Frequently Asked Questions About Iodine-131 Found in Surface Water

Several states have reported finding Iodine-131 in surface water (e.g., lakes, rivers, and reservoirs) and rain water. What does this mean for the public’s health?

Highly sensitive radiation monitors operated by EPA and others have detected very low levels of radioactive material in the air in the United States. These levels are consistent with estimated releases from the damaged nuclear reactors.

These findings were expected, given the sensitivity of our monitors and the fact that radioactive material is known to travel in the atmosphere. Federal, state, and local authorities will continue to monitor levels.

Will contaminated rainwater hurt me? Is it okay for my kids to play in the rain?

The very low levels of radioactive material currently being measured in surface water and rain water are far below those of public health concern.

Is it okay for my pet to drink the rainwater?

Drinking rainwater contaminated with radioactive material at the levels currently being detected is unlikely to harm your pet.

Since contaminated rain may have fallen in my area, is it okay to eat food from my garden or use rain water to irrigate it?

Yes. Keep in mind that it is always a good idea to wash food from your garden before you eat it.

Are there any groups of people that should be especially sensitive to radiation?

Infants, pregnant women and women who are breastfeeding are particularly sensitive to radiation. However, levels being measured now are still many times below the risk for even these groups, even for people who drink rainwater. Drinking water levels are many times below this. At this time, there is no need to take extra precautions with regard to drinking water.

Is it okay to take a shower or bath? Swim in a pool? In a river or lake?

Showering, bathing, or swimming in water with the amount of radioactive material that is currently being measured will not harm your health.

Should I drink bottled water instead of tap water?

At this time, there is no reason to switch to bottled water. State and local authorities will provide information for your community if this situation changes.

Should I be testing my water?

At this time, there is no need to take extra precautions with regard to drinking water.

States and the federal government routinely conduct water monitoring for safety and are working to ensure that drinking water does not pose a health risk to people in the US.

Is this likely to be a long-term problem?

Given the uncertainty related to the nuclear reactors in Japan, we don’t know how levels of radiation currently seen in surface water and rain water will change in the immediate time period. However, we do know that Iodine-131 disappears relatively quickly in the environment.

Who can I contact for the best information about my community?

The best source of information about your community is your local drinking water program or department, or your state environmental protection division or program.

The Centers for Disease Control and Prevention (CDC) protects people's health and safety by preventing and controlling diseases and injuries; enhances health decisions by providing credible information on critical health issues; and promotes healthy living through strong partnerships with local, national, and international organizations.