Blue baby syndrome, or methaemoglobinemia, in infants is caused by an excess of which substance in drinking water?
- A.Fluoride
- B.Nitrate
- C.Iron
- D.Calcium
Correct answer
Explanation
The correct answer is B, nitrate. Nitrate from fertiliser run-off and from sewage seeps into groundwater; in an infant it is converted to nitrite, which binds to haemoglobin and forms methaemoglobin, a compound that cannot carry oxygen. The child becomes short of oxygen and the skin takes on a bluish tinge, which gives the condition its common name of blue baby syndrome. Option A is wrong because excess fluoride causes fluorosis, mottling the teeth and deforming the bones. Option C is wrong because iron in water chiefly causes taste, colour and staining problems, not this disorder. Option D is wrong because calcium makes water hard, which affects soap and boilers but does not produce methaemoglobinemia. The practical lesson is that agricultural run-off is a leading non-point source of water pollution.
Read the full article: Water Pollution and River Cleaning: Causes and Schemes
Practice Questions
View allWhich pollution causes Itai-Itai disease in human beings?
- A.Mercury pollution
- B.Cadmium pollution
- C.Arsenic pollution
- D.Nitrate pollution
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Itai-Itai disease was first identified in Japan among people who ate rice grown with water polluted by cadmium from mining waste.
Read the full explanation →Minamata disease is caused by the pollution of water with which metal?
- A.Lead
- B.Mercury
- C.Cadmium
- D.Chromium
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Minamata disease takes its name from Minamata Bay in Japan, where a factory discharged mercury compounds that were converted by bacteria into methylmercury, concentrated in fish through biomagnification and then eaten by people.
Read the full explanation →A high value of biochemical oxygen demand in a water sample indicates:
- A.The water is clean and fit to drink
- B.Heavy load of organic pollution
- C.High dissolved oxygen
- D.Absence of bacteria
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Biochemical oxygen demand measures the oxygen that micro-organisms need in order to break down the organic matter present in a sample.
Read the full explanation →The excessive growth of algae in a water body due to enrichment with nitrates and phosphates is called:
- A.Biomagnification
- B.Eutrophication
- C.Salinisation
- D.Sedimentation
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When fertilisers, detergents and sewage add nitrates and phosphates to a lake or a slow-moving river, algae multiply into a bloom that covers the surface.
Read the full explanation →The Water (Prevention and Control of Pollution) Act, which set up the Central and State Pollution Control Boards, was enacted in which year?
- A.1972
- B.1974
- C.1981
- D.1986
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The Water (Prevention and Control of Pollution) Act of 1974 was India’s first comprehensive law on pollution.
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