Experts Allay Fears About Radiation Exposure

By Kristen Bole

State health experts are urging calm amidst the widespread media coverage of Japan’s nuclear crisis and growing fears in California and along the West Coast about the potential for radiation exposure here.

The California Department of Public health, the U.S. Environmental Protection Agency, the U.S. Nuclear Regulatory Commission and the U.S. Department of Health and Human Services have all stated that there is no risk expected to California or its residents as a result of the situation in Japan.

Closer to home, the California Poison Control System is advising both health care providers and the general public to hold off on prescribing or taking iodide medication for the time being. The poison control system is the around-the-clock  point of contact on this topic for the general public and health care professionals at UCSF and statewide.

“Potassium iodide definitely has a place in the medical response to extremely high levels of radiation exposure, but this is not that time or place,” said Stuart Heard, PharmD, FCSHP, a faculty member in the UCSF School of Pharmacy, Department of Clinical Pharmacy, and the executive director of the poison control system statewide. “People in Japan near the nuclear reactor should be taking it and are doing so, but they are the only ones who should be.”

While he said that iodide does offer protection against thyroid damage for people with acute exposure, such as those nearby Japan’s nuclear reactors, it is not appropriate for low-level exposure, including  residents of Japan not exposed to higher levels at this point. 

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While the plume that is expected to reach Southern California this weekend will be tested for radiation and is expected to have minute amounts of radiation in it, current expectations are that those will be far below the level warranting medical intervention.

“It’s completely understandable that people would want to take every precaution they can, but they also have to make sure they’re not making themselves sick in the process,” Heard said. “Potassium iodide is completely ineffective when taken at the wrong time – either too early or too late after high-level exposure – and can have serious side effects for many people if not taken in the right dosage.”

That includes a direct danger to people with allergies to iodine, some shellfish or who have thyroid problems. Inappropriate use of potassium iodide also can have potentially serious side effects, such as abnormal heart rhythms, nausea, vomiting, electrolyte abnormalities and bleeding. While the U.S. Centers for Disease Control (CDC) and Prevention do stockpile potassium iodide to use in emergency situations, there is no indication for recommending prescribing any iodine at this time, Heard said.

UCSF Issues Radiation Health Advisory

The UCSF Emergency Management provides this health advisory to the UCSF community based on current information.


Currently, there is no danger to San Francisco residents from Japan's nuclear emergency. The U.S. Nuclear Regulatory Commission (NRC) has stated that “given the thousands of miles between the two countries, Hawaii, Alaska, the US territories and the US West Coast are not expected to experience any harmful levels of radioactivity.” Radiation surveillance systems are in place at the state and federal level. Current levels are normal.

UCSF Medical Center and UCSF Police continue to monitor the San Francisco Department of Public Health, California Department of Public Health (CDPH), U.S. Centers for Disease Control and Prevention (CDC) and U.S. Nuclear Regulatory Commission (NRC) bulletins and advisories. Should the situation change, an updated advisory will be distributed.


UCSF Chief Medical Officer Joshua Adler, MD, and the San Francisco Department of Public Health do not recommend taking potassium iodide, unless and until advised by public health officials. Potassium iodide (also called KI) can protect the thyroid gland from absorbing radioactive iodine. However, potassium iodide can have serious side effects including allergic reactions in people who have sensitivity to iodine or shellfish and adverse reactions in people who have thyroid problems. UCSF officials are monitoring the situation closely and will alert the UCSF campus community if recommendations change. 


Health experts statewide are encouraging concerned citizens to go to the links below for further information.

For questions about potassium iodide, call California Poison Control System (toll free): 1-800-222-1222

For general inquiries call California Department of Public Health (CDPH): 

CDPH Radiation Hotline: 916/341-3947

FAQs on radiation (CDPH): 


Nuclear Regulatory Commission

Please note: Californians with questions about radiation exposure can contact the California Department of Public Health’s Emergency Operations information line at 916/341-3947.  

For updated information on monitoring, response and relief efforts in California and Japan, please visit the California Emergency Management Agency website.

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