Scientific poster, presentation or proceeding
In the 2017-2021 project, the Belgian BioElectroMagnetics Group (BBEMG), a consortium of six different teams of Belgian researchers, is carrying out a research on long-term effects of residential and occupational exposure to extremely low frequency electric and magnetic fields (ELF-EMF). In the general population, the first phase of the ExpoHealth project intends to study the contribution of cumulative exposure to EMF (ELF and RF), air pollution and noise (perceived vs measured) on health of the Brussels inhabitants.It also aims to investigate the perceptions, the behaviours and the report of non-specific symptoms and hypersensitivities related to residential and environmental exposures to the above-mentioned agents (perceived vs measured). All agents will be considered in combination and separately. In a second phase, not covered here, cytogenetic analyses will be carried out on the blood cells of inhabitants the most and least exposed to 50 Hz magnetic fields (MF). In this paper, we will focus on long-term exposure to 50 Hz MF.
Indeed, despite much research all over the world there are still a lot of controversies on the possible health effects resulting from exposure to ELF-EMF. In 2002 the International Agency for Research on Cancer (IARC) classified ELF-magnetic fields (ELF-MF) in the group of “possible human carcinogens” (class 2B). This conclusion was based on observations of an association between exposure to 50/60 Hz MF and increased risk of childhood leukaemia and is presently still valid (Swanson et al., 2019) although experimental evidence is lacking and therefore causality is not established. Evidence of ELF-EMF-induced carcinogenicity in adults is more speculative. There also exists suggestive, yet unconvincing, evidence that occupational and residential exposure to ELF-EMF may be associated with an increased risk of neurological disorders, e.g. Alzheimer’s disease. Finally, some people claim that they are hypersensitive to EMF which are, in their opinion, responsible for a variety of mild to severe health complaints. However, despite the great distress of some electrohypersensitive (EHS) people, no firm link has been established to date between the onset of symptoms and the presence of EMF (Anses, 2018). Several researchers (Oftedal et al, 2007; Regel et al., 2006; Rubin et al., 2010) have put forward the hypothesis of a nocebo response, i.e. the anticipation (conscious or not) by hypersensitive subjects of the negative consequences of exposures rather than exposures themselves, causing the appearance of symptoms. Nonetheless, provocation protocols are widely used to test the electromagnetic hypothesis in EHS. However, these studies involve testing with only relatively short-term exposures. For their parts, observational studies are of interest in assessing the possible impact of long-term EMF exposure. Recently, several researchers (Baliatsas et al., 2011; Bolte et al., 2015; Martens et al., 2017; Porsius, et al, 2014) focused their research on environmental exposures to 50 Hz and RF EMF. The visibility of sources was also considered in Martens et al (2018).
The ExpoHealth study in the general population was built in the continuity of these observational studies. It mainly focuses on exposure to 50 Hz MF generated by collective electrical infrastructure. Its objectives are to analyse the perceptions, behaviours and health of individuals living in the vicinity of visible (e. g. transformers) and non-visible infrastructure (e.g. underground HV cables) contributing to similar exposures, and to analyse the contribution of the perceived and actual exposures together with the visibility of electrical equipment to the report of non-specific symptoms and hypersensitivity.
In this paper we will describe parameters used to select groups of inhabitants, based on their environmental exposure to 50 Hz MF.
The target population is people living in the Brussels Region. Two groups of inhabitants will be selected, based on the location of their home in areas with either dense or sparse collective electrical infrastructure. In addition, in both areas, participants will be classified as highly and weakly exposed to 50 Hz MF based on the presence of electrical infrastructure in the immediate vicinity of their home and their actual environmental exposure to 50 Hz MF. The visibility of the infrastructure will also be considered.
The recruitment is based on the following steps:
1. Selection of statistical sectors of interest based on the characteristics of the collective electrical infrastructure; information provided by Elia and Sibelga, respectively operators of the transmission and distribution electrical grids.
2. In situ 50 Hz measurement
In-street measurements within the chosen statistical sectors will provide accurate environmental exposure values (from all 50 Hz sources/networks). Exposures to specific environmental sources (e. g. in-built transformers) will be considered on a case-by-case basis, based on the volunteers' addresses.
3. Inclusion criteria
All adults (18-45-year-old) living in selected streets will be invited to participate. For multi-apartment buildings only inhabitants living on the ground floor and the first floor will be selected as ‘exposed people’.
ExpoHealth includes the collection of data by questionnaire and individual measurements. Volunteers will be invited to complete a consolidated questionnaire including various topics: (1) socio-economic parameters; (2) dwelling characteristics; (3) medical and genetic histories (based on Carrano & Natarajan, 1988); (4) lifestyle & behaviours (based on Carrano & Natarajan, 1988); (5) exposure history (indoor and outdoor); (6) perceived health and nonspecific symptoms; (7) perceived environmental exposure (air pollution, ELF-EMF, RF-EMF, noise) ; (8) sensitivities to environment.
Moreover, participants will be asked to wear a dosimeter (Emdex-II) for 24 hours. Their actual exposure to 50 Hz MF will be recorded. Participants will be invited to complete a diary of activities to evaluate levels of exposure in the workplace, at home and during external activities. A GPS logger should be added to ensure a higher quality of the data.
