Official statements - which must be treated with some skepticism - now declare aerial radiation levels at Fukushima as 100,000 times "normal" with readings of 1,000 millisieverts an hour. A dose of 100 millisieverts a year is considered the threshold above which there is a risk of cancer. Again, the are calculations, not measurements and dose rates are generally not based on the most vulnerable such as pregnant women, unborn fetus and small children.