How Does Arsenic in Nature Threaten Our Health? The Global Arsenic Problem

Arsenic naturally present in groundwater creates a major public health problem, significantly affecting millions of people in many countries worldwide. Long-term exposure to arsenic-containing water is known to cause numerous health problems, and research indicates that arsenic-contaminated drinking water causes various cancers, including skin, lung, bladder and kidney cancer, as well as cardiovascular diseases.

What Is Arsenic?

Arsenic is an element represented by the symbol As, with atomic number 33 and properties intermediate between metals and nonmetals. It enters the environment naturally through erosion of arsenic-containing rocks and volcanic eruptions, and through human activities such as mining contamination and arsenic-containing agricultural pest control. It occurs in organic and inorganic substances in water, air, food and soil. Arsenic is scarce at the earth’s crustal surface but relatively more abundant deeper down; water is therefore the most important source of exposure.

The greatest groundwater arsenic contamination occurs in Bangladesh, India’s West Bengal region and South Asia.

According to a new study published in the Journal of the National Cancer Institute, arsenic in drinking water, compared with most other carcinogenic substances, can remain in water much longer. Researchers following death rates in people exposed to arsenic-containing drinking water in a region of Chile identified increased lung, bladder and kidney cancer even 40 years after high exposure ended.

In 1958, a sudden large increase in arsenic occurred in water supplies in Antofagasta, northern Chile. An arsenic-removal plant established in 1970 then greatly reduced exposure. In a study examining exposure and cancer mortality, lung, bladder and kidney cancer death rates rose 10 years after the study began. In both men and women, death rates from these cancers stopped increasing only 40 years after high arsenic exposure.

Although research on this population continues, arsenic is already expected to prove one of the carcinogens with the longest-lasting effects on cancer development. This information should not remain merely theoretical; attention and solutions should address this major public health threat.

Are There Different Types of Arsenic?

Arsenic found in water, food, air and soil may occur in organic or inorganic form. Inorganic arsenic is markedly more harmful. It occurs in drinking water and cigarettes, while organic forms occur in seawater, seafood, meat and everyday products.

In our country, drinking water arsenic is measured regularly under the Regulation on Water Intended for Human Consumption published in 2005. According to this regulation; “Samples of spring and drinking waters placed on the market are collected at three-month intervals and analyzed for monitoring parameters and for arsenic, fluoride, bromate and bromoform.”

In our country, Public Health Laboratories affiliated with the Republic of Türkiye Ministry of Health measure arsenic in spring water, drinking water and natural mineral waters.

In 2008, high arsenic levels in mains water were detected in İzmir and some other Aegean and inland Aegean cities, drawing attention to the issue. Treatment plants were subsequently established quickly to try to prevent serious health problems.

Apart from water, foods containing arsenic include seafood, rice, mushrooms and poultry (in organic form). Because arsenic is also used in paints, it can enter the body orally through transfer to hands or food, lipstick use or smoking. Poor-quality, unregulated paints and cosmetics should therefore be avoided. Since paints occur in many materials such as artwork, wood, toys and porcelain, attention should be paid to products from China. A “Regulation on Restriction and Prohibition of Harmful Substances and Mixtures,” also issued in our country in 2008, specified limits on arsenic in substances used on boats and for wood preservation.

What Methods Remove Arsenic?

The main methods for removing arsenic from water supplies are coagulation with lime, alum or iron, reverse osmosis, membrane filtration and ion exchange. Treatment methods validated and selected by the United States Environmental Protection Agency can reduce concentrations to the World Health Organization (WHO) value of 10 μg/L. In our country (Ülkemizde), in 2008, the arsenic contamination limit was reduced from 50 μg/L to 10 μg/L. Widely used chemical treatment and filtration units remain inadequate in some regions. These problems should not be overlooked, and necessary steps should improve efficiency.

In conclusion water is the most important source of arsenic exposure, so we should choose water whose arsenic levels are measured regularly. To reduce long-term cancer risk following high exposure, further work is needed on disease screening, monitoring arsenic levels, treatment and healthcare resource planning, and public awareness of arsenic’s health effects.

Summary

• Arsenic naturally occurs at high levels in the groundwater of some countries.
• Arsenic is highly toxic in its inorganic form.
• Water with high arsenic contamination used for drinking, food preparation and irrigating fruits and vegetables constitutes the greatest arsenic-related public health risk.
• Long-term exposure to arsenic in drinking water and food may cause cancer and skin lesions. It also affects growth/development and has been associated with cardiovascular disease, neurological diseases and diabetes.
• The most important action in affected communities is preventing further arsenic exposure by providing safe water supplies.