Arsenic pollution in ground water is due to

Correct option is C

Arsenic pollution in groundwater is often associated with arsenic acids, specifically arsenous acid (H₃AsO₃) and arsenic acid (H₃AsO₄). These acids form when arsenic-containing minerals, such as arsenopyrite (FeAsS), naturally weather or dissolve in water under certain conditions, leading to the release of arsenic ions into groundwater. The primary forms of dissolved arsenic are arsenite (As³⁺) and arsenate (As⁵⁺), both of which are derived from arsenous and arsenic acids, respectively.
Arsenous acid and arsenic acid are highly soluble in water, enabling the mobilization of arsenic in groundwater, especially under reducing (low oxygen) conditions, which are common in deep aquifers. This solubility makes these acids a direct cause of arsenic contamination in groundwater, posing significant health risks when consumed, including skin lesions, cancers, cardiovascular diseases, and developmental effects.
Information Booster Arsenic acids are key contributors to groundwater contamination:
· Arsenous acid (H₃AsO₃): This form of arsenic (As³⁺ or arsenite) is more toxic and is typically found in reduced (low-oxygen) groundwater conditions. It has higher mobility in water and is challenging to remove from drinking water supplies.
· Arsenic acid (H₃AsO₄): This form (As⁵⁺ or arsenate) is less toxic compared to arsenite but still poses serious health risks. It is commonly present in oxidizing environments and is usually easier to treat in water systems than arsenite.
These acids arise from natural geological sources in the Earth’s crust and are also influenced by human activities, such as mining and the use of arsenic-containing pesticides, which further increase arsenic levels in groundwater.
Additional Knowledge
· Oxides of Arsenic (Option a): Arsenic oxides, like arsenic trioxide (As₂O₃), are typically found in solid form and are not directly soluble in groundwater. They can, however, convert to arsenic acids under specific conditions.
· Sulphates of Arsenic (Option b): Sulfate compounds of arsenic are rare in groundwater and do not contribute significantly to arsenic pollution.
· Nitrates of Arsenic (Option d): Nitrates do not naturally contain arsenic and are associated with other types of groundwater contamination, primarily from agricultural runoff and fertilizers.