Cancer death risk after exposure to low dose ionising radiation underestimated

Prolonged exposure to low-dose ionizing radiation is associated with a higher risk of death from cancer than previously thought, suggests research tracking the deaths of workers in the nuclear industry, published in The BMJ recently.

The researchers tracked and analyzed deaths among 309,932 workers in the nuclear industry in the UK, France, and the US (INWORKS) for whom individual monitoring data for external exposure to ionizing radiation were available.

During a monitoring period spanning 1944 to 2016, 103,553 workers died: 28,089 of these deaths were due to solid cancers, which include most cancers other than leukemia.

The researchers then used this information to estimate the risk of death from solid cancers based on workers’ exposure to radiation 10 years previously.

They estimated that this risk increased by 52% for every unit of radiation (Gray; Gy) workers had absorbed. But when the analysis was restricted to workers who had been exposed to the lowest cumulative doses of radiation (0-100 mGy), this approximately doubled the risk of death from solid cancers per unit Gy absorbed.

Similarly, restricting the analysis only to workers hired in more recent years when estimates of occupational external penetrating radiation dose were more accurate also increased the risk of death from solid cancer per unit Gy absorbed.

Reference: Cancer mortality after low dose exposure to ionizing radiation in workers in France, the United Kingdom, and the United States (INWORKS): cohort study, The BMJ, DOI 10.1136/bmj-2022-074520