Arsenic

• Arsenic is a toxic metalloid found naturally in the environment.
• Exposure primarily occurs through contaminated drinking water, food, and industrial activities.
• Both acute and chronic exposure can lead to severe health issues, including various cancers and organ damage.
• Symptoms of arsenic poisoning range from gastrointestinal distress to neurological problems and skin lesions.
• Monitoring and mitigation of arsenic in water and food sources are crucial for public health protection.

What is Arsenic?

Arsenic refers to a chemical element (As) that is widely distributed in nature, existing in both organic and inorganic forms. Inorganic arsenic, which is more toxic, is commonly found in rocks, soil, water, and air. It is a known human carcinogen, meaning it can cause cancer. The World Health Organization (WHO) highlights that even low levels of chronic exposure to inorganic arsenic can lead to serious health problems over time. Recognizing the nature of arsenic is crucial for understanding its potential risks and implementing effective public health interventions.

Sources of Arsenic Exposure

Exposure to arsenic can occur through various pathways, primarily affecting populations globally. Where is arsenic found in ways that lead to human exposure? The main sources include:

• Contaminated Drinking Water: This is the most significant source of arsenic exposure worldwide, particularly in regions where groundwater is naturally high in arsenic. Wells drilled into arsenic-rich geological formations can deliver contaminated water for consumption.
• Food: Arsenic can accumulate in food crops, especially rice, as it absorbs arsenic from contaminated soil and irrigation water. Fish and shellfish can also contain arsenic, though often in less toxic organic forms.
• Industrial Processes: Activities such as mining, smelting, and the use of arsenic in pesticides, wood preservatives, and some industrial chemicals can release arsenic into the environment, leading to occupational or localized community exposure.
• Tobacco Smoke: Tobacco plants can absorb arsenic from the soil, contributing to exposure for smokers.

The United States Environmental Protection Agency (EPA) sets a maximum contaminant level (MCL) for arsenic in drinking water at 10 parts per billion (ppb) to protect public health.

Arsenic Health Effects and Poisoning Symptoms

Exposure to arsenic, particularly its inorganic form, can lead to a wide range of adverse health outcomes, collectively known as arsenic health effects. These effects can manifest differently depending on the dose, duration of exposure, and individual susceptibility. Chronic exposure to low levels of arsenic is associated with an increased risk of various cancers, including skin, bladder, lung, and liver cancers. It can also cause skin lesions, such as hyperkeratosis and pigmentation changes, which are often early indicators of chronic arsenicosis.

Arsenic poisoning symptoms can vary significantly between acute (short-term, high-dose) and chronic (long-term, low-dose) exposure:

• Acute Arsenic Poisoning: Symptoms can appear rapidly and include severe gastrointestinal distress (nausea, vomiting, diarrhea, abdominal pain), dehydration, cardiac abnormalities (arrhythmias), neurological effects (muscle cramps, weakness, delirium, seizures), kidney failure, and liver damage. In severe cases, it can lead to coma and death.
• Chronic Arsenic Poisoning (Arsenicosis): This form develops over time and is characterized by skin manifestations like darkening of the skin (hyperpigmentation) and thickening of the palms and soles (hyperkeratosis). Other effects include cardiovascular diseases (hypertension, peripheral vascular disease, “blackfoot disease”), neurological issues (peripheral neuropathy), respiratory problems (chronic cough, bronchitis), liver and kidney damage, and an increased risk of diabetes and developmental effects in children.

According to the WHO, millions of people worldwide are exposed to arsenic levels in drinking water that exceed safe limits, leading to a substantial global health burden from these diverse health effects.