Stable and radioiodine concentrations in cow milk: dependence on iodine intake

Area of Science:

• Environmental Science
• Animal Science
• Food Safety

Background:

• Radioiodine contamination of milk poses a public health risk.
• Stable iodine (I) is explored as a potential countermeasure.
• Understanding radioiodine transfer dynamics in dairy cows is crucial.

Purpose of the Study:

• To evaluate the efficacy of stable iodine supplementation in reducing radioiodine transfer to milk.
• To determine the dose-response relationship between stable iodine intake and radioiodine reduction.
• To assess the safety and practicality of using stable iodine as a countermeasure.

Main Methods:

• Dairy cows were fed varying amounts of stable iodine.
• Concentrations of stable iodine and radioiodine in milk were measured.
• Radioiodine transfer rates were calculated based on dietary intake and milk concentrations.

Main Results:

• Low iodine intake (<1.5 mg/day) reduced radioiodine transfer by 25%.
• Intakes between 10-500 mg/day had no significant effect.
• Intakes >1000 mg/day reduced transfer by approximately 50%.
• High stable iodine doses resulted in milk concentrations exceeding human consumption limits.

Conclusions:

• Significant reduction of radioiodine transfer requires very high stable iodine intake.
• Current stable iodine levels in milk from supplemented cows exceed safety limits.
• Stable iodine administration may be considered for emergency dose reduction in humans via the milk pathway.