Arsenic

Overview

Arsenic comes in two general forms: organic and inorganic. Organic arsenic compounds contain carbon and can be found in plants (e.g., seaweed) or meat of animals (e.g., fish, chicken). Inorganic arsenic compounds are simpler in make-up. They are often found in water and also may be found in food (e.g., rice) and juices (e.g., apple). Inorganic arsenic is more toxic, but all arsenic is harmful to people of any age or health status even at low levels of exposure.

The most common source of arsenic exposure is through drinking water. Health effects may be barely noticeable at first, but if exposure continues, it can have severe, long-term effects. There is particular concern for infants and children exposed to arsenic in drinking water and some foods during their development. That’s why the U.S. Food and Drug Administration (FDA) regulates levels of arsenic in certain foods and monitors inorganic arsenic levels in foods like rice cereal and apple juice that are more likely to be eaten by young children.

Related Health Effects

Arsenic is known to cause cancer in humans and has been linked to cancer of the skin, lung, bladder, kidney, prostate, and liver.

Several studies suggest a link between arsenic and diseases like diabetes, heart disease, and stroke.

Researchers are finding that arsenic, even at low levels, can interfere with the body’s endocrine system and act as an endocrine disruptor. The endocrine system keeps our bodies in balance and guides growth and development.

Risk Factors

People are usually exposed by drinking water contaminated with arsenic. Arsenic levels tend to be higher in underground water sources like private wells than in lakes or reservoirs. About 2.1 million people in the U.S. may be getting their drinking water from wells that have high concentrations of arsenic.

Other sources of arsenic exposure include:

• Plants, especially rice, irrigated with arsenic-contaminated water or grown in contaminated soil
• Fish raised in contaminated water
• Mining and fracking contamination
• Coal-fired power plants
• Arsenic-treated lumber
• Pesticides
• Air pollution
• Tobacco smoke

Where you live plays a role in arsenic risk. In the U.S., areas of the West, Southwest, Midwest, and Northeast have higher levels of natural arsenic.

Children face greater risk from arsenic for several reasons:

• Relative to their size, children eat, drink, and inhale more air relative to their body weight than adults.
• The body’s natural defense systems that filter and process chemicals are not fully mature in children.
• Children often play on the floor or ground and put objects in their mouths.
• During important growth periods their development can be more easily disrupted by environmental chemicals.

Prevention Guidance

Safe water for drinking, cooking, and watering crops is the most important way to avoid arsenic. Other steps you can take include the following:

• Test your water. You can’t see, smell, or taste arsenic, so you must have your water tested to know if it’s there. Your local health department can help.
• Filter water. Special filters, like reverse osmosis or ion exchange systems, can be placed near a faucet. A whole-home water filter system can remove arsenic from water.

In addition, studies have shown that taking a folic acid supplement (400 micrograms daily, which is the recommended amount) may help your body get rid of arsenic if you’ve been exposed to it in drinking water over a long period.

Find Clinical Trials

Clinical trials uncover better ways to prevent, diagnose, treat, and understand diseases and conditions. To ensure results apply to everyone, volunteers of all ages, sexes, and backgrounds, including both healthy individuals and those with specific medical conditions, are needed. Find clinical trials on arsenic.

Community Support

The U.S. Environmental Protection Agency lists state programs for well water testing.

Research Information

The National Institutes of Health (NIH) is the largest public funder of biomedical research in the world. NIH invests most of its budget in medical research seeking to enhance life and to reduce illness and disability. NIH-funded research has led to breakthroughs and new treatments helping people live longer, healthier lives, and building the research foundation that drives discovery.  

NIH research has shown that teaching the public about arsenic and supporting water testing programs can effectively reduce exposure. The Superfund Research Program, which is administered by NIH’s National Institute of Environmental Health Sciences, supports these activities. It funds research groups across the country that provide education, well testing, and other resources to keep drinking water safe.

Find NIH-funded research projects using NIH RePORTER, a searchable database of current and past research projects supported by NIH and other federal agencies.