Occupational Doses from the use of Thoriated Optical Components.

Area of Science:

• Optics and Photonics
• Radiation Physics
• Occupational Health

Background:

• Thorium is used in high refractive index optical glasses, found in professional and military equipment.
• Concerns exist regarding radiation exposure to the head and eye lens from thorium-containing optics.
• Radiation sensitivity of the eye lens has been re-evaluated.

Purpose of the Study:

• To measure dose rates from thorium decay chains in optical systems.
• To evaluate radiation exposure for optical technicians and users.
• To determine if radiation protection measures are necessary.

Main Methods:

• Dose rate measurements of beta and gamma emissions from thorium decay.
• Analysis of isolated lenses and entire optical systems.
• Identification of dose quantities H'(0.07) and H*(10).

Main Results:

• Dose rates from thorium decay chains were measured for optical systems.
• Exposure scenarios for technicians and users were evaluated.
• Measured dose rates are below established radiation protection limits.

Conclusions:

• Optical systems containing thorium do not necessitate radiation protection measures.
• Exposure levels for both occupational and unintentional use are considered safe.
• The re-evaluated radiation sensitivity of the eye lens is not a concern in these scenarios.