What is Arsenic?

Arsenic is a chemical element present in the environment.
It occurs – both naturally and through human sources.
Naturally – erosion of arsenic-containing rocks, volcanic eruptions
Human sources – mining and smelting ores, use of arsenic-containing pesticides. (Note: Source based questions are imp. UPSC has a habit of harping on sources)

II. Types of arsenic
Two types of arsenic compounds in water, food, air and soil – organic and inorganic
The inorganic forms of arsenic are more dangerous and have been associated with long-term health effects.

III. Arsenic in ground water
Mostly due to the leaching of minerals in rocks
dissolution of unstable arsenic minerals
pesticides and fertilisers
It enters the grazing food chain when this groundwater is used for drinking purposes and irrigation of crops.

IV. Arsenic in food (especially in Rice)
While most crops don’t readily take up much arsenic from the ground but rice is different. Rice takes up arsenic from soil and water.
Rice is usually grown in flooded fields where arsenic may come from – arsenic contaminated irrigated water or ground water.
Some seafood contains high levels of organic arsenic.
India and Vietnam are currently two of the world’s largest exporters of rice.

V. Do organic foods have less arsenic than non-organic foods?
Because arsenic is naturally found in the soil and water, it is absorbed by plants regardless of whether they are grown under conventional or organic farming practices.
[Note: This can be a converted into a logical question to confuse candidates into thinking organic forms must be arsenic free]

VI. Arsenic in Indian crops
West Bengal have been found to have high levels of groundwater arsenic. A recent study(2009) found that an adult in Kolkata consumes 44 μg of inorganic arsenic from cooked rice per day.
India has currently not set any standards regarding the presence of arsenic in rice and follows the internationally set standards.

VII. International standard on arsenic in Rice
On 17-July-2014, Codex Alimentarius Commission(under FAO), the UN body responsible for setting food safety standards, announced guidelines regarding permissible levels of arsenic in rice.
It has said that the approved arsenic limit in rice which should NOT be more than 0.2mg of arsenic per kg of rice.

VIII. Ways to reduce arsenic contamination in Rice
Improved irrigation of water (arsenic free)
Better agricultural practices – e.g. growing crops in raised beds instead of flooded fields