Groundwater in 12 Indian states found to be contaminated with uranium

Subject :Environment

Section: Pollution

Context:

Twelve Indian states have uranium levels beyond permissible limits in their groundwater, the most recent report on the state of groundwater released by the Central Groundwater Board, revealed.

Details:

Uranium concentrations in the country’s shallow groundwater range from 0-532 parts per billion (ppb).
Uranium concentration is within safe limits in 13 states and none of the samples collected from Kerala had its presence.

Uranium contamination:

Uranium is a nephrotoxic element and can have an adverse impact at very high concentrations.
This means that people dependent on groundwater containing the element are at a higher risk of impaired renal function and kidney disease.
Exposure to uranium may also lead to bone toxicity.

The permissible limit of uranium in groundwater:

30 ppb is the safe level prescribed by the Bureau of Indian Standards (BIS) and the World Health Organization (WHO).

Worst affected states:

Punjab is worst affected with uranium presence being more than 17.7 times the prescribed limit. Nearly 29% of wells in Punjab is contaminated with uranium.
The 12 affected states are Punjab, Haryana, UP, Rajasthan, Tamilnadu, MP, Odisha, Delhi, Telangana, Chhattisgarh and Bihar.

2019 vs 2022; a comparison

In a 2019 assessment, groundwater in 18 states was found to be contaminated with uranium.
Of those, the uranium levels in six states– Andhra Pradesh, Himachal Pradesh, Maharashtra, Goa, Karnataka and West Bengal– are currently upgraded to ‘within the prescribed limits’ zone.

Causes of contamination:

Geogenic processes are responsible for uranium contamination.
- High levels of uranium are largely due to natural uranium content in aquifer rocks,oxidation state and groundwater chemistry.
- Extreme bicarbonate levels were also found at the sites with high uranium levels. Bicarbonates help to bring the uranium out of the source rocks.
Anthropogenic causes include:
- Overexploitation of groundwater
- Groundwater-table decline
- Nitrate pollution

Solution:

Reverse osmosis (RO) is one of the latest membrane-based technologies used in water purification systems to remove uranium.