2011 Japanese Nuclear Emergency: Data Summaries
This page contains historical data summaries and statements issued from March 17, 2011 to June 30, 2011 about RadNet monitoring in response to the Fukushima, Japan, nuclear power plant accident. Monitoring and sample analysis results from this time period are available for download on Envirofacts. Obtain RadNet data on Envirofacts database.
On this page:
June 2011
June 30, 2011
- Statement—In response to the Japanese nuclear incident, EPA accelerated and increased sampling frequency and analysis to confirm that there were no harmful levels of radiation reaching the U.S. from Japan and to inform the public about any level of radiation detected. After a thorough data review showing declining radiation levels, on May 3, 2011, EPA returned to the routine RadNet sampling and analysis process for precipitation, drinking water and milk. As always, our 24/7 air monitoring stations continue to measure radiation levels, alerting scientists to even slight changes.
It is important to note that all of the radiation levels detected by RadNet monitors and sampling have been very low, well below any level of public health concern. Across the RadNet system, we saw decreasing radiation levels during April and May. Since May, sample analyses have predominantly shown no detections of radionuclides associated with the Japanese nuclear incident. EPA continues to work with federal partners to monitor the situation in Japan and stands prepared to accelerate radiation sampling and analysis if the need arises. Data will continue to be available on EPA's public website. EPA's nationwide radiation monitoring system, RadNet, detects radiation in two ways: air monitoring and sample analysis.
Air Monitoring: More than 100 air monitors measure radiation 24 hours a day, 7 days a week. This system allows our scientists to keep very close watch over radiation levels at all times. This system lets us identify normal background radiation levels in an area. The air monitoring system alerts us if radiation levels increase outside of this normal range, allowing us to take action if necessary.
Sample Analysis: During normal operations, EPA analyzes precipitation samples every month, and drinking water and milk samples every three months. This analysis allows us to detect minuscule amounts of radioactive material and gives our scientists information about the specific radioactive materials present.
June 16, 2011
- Today, EPA released the final results from the second round drinking water samples, which were previously analyzed for iodine. 40 samples were analyzed. No radionuclides of concern were detected.
June 1, 2011
- Today, EPA released new drinking water data. One sample detected very low levels of cesium-137. The level detected is far below a level of public health concern.
May 2011
May 24, 2011
- Today, EPA released new data for drinking water, precipitation and milk. Results from two precipitation samples detected low levels of radioactive material consistent with estimated releases from the damaged nuclear reactors. These detections were expected and the levels detected are far below levels of public health concern.
May 3, 2011
- Today, EPA released new data for drinking water, precipitation and milk. Results from one drinking water and two precipitation samples detected low levels of radioactive material consistent with estimated releases from the damaged nuclear reactors. These detections were expected and the levels detected are far below levels of public health concern.
April 2011
April 28, 2011
- As of 9:00 am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern. Today, EPA also released new data for drinking water. Both drinking water results were non-detects for iodine-131.
April 27, 2011
- As of 9:00 am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
Today, EPA also released new data for drinking water. All of the drinking water results were non-detects for iodine-131.
April 26, 2011
- As of 9:00 am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
Today, EPA also released new data for precipitation, milk and drinking water. Results for precipitation and milk have detected low levels of radioactive material consistent with estimated releases from the damaged nuclear reactors. These detections were expected and the levels detected are far below levels of public-health concern.
April 25, 2011
- As of 9:00 am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
Today, EPA also released new data for precipitation and milk. Results for precipitation have detected low levels of radioactive material consistent with estimated releases from the damaged nuclear reactors. These detections were expected and the levels detected are far below levels of public-health concern.
April 22, 2011
- As of 9:00 am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
Today, EPA also released new data for drinking water, precipitation and milk. Results for precipitation and drinking water have detected low levels of radioactive material consistent with estimated releases from the damaged nuclear reactors. These detections were expected and the levels detected are far below levels of public-health concern.
April 21, 2011
- As of 9:00 am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
April 20, 2011
- As of 3:00 pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
Today, EPA also released new data for drinking water, precipitation and milk. Results for precipitation and milk have detected low levels of radioactive material consistent with estimated releases from the damaged nuclear reactors. These detections were expected and the levels detected are far below levels of public-health concern. - As of 9:00 am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
April 19, 2011
- As of 3:00pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- As of 9:00am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
April 18, 2011
- As of 3:00pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- As of 9:00am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
April 16, 2011
- As of 9:00am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
April 15, 2011
- As of 3:00pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
Today, EPA also released new data for drinking water and precipitation. Results for precipitation have detected low levels of radioactive material consistent with estimated releases from the damaged nuclear reactors. These detections were expected and the levels detected are far below levels of public-health concern. - As of 9:00am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
April 14, 2011
- As of 9:00am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
April 13, 2011
- As of 3:00pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
Today, EPA also released new data for milk, drinking water and precipitation. Results have detected low levels of radioactive material consistent with estimated releases from the damaged nuclear reactors. These detections were expected and the levels detected are far below levels of public-health concern.
