Pollution

81. The use of plastics has led to a number of environment-related problem

The use of plastics has led to a number of environment-related problems. For this, which one of the following statements is correct?

[amp_mcq option1=”They are non-biodegradable.” option2=”They do not get released into water and food.” option3=”They do not have any biochemical synthesis activity.” option4=”They are harmless to humans.” correct=”option1″]

This question was previously asked in
UPSC CDS-1 – 2024
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The main environmental problem associated with plastics is their persistence in the environment. This is because most plastics are not biodegradable, meaning they are not broken down by natural processes like microbial action within a reasonable timeframe.
Plastics are non-biodegradable and accumulate in the environment, leading to pollution of land, water, and air.
While plastics themselves might not have direct biochemical synthesis activity, their disposal and breakdown into microplastics can release harmful chemicals into the environment. They do get released into water bodies and can enter the food chain. Many types of plastics contain additives that are harmful to humans and wildlife.

82. Which one of the following is the most important factor for the formul

Which one of the following is the most important factor for the formulation of smog?

[amp_mcq option1=”Formation of an ‘inversion lid'” option2=”Long winter nights” option3=”Presence of many air pollutant resources” option4=”Rapid fall in temperature with increasing height above the sea level” correct=”option1″]

This question was previously asked in
UPSC CDS-1 – 2022
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Smog is formed when pollutants (like smoke, sulfur dioxide, or vehicular emissions) combine with fog or react in the presence of sunlight (photochemical smog). A temperature inversion, forming an ‘inversion lid’, traps these pollutants close to the ground, preventing vertical mixing and dispersion. This concentration of pollutants significantly enhances the formation and severity of smog. While the presence of pollutants is necessary, their accumulation caused by the inversion is the most critical factor for formulation (concentration and reactions) of intense smog events.
Temperature inversion (inversion lid) is crucial for trapping pollutants near the surface, leading to high concentrations necessary for smog formation.
Normal atmospheric conditions involve temperature decreasing with height, promoting vertical air movement and dispersion of pollutants. An inversion layer is a layer where temperature increases with height, acting like a lid on the air below it. Long winter nights can contribute to stable conditions and ground-level inversions, but the inversion itself is the direct mechanism trapping pollutants. Rapid fall in temperature with height (normal lapse rate) disperses pollutants, preventing smog formation.

83. Which one of the following is the main reason of acid rains ?

Which one of the following is the main reason of acid rains ?

[amp_mcq option1=”Dissolution of sulphur and nitrogen oxides in rain” option2=”Dissolution of minerals in rain” option3=”Dissolution of dust particles in rain” option4=”Dissolution of soil solution in rain” correct=”option1″]

This question was previously asked in
UPSC CDS-1 – 2022
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The main reason for acid rain is the dissolution of sulphur and nitrogen oxides in rain.
Acid rain is caused by atmospheric pollution, primarily from industrial processes, vehicles, and burning of fossil fuels. These activities release sulfur dioxide (SO₂) and nitrogen oxides (NOₓ) into the atmosphere. These gases react with water, oxygen, and other chemicals to form sulfuric acid (H₂SO₄) and nitric acid (HNO₃), which then fall to the ground in precipitation (rain, snow, fog, etc.).
While rain naturally contains dissolved carbon dioxide, making it slightly acidic (pH ~5.6), acid rain has a significantly lower pH (typically below 5.0, and can be much lower). The dissolution of minerals, dust particles, or soil solution in rain do not cause acid rain; they might affect the pH of runoff or surface water but are not the primary cause of acidic precipitation itself.

84. The ‘Basel Convention’ is aimed at protecting human health and environ

The ‘Basel Convention’ is aimed at protecting human health and environment against adverse effects of which of the following?

[amp_mcq option1=”Hazardous wastes” option2=”Persistent Organic Pollutants (POPs)” option3=”Mercury” option4=”Chemicals and pesticides” correct=”option1″]

This question was previously asked in
UPSC CDS-1 – 2020
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The ‘Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal’ is an international treaty that was designed to reduce the movements of hazardous waste between nations, and specifically to prevent transfer of hazardous waste from developed to less developed countries (LDCs). Its aim is to protect human health and the environment against the adverse effects of hazardous wastes.
– Basel Convention regulates the transboundary movement of hazardous wastes and other wastes.
– It requires prior informed consent for such movements.
– It promotes environmentally sound management of hazardous wastes.
Other conventions related to chemicals and pollutants include:
– Stockholm Convention on Persistent Organic Pollutants (POPs).
– Minamata Convention on Mercury.
– Rotterdam Convention on the Prior Informed Consent Procedure for Certain Hazardous Chemicals and Pesticides in International Trade.

