Question

In agricultural regions, groundwater can have significant concentration of which pollutant?

• A. Cadmium
• B. Lead
• C. Nitrate
• D. Selenium

Hint:

The WHO's safe limit for nitrate in drinking water is 50 mg/L. Excess levels are linked to agricultural runoff.

Answer 1

The Correct Option is C

In agricultural regions, nitrate (NO_textsubscript{3}_textsuperscript{-}) is the most common groundwater pollutant due to:
- Excessive use of nitrogen-based fertilizers.
- Leaching from animal manure and septic systems.
- High solubility in water, allowing it to easily infiltrate groundwater. While heavy metals like cadmium, lead, or selenium may occur due to industrial waste, nitrates dominate in farming areas and pose risks like methemoglobinemia ("blue baby syndrome"). Thus, the correct answer is (3) Nitrate.