Environmental radiation and cancer in India.

The hormesis hypothesis, which suggests that ecologically realistic low levels of ionising radiations may be beneficial to humans, seems to be substantiated significantly by the data available on cancer incidence/mortality rates and environmental radiation levels in various cities and states of India. Where the radiation level is greater, cancer risk is invariably less. The annual cancer incidence rate (per 100,000 population) seems to decrease by 0.03/microSv increase in the external background radiation dose from a hypothetical incidence level of 79 per 100,000 corresponding to "zero environmental radiation".