Exposure to risks arising from electromagnetic fields

1. Exposure to risks arising from electromagnetic fields Chris Marshman York EMC Services Ltd University of York

2. Introduction • The threat to health posed by electromagnetic fields has been the subject of discussion for over 20 years • This has focussed largely on: • The links to cancers induced by 50Hz ac Overhead Powerlines • Microwave ovens • And the emissions from Mobile Telephones • There are other well known sources of high RF energy eg RF wood gluing machines

3. Introduction • The WHO has been active in assessing the risks to health from EMFs • Absorption of RF energy by the Human body has been the subject of considerable research activity triggered by the extensive use of Mobiles, including the Dept. of Electronics at the University of York under the Dti’s MTHR programme • The Radio Agency (Ofcom) have also mapped all the mobile base stations in the UK, this information is available from the Ofcom website

4. European Legislation • 1999 Recommendation (L1999/59) • limitation of exposure of the general public to electromagnetic fields • Implemented via LVD, R&TTED • Stds under LVD: eg EN50366:2003 Household appliances, EN50371:2002 Generic • 2004 Directive (2004/40/EC) • minimum health & safety requirements regarding the exposure of workers to risks arising from electromagnetic fields

5. Limits designed to protect from these phenomena: induction of electric fields and currents in body tissue(< 100 kHz) heating of tissues(> 100 kHz) surface heating(> 10 GHz) Basic restrictions on: Current density(1 Hz – 10 MHz) SAR(100 kHz – 10 GHz) Power density(10 GHz – 300 GHz) Scientific basis

6. Hz kHz GHz THz

7. Hz kHz GHz THz

8. Employers’ Duties under 2004/40/EC • Assess, measure and calculate levels of exposure to electromagnetic fields • Compare with “action values” ICNIRP • Assess and/or calculate exposure limit values (competent person) • Ensure exposure limit values aren’t exceeded • Provide appropriate info & training

9. Examples of EMF Measurements YES Ltd has been requested to specifically measure EMFs where there has been a perceived threat to health: • Measurement of magnetic fields from a high current transformer feeding a heating element in a glass factory • Measurement of magnetic fields from a railway substation relocated close to an office block • Potential interference to a heart pacemaker caused by short range wireless device operating at 2.4GHz close to the operator’s chest

10. Examples of EMF Measurements • Measurement of the potential fields from communications masts located close to a proposed accommodation building on an RAF site • Measurement of the threats posed to maintenance staff working in the vicinity of a Council building roof fitted with a number of mobile phone transmitting antennas • Assessment of the exposure of operators of RF wood gluing machines in a kitchen cabinet manufacturing company

11. EMCIA opportunities? • Directive 2004/40/EC affects all employers – hence large potential market by 2008, on the other hand, • Generic European Std being prepared may well indicate that many employers have to do nothing! • EMCIA members opportunities: • On-site measurement • Competent person for assessment • Measurement equipment, compared to EMC crude! • Where identified threats – mitigation methods: shielding, etc • So we don’t really know level of take-up, hence need to monitor progress eg UK legislation, HSE/HPA activity