More research needed into health effects of electromagnetic fields, say experts
Further research is needed to determine the impact of electromagnetic fields on health, particularly in the long term, according to the latest Opinion published by the European Commission's Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR). Electromagnetic fields come from a range of devices, including power lines, electrical appliances, mobile phones, video displays and certain diagnostic instrumentation. Exposure to strong fields can have health effects; at frequencies below 100kHz, this happens through the stimulation of nerve and muscle cells due to induced currents, while for higher frequencies tissue heating is the main mechanism. Guidelines from the International Commission on Non Ionising Radiation Protection (ICNIRP) set out exposure limits which are designed to protect the general public from these effects, and these have been incorporated into European legislation. However, little is known about the health risks associated with long term exposure to low exposure levels. This latest opinion follows an earlier opinion on the same subject from 2001. A lot of research has been carried out since then on Radio Frequency (RF) fields, which come from mobile phones. 'The balance of epidemiologic evidence indicates that mobile phone use of less than 10 years does not pose any increased risk of brain tumour or acoustic neuroma,' the authors write. There is little evidence of an increased risk for brain tumours in long term users, although there are indications of an association with long-term use and acoustic neuroma. The authors recommend a long-term cohort study to find out more about the long term effects of mobile phone use, as well as a study using personal dosimeters to accurately assess individual exposure to RF fields. Children may be more sensitive to RF fields as their brains are still developing. However, no studies on children are available, and so research into the matter is urgently needed, according to the report. Sources of Intermediate Frequency (IF) fields include anti-theft devices in shops and card readers. There is very little data on these fields. 'Proper evaluation and assessment of possible health effects from long term exposure to IF fields are important because human exposure to such fields is increasing due to new and emerging technologies,' the committee states. Extremely Low Frequency (ELF) Fields come from power lines, domestic appliances and electric engines in cars and trains. Here the SCENIHR confirms that ELF magnetic fields could be a carcinogen, based on their association with childhood leukaemia. However, they note that research is needed to understand the mechanisms behind this association. For other diseases, they note that an association between ELF fields and breast cancer and cardiovascular disease is 'unlikely', while the link between neurodegenerative diseases and brain tumours remains 'uncertain'. Finally the group considers static fields, which come from video displays as well as medical technologies such as MRI (magnetic resonance imaging) equipment. Here again, a major lack of data is identified and the committee recommends a cohort study on personnel dealing with such equipment as well as studies on carcinogenicity, genotoxicity and developmental and neurobehavioural effects. Some of the knowledge gaps identified will be filled by EU-funded projects on the subject, as well as data from national research initiatives and the World Health Organisation's International EMF project which was set up in 1996. Meanwhile the European Commission will take the SCENIHR's recommendations into account in work planned under the Seventh Framework Programme (FP7).