As the EPA notes:

Cesium-133 is the only naturally occurring isotope and is non-radioactive; all other isotopes, including cesium-137, are produced by human activity.

What people call “background” radiation is really the amount of radiation deposited into the environment within the last 100 years from nuclear tests and nuclear accidents (and naturally-occurring substances, such as radon).

2,053 nuclear tests occurred between 1945 and 1998.

Above-ground nuclear tests – which caused numerous cancers to the “downwinders” – were covered up by the American, French and other governments for decades. See this, this, this, this, this and this.

But the amount of radiation pumped out by Fukushima dwarfs the amount released by the nuclear tests.

As nuclear engineer and former nuclear executive Arnie Gundersen notes, the wave of radioactive cesium from Fukushima which is going to hit the West Coast of North America will be 10 times greater than from the nuclear tests.

The Canadian government has confirmed in October that Fukushima radiation will exceed “levels higherthan maximum fallout” from the nuclear tests.

The party line from the Japanese, Canadian and American governments are that these are safe levels of radiation. Given that those countries have tried to ban investigative journalism and have tried to cover up the scope of the Fukushima disaster, people may want to investigate for ourselves.

For example, Gundersen notes that the U.S. government flew helicopters with special radiation testing equipment 90 days after the Fukushima meltdown happened. The government said it was just doing a routine “background radiation” check, but that it was really measuring the amount of “hot particles” in the Seattle area (starting at 27:00). Hot particles are inhaled and become very dangerous “internal emitters”. The government then covered up the results on the basis of “national security”.

As the Washington Department of Health noted at the time:

A helicopter flying over some urban areas of King and Pierce counties will gather radiological readings July 11-28, 2011. [Seattle is in King County.] The U.S. Department of Energy’s Remote Sensing Laboratory Aerial Measurement System will collect baseline levels of radioactive materials.

Some of the data may be withheld for national security purposes.

Similarly, the Department of Homeland Security and National Nuclear Security Administration sent low-flying helicopters over the San Francisco Bay Area in 2012 to test for radiation. But they have not released the results.

Indeed, residents of Seattle breathed in 5 hot particles each day in April of 2011 … a full 50% of what Tokyo residents were breathing at the time.

After all, the reactors at Fukushima literally exploded … and ejected cladding from the reactors and fuel particles. And see this.

Gundersen says that geiger counters don’t measure hot particles. Unless the government or nuclear scientists measure and share their data, we are in the dark as to what’s really going on.