Geiger counters continue to play a vital role in identifying the extent of contamination in Fukushima Prefecture. While there are areas that seem to be normal, there are some very hot spots around Koriyama and some outlying areas. Some of the observations that are being made: Rooftop contamination is a major contributor to high radiation levels in homes. Top floor measurements are found to be higher than ground floor measurements. Places where water collects and then condenses tend to yield the highest radiation readings. These types of places include rain spouts, places where water puddles on pavement.
Geiger counters that can detect alpha and beta radiation are showing that there is soil and surface contamination at levels of immediate concern for population health, especially where children are present. The risk from these alpha and beta radiation emitting isotopes attached to dust in the air is that they become a source of internal radiation exposure. This highlights the importance of taking internal radiation exposure into account in risk modeling.
It is understandable that resources are focused on stabilizing the reactors and dealing with impacts of earthquake and tsunami. Fortunately private citizens and organizations with geiger counters have worked rapidly to increase government and public awareness of other vital issues, and pointed out areas of concern – including radioactive schools and day care centers.