"We got lots of e-mails and phone calls about it, way above the normal background level.
Over a year's work, airline crews can receive about twice the normal background radiation dose of someone working on the ground, and they have to monitor their exposure.
In enviro-speak, Mrs. Whitman, political turmoil went from the normal background level of 20 parts per billion to a fully saturated solution.
Helsinki reported six times the normal background level, Stockholm twice the usual level and Oslo 50percentnt higher than normal.
Further into the evacuation zone, near a disused public relations office belonging to the plant's owner, Tokyo Electric Power (Tepco), radiation levels rise to 2 microsieverts/hour (the normal background level is 0.2-0.3 0.2-0.3
The normal background level of radiation, which varies by altitude, averages about 0.02 millirems an hour in New York, one ten-thousandth of the amount radiating from the surface of the pillow.
Mass extinctions often come to mind when the term extinction is mentioned, but the normal background extinctions that occur throughout geologic time probably account for most losses of biodiversity.
Radiation levels hover around 62.3 microroentgens an hour (0.62 microsieverts): just over twice the normal background radiation in London, and less than going through an airport security scanner three times – which makes Pripyat safe enough for a brief visit, but not long-term habitation.
For the other particles biodegradability was below the normal background fluctuation of 5%.
It is however unlikely that small genotoxic effects, i.e. within the normal background range, can be excluded experimentally.
