Occupational Health Research
Many workers receive higher EMF exposure at work than at home, despite spending less time there. EMFs in workplaces tend to be higher than in homes, partly because of the greater concentration of appliances. The mean EMF exposure experienced at work by a recent sample of office workers was 0.18 microtesla (µT).
Certain industries have items of equipment which involve high currents and produce high EMFs. In the electricity industry, examples are live-line work, generator busbars in power stations, and reactive-compensation plant in substations. In other industries, certain welding, heating, and electrolytic processes can produce high fields. In general, these high fields affect only specific workers and not the general public. There are statutory regulations in place in the UK to protect workers against EMF exposure.
The UK electricity industry supports research into the health of its own workers. A database of everyone who worked for the then Central Electricity Generating Board (CEGB) in the late 1970s, included over 80,000 people, is maintained by for occupational health research. When members of this database eventually die, the cause of death is recorded. New techniques have been developed for assessing people’s exposure to magnetic fields over their working life. It is then possible to see whether the cause of death is linked to exposure to magnetic fields.
This research is summarised in the CEGB Cohort Information page, but the broad conclusions are that those in high EMF exposure roles tend to live slightly longer than the general populations and die less of cancer related diseases than the general populations.
In 2008, a large scale review of the future needs of occupational epidemiology of power-frequency electric and magnetic fields (EMF) was performed by a range of scientists who made a number of recommendations. The key messages from that review were:
"Exposures to extremely low frequency electric and magnetic fields (ELF EMF) are widespread and highly variable in many work environments; thus, potentially related health risks warrant continued epidemiologic investigation.
Although a small risk increase for leukaemia and brain cancer cannot be entirely excluded, the lack of a clear exposure-outcome pattern suggests that magnetic fields as presently measured are by themselves not responsible. No consistent indication of an association has been found for other cancers.
The evidence speaks against an aetiologic role for EMF exposure in cardiovascular disease.
Among the major neurodegenerative disorders, amyotrophic lateral sclerosis (ALS) has been most strongly and consistently related to electrical occupations, thus warranting further investigation. Multi-country collaborative studies of ALS are needed to clarify this relationship.
Future research will benefit from methodologic work, including exposure assessment improvements."
These recommendations were taken onboard by the CEGB cohort study and were the focus of much of its research work. Research to date feeds into the formulation of the statutory exposure limits which are in place to protect employees.