ARSENIC AND FLUORIDE CONTAMINATION – ENVIRONMENT
News:
Arsenic and fluoride in
groundwater: NGT issues notices to 24 states, four UTs
What's
in the news?
●
The National Green Tribunal has issued
notices to 24 states and four Union Territories in a matter regarding the
presence of arsenic and fluoride in groundwater.
Key
takeaways:
●
The tribunal noted in its recent order
that a media report stated that arsenic was detected in groundwater in parts of
230 districts across 25 states while fluoride was found in some pockets of 469
districts in 27 states.
1.
Arsenic:
●
It is a highly toxic element naturally
present in the environment and in the earth crust and groundwater of a number
of countries.
●
Arsenic contamination is found in 230
districts across 25 states.
●
The states of West Bengal, Jharkhand, Bihar, Uttar Pradesh, Assam, Manipur and
Chhattisgarh are reported to be most affected by arsenic contamination of
groundwater above the permissible level.
Sources:
●
Include both anthropogenic and geogenic,
with hotspots in the Ganga-Meghna-Brahmaputra
basin and Bihar being majorly affected.
Concerns:
●
Arsenic’s long-term exposure from
drinking-water and food can cause cancer,
skin disease, cardiovascular disease and diabetes.
Permissible
Limit:
●
World Health Organisation’s provisional
guideline value for arsenic in drinking water – 0.01 mg/l (10 μg/l).
●
Permissible limit of arsenic in India in
absence of an alternative source – 0.05
mg/l (50 μg/l).
Health
Impacts - Arsenic Poisoning:
●
Can lead to skin, lung, kidney, bladder
cancer, and other health issues such as skin manifestations, gastrointestinal
disorders, neurological effects, hormone disruption, and infertility.
2.
Fluoride:
●
Soil, water, plants, and foods contain
trace amounts of fluoride. Most of the fluoride that people consume comes from
fluoridated water, foods and beverages prepared with fluoridated water, and
toothpaste and other dental products containing fluoride.
●
Fluoride contamination is found in 469
districts across 27 states.
●
Rajasthan,
Andhra Pradesh, Telangana, Tamil Nadu, Gujarat, and West Bengal
are the relatively high-fluoride-contaminated states in India.
Toxicity:
●
It is highly toxic.
●
Death may result from ingesting as little
as 2 g of fluoride in an adult and 16 mg/kg in children.
●
Dark
yellow pigmentation of their teeth – a common visible sign
of excessive ingestion of fluoride.
Permissible
Limit:
●
According to WHO 1984 and Indian standard
drinking water specification 1991 the maximum permissible limit of fluoride in
drinking water is 1.5 ppm and
highest desirable limit is 1.0 ppm.
Health
Impacts:
●
Can lead to dental fluorosis, skeletal
fluorosis, and chronic diseases such as miscarriages, renal injury,
arteriosclerosis, and myocardial damage.