Question

Which disease in children is caused by intensive use of nitrate fertiliser?
A. Jaundice
B. Methemoglobinemia
C. Mumps
D. Septicemia

Answer 1

Hint: Methemoglobinemia is a blood disorder in which the iron in heme is oxidised to the ferric $ \left[ {F{e^{3 + }}} \right] $ form, resulting in a rise in haemoglobin levels. Methemoglobin is a non-functional oxygen carrier, resulting in cyanosis to variable degrees.

Complete Step By Step Answer:
Methemoglobinemia is a condition in which the blood contains a greater than normal level of methemoglobin (metHb, i.e. ferric $ \left[ {F{e^{3 + }}} \right] $ rather than ferrous $ \left[ {F{e^2}^ + {\text{ }}} \right] $ haemoglobin). Methemoglobin is a kind of haemoglobin that has a lower affinity for oxygen and contains ferric [Fe3+] iron. Ferric iron, on the other hand, has a higher affinity for bound oxygen. When oxygen binds to methemoglobin, it has a higher attraction for the three other heme sites (all of which are still ferrous) inside the same tetrameric haemoglobin unit. As a result, the red blood cell's overall ability to deliver oxygen to tissues is diminished, and the oxygen hemoglobin dissociation curve is pushed to the left. Tissue hypoxia can occur when methemoglobin levels in red blood cells are high.
The correct option is: B. Methemoglobinemia.

Note:
People should avoid known sources of MethHb, such as benzocaine, which is one of the most common initiators. Many over-the-counter drugs include benzocaine, however topical sprays containing the anaesthetic benzocaine are responsible for the majority of the severe cases. Foods containing nitrates, such as spinach, beets, and carrots, should be avoided by children under the age of six months.