Occupational Dose and Dose Limits: Experience in a Large Multisite Hospital System.

Area of Science:

• Medical Physics
• Radiological Health
• Occupational Safety

Background:

• The Nuclear Regulatory Commission (NRC) has proposed reducing occupational dose limits for lens dose equivalent (LDE), embryo/fetus dose, and deep dose equivalent (DDE) administrative control levels (ACLs).
• Understanding the impact of these proposed changes on healthcare workers is crucial for maintaining safety and operational efficiency.

Purpose of the Study:

• To assess the potential impact of proposed NRC regulatory changes on occupational radiation dose limits within a large hospital system.
• To determine how revised limits for LDE, embryo/fetus dose, and DDE ACLs may affect worker workflows and compliance.

Main Methods:

• Collected occupational radiation badge data from 1,305 workers (2013-2014) and 180 pregnancies (2009-2014).
• Calculated median LDE, DDE, and embryo/fetus doses and applied current and proposed NRC regulations.
• Used Fisher's exact test to analyze disproportionate effects on physicians regarding dose regulations.

Main Results:

• Median occupational doses were significantly lower than current NRC annual limits.
• Proposed NRC regulations substantially increased the percentage of workers exceeding established limits and ACLs.
• Physicians (especially interventional radiologists, pain medicine, cardiologists) and pregnant nuclear medicine technologists were most impacted by proposed LDE, DDE, and embryo/fetus dose limits.

Conclusions:

• The proposed NRC regulatory changes are expected to lead to a modest rise in workers exceeding dose limits and ACLs.
• Physicians and pregnant nuclear medicine professionals may require modifications to their work schedules or practices.
• Implementation challenges include cumulative dose tracking and the application of LDE shielding factors.