85. Statement I : Bioaccumulation is a process of progressive accumulation

Statement I :
Bioaccumulation is a process of progressive accumulation of heavy metals and pesticides in an organism.
Statement II :
Large fishes of the pond are found to have higher concentration of pesticides than planktons of the same pond.

[amp_mcq option1=”Option text is missing in the image.” option2=”Option text is missing in the image.” option3=”Option text is missing in the image.” option4=”Option text is missing in the image.” correct=”option2″]

This question was previously asked in
UPSC CDS-1 – 2018
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Statement I is true. Bioaccumulation is defined as the gradual accumulation of substances, such as pesticides, or other chemicals in an organism. This happens when the rate of intake of the substance exceeds the organism’s ability to remove it through metabolism or excretion. Statement II is also true. This phenomenon, where concentrations of substances like pesticides increase at successively higher levels in a food chain, is called biomagnification. Large fish are typically at higher trophic levels than plankton, and thus accumulate higher concentrations of persistent chemicals that are bioaccumulated by organisms at lower levels and passed up the chain. However, Statement II describes the *result* of bioaccumulation and biomagnification across a food chain, it does not explain the *process* of bioaccumulation (accumulation within a single organism) defined in Statement I. Therefore, Statement II is not the correct explanation for Statement I.
Bioaccumulation is the accumulation within one organism. Biomagnification is the increase in concentration of a substance as it moves up the food chain.
Persistent organic pollutants (POPs) and heavy metals are common substances that undergo bioaccumulation and biomagnification, posing risks to organisms at higher trophic levels, including humans who consume contaminated fish or meat.

86. Which of the following statements is / are correct ? 1. Acid rain re

Which of the following statements is / are correct ?

  • 1. Acid rain reacts with buildings made from limestone
  • 2. Burning of sulphur containing coal can contribute to acid rain
  • 3. Eutrophication is an effective measure to control pollution

Select the correct answer using the code given below :

[amp_mcq option1=”1 and 2 only” option2=”2 and 3 only” option3=”1 only” option4=”1, 2 and 3″ correct=”option1″]

This question was previously asked in
UPSC CDS-1 – 2016
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Statements 1 and 2 are correct, while statement 3 is incorrect.
Acid rain is corrosive and can damage buildings made of materials like limestone (calcium carbonate) through chemical reaction. Burning fossil fuels containing sulfur, such as coal, releases sulfur dioxide (SO2), which is a major precursor to acid rain. Eutrophication is the process of excessive nutrient enrichment in a water body, often caused by pollution (e.g., nutrient runoff), leading to algal blooms and oxygen depletion; it is a type of pollution, not a method to control it.
Acid rain also affects forests, lakes, and aquatic life. Major sources of acid rain precursors include sulfur dioxide (SO2) from burning fossil fuels and nitrogen oxides (NOx) from vehicle emissions and industrial processes. Controlling pollution sources is the way to prevent eutrophication.

87. Methyl Isocyanate gas, which was involved in the disaster in Bhopal in

Methyl Isocyanate gas, which was involved in the disaster in Bhopal in December 1984, was used in the Union Carbide factory for production of :

[amp_mcq option1=”Dyes” option2=”Detergents” option3=”Explosives” option4=”Pesticides” correct=”option4″]

This question was previously asked in
UPSC CDS-1 – 2016
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Methyl Isocyanate (MIC) gas involved in the Bhopal disaster was used in the production of pesticides.
The Union Carbide India Limited (UCIL) plant in Bhopal produced the pesticide Carbaryl, marketed under the brand name Sevin. Methyl Isocyanate (MIC) was a key intermediate chemical used in the synthesis of Carbaryl. The disaster occurred due to a leak of MIC gas from the plant.
Carbaryl is a carbamate insecticide used to control insect pests on crops. The Bhopal gas tragedy is one of the world’s worst industrial disasters.
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