- As of 9:00am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
April 12, 2011
- As of 3:00pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- As of 9:00am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
April 11, 2011
- As of 3:30pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- As of 8:00am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
April 10, 2011
- As of 8:00am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
Today, EPA also released new data for milk, drinking water, precipitation and laboratory air analyses. Results have detected low levels of radioactive material consistent with estimated releases from the damaged nuclear reactors. These detections were expected and the levels detected are far below levels of public-health concern.
April 9, 2011
- As of 8:00am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
Today, EPA also released new data for milk, drinking water and laboratory air analyses. Results have detected low levels of radioactive material consistent with estimated releases from the damaged nuclear reactors. These detections were expected and the levels detected are far below levels of public-health concern.
April 8, 2011
- As of 8:00am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
Today, EPA also released new data for milk, precipitation, drinking water and laboratory air analyses. Results have detected low levels of radioactive material consistent with estimated releases from the damaged nuclear reactors. These detections were expected and the levels detected are far below levels of public-health concern.
April 7, 2011
- As of 8:30am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
Results of EPA's drinking water sampling, precipitation sampling, milk sampling, and air filter and cartridge analysis have detected low levels of radioactive material consistent with estimated releases from the damaged nuclear reactors. These detections were expected and the levels detected are far below levels of public-health concern.
April 6, 2011
- As of 3:30pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- As of 8:30am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
Results of EPA's drinking water sampling, precipitation sampling, milk sampling, and air filter and cartridge analysis have detected low levels of radioactive material consistent with estimated releases from the damaged nuclear reactors. These detections were expected and the levels detected are far below levels of public-health concern.
April 5, 2011
- As of 3:30pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- As of 8:30am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
Results of EPA's drinking water sampling, precipitation sampling, milk sampling, and air filter and cartridge analysis have detected low levels of radioactive material consistent with estimated releases from the damaged nuclear reactors. These detections were expected and the levels detected are far below levels of public-health concern.
April 4, 2011
- As of 12:30pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- As of 8:30am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- EPA STATEMENT: Update on Ongoing Monitoring
Release date: 04/04/2011
Contact Information: EPA Press Office, [email protected]
WASHINGTON — As a result of the incident with the Fukushima nuclear plant in Japan, several EPA air monitors have detected very low levels of radioactive material in the United States consistent with estimated releases from the damaged nuclear reactors. EPA has stepped up monitoring of precipitation, milk, and drinking water in response to the Fukushima events. The detections in air, precipitation, and milk were expected, and the levels detected have been far below levels of public-health concern.
Today, EPA released its latest RadNet results, which include the first results for drinking water. Drinking water samples from two locations, Boise, Idaho and Richland, Washington, showed trace amounts of Iodine-131 — about 0.2 picocuries per liter in each case. An infant would have to drink almost 7,000 liters of this water to receive a radiation dose equivalent to a day's worth of the natural background radiation exposure we experience continuously from natural sources of radioactivity in our environment.
Earlier precipitation samples collected by EPA have shown trace amounts of radioactivity, so EPA has expected to find results such as these in some drinking water samples. Similar findings are to be expected in the coming weeks.
In addition, results of EPA's precipitation sampling and air filter analyses continue to detect very low levels of radioactive material consistent with estimated releases from the damaged nuclear reactors. These detections were expected and the levels detected are far below levels of public-health concern.
April 3, 2011
- As of 9:00am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
April 2, 2011
- As of 9:00am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- EPA STATEMENT: Update on Ongoing Monitoring
Release date: 04/02/2011
Contact Information: EPA Press Office, [email protected]
WASHINGTON — As a result of the incident with the Fukushima nuclear plant in Japan, several EPA air monitors have detected very low levels of radioactive material in the United States consistent with estimates from the damaged nuclear reactors. These detections were expected and the levels detected are far below levels of public-health concern.
Elevated levels of radioactive material in rainwater have been expected as a result of the nuclear incident after the events in Japan since radiation is known to travel in the atmosphere — precipitation samples collected by EPA in the states of California, Idaho and Minnesota have seen very slightly elevated levels of radiation.
In addition to iodine-131, EPA monitors have also identified trace amounts of other isotopes, which we expected to see because they are consistent with releases from the damaged Japanese nuclear reactors.
April 1, 2011
- As of 12:30pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- As of 8:30am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
March 2011
March 31, 2011
- As of 8:30am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
Detailed analysis of RadNet air filter monitors from Saipan and Guam continue to show trace amounts of radioactive isotopes consistent with the damaged Japanese nuclear reactors. These levels also continue to be far below potential levels of public health concern.)
