A Source-based Measurement Database for Occupational Exposure Assessment of Electromagnetic Fields in the INTEROCC Study: A Literature Review Approach

Abstract

Introduction: To date, occupational exposure assessment of electromagnetic fields (EMF) has relied on occupation-based measurements and exposure estimates. However, misclassification due to between-worker variability remains an unsolved challenge. A source-based approach, supported by detailed subject data on determinants of exposure, may allow for a more individualized exposure assessment. Detailed information on the use of occupational sources of exposure to EMF was collected as part of the INTERPHONE-INTEROCC study. To support a source-based exposure assessment effort within this study, this work aimed to construct a measurement database for the occupational sources of EMF exposure identified, assembling available measurements from the scientific literature.

Methods: First, a comprehensive literature search was performed for published and unpublished documents containing exposure measurements for the EMF sources identified, a priori as well as from answers of study subjects. Then, the measurements identified were assessed for quality and relevance to the study objectives. Finally, the measurements selected and complementary information were compiled into an Occupational Exposure Measurement Database (OEMD).

Results: Currently, the OEMD contains 1624 sets of measurements (>3000 entries) for 285 sources of EMF exposure, organized by frequency band (0 Hz to 300 GHz) and dosimetry type. Ninety-five documents were selected from the literature (almost 35% of them are unpublished technical reports), containing measurements which were considered informative and valid for our purpose. Measurement data and complementary information collected from these documents came from 16 different countries and cover the time period between 1974 and 2013.

Conclusion: We have constructed a database with measurements and complementary information for the most common sources of exposure to EMF in the workplace, based on the responses to the INTERPHONE-INTEROCC study questionnaire. This database covers the entire EMF frequency range and represents the most comprehensive resource of information on occupational EMF exposure. It is available at www.crealradiation.com/index.php/en/databases.

Keywords: EMF sources; electromagnetic fields; exposure database; literature review.

Figure 1

Overview of source-based occupational exposure assessment to EMF in INTEROCC. This flowchart outlines the different steps of the exposure assessment approach developed within the INTEROCC project. The current manuscript entails steps 1 through 4 which led to the development of the EMF Occupational Exposure Measurement Database (OEMD). Steps 5 and 6 will be described and published elsewhere.

Figure 2

Description of the literature review performed to construct the OEMD. This flowchart describes the different steps and number of documents identified, included and excluded throughout the literature review carried out to construct the OEMD. (a) This figure includes some books, book chapters or actual measurements (n = 5). (b) This figure includes both published (n = 59) and unpublished articles (n = 3). (c) This rating refers to the full document or sets of measurements within the document. As stated in the text, documents with a rating <1 were included in the database if they made a unique contribution to the exposure assessment.

Figure 3

B-field versus distance for ELF (50/60 Hz) sources (A) and E-field versus distance for RF sources (continuous shortwave diathermy, 27.12 MHz and roof-top paging antenna, 678.4 MHz) (B). The EMF magnitudes available in the OEMD were fit by regression techniques to functions of the inverse distance = constant × d⁻ⁿ.