How Does Arsenic Exposure Impact Health?

There are more than 250 known substances that cause cancer in humans. These substances, called carcinogens, are often present in our everyday surroundings—but there are ways to reduce exposure.

“Carcinogens are in the air we breathe, the water we drink, and the food we eat,” says Ana Navas-Acien, MD, PhD, MPH, a physician and epidemiologist at Columbia’s Mailman School of Public Health and member of the Herbert Irving Comprehensive Cancer Center.

Arsenic, the oldest known carcinogen, is a particularly serious problem. It consistently ranks as the most dangerous substance on the The U.S. Agency for Toxic Substances and Disease Registry’s Substance Priority List.

Dr. Navas-Acien explains how arsenic in the environment can impact health, who is most affected, and how to lessen your exposure.

What is arsenic?

Arsenic is a naturally occurring metal found in soil and water. However, it’s also a human-made contaminant produced by some farms, factories, and mines due to the chemicals they use. People are typically exposed to arsenic from drinking contaminated water, eating food grown in contaminated soil, and breathing in dust and air near hazardous sites.

Eating rice in particular can lead to chronic arsenic exposure because rice easily absorbs arsenic from the ground while it’s growing.

Used in the past as a poison, arsenic is odorless and tasteless, so people can consume or inhale it without realizing.

Arsenic has no nutritional benefit and is highly toxic, causing health problems even when levels are below governmental safety standards.

How does arsenic affect health?

Acute arsenic poisoningcan damage the digestive system, heart, lungs, and kidneys. The most common symptoms are nausea, vomiting, diarrhea, abdominal pain, and low blood pressure. Severe arsenic poisoning is rare but can lead to death within a few days of exposure, but medications that bind to the metal, known as chelating agents, are effective treatments in the presence of acute toxicity.

Chronic arsenic exposure often happens from regularly drinking contaminated water. Over time, chronic arsenic exposure increases the risk of developing several cancers, including:

• Lung cancer
• Prostate cancer
• Pancreatic cancer
• Bladder cancer
• Liver cancer
• Skin cancer

Long-term arsenic exposure can also lead to heart disease, diabetes, skin lesions, and problems with brain development in babies and young children. Dr. Navas-Acien’s research has shownthat people exposed to low to moderate levels of arsenic over long periods of time are more likely to die of cancer, heart disease, and other causes. 

Who is most at risk of arsenic exposure?

“Some people are more exposed to arsenic pollution than others,” says Dr. Navas-Acien. People who live and work in certain parts of the Midwest and the Southwest of the United States have among the highest rates of arsenic exposure in the country from drinking water, as do those living in rural areas where private wells are the primary water source.

Research also shows that Hispanic/Latino, American Indian, and Alaska Native communities, as well as small communities, are disproportionately exposed to arsenic and other carcinogens like uranium from their drinking water. In fact, Columbia epidemiologists found that people living in some American Indian Reservations in the Southwest have nearly three times more uranium in their bodiesthan the general U.S. population.

“It’s important to understand these patterns so we can prioritize reducing exposure and preventing cancer in the communities that are most at risk,” says Dr. Navas-Acien. “It’s an issue of environmental justice.”

How can I reduce my exposure to arsenic?

Certain foods easily absorb arsenic from the environment. Rinsing rice before cooking it, washing produce, limiting fruit juice intake, and eating a varied diet can help lower your exposure. If you have a private well, be sure to test the water quality regularly.

If you’re concerned about your arsenic exposure, your doctor can order a test to measure how much arsenic is in your urine. Avoid eating seafood for at least one week before the test. Seafood often has high levels of non-toxic forms of arsenic, which will complicate test results.

Ultimately, arsenic contamination is a large-scale problem that requires large-scale solutions. “There is no safe level of exposure to inorganic arsenic,” says Dr. Navas-Acien. “Improved regulations and investments in upgraded infrastructure can help protect everyone’s long-term health.”