The higher radiation levels were linked to lower levels of lung, pancreatic and colon cancers in both men and women and lower rates of brain and bladder cancers in men. People living in areas with with relatively high background radiation had a life expectancy about 2.5 years longer than those living in areas with relatively low levels.
The higher life expectancy may be linked to the lower cancer mortality rates found in areas with higher background radiation.
The study was conducted by using the US Environmental Protection Agency's radiation dose calculator to retrieve data from 3,129 US counties, cancer rate data from the US Cancer Statistics and life expectancy data from the Institute for Health Metrics and Evaluation at the University of Washington Medical Center.
Background radiation is an ionizing radiation that exists in the environment from natural sources, including radiation from space and terrestrial sources.
Background radiation fluctuates between 92 to 227 millirem per year in the US, according to BGU. A millirem is one thousandth of a Roentgen Equivalent Man (REM), a measure of the health effect of low-level ionizing radiation on the human body.
The scientists stated that the findings indicate "clear beneficial health effects in humans" related to higher background radiation, adding that the linear no-threshold (LNT) paradigm, which assumes that any exposure to ionizing radiation is risky, should be reevaluated.
The researchers stressed that hundreds of billions of dollars are spent each year to maintain extremely low radiation levels based on the LNT paradigm which their findings indicate may not be necessary. They suggested setting a threshold level, instead of operating on the assumption that any amount of radiation is bad.