Definition of statistical sectors of interest
Characteristics of HV and MV/LV grids in Brussels
The HV grid in the Brussels Region is mainly composed of 36 kV cables and some 150 kV cables or lines. No cables are shielded. All cables are buried according to standardised specifications (e.g. burial depth and trefoil formation). Due to technical constraints, the trefoil formation is suspended in junction areas, which are about ten meters long. Cables are then in flat formation (the three conductors are positioned 40 cm apart in a horizontal position).
The MV/LV grids in the Brussels Region includes the voltage levels of 5, 6.6 and 11 kV. It consists of more than 3000 MV/LV substations, transforming electricity into 230/400 volts and more than 5500 boxes distributing electricity via more than 4000 km of cables.
Parameters used in the selection of statistical sectors
Based on the relatively uniform distribution of MV/LV electrical infrastructure in the selected residential areas, the statistical sectors will be mainly differentiated on the characteristics of the HV grid: (1) the density of energized cables and lines; (2) the density of junction areas; (3) the provisional calculation of the load (planned active power in MW in the Brussels HV grid in 2020) of cables and lines, on a quarterly basis.
The density of ML/LV transformers, their average load and the average electricity consumption will be controlled, statistical sector by statistical sector. Precautions will be taken to ensure that the selected statistical sectors have similar socio-economic characteristics. Information on the socio-economic status of the district and its degree of urbanisation will be gathered from dedicated databases (Brussels statistics and Mini-Bru). Moreover, specific environmental exposure conditions (e. g. in-built transformers) will be considered on a case-by-case basis.
Data on the characteristics of the collective electrical infrastructure are managed and analyse in a Geographical Information System (GIS). The map of the statistical sectors selected and their characteristics will be provided at the conference.
Anses. (2018). Hypersensibilité électromagnétique ou intolérance environnementale idiopathique attribuée aux champs électromagnétiques. Rapport d'expertise collective (Vol. Saisine n°2011-SA-0150). Maisons-Alfort.
Baliatsas, C., van Kamp, I., Kelfkens, G., Schipper, M., Bolte, J., Yzermans, J., & Lebret, E. (2011). Non-specific physical symptoms in relation to actual and perceived proximity to mobile phone base stations and powerlines. BMC Public Health, 11(1), 421. http://doi.org/10.1186/1471-2458-11-421.
Bolte, J.F.B., Baliatsas, C., Eikelboom, T. & van Kamp, I. (2015). Everyday exposure to power frequency magnetic fields and associations with non-specific physical symptoms, Environmental Pollution (Barking, Essex: 1987), 196, 224‑229.
Carrano, A.V. & Natarajan,A.T. (1988). International commission for protection against environmental mutagens and carcinogens (ICPEMC), Publication No. 14, Considerations for population monitoring using cytogenetic techniques. Mutation Research, 204 (1988) 379-406379.
Martens, A.L., Slottje, P. , Timmermans, D.R.M.M., Kromhout, H., Reedijk, M., Vermeulen, R.C.H.H. & Smid T. (2017). Modeled and perceived exposure to radio-frequency electromagnetic fields from mobile-phone base stations and the development of symptoms over time in a general population cohort Am. J. Epidemiol., 186 (2017), pp. 210-219, 10.1093/aje/kwx041.
Martens, A. L., Slottje, P., Timmermans, D. R. M., Kromhout, H., Reedijk, M., Vermeulen, R. C. H., & Smid, T. (2017). Modeled and Perceived Exposure to Radio-Frequency Electromagnetic Fields From Mobile-Phone Base Stations and the Development of Symptoms Over Time in a General Population Cohort. American Journal of Epidemiology, 1–10. http://doi.org/10.1093/aje/kwx041
Porsius, J. T., Claassen, L., Smid, T., Woudenberg, F., & Timmermans, D. R. (2014). Health responses to a new high-voltage power line route: design of a quasi-experimental prospective field study in the Netherlands. BMC Public Health, 14(1), 237. http://doi.org/10.1186/1471-2458-14-237.
Oftedal, G., Straume, A., Johnsson, A. & Stovner L.J. (2007). Mobile phone headache: a double blind, sham-controlled provocation study, Cephalalgia: An International Journal of Headache, 27, 5, 447‑455.
Regel, S.J., Negovetic, S., Röösli, M., Berdiñas, V., Schuderer, J., Huss, A., et al. (2006). UMTS base station-like exposure, well-being, and cognitive performance, Environmental Health Perspectives, 114, 8, 1270‑1275.
Rubin, G. J., Nieto-Hernandez, R., &Wessely, S. (2010). Idiopathic environmental intolerance attributed to electromagnetic fields (formerly 'electromagnetic hypersensitivity'): An updated systematic review of provocation studies. Bioelectromagnetics 31 (1):1-11. doi: 10.1002/bem.20536.
Swanson J, Kheifets LI, Vergara X. Changes over time in the reported risk for childhood leukaemia and magnetic fields. J Radiol Prot. 2019 Feb 8;[Epub ahead of print]. https://doi.org/10.1088/1361-6498/ab0586