water hyacinth
C) Lotus
D) Water lettuce

B) Water hyacinth (Eichhornia crassipes) grows abundantly in eutrophic waters.

What are the two steps in integrated wastewater treatment?

Conventional sedimentation-filtration-chlorine treatment, then biological purification using marsh organisms.

Fill in the blank: Ecosan toilets recycle human excreta into _____ to reduce chemical fertiliser needs.

Natural fertiliser to reduce the need for chemical fertilisers.

Which method involves burning municipal waste in open areas?

Open burning involves burning municipal waste in open dumps.

What is the main problem with sanitary landfills?

Chemical seepage from landfills can pollute underground water resources.

True or False: Polyblend mixture increases road life by factor of three.

True. This recycled plastic-bitumen mixture enhances water repellant properties.

Which farming method follows zero-waste cyclical processes?
A) Industrial farming
B) Organic farming
C) Hydroponic farming
D) Precision farming

B) Organic farming uses cyclical, zero-waste methods maximising resource utilisation.

What causes soil to become unfertile?

Excessive use of inorganic fertilisers, pesticides and chemical seepage from industries.

Fill in the blank: Radioactive wastes are buried _____ meters deep below earth's surface.

500 meters deep below the earth's surface after pretreatment.

What are the two serious problems with nuclear energy?

Accidental leakages like Chernobyl and safe disposal of radioactive wastes.

At what radiation dose levels do disorders and cancer occur?

At low doses, nuclear radiations cause disorders and diseases like cancer.