That dose is about 10,000 times that typical exposure rate for the U.S., but it is applied to the cancerous tissue; the total-body exposure during radiation therapy is much less.

That dose is about 10, 000 times that typical exposure rate for the U.S., but it is applied to the cancerous tissue; the total-body exposure during radiation therapy is much less.

This paper evaluates the airborne radioactive concentration, dose-rate of internal and external exposure as well as purification mode and operating time of ventilation systems in reactor building.