Reassessing lead protective garment assessment using ICRP 103 tissue weighting factors

Area of Science:

• Medical Physics
• Radiation Protection
• Occupational Health

Background:

• Lead protective garments are essential for medical staff working with X-rays.
• These garments degrade over time, potentially compromising their protective efficacy.
• Existing assessment methods for garment defects may not fully account for evolving radiobiology data.

Purpose of the Study:

• To propose a novel method for assessing the protective efficacy of lead garments.
• To calculate maximum allowed defect areas based on updated radiobiology data and the ALARA principle.
• To provide specific defect area limits for different regions of the body (above waist, below waist, thyroid).

Main Methods:

• Applied updated radiobiology data from the International Commission on Radiological Protection (ICRP) 103.
• Utilized the as low as reasonably achievable (ALARA) principle to derive a formula for maximum defect area.
• Incorporated organ cross-sectional areas (A), ICRP 103 tissue weighting factors (wt), maximum allowed additional effective dose (d), and unattenuated absorbed dose (D).

Main Results:

• Calculated maximum allowed defect areas: 370 mm² (above waist), 37 mm² (below waist), and 279 mm² (thyroid).
• These calculated values are generally more restrictive than commonly published values, especially for thyroid and below the waist regions.
• The method assumes conservative values for D (50 mGy yr⁻¹) and d (0.3 mSv yr⁻¹), and 0% transmission.

Conclusions:

• The proposed method offers a quantifiable and adaptable approach to assessing lead garment integrity.
• It allows for adjustments based on updated radiobiology data and varying jurisdictional dose limits.
• Future work will refine defect area calculations by considering profession-specific radiation dose variations.