Lead exposure in clinical imaging - The elephant in the room.

PURPOSE: Radiation Protection Apparel (RPA) is used during diagnostic imaging and interventional procedures to minimise incidental radiation exposure. The majority of RPA in use are lead-containing, which has until now been considered safe. A recent single-centre study has demonstrated that the external surface of 63 % of RPA was contaminated with lead dust. The purpose of this study was to reproduce this investigation with a larger sample size across Europe and assess whether decontamination procedures were possible.

METHOD: The routine RPA Quality Control (QC) process was adapted to include lead dust contamination tests and decontamination if present. The presence of lead dust was determined using a commercially available colorimetric method. RPA that failed initial QC or could not be decontaminated were removed from use.

RESULTS: From June to October 2019, 728 RPA from 85 imaging centres from five countries underwent initial QC. Of these, 712 were tested for lead dust contamination which was present on 162 (23 %). Following cleaning, 85 (12 %) remained contaminated and were removed from use. Linear regression analysis shows a significant correlation between type of RPA and contamination, (p = 0.0015). There was no correlation between contamination and imaging department, year of manufacture, country and RPA condition (p-values 0.98, 0.90, 0.94 and 0.14 respectively).

CONCLUSIONS: Lead dust contamination is present on 23 % of RPA that would pass routine QC procedures. Approximately half were not amenable to decontamination and were removed from use. Procedures were introduced for the routine handling of RPA, and updated QC steps for assessment and cleaning. Lead-free RPA should be considered.