With Fukushima giving off radiactive steam it's important to monitor radiation levels where you live on a daily basis. If you don't have a Geiger counter you need to access a website which informs about radiation level. Here are some good websites:
EURDEP: EUropean Radioactivity Data Exchange Platform.
http://eurdepweb.jrc.ec.europa.eu/EurdepMap/Default.aspx
You can click on a city and change the date range to see the radiation levels over time.
https://remap.jrc.ec.europa.eu/GammaDoseRates.aspx
Home Radiation Devices
http://radioactiveathome.org/map/
EPA Radnet Query Tool
https://radnet.epa.gov/radnet-public/query.do
https://www.epa.gov/radnet/radnet-air-data-champaign-il
Remember ad radiation reading of 300 CPM or 10 microSV/h is DANGER and you need relocate right away.
If the radiation rate is 100 CPM or 2 microSV/h you need to take safety precautions and limit your exposure. e.g. stay indoors.