FAQs About Radiation
According to the Nuclear Regulatory Commission (NRC), Japan’s nuclear emergency presents no danger to California. CDPH is working closely with our state and federal partners, including NRC, U.S. Environmental Protection Agency, the U.S. Department of Energy, FEMA Region IX, and the California Emergency Management Agency (CalEMA).
California has a plan of response for radiological emergencies if one were to arise. Plans include the Nuclear Radiological Emergency Program and the National Response Framework.
Frequently Asked Questions
Updated: April 1, 6:03 p.m.
Q. How much radiation was found?
A. The amount of radiation identified in the tests was ten thousand times below amounts that would pose human health concerns.
Q. Does California test milk products for radiation?
A. California routinely screens milk for radioactivity on a quarterly basis. Since the Japan nuclear emergency, the California Department of Public Health (CDPH) has increased milk monitoring to once a week in San Luis Obispo County.
Q. Has CDPH found radiation in milk?
A. CDPH sampled milk on March 28 and preliminary results indicate a trace amount of iodine-131 which does not pose a threat to public health. California's full report and data will be posted on this site. These results are in line with the U.S. Environmental Protection Agency tests of milk in the state of Washington.
- Q. Does that mean that the milk is unsafe?
A. The milk is safe and there is no public threat. The result of the recent milk sampling in California shows that the amount of iodine found is nearly 1400 times less than U.S. Food and Drug Administration health standards. The level of iodine detected in milk in Washington State was nearly 5000 times lower than the U.S. Food and Drug Administrations (FDA) health standard.
Q. How long does iodine-131 persist in the environment?
A. Based on what we now know about Japan's nuclear accident, radioactive iodine should decrease in the coming weeks. It is estimated that levels will be virtually undetectable soon and dissipate completely in the coming months. The amounts detected are so small they pose no public health risk.
Q. Why aren't you testing more sites for milk?
A. Combined, the U.S. EPA and state monitors have 20 air monitoring stations around the state. Air testing is the best predictor of any public health risk and so far, all testing stations have been reporting only trace amounts of radioactivity that do not pose a threat to human health.
Q. How can radioactivity get into milk?
A. When radioactive material is spread through the atmosphere, it drops to the ground and gets into the environment. When cows consume grass, hay, feed, and water, radioactivity will be processed and become part of the milk we drink. However, the amounts are so small they pose no threat to public health.
Q. What about breast milk? Am I breathing contaminated air and then poisoning my child?
A. No. The amounts of radiation detected in California are very small trace amounts that are not considered to pose a risk to human health. Breastfeeding is one of the best ways to protect the health of your child. No one should consider stopping breastfeeding for this reason.
Q. How does this compare with radiation we are exposed to daily?
A. Radiation is all around us in our daily lives, and these findings are a minuscule amount compared to what people experience every day. For example, a person would be exposed to low levels of radiation on a round-trip cross-country flight, watching television, and even from construction materials.
Previously Posted FAQ
Q. Is a plume of radiation coming to California?
A. At present, all data from state and federal sources show that harmful radiation won’t reach California. CDPH is monitoring the situation, working closely with our federal, state and local partners.
Q. How much radiation will reach California?
A. No harmful radiation. Distance, time, and weather is in our favor. Japan is 5,000 miles from California. Radiation levels lessen with distance and we don’t expect much above the amounts we see everyday. Precipitation removes radiation from the atmosphere.
Q. What’s everyday level of radiation we receive?
A. The typical North American exposure from natural background radiation is 2.0 millirem per day. A chest x-ray would expose an individual to 10 millirems. Radiation from Japan is expected to be thousands of times less than daily background radiation from natural and man-made sources—like the sun, air, soil, medical imaging, and life-saving therapies.
Q. What’s a millirem?
A. A millirem is a dose of ionizing radiation. The average American is exposed to approximately 620 millirems of radiation each year from natural and medical sources.
Q. Is there a danger of radiation from the Japanese nuclear incident making it to the United States?
A. Given the thousands of miles between the two countries, Hawaii, Alaska, the U.S. Territories and the U.S., the West Coast is not expected to experience any harmful levels of radioactivity. In response to nuclear emergencies, CDPH works with state and federal agencies to monitor radioactive releases and predict their paths.
Q. What is the state and federal government doing to monitor radiation?
A. CDPH Radiologic Health Branch maintains nine air monitoring stations throughout California. They are located in Eureka (2 units), Richmond, Livermore, Avila Beach, San Luis Obispo, Los Angeles, San Clemente and San Diego. CDPH has increased surveillance from once a week to every 48 hours. The United States Environmental Protection Agency operates a network of air monitors in California and has recently enhanced its capability in response to the Japan nuclear crisis (U.S. EPA has real time monitoring capability).
Q. Does California have a plan in place to respond to a radiological emergency?
A. CDPH has a plan for response to radiological emergencies, called the Nuclear Emergency Response Plan
. This plan is exercised regularly with local and federal partners in the communities around our nuclear power plants.
Q. Does California stockpile supplies for such an emergency?
A. California does stockpile emergency supplies, including potassium iodide (KI) tablets. Potassium iodide tablets are not recommended at this time, and can cause significant side effects in people with allergies to iodine or who have thyroid problems. Potassium iodide tablets should not be taken unless directed by authorities. A seafood or shellfish allergy does not necessarily mean that you are allergic to iodine.
Q. Why are potassium iodide tablets used during emergencies involving radiation exposure?
A. Potassium iodide (KI) tablets may be recommended to individuals who are at risk for radiation exposure or have been exposed to excessive radiation to block the body’s absorption of radioactive iodine. Using KI when inappropriate could have rare but serious side effects such as abnormal heart rhythms, nausea, vomiting, electrolyte abnormalities and bleeding.
Q. Should I be taking potassium iodide to protect myself?
A. No. Potassium iodide (KI) tablets are not recommended at this time, and can present a danger to people with allergies to iodine, some skin conditions or who have thyroid problems. A seafood or shellfish allergy does not necessarily mean that you are allergic to iodine.
- Q. Should I purchase potassium iodide as a precaution?
A. No. KI is only appropriate within close proximity to a nuclear event. Using KI when inappropriate could have potential serious side effects such as abnormal heart rhythms, nausea, vomiting, electrolyte abnormalities and bleeding.
- Q. Are there any protective measures I should currently take?
A. The best thing anyone can do is to stay informed. CDPH and other state and federal partners are monitoring the situation. If circumstances change, officials will alert the public to appropriate precautionary procedures. But, again, at this time, the Nuclear Regulatory Commission reports Japan’s nuclear emergency presents no danger to California.
While California is not at risk of significant radiation from Japan, we are at risk of major earthquakes. People who live in earthquake prone regions should stock emergency supplies of food, water, and other emergency supplies to be self-sufficient for at least 3-5 days.
For additional information:
CDPH Information Line: (916) 341-3947 Monday - Friday, 8 a.m. - 5 p.m. Pacific Daylight Time
CDPH Media Inquiries: (916) 440-7259, CDPHPress@cdph.ca.gov
Centers for Disease Control and Prevention (CDC):
1-800-CDC-INFO (1-800-232-4636), Seven days a week, 24 hours a day