Risk of Lung Cancer Mortality in Nuclear Workers from Internal Exposure to Alpha Particle-emitting Radionuclides

Area of Science:

• Occupational Health
• Radiation Epidemiology
• Nuclear Medicine

Background:

• Carcinogenic risks from internal alpha-emitter exposures (excluding radon) are not well understood.
• Inhalation of alpha particles occurs in various occupational settings, making risk assessment a public health priority.
• Understanding these risks is crucial for nuclear workers exposed to alpha-emitting substances.

Purpose of the Study:

• To quantify the dose-response relationship between lung dose from internal alpha-emitters and lung cancer incidence in nuclear workers.
• To assess the risks associated with specific alpha-emitters like uranium and plutonium.
• To provide data for public health policies regarding radiation protection.

Main Methods:

• A nested case-control study was conducted within Belgian, French, and UK cohorts of uranium and plutonium workers.
• Lung doses from alpha-emitters were determined using bioassay data.
• Excess odds ratio (OR) of lung cancer per gray (Gy) of lung dose was estimated, adjusting for confounding factors.

Main Results:

• The study included 553 lung cancer cases and 1,333 controls.
• A significant excess odds ratio per gray was found for total alpha dose (11), plutonium (50), and uranium (5.3).
• Risk estimates for plutonium were higher than for uranium, though confidence intervals overlapped.

Conclusions:

• Strong evidence supports associations between low-dose internal alpha-emitter exposure and lung cancer risk.
• Risk estimates are comparable to previous findings in plutonium workers and uranium miners.
• The findings are consistent with, though somewhat larger than, risk estimates for atomic bomb survivors when expressed per sievert (Sv).