Arsenic in Water: The Silent Poison

Arsenic is a naturally occurring element that can enter drinking water through rock weathering, mining, smelting, and agricultural runoff. In water, inorganic arsenic compounds—mainly arsenite and arsenate—are the most toxic. Because arsenic-contaminated water often has no taste, color, or smell, people may consume it for years without knowing.

The World Health Organization recommends a maximum level of 10 micrograms per liter, yet many regions still exceed this guideline.

Health Effects

At high doses, arsenic causes acute poisoning: nausea, vomiting, abdominal pain, diarrhea, dehydration, and in severe cases, shock and death. More commonly, the danger comes from long-term exposure to lower concentrations. Chronic arsenic poisoning, known as arsenicosis, produces characteristic skin changes such as dark patches and hard, raised lesions on the palms and soles. These are early warning signs of a deeper problem.

Over time, arsenic damages multiple organ systems. It is classified as a human carcinogen and is linked to skin, bladder, lung, kidney, and liver cancers. It also contributes to cardiovascular disease, including hypertension, heart attack, and stroke. 

Neurological effects range from numbness and tingling in the hands and feet to cognitive impairment. Arsenic exposure has been associated with diabetes, respiratory illness, liver fibrosis, and weakened immune function. In pregnant women, it raises the risk of miscarriage, stillbirth, and low birth weight, while children exposed early in life may suffer impaired growth and reduced intellectual development.

Environmental and Social Consequences

Arsenic does not stay in water alone. Contaminated irrigation water poisons soil and accumulates in crops, especially rice, which is particularly efficient at taking up arsenic. Aquatic organisms suffer direct toxicity, and bioaccumulation can spread arsenic through the food chain, reducing biodiversity and threatening fisheries. Livestock that drink contaminated water may also accumulate arsenic in their tissues.

The social and economic costs are equally serious. Families affected by arsenicosis face chronic medical expenses, lost income, and social stigma. Communities may be forced to abandon their homes or rely on distant, expensive water sources. In poorer regions, the burden falls hardest on children, pregnant women, the elderly, and the malnourished, who are already more vulnerable.