What are the most common sources of low frequency magnetic fields?

There are many sources of low frequency magnetic fields which are nowaday very common and wide spread both outside and inside our houses.
For example, on the outside we can find overhead and underground power lines, power stations, electrical substations, street light systems, electrical systems and switchgears, to name just a few.
On the other hand, inside our houses we can find, for instance, electrical appliances and everyday objects, ordinary office machinery and electrical wiring.
Here are some examples of the magnetic field generated by some of the most common appliances:
magnetic field generated by common appliances

W hat is certain about human exposure to low frequency magnetic field?

Nowadays there is a good level of knowledge of the physical consequences of the interaction between low frequency magnetic induction and living organisms.
We have long known what are the acute effects originating from the short-term exposure of human beings to low frequency magnetic induction, nevertheless, as far as long-term effects are concerned, it is not possible to know with absolute certainty whether the prolonged exposure may cause negative health effects or not.
This is the reason why current safety regulations prescribing limits of exposure to magnetic fields are determined just according to shortterm
acute effects.

What is the purpose of safety regulations concerning human exposure to low frequency magnetic fields?

Safety regulations are designed in order to protect the health of human beings against the possible harmful effects caused by the exposure to low frequency magnetic induction, both in case of exposure due to professional reasons (workers who are exposed due to the features of their job) and the case of exposure that is not linked with professional reasons (such as when dealing with general public, residents or workers which are not in contact with magnetic fields due to the characteristics of their occupation).

W hich are the main national (Italian) and international safety regulations concerning human exposure to low frequency magnetic fields?

The main national and international safety regulations concerning human exposure to low frequency magnetic induction are:
– European Council Recommendation of 12 July 1999 on the limitation of exposure of the general public to electromagnetic fields (0 Hz to 300 GHz) (1999/519 CE): http://www.etsi.org/WebSite/document/aboutETSI/EC_OJ_Council/1999-519-EC.pdf

– Directive 2004/40/CE of the European Parliament and of the Council of April 2004 on the minimum health and safety requirements
regarding the exposure of workers to the risks arising from physical agents (electromagnetic fields) (18th individual Directive within the meaning of Article 16(1) of Directive 89/391/EEC) http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32004L0040&from=EN

– Directive 2013/35/EU of the European Parliament and of the Council of 26 June 2013 on the minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents (electromagnetic fields) (20th individual Directive within the meaning of Article 16(1) of Directive 89/391/EEC) and repealing Directive 2004/40/EC: http://eurlex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2013:179:0001:0021:EN:PDF

W hat are the limits of human exposure to low frequency magnetic fields prescribed by safety regulations?

*ICNIRP (International Commission on Non-Ionizing Radiation Protection)
European Council
Italian Government

Interim guidelines on limits of exposure to 50/60 Hz electric and magnetic fields

Council Recommendation of 12 July 1999 on the limitation of exposure of the general public to electromagnetic fields (0 Hz to 300 GHz)

D.P.C.M. 8/7/2003. Fixing of limits of exposure, values of attention and quality targets to protect people against the exposure to the
electromagnetic field generated by 50 Hz power lines

≤ 100 μT
Limit of exposure: ≤ 100 μT
Values of attention: ≤ 10 μT in case of exposures that last more than 4 hours a day
Quality target: ≤ 3 μT for buildings or electrical installations built after the regulation came into force