KentuckyFC writes "Parents in the Fukushima region of Japan are intensely worried that their children may be consuming food and water contaminated with radiation. But whole body scanners used to monitor the internal radiation levels of adults don't work for children who cannot stand up inside them. What's more, the machines are not sensitive enough to detect problematic radiation levels in children. That's because children metabolize substances faster than adults and have a lower mass to start with, so the levels of radiation in their bodies tend to be lower. For example, if each adult ingests 3 Becquerels of cesium-137 every day, the internal levels would reach an equilibrium of about 400 Bq/adult body. But a similar intake for a 1-year old child would result in an equilibrium level of about 60 Bq/body, well below the 250 Bq/body sensitivity of adult scanners. Now a team of engineers has built a whole body scanner that is sensitive enough for the job and that children can play inside for the 4 minutes necessary to scan them. And they say the results of the first 100 scans of Fukushima children (average age 4.2 years) are reassuring--none show any evidence of cesium-137. So far."