Dose assessment for polonium-210 (Po-210) in New Zealand shellfish

Area of Science:

• Environmental Science
• Radiation Biology
• Public Health

Background:

• Polonium-210 (Po-210) is a significant source of human radiation exposure globally, primarily through dietary intake.
• Shellfish can accumulate Po-210, presenting a potential radiation dose concern for consumers.

Purpose of the Study:

• To assess the ionizing radiation dose received by New Zealanders from Po-210 present in consumed shellfish.
• To identify populations at higher risk due to consumption patterns and geographical location.

Main Methods:

• Developed deterministic and probabilistic dietary models incorporating shellfish consumption rates and measured Po-210 activity concentrations.
• Modeled radiation doses for various shellfish consumer groups and geographical regions within New Zealand.

Main Results:

• Estimated annual Po-210 doses from shellfish ranged from 4 μSv to 6070 μSv.
• The majority of New Zealanders received doses below the 1000 μSv reference level.
• Approximately 50% of high shellfish consumers in areas with elevated Po-210 levels exceeded the 1000 μSv reference level.
• Higher shellfish consumption among the Māori population resulted in elevated radiation doses for this demographic.

Conclusions:

• Po-210 in shellfish is generally not a concern for most New Zealanders.
• Specific high-consumption groups and the Māori population require attention regarding Po-210 radiation exposure.
• Further monitoring and risk communication may be necessary for at-risk populations.