March 30, 2011
- As of 4:30pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- As of 8:30am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
March 29, 2011
- As of 3:30pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- As of 8:30am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
March 28, 2011
- As of 12:30pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- As of 8:30am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
March 27, 2011
- As of 8:30am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
March 26, 2011
- As of 12:00pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- As of 8:00am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
March 25, 2011
- As of 1:00pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- As of 9:00am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
March 24, 2011
- As of 1:00pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- On Monday, March 21 — preliminary monitor results in Hawaii detected minuscule levels of an isotope that were consistent with the Japanese nuclear incident. This detection varied from background and historical data in Hawaii. This isotope was detected at our stationary monitor in Hawaii, and it was far below any level of concern for human health. The sampling filter from this monitor has been sent to our national radiation lab for further analysis.
March 23, 2011
- As of 5:00pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- As of 1:00pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- On Monday, March 21 — preliminary monitor results in Hawaii detected minuscule levels of an isotope that were consistent with the Japanese nuclear incident. This detection varied from background and historical data in Hawaii. This isotope was detected at our stationary monitor in Hawaii, and it was far below any level of concern for human health. The sampling filter from this monitor has been sent to our national radiation lab for further analysis.
March 22, 2011
- As of 6:30pm (EDT) Last night preliminary monitor results in Hawaii detected minuscule levels of an isotope that is consistent with the Japanese nuclear incident. This detection varies from background and historical data in Hawaii. This isotope was detected at our stationary monitor in Hawaii, and it is far below any level of concern for human health. The sampling filter from this monitor is being sent to our national radiation lab for further analysis.
EPA's RadNet radiation air monitors across the rest of the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- CORRECTION: UPDATED
Please note the addition of "hundreds of thousands" in the second and sixth paragraphs Radiation Monitors Continue to Confirm That No Radiation Levels of Concern Have Reached the United States
Release date: 03/22/2011
Contact Information: EPA Press Office [email protected]
WASHINGTON — During a detailed analysis of four west coast RadNet air monitor filters, the U.S. Environmental Protection Agency (EPA) identified trace amounts of radioactive iodine, cesium, and tellurium consistent with the Japanese nuclear incident. These levels are consistent with the levels found by a Department of Energy monitor last week and are to be expected in the coming days.
EPA's samples were captured by three monitors in California and one in Washington State on Friday, March 18 and sent to EPA scientists for detailed laboratory analysis. The data was reviewed over the weekend and the analysis was completed Monday night. The radiation levels detected on the filters from California and Washington monitors are hundreds of thousands to millions of times below levels of concern.
In addition, last night preliminary monitor results in Hawaii detected minuscule levels of an isotope that is also consistent with the Japanese nuclear incident. This detection varies from background and historical data in Hawaii. This isotope was detected at our stationary monitor in Hawaii, and it is far below any level of concern for human health. The sampling filter from this monitor is being sent to our national radiation lab for further analysis.
In a typical day, Americans receive doses of radiation from natural sources like rocks, bricks and the sun that are about 100,000 times higher than what we have detected coming from Japan. For example, the levels we're seeing coming from Japan are 100,000 times lower than what you get from taking a roundtrip international flight.
EPA is in the process of conducting detailed filter analyses for stationary monitors located in Oregon.
EPA's RadNet filter results for San Francisco, Seattle, Riverside and Anaheim, California detected minuscule quantities of iodine isotopes and other radioactive particles that pose no health concern at the detected levels. Below are the results of the detailed filter analysis. All of the radiation levels detected during the detailed filter analysis are hundreds of thousands to millions of times below levels of concern.
All units are in Picocuries per meter cubed.
- Filter results for Anaheim, Calif. found:
- Cesium-137: 0.0017
- Tellurium-132: 0.012
- Iodine-132: 0.0095
- Iodine-131: 0.046
- Filter results for Riverside, Calif. found:
- Cesium-137: 0.00024
- Tellurium-132: 0.0014
- Iodine-132: 0.0015
- Iodine-131: 0.011
- Filter results for Seattle, Wash. found:
- Cesium-137: 0.00045
- Tellurium-132: 0.0034
- Iodine-132: 0.0029
- Iodine-131: 0.013
- Filter results for San Francisco, Calif. found:
- Cesium-137: 0.0013
- Tellurium-132: 0.0075
- Iodine-132: 0.0066
- Iodine-131: 0.068
EPA's RadNet system is designed to protect the public by notifying scientists, in near real time, of elevated levels of radiation so they can determine whether protective action is required. In addition, an analysis of the filters in the monitors can identify even the smallest trace amounts of specific radioactive isotopes.
March 21, 2011
- As of 1:00pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- As of 9:00am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
March 20, 2011
- As of 1:00pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- As of 9:00am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
March 19, 2011
- As of 11:30am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- As of 8:30am (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
March 18, 2011
- As of 4:00pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
- As of 12:00pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.
March 17, 2011
- As of 2:00pm (EDT) EPA's RadNet radiation air monitors across the U.S. show typical fluctuations in background radiation levels. The levels detected are far below levels of concern.