Thyroid tumors and thyroid function in women exposed to internal and external radiation

Area of Science:

• Occupational Health
• Radiation Epidemiology
• Endocrinology

Background:

• Female radium dial workers employed before 1930 were exposed to internal and external radiation.
• Thyroid gland health is a concern due to potential radiation-induced damage.

Purpose of the Study:

• To investigate the frequency of thyroid tumors and conditions in female radium dial workers.
• To estimate the risk of thyroid cancer associated with radiation dose.
• To assess the relationship between radiation dose and benign thyroid conditions.

Main Methods:

• Analysis of thyroid tumor and condition frequencies in 686 female radium dial workers with radium body-burden measurements.
• Estimation of thyroid cancer risk using observed cases and expected numbers from tumor registries.
• Evaluation of benign tumor, nodule, and goiter frequencies across different thyroid dose groups.
• Assessment of thyroid cancer mortality and thyroid function tests in subgroups of workers.

Main Results:

• An estimated thyroid cancer risk of 69 per 10(6) person-rem was calculated assuming a linear dose-response relationship.
• Observed thyroid cancer cases were higher than expected, suggesting a risk of 46 excess cases per 10(6) person-rem.
• No significant increase in benign tumors, nodules, or goiters was observed in higher thyroid dose groups.
• No thyroid cancer deaths were observed in a larger cohort, and thyroid function tests did not differ by dose group.

Conclusions:

• Radiation exposure in female radium dial workers may be associated with an increased risk of thyroid cancer.
• Benign thyroid conditions do not appear to be significantly elevated by radiation dose in this cohort.
• Further research is needed to refine risk estimates due to uncertainties in dose assessment.