Wavecontrol Human exposure to EMF Electromagnetic fields and Workers’ safety
Index 1 Introduction to EMF 2 EMF health effects 3 Standards and normative 4 Applications and sectors 5 Wavecontrol solutions: EMF assessment 6 Measurement in the field - examples 7 Measurement demo
EMF: what is it? They are invisible and perfectly silent : if you live in an area with electrical power and mobile phone service, some level of artificial (man-made) EMF is surrounding you. There are two types of EMF Natural EMFs - We are surrounded by these : The earth produces an electromagnetic field (EMF), The human body does as well. These are extremely low frequency ELF’s. In fact, scientific research has demonstrated that every cell in your body may have it’s own EMF, helping to regulate important functions and keep you healthy. Natural EMFs or ELF’s are low in intensity; for example, a healthy human body resonates with the earth's magnetic field at around 10 hertz. Artificial EMFs - we are surrounded by theses too. These are “man - made” and emanate from all things electrical and electronic. Everything from hairdryers and mobile phones to high voltage wires, to the mains cable running around building - they all create EMFs. Some are stronger than others and some studies have been shown them disturb the human body’s natural energetic field with variable effects. Fact : We’re exposed to 100 million times greater artificial EMF radiation than our grandparents were, and that exposure grows each year.
what makes EMF? An electromagnetic field (EMF) is made of: an electric field and a magnetic field. The electric field: Created by electric charges, or voltage (the force of the electricity) Always there when an appliance is plugged in (even if the appliance is turned off) Can be shielded or blocked by metal housing and other barriers. Measured in units of hertz The magnetic field Created by moving electric charges (electric current) Only there when the appliance is operating (when current is flowing) Hard to shield: can penetrate steel, concrete and human bodies (human bodies have the same permeability as air when it comes to magnetic fields, which is why x-rays work so well). The more powerful the current is, the more powerful the magnetic field it creates Measured in units of gauss (G), Tesla or A/m.
Characteristics of a