Is There Radioactive Radium in Your Tap Water?
photo courtesy of Craig Cutler / Trunk Archive

Is There Radioactive Radium in Your Tap Water?


Ask Anne: The Right Way to Mix Metals?

To follow the news is to know that there are chemicals in our waterways and carcinogens in our food supply. But what and where and how much? That’s when things get murky. Which is why we tapped Nneka Leiba, the director of healthy living science at Environmental Working Group. This is the first installment of a monthly column in which Leiba answers our most pressing concerns about toxicity, the environment, and the health of the planet. Got a question for her? You can send it to [email protected].

The US has some of the cleanest drinking water in the world. Yet our tap water supply still contains hundreds of contaminants linked to cancer, brain and nervous system damage, endocrine disruption, and many other health effects. Most Americans’ water meets the federal government’s legal requirements. But there is often a big gap between what’s legal and what’s safe.

One of these contaminants is radium—found in the tap water supplies of more than half of all Americans. Exposure to even small amounts of radium can increase the risk of cancer, but there are steps you can take to protect yourself and anyone who drinks out of your tap.

What is radium?

Radium is a radioactive element found naturally in the Earth’s crust. It can leach from rocks and soil into water supplies. Radioactive elements produce ionizing radiation, releasing free radicals, which can damage DNA and lead to cancer.

How common is radioactive tap water?

A recent Environmental Working Group investigation found that tap water for more than 170 million Americans in all fifty states has detectable amounts of radium.

EWG compiled test data for almost 48,000 community water systems and mapped the occurrence of radium. From 2010 to 2015, more than 20,000 utilities reported the presence of radium in their water. (Use this interactive map to see if your utility is on the list.)

What are the health risks?

High doses of radium–typically higher than the levels seen in drinking water–are known to cause cancer. No amount of exposure to radium is risk-free, but the risk of cancer does decrease with lower doses.

As with many carcinogens, exposure to radium in early life is more harmful than being exposed as a healthy adult. The developing fetus is especially sensitive to the effects of ionizing radiation, which can cause birth defects and damage brain development. There is no evidence of a level below which a fetus would be safe from these effects. In other words, even very small amounts of radioactive contaminants in tap water may pose a risk during pregnancy.

Radium is most strongly associated with bone cancer but may also cause cancer in other parts of the body. The latest research also finds that radioactive substances may damage the nervous, immune, and endocrine systems.

What is the legal limit of radium in water?

Radioactivity is measured in units called picocuries. The Environmental Protection Agency’s legal limit for the combined amount of the two most widespread isotopes of radium (known as radium-226 and radium-228) is five picocuries per liter of water. Between 2010 and 2015, 158 water utilities in twenty-seven states reported radium in amounts that exceeded the federal legal limit.

If your water meets federal legal limits, does that mean it’s safe?

Not necessarily. Federal drinking water standards are not solely based on protecting health. The EPA also factors in the cost and feasibility to remove or reduce the contaminant. If a contaminant is costly to remove, the legal limit could be much higher than the level deemed safe. In addition, many of the legal limits are based on decades-old science. The EPA limit for radium was set more than forty years ago and has not been updated since.

Is there a safe level of radium in tap water?

Ideally, tap water would be completely free of radium and other carcinogens, but that’s not the case. So scientists have developed acceptable health benchmarks for contaminants that would pose a minimal risk to health.

In 2006, the California Office of Environmental Health Hazard Assessment set new public health goals for radium in drinking water. These goals are not legally enforceable but represent levels of radium that pose only a minimal risk – typically a one-in-a-million increase in the likelihood of developing cancer over a lifetime. The California public health goals–0.05 picocuries for radium-226 and 0.019 picocuries for radium-228–are at least 100 times lower than the federal limits.

What can I do about radioactivity in my tap water?

First, find out if there is any radioactivity measured in your drinking water. Visit EWG’s Tap Water Database and enter your ZIP code. If your water provider is not listed, contact the utility for records of recent testing. If you drink well water, your county health department should be able to inform you if it detects radioactive elements in any wells in your area. If there are any indications of radioactivity in your area, get your well water tested.

If radiation is detected in your water, consider buying a water filter. Radiation can be difficult to remove, and the type of filter you need will depend on the form of radioactivity detected. Choose a water filter that is certified to remove radium. And check your house for radon, a naturally occurring radioactive gas that can be found in indoor air in basements and crawl spaces.

As the director of healthy living science at Environmental Working Group, Nneka Leiba, M.Phil., M.P.H., translates complicated scientific topics, particularly ones dealing with the effects of everyday chemical exposures on our health, into easily accessible tips and advice. Leiba has become an expert in a wide range of issues, including the safety of ingredients in cosmetics and other consumer products, and drinking water quality. She earned graduate degrees in zoology and public health from the University of the West Indies and Johns Hopkins University, respectively.