For those of you who live on the west coast of North America, for those of you who love surfing or the taste of fresh seafood, and for those of you who enjoy not dying from cancer, we have some really good news to start your new year.

Right now, just like some club kid spinning on Molly, the Pacific Ocean is peaking. But it’s peaking hard on radiation not some fun club drugs. You probably recall, back in 2011, after a 9.0 earthquake off the coast of Japan, the Pacific ocean raised up in a terrifying tsunami and absolutely wrecked shop on the Fukushima Daiichi nuclear power plant. The resulting nuclear catastrophe was rated a Level 5 on the seven-level International Nuclear Event Scale. Fukushima was a radioactive disaster zone unlike the world had ever seen before. Prior to that, the only sort of freak event that fucked up the coast of Japan that bad was Godzilla.

(courtesy Wikipedia)

After four nuclear reactors were destroyed by the relentless crush of the sea, there was no way to contain the massive radioactive discharge from the power plant. Like a kid pissing in the pool, radioactive water streamed out and contaminated the Pacific. That was nearly four years ago. To this day, the Fukushima nuclear facility continues to leak radioactive water into the sea.

Since 2011, a steady plume of Cesium 134 and Cesium 137 has spread across the North Pacific water column. It started north, then headed east, and now it’s washing ashore on the coastlines of Alaska, Canada, Washington, Oregon, California and Mexico.

…And this is where the good news comes in!

In the Proceedings of the National Academy of the Sciences of the United States of America, researchers just released “the first systematic study” of the “transport of the Fukushima marine radioactivity signal to the eastern North Pacific.” Which is just a dry and complicated way of saying we followed the flow of radioactive water across the ocean from Japan.

So, what’s the good word, Science?

Time series measurements of 134Cs and137Cs in seawater revealed the initial arrival of the Fukushima signal by ocean current transport at a location 1,500 km west of British Columbia, Canada, in June 2012, about 1.3 y after the accident. By June 2013, the Fukushima signal had spread onto the Canadian continental shelf, and by February 2014, it had increased to a value of 2 Bq/m3 throughout the upper 150 m of the water column, resulting in an overall doubling of the fallout background from atmospheric nuclear weapons tests.

Okay. So far, it took the radioactive water two years to reach Canada. More recently, this radioactive water cloud has been reported a hundred miles off the California coast. This means the leading edge has reached the west coast. And it’s being followed by a much wider plume of radioactive water spread across the skin of the sea for thousands of miles. This infusion of radioactive seawater will raise the local levels of radiation up to 3 to 5 times what they were prior to the Fukushima disaster.

Whoa … that sounds like really bad news. A fivefold increase seems dangerous for, you know, living things that don’t dig on radiation poisoning and cancer.

However, according to the latest data, the health threat from this radioactive water is actually, statistically slight.

Number-crunching oceanic researchers are happy to report their most recent measurements of radioactivity at an increase of ~2 becquerels/per cubic meter of seawater. To put that in perspective, we’ve gone from 1.8 becquerels/cubic meter up to levels varying between ~3 to 5 becquerels/cubic meter. All in all, that’s not terrible.

For more perspective, check the map below … and for a stark contrast to the Pacific, check out the radioactivity of the Irish Sea.

(Data courtesy of MARiS/IAEAand CMER; Illustration by Jack Cook, courtesy Coastal Ocean Institute, Woods Hole Oceanographic Institution)

Hey, so uh, Science, how would you describe this radioactive water cloud in … hard data?

Ocean circulation model estimates that are in reasonable agreement with our measured values indicate that future total levels of 137Cs (Fukushima-derived plus fallout 137Cs) off the North American coast will likely attain maximum values in the 3–5 Bq/m3 range by 2015–2016 before declining to levels closer to the fallout background of about 1 Bq/m3 by 2021. The increase in 137Cs levels in the eastern North Pacific from Fukushima inputs will probably return eastern North Pacific concentrations to the fallout levels that prevailed during the 1980s but does not represent a threat to human health or the environment.

There it is! There’s our good news … expressed in becquerels per cubic meter.

As the radioactive plume of water from Fukushima washes across the west coast, throughout 2015 and into 2016, the threat from radiation will peak. It will reach its highest levels at roughly 5 Bq/cubic meter. Then the levels of radioactivity will begin to subside. They will return to somewhere near the previously recorded levels for background radiation in the ocean.

If you enjoy sushi, you may be wondering: Isn’t it dangerous to eat things that have been swimming around in all that cesium 134 and 137?

According to the latest data, the amount of radioactivity in the water should not be harmful to any fish you plan to eat. Of course, as with all things, the dose makes the poison. For in-depth analysis of radiation and seafood, this data breaks it down nicely.

Although the northwest Pacific Ocean will reach levels of radioactivity far greater than previous background radiation levels that had resulted from nuclear testing and its fallout, these new measurements are still way, way lower than the allowable limits for safe drinking water set by the World Health Organization.

A cubic meter is 1000 liters.

The WHO sets the allowable level for radioactivity in drinking water at 1Bq per Liter.

The Pacific Ocean is currently clocking in at ~3 to 5Bq per 1000 liters.

Does this mean the Pacific Ocean is safe to enjoy for surfers and seafood eaters?

Yes. It would need to reach 1000Bq/cubic meter before it’s considered unsafe. According to the data and analysis set forth by leading researchers, the verdict is clear: the Pacific is still safe for food and fun.

bonus science fun: If you’d like to see a dynamic model of how contamination spreads across the ocean, click here and you can pollute the Pacific with rubber duckies.