Occupational exposure to extremely low frequency electric and magnetic fields is normally low but can be elevated for certain occupations. There are international guidelines for limiting exposure to workers and there are no established health effects below these limits.
What do I need to know?
Extremely low frequency (ELF) electric and magnetic fields (EMF) exist wherever electricity is distributed in power lines or cables, or used in electrical appliances and equipment. The widespread use of electricity means that people are exposed to ELF EMF everywhere, including the workplace. Although exposure to ELF EMF in most workplaces is usually low, there are certain occupations where elevated exposure can occur and there is some concern of possible health effects.
What is the possible exposure?
Occupational exposure to ELF EMF in workplaces has been found to be generally higher for electrical occupations. The average magnetic field exposure can range from 0.4–0.6 microtesla (μT) for electricians and electrical engineers to approximately 1.0 μT for power line workers. In the electrical supply industry, workers may be exposed to magnetic fields which can exceed 2000 µT and electric fields up to 30 kilovolts per metre (kV/m). Workers in some non-electrical occupations can also be exposed to elevated EMF, for example welders, railway engine drivers and sewing machine operators can be exposed to magnetic fields above 3 μT.
What are the possible health effects?
It is known that acute exposure to ELF EMF at high levels can affect the function of the nervous system and cause cardiovascular effects and tissue burns.
There is no established evidence that occupational exposure to ELF EMF at any level is associated with long-term health effects. Some studies have reported a possible association between electrical occupations and certain neurodegenerative disorders such as amyotrophic lateral sclerosis and Alzheimer disease, however it has been suggested that this is due to increased occurrences of electric shock not ELF-EMF exposure.
The possible association between occupational ELF EMF exposure and cancer has also been investigated and particularly female breast cancer. Early studies reported a weak association with breast cancer, however more recent, larger and better quality studies showed no associated risk. Overall, the link between occupational exposure to ELF-EMF and any type of cancer is not supported by the evidence.
What are the exposure limits?
The International Commission on Non-Ionizing Radiation Protection (ICNIRP) has issued guidelines for limiting exposure to ELF EMF for protecting the public and workers against the established health effects. For workers that are aware and/or have been trained on ELF EMF, the ICNIRP guidelines specify occupational limits. For all other workers that are unaware of their exposure to EMF and for pregnant workers the more stringent general public limits apply.