Electromagnetic fields & health: The most controversial issues in epidemiological research

1. Electromagnetic fields & health: The most controversial issues in epidemiological research Prof. Dr. Martin Röösli Institute of Social and Preventive Medicine at Swiss Tropical Institute, Basel Associated Institute of the University of Basel

2. Content • Exposure to power lines: • childhood leukaemia • Occupational exposure to ELF-MF: • leukaemia • neurodegenerative diseases • Mobile phone exposure: • brain tumour • All type of electromagnetic fields • symptoms (electromagnetic hypersensitivity)

3. Childhood leukaemia and power lines From Greenland, 2005

4. Childhood leukaemia • No consistent results from animal research; no biological mechanism. • Multiple-bias modelling (Greenland, 2005): (a) confounders: uncontrolled shared causes of field exposure and leukaemia, (b) sampling and response biases: possible uncontrolled associations of exposure and disease with selection and participation (c) measurement errors

5. Results of multipe bias modelling (OR for >0.3 µT) †meta-analysis without bias Greenland, 2005

6. IARC classification • Possibly carcinogenic to humans

7. Attributable leukaemia cases • Attributable fraction due to power lines: 0.1 -5% • Number of leukaemia cases in CH (0-15y): 55.  0.2-2 annual cases due to power lines. Kheifets, EHP, 2006

8. Occupational ELF-MF exposure • Occupational exposures levels and duration are generally higher than in the everyday environment (e.g. welder, electrician, railway workers). • Appealing for epidemiologic research. • Limitations: co-exposures, healthy worker effects

9. Past and new studies of occupational ELF exposure and leukemia Kheifets et al. JOEM 2008

10. Past and new studies of occupational ELF exposure and brain tumours Kheifets et al. JOEM 2008

11. Occupational ELF-MF exposure and amyotrophic lateral sclerosis (ALS) Kheifets, OEM, 2009

12. Occupational ELF-MF exposure and Alzheimer’s disease (AD) Kheifets, OEM, 2009

13. Extent of occupational exposure From Table 1: Hug, Röösli & Rapp, Soz Prav Med, 2006

14. Exposure levels from power lines Bafu, 2005

15. Study on neurodegenerative disease and power line exposure • Cohort study of the whole Swiss population • All deaths between 2000 and 2005 • Exposure: distance of place of residence to the nearest powerline (220 and 380 kV) Huss et al., AJE, 2009

16. Alzheimer’s disease and distance to power line * adjusted for sex, educational level, occupational attainment, urban-rural area, civil status, language region, number of apartments per building, and living within 50 m of a major road.

17. Alzheimer’s disease and distance to power line Huss et al., AJE, 2009 * adjusted for sex, educational level, occupational attainment, urban-rural area, civil status, language region, number of apartments per building, and living within 50 m of a major road.

18. Other neurodegenerative diseases (Swiss study) • No indication of an association for • Parkinson disease • Amyotrophic lateral sclerosis • Multiple sclerosis

19. Strengths/limitations • Selection bias unlikely • Confounding unlikely (control outcomes are not related to power lines: total mortality, lung cancer, alcoholic liver disease, cancer of esophagus) • Limited number of cases <100m of power lines • No modelling/measurement of exposure • Diagnosis misclassification from the limitations one rather expects an underestimation of the risk than a spurious association

20. Review of the EU Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR), 2009 SCENIHR Research priorities (2009):

21. Epidemiological papers about mobile phone exposure from http://www.emf-portal.de

22. Why brain tumour? • No direct DNA damage (non-ionzing radiation) • Hypothetical biological mechanisms discussed (e.g. free radicals, DNA repair mechanism) but no mechanism established for radio- and microwave frequency radiation • Head is most exposed part of the body when using a mobile phone • But why tumours and not other head related outcomes???

23. Indication for risk or forrecall bias? Protective? No, indication of selection bias Indication for risk increase? Indication of recall bias INTERPHONE: Mobile phone and cancer SCENIHR 2009

24. Time trends of male brain tumour cancer rates Incidence rate per 100,000 in Denmark, Finland, Norway, and Sweden, 1974 – 2003: Glioma Meningioma triangles: 60 – 79 year^s squares: 40 – 59 years Circles: 20 – 39 years Deltour et al., JNCI, 2009

25. Time trends of female brain tumour cancer rates Incidence rate per 100,000 in Denmark, Finland, Norway, and Sweden, 1974 – 2003: Glioma Meningioma triangles: 60 – 79 year^s squares: 40 – 59 years Circles: 20 – 39 years Deltour et al., JNCI, 2009

26. Summary brain tumour • Many studies available. • Many studies and cancer registries allows to identify a possible risk if present. • Inherent uncertainties regarding long term use.

27. Electromagnetic Hypersensitivity (EHS) • Other terms: • Electrosensitivity • Idiopathic environmental Intolerances (IEI-EMF) • EHS is characterized by a variety of non-specific symptoms, which afflicted individuals attribute to exposure to EMF (WHO, fact sheet N° 296). • No established biological mechanism

28. 3 different aspects of EHS • Perception of low-level fields: sensibility (Leitgeb and Schröttner, 2003)provocation studies • Symptoms and RF-EMF: short termprovocation studies / randomized trials / human laboratory study • Symptoms and RF-EMF: long termepidemiological/observational studies

29. Perception of low level RF-EMF under double blind conditions Röösli, EnvRes 2008

30. ?Ridder-vold 2008o ?Augner? 2008o Hillert2008* ?Cinel? 2008* ?Eltiti?2007o Furubaya-shi 2009o Kleinlogel 2008o Johansson 2008* Fritzer2007* Evidence for nocebo Koivisto2001* Wilen2006* Hietanen2001* Nocebo not considered Regel2006o Oftedal2007* Rubin2006 * Symptoms, well-being: acute effects effect1) 1) at least 1out of several no effect *) near field (mobile phone) o) far field (base station)

31. Symptoms, well-being: Long term effects Major Challenge: • Most cross-sectional studies based on measured exposure levels do not indicate an increased risk: Hutter et al. 2006, Thomas et al. BioEM, 2008 Berg-Beckhoff et al., 2009, Kühnlein et al. BioEM • By design, cross-sectional studies are limited in terms of causality. Subjective reporting of symptoms Knowledge about exposure

32. Evidence Number of cases Conclusions • childhood leukaemia and exposure to power lines • neurodegenerative diseases and ELF-MF • adult Leukaemia/brain cancer and ELF-MF • brain tumour and use of mobile phones • electromagnetic hypersensitivity and EMF