2016 · Q11
Excessive use of which of the following fertilizers may be responsible for the presence of a toxic substance in groundwater?
General KnowledgeChemistry
- ANitrogen
- BPhosphate only
- CPotassium only
- DPhosphate and potassium
Explanation
Excessive application of nitrogenous fertilizers leads to nitrate leaching into groundwater; ingested nitrate converts to nitrite in the body and causes methemoglobinemia ("blue baby syndrome"), a toxic effect. Phosphate and potassium fertilizers do not produce this characteristic groundwater toxin — phosphates mainly cause surface-water eutrophication. Hence nitrogen fertilizers are the answer.