Yokohama City officials are testing their soil for strontium, after a private testing firm said they found high levels of strontium on some roof tops.

The company said they detected 195 becquerels of strontium per kilogram, more than six times the government safety limit.  Yokohama has already suffered cesium levels at 80 times the government limits.

Yokohama is about 250 kilometers (155 miles) from the damaged Fukushima Daiichi nuclear plant.