Question

Assertion: Excess of nitrates in drinking water is harmful to infants.
Reason: Nitrates are responsible for the blue baby syndrome.
A. Both assertion and reason are correct and the reason is the correct explanation for the assertion.
B. Both assertion and reason are correct but the reason is not the correct explanation for the assertion.
C. Assertion is correct but the reason is incorrect
D. Both assertion and reason is incorrect.

Answer 1

In ventricular septal defect, the inner ventricular septum is incomplete thus, allows the mixing of the blood in the two ventricles. The mixing of the impure deoxygenated blood in the pure oxygenated blood leads to the decrease in the quantity of the oxygen supply to the body.
Due to these symptoms, blue baby syndrome develops.

Complete answer: The ‘Blue baby syndrome’ is a condition in which infants suffer from breathing problems and certain parts of the body appear blue-purple. In blue baby syndrome. the blood is not properly oxygenated and poor oxygenated blood transfers throughout the body. The reason for poorly oxygenated blood is the production of methemoglobin. Methemoglobin is a form of haemoglobin that contains ferric ions and has less ability to bind to the oxygen. When nitrates circulate throughout the body, they bind with haemoglobin and form methemoglobin. Methemoglobin has less affinity for oxygen, hence, infants contain high amounts of nitrate, that may cause the blue- baby syndrome.
Therefore, the correct answer is option A.

Additional information: The most common cause of the blue baby syndrome is the water contaminated with nitrates. After a baby drinks nitrate-rich water, the body converts the nitrates into nitrites. These nitrites bind to the haemoglobin in the body, forming methemoglobin, that is unable to carry oxygen. Nitrate is one of the most common groundwater contaminants in rural areas.

Note: The nitrite combines with fetal haemoglobin in the fetus or infant less than six months old, preventing the oxygen from the binding and being distributed around the body. Symptoms include the blueness around the mouth, hands and feet.