MAP: The Troubling Spread of Radiation in Japan

Fight disinformation. Get a daily recap of the facts that matter. Sign up for the free Mother Jones newsletter.


A map of radiation levels in Japan released by the US Department of Energy on Tuesday evening indicates that potentially dangerous levels of radioactive contamination have spread beyond the 13-mile evacuation zone surrounding the Fukushima Daiichi nuclear plant. The data is sure to further undermine confidence in Japan’s response to the disaster. US authorities have recommended that Americans stay at least 50 miles from the Fukushima Daiichi plant. Here’s the map, which was generated from the DOE’s Aerial Monitoring System and ground sensors:

Spread of radiation for the Fukushima Daiichi nuclear plantSpread of radiation from the Fukushima Daiichi nuclear plant

To put these numbers in context, a typical chest X-ray produces 10 mRem. US EPA guidelines require government intervention if the public is exposed to more than 1000 mRem over four days. People near Fukushima could be exposed to that amount of radiation at least every 3.3 days in the red zone and anywhere from there to every 19 days in the orange zone above. Of course, it’s unclear from the chart to what degree radiation levels in the area fluctuate over time. “Measurements show an area of greater radiation extending northwest from the accident,” a DOE backgrounder notes, adding with dry understatement: “This area may be of interest to public safety officials and responders.”

ONE MORE QUICK THING:

Or at least we hope. It’s fall fundraising time, and we’re trying to raise $250,000 to help fund Mother Jones’ journalism during a shorter than normal three-week push.

If you’re reading this, a fundraising pitch at the bottom of an article, you must find our team’s reporting valuable and we hope you’ll consider supporting it with a donation of any amount right now if you can.

It’s really that simple. But if you’d like to read a bit more, our membership lead, Brian Hiatt, has a post for you highlighting some of our newsroom's impressive, impactful work of late—including two big investigations in just one day and covering voting rights the way it needs to be done—that we hope you'll agree is worth supporting.

payment methods

ONE MORE QUICK THING:

Or at least we hope. It’s fall fundraising time, and we’re trying to raise $250,000 to help fund Mother Jones’ journalism during a shorter than normal three-week push.

If you’re reading this, a fundraising pitch at the bottom of an article, you must find our team’s reporting valuable and we hope you’ll consider supporting it with a donation of any amount right now if you can.

It’s really that simple. But if you’d like to read a bit more, our membership lead, Brian Hiatt, has a post for you highlighting some of our newsroom's impressive, impactful work of late—including two big investigations in just one day and covering voting rights the way it needs to be done—that we hope you’ll agree is worth supporting.

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate