Excessive nitrates found in groundwater in 440 districts

Context: Excessive nitrates have been found in groundwater in 440 districts as of
2023, an in-crease from 359 such districts in 2017, a report by the Central
Groundwater Board (CGWB) said on Wednesday. This is a health hazard,
particularly for young children, and a source of environmental toxicity. The
data suggest that about 56% of India’s districts have excessive nitrates —
defined as more than 45 mg per litre — in groundwater, largely due to the use
of subsidised synthetic nitrogenous fertilizer, a key input for farming. Of the
15,239 groundwater samples collected from across the country for testing, 19.8%
had nitrates or nitrogen compounds above the safe limits.

Nitrogen Pollution

·       About: Nitrogen
pollution refers to the excessive presence of nitrogen compounds in the
environment, primarily in water bodies like rivers and lakes. According to the
United Nations Environment Programme (UNEP), each year, 200 million tonnes of
reactive nitrogen, 80% of the total, is lost to the environment.

·       Sources
of Nitrogen Pollution: Agricultural Activities - One of the main
drivers of nitrogen pollution has been the rising consumption of nitrogen-based
fertilizer, which can leach into groundwater or runoff into surface water
bodies.

Industrial
Processes - Manufacturing processes, particularly those involved in the production
of nitrogen-based chemicals and fertilisers, release nitrogen compounds into
the environment.

Livestock
Farming - Livestock waste, primarily from manure and urine, contains nitrogen
compounds such as ammonia.

Biomass Burning
-
Wildfires and burning of cow dung cake as a fuel release nitrogen oxide (NOx)
and nitrous oxide (N2O) into the atmosphere.

·       Major
Impacts of Nitrogen Pollution: Eutrophication - Excess nitrogen acts
as a nutrient fertiliser for aquatic plants, leading to excessive growth of
algae and other aquatic vegetation. This phenomenon is known as eutrophication
and leads to algal blooming.

Human Health
Impacts - Nitrogen pollution can have direct and indirect effects on human health.
High levels of nitrogen dioxide (NO2) in the air can exacerbate respiratory
conditions such as asthma and increase the risk of respiratory infections.

Ozone Depletion
-
Nitrous oxide (N2O) released into the atmosphere can lead to the depletion of
the stratospheric ozone layer, which protects the Earth from harmful
ultraviolet (UV) radiation.

·       Government
Initiatives: Bharat Stage (BS VI) Emission Standards - Stricter emission
standards for vehicles and industries aim to curb the release of nitrogen
oxides and particulate matter, which are precursors to air and water pollution.

Nano Urea - It is a
fertiliser patented and sold by the Indian Farmers Fertiliser Cooperative
Limited (IFFCO) and has been approved by the government for commercial use. Nano
urea reduces the unbalanced and indiscriminate use of conventional urea and
increases crop productivity.

·       Way
Forward: Incentivizing Green Infrastructure - Offering incentives and
subsidies for the implementation of green infrastructure projects, such as
green roofs, rain gardens, and permeable pavements, which help mitigate
nitrogen runoff by absorbing and filtering stormwater.

Improved
Wastewater Treatment - Upgrading and expanding wastewater treatment
infrastructure ensures proper treatment and disposal of industrial and urban
sewage, preventing nitrogen-rich compounds from entering water bodies.