Consider the following statements regarding mercury pollution : 1. Gold mining activity is a source of mercury pollution in the world. 2. Coal-based thermal power plants cause mercury pollution. 3. There is no known safe level of exposure to mercury. How many of the above statements are correct?
- A.Only one
- B.Only two
- C.All three
- D.None
Correct answer
Explanation
The correct answer is C, All three. Gold mining and coal burning are the two biggest human sources of mercury, and no level of exposure is known to be safe.
Artisanal and small-scale gold mining uses mercury to bind gold into an amalgam, which is then heated, releasing mercury vapour; it is the largest human source of mercury emissions in the world. Burning coal is the next big source, because coal contains traces of mercury that escape through the chimneys of thermal power plants. Mercury that reaches water turns into methylmercury, which builds up in fish and moves up the food chain. The World Health Organization notes that there may be no threshold below which mercury causes no harm. Minamata disease in Japan showed its damage to the nervous system, and the Minamata Convention of 2013 seeks to curb its use.
A and B are wrong because all three statements are correct, not just one or two. D is wrong for the same reason.
Exam tip: Mercury: gold mining is the top source, coal burning second; Minamata Convention, 2013.
Practice Questions
View allIn India, Indus Dolphin, one of the world's rarest mammals, is mainly found in which one of the following rivers?
- A.Ganga
- B.Cauvery
- C.Brahmaputra
- D.Beas
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In India the Indus river dolphin survives only in a short stretch of the Beas in Punjab, around the Harike wetland.
Read the full explanation →Transition zone of varied natural vegetation occupying the boundary between two adjacent and differing plant communities is known as
- A.ecological succession
- B.ecotone
- C.ecological niche
- D.climax
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An ecotone is the zone of transition where two different communities or ecosystems meet and blend. Examples of ecotones are the belt between forest and grassland, the mangrove zone between land and sea, an estuary where river water meets the ocean, and the margin between a lake and its shore.
Read the full explanation →The Cartagena Protocol, to which India is a party, is related to
- A.combat the green house gasses and to reduce the global warming and climate change
- B.biosafety, negotiated under the aegis of the Convention on Biological Diversity
- C.combat the ozone depleting substances to protect the human lives from diseases
- D.combat the phenomenon of desertification by improving dry land farming in dry regions
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The Cartagena Protocol on Biosafety deals with the safe handling of living modified organisms. The protocol was adopted in 2000 as a supplementary agreement to the Convention on Biological Diversity and came into force in 2003; India is a party to it.
Read the full explanation →Consider the following statements :
1. Many urban and suburban areas experience a higher temperature than surrounding rural areas known as urban heat islands.
2. The reduction in urban green cover and the increase of built-up hard surface is the only cause of urban heat island.
Which of the statements given above is/are correct?
- A.1 only
- B.2 only
- C.Both 1 and 2
- D.Neither 1 nor 2
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Statement 1 defines the urban heat island correctly, but statement 2 is wrong because loss of green cover and more hard surfaces are not the only cause.
Read the full explanation →With reference to an initiative called 'The Economics of Ecosystems and Biodiversity (TEEB)', which of the following statements is/are correct?
1. It is an initiative hosted by UNEP, IMF and World Economic Forum.
2. It is a global initiative that focuses on drawing attention to the economic benefits of biodiversity.
3. It presents an approach that can help decision-makers recognize, demonstrate and capture the value of ecosystems and biodiversity.
Select the correct answer using the code given below.
- A.1 and 2 only
- B.3 only
- C.2 and 3 only
- D.1, 2 and 3
Show answer
Statement 1 is wrong because TEEB is hosted by the UN Environment Programme alone, not jointly with the IMF and the World Economic Forum.
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