We’ve known Fukushima’s been hemorrhaging radiation steadily since the disaster began in March. But now we’ve got a horrid new way to quantify it: the amount of terribly dangerous cesium-137 released by the plant is equal to 168 nuclear bombings.

The Guardian reports that the Japanese government’s own calculations put the release of cesium-137—a particularly lethal isotope—at 15,000 tera becquerels. That’s an esoteric unit of measurement, but you can ignore it. Just think of it this way: the atomic bomb dropped on Hiroshima released 89 tera becquerels of cesium-137 when it leveled the city.