M. Almalki et al.: Radioprotection 2025, 60( 3), 234 – 241 235
long-serving personnel in interventional cardiology( Ciraj- Bjelac et al., 2010). Despite this, studies have shown that interventionists in high-volume catheterization labs often exceed these limits( Kwon et al., 2011).
Ensuring radiation safety is crucial for individuals working in environments with radiation exposure. The daily exposure to radiation experienced by medical personnel in interventional cardiology raises health concerns if proper protective measures are not implemented. It is essential to monitor radiation doses and employ protective strategies to maintain occupational exposure within safe limits, preventing deterministic effects and minimizing stochastic risks associated with ionizing radiation, as recommended by the International Atomic Energy Agency( IAEA, 2014). Occupational dose monitoring is typically conducted using personal radiation monitoring devices like thermoluminescent dosimeters( TLDs). For the purposes of radiological protection, the assessment of occupational exposure is primarily based on the measurement of effective and equivalent doses, as outlined by the IAEA and the United Nations Scientific Committee on the Effects of Atomic Radiation( UNSCEAR, 2010; IAEA, 2006).
The purpose of this study was to assess the occupational radiation exposure among medical personnel in interventional cardiology and to determine if the exposure levels are within the recommended occupational dose limits set by regulatory bodies. The International Commission on Radiological Protection( ICRP) has set the occupational radiation dose limits at 20 mSv per year, with a five-year cumulative limit of 100 mSv and no single year exceeding 50 mSv, to safeguard medical staff( ICRP, 2007). Therefore, monitoring and analyzing the annual mean effective doses( AMED) and the five-year average doses( MED-5y) is crucial for ensuring compliance with these regulatory limits and for identifying any trends or differences in exposure levels across medical professions and gender that may warrant further investigation or intervention. We hypothesize that the occupational radiation exposure among medical personnel in interventional cardiology will be within the recommended dose limits, but may vary significantly across professions and gender groups. The results of this study will provide valuable insights into the current state of radiation safety in interventional cardiology and may inform future strategies for minimizing occupational radiation exposure.
2 Methods and materials
2.1 Study design and period
This study was conducted to assess occupational radiation exposure among medical personnel in interventional cardiology clinics in the western region in Saudi Arabia. The investigation encompassed a period of five years, extending from 2018 to 2022. The study population included various professional groups actively engaged in these settings, namely anesthesiologists, cardiologists, radiologists, nurses, and radiologic technologists. Approval from the Institutional Review Board( IRB) was obtained, and participant confidentiality was maintained.
2.2 Dosimetry monitoring and effective dose estimation
TLDs were employed as the tool for monitoring personal radiation doses. These devices were distributed and subsequently collected on a quarterly basis by the Ministry of Health( MOH) radiation protection offices located in each region. Each worker was assigned a personal bar-coded TLD, which contained individualized data such as the worker’ s name, sex, date of birth, department, and historical radiation exposure records. To ensure an accurate assessment of whole-body radiation dose, workers were instructed to wear their TLDs at chest level. It is crucial to note that the placement of TLDs, whether worn inside or outside personal protective equipment, can significantly influence the dose measurements. In our protocol, TLDs were worn outside any protective gear to standardize exposure assessments across all personnel, acknowledging that this placement provides a conservative estimate of actual body dose. The effective dose received by each worker was estimated by equating it to the measured Hp( 10). This approach is generally considered a conservative method for assessing effective dose, particularly under the assumption of uniform whole-body exposure( ICRP, 2007). Thus, the effective dose in this study was estimated by setting it as equal to the measured Hp( 10).
2.3 Specifications and calibration
The TLDs utilized in this research( TLD-100 chip; Thermo Fisher Scientific, Massachusetts, United States) were constructed from lithium fluoride( Li natural) LiF: Mg. Ti materials. The dosimetric readings were obtained using a Harshaw Model 6600 Plus Automated Reader Instrument( Thermo Electron Corporation, Ohio, USA), capable of detecting doses ranging from 10 mGy to 1 Gy. The calibration of this instrument is critically important to the accuracy of our measurements and is performed annually using a 137Cs source under free-air exposure conditions to a standardized dose of 0.5 mSv. This calibration process ensures that the reader’ s sensitivity and accuracy remain within the required standards for precise dose measurement. Furthermore, to address variability in thermoluminescence efficiency across different TLD chips, which can affect the accuracy of dose readings, the reader’ s built-in internal irradiator( 90Sr / 90Y) is utilized to generate element correction coefficients( ECCs). These ECCs are essential for calibrating each TLD to ensure that all devices respond uniformly to identical radiation doses. Control TLDs are also employed to measure and account for background radiation, ensuring that the reported doses are net exposures after subtracting any ambient radiation influences.
2.4 Statistical analysis
To analyze the dosimetry data, the Statistical Package for the Social Sciences( SPSS version 20, IBM Inc., Chicago, IL, USA) was used to obtain descriptive and inferential statistics. Analysis of the effective doses, Hp( 10), were presented as the annual mean effective dose( AMED) and the averaged over the 5-year study period( MED-5y). Further statistical examination