Which of the following can be found as pollutants in the drinking water in some parts of India? Select the correct answer using the codes given below.

Answer: (c) 1, 3 and 5 only

Arsenic, fluoride and uranium occur naturally in Indian groundwater.

Statement by statement

1. ✓ YES Arsenic in groundwater of the Ganga–Brahmaputra plains (West Bengal, Bihar).

2. ✗ NO Sorbitol is a sweetener, not a water pollutant.

3. ✓ YES Fluoride in Rajasthan, Andhra, Telangana and more.

4. ✗ NO Formaldehyde is not a groundwater contaminant in India.

5. ✓ YES Uranium in groundwater of Punjab and Rajasthan.

The idea

These three can come from industry and mining too. In groundwater they often come from the rocks themselves: certain minerals deep underground slowly dissolve into groundwater. People began drinking them when hand pumps and tube wells replaced surface water. This is called geogenic contamination.

Mineral in deep rock or sediment → Dissolves slowly into groundwater → Tube well draws that water → Drunk for years → Slow poisoning shows up

The trap

Uranium sounds unlikely in water, but Punjab’s aquifers have it.

Also know

Arsenic: Ganga–Brahmaputra plains (West Bengal, Bihar, Uttar Pradesh, Assam); causes skin lesions and cancer. Fluoride: Rajasthan, Telangana, Andhra Pradesh, Gujarat; damages teeth and bones (fluorosis). Uranium: Malwa region of Punjab; harms the kidneys. Nitrate is different: it comes from fertiliser and sewage and causes blue baby syndrome.