First Fukushima Plume Brought Sharply Increading Levels of Radiation To West Coast Cities

The report below from the Radiation and Public Health Project (RPHP) analyzes the first radioactive plume to reach the West Coast of the US.

Using data from the Environmental Protection Agency’s RadNet monitors, the RPHP found “sharply increasing levels of radiation in the air of several West Coast cities.”

The Radiation and Public Health Project conducts research looking at the effects of radiation released from nuclear power plants on public health.

In recent years the RPHP has been conducting the Tooth Fairy Project. This project analyzes baby teeth for the presence of radioactive strontium. Its studies have found a connection between elevated levels of strontium 90 in baby teeth and subsequent increased levels of cancers for the donors of those teeth.

For more information, check out the RPHP website at radiation.org.

What follows is their May 24 report on Fukushima radiation arriving in the US:

JAPAN RADIATION PLUME HITS U.S.; EPA DATA SHOW
AIRBORNE RADIATION LEVELS RISE ALONG THE WEST COAST

Joseph J. Mangano MPH MBA
Radiation and Public Health Project
March 24, 2011

The airborne radioactive plume from the stricken Fukushima nuclear plant moved across the Pacific Ocean, reaching the West Coast of the United States on March 17, and sharply increasing levels of radiation in the air of several West Coast cities.

From March 16-21, radiation in the air rose steadily each day in several cities, nearly doubling in Portland OR (up 83%) and Seattle WA (up 68%). Data were obtained from the U.S. Environmental Protection Agency’s Radnet system of monitors across the U.S.

One type of radiation in the air is “gross beta” or the total amount of radioactive chemicals that emit a beta particle. Other types of radioactivity are alpha, gamma, and X-ray emissions. Some gross beta represents natural/background radiation, while some represent man-made chemicals.

The “gross beta” figures from March 17-22 in several West Coast cities are displayed here. Daily levels are the average of measurements made hourly, all in Counts per Minute, with the number of hourly measurements in parentheses.

Date Portland OR Seattle WA San Francisco CA
March 15 14.64 (22) 11.75 (24) 12.08 (24)
March 16 12.79 (24) 9.21 (24) 11.71 (24)
March 17 13.91 (23) 9.26 (23) 14.88 (24)
March 18 16.46 (24) 11.71 (24) 13.79 (24)
March 19 16.74 (23) 13.00 (24) 15.58 (24)
March 20 18.25 (24) 14.21 (24) 16.25 (24)
March 21 23.43 (23) 15.46 (24) 15.26 (23)

% Change +83% +68% +30%
March 16-21

The increases were not always steady hour by hour. Some were “spikes” of higher levels, which took hours or days to return to customary levels. Examples of hourly readings are below:

San Francisco, noon to midnight, March 19:
13, 13, 13, 14, 12, 15, 32, 21, 18, 15, 17, 18

Portland, noon to midnight, March 20
17, 18, 19, 19, 20, 20, 22, 23, 43, 26, 24, 27

The greatest spikes occurred at the following locations and times:
Portland, afternoon, March 23 67 (previous reading 21)
Idaho Falls, afternoon, March 19 210 (previous 85)
Denver, morning March 21 225 (previous 80)

All data are from the EPA,
available at https://cdxnode64.epa.gov/radnet_public/queryResult.do