Question

Most harmful type of environmental pollutants are
A) Human organic waste
B) Natural nutrients in excess
C) Waste animal feed
D) Non-biodegradable waste

Answer 1

Hint: Waste which cannot be decayed as well as decomposed by the environment acts as a source of pollution. They can cause damage to the environment and also cause adverse health effects.

Complete answer:
Let us analyse the options to find the correct answer.
Option A: Human organic waste is considered biodegradable as it can be broken down into simple organic molecules by the action of microorganism and other living things. Biodegradable waste can be found in the municipal solid waste. In the absence of oxygen this waste will decay to methane by the Anaerobic bacteria. The main problem created by this waste is the production of the landfill gas. Landfill gases consist of carbon dioxide, methane and various other components. Hence, option A is incorrect.
Option B: Nutrients in excess can harm the ecosystems. The nutrients which are present in excess can be essential or non-essential. Excessive nutrients like nitrogen and phosphorus can stimulate the algal growth. Hence, option B is incorrect.
Option C: Waste animal feed can provide various functions. Waste like cow dung can be used both as electricity and fuel. Animal feed is stored in open ponds called lagoons or pits where it is untreated and is used as a farm fertilizer. Hence, option C is incorrect.
Option D: Non-biodegradable waste cannot be decomposed by the environment. They are extremely harmful for the environment. For example plastics, aluminium cans, toxic chemicals, etc. Hence, option D is correct.

Thus, the correct answer is option (D) Non-biodegradable waste.

Note: The effects of environmental pollution are as follows,
-They can lead to air, soil, water pollution.
-In case air is polluted it causes various kinds of respiratory diseases in humans.
-In case the soil is polluted the fertility of the soil will be affected thereby affecting the quality of crops.
-In case the water is polluted then there can be scarcity of drinking water and also various kinds of water borne disease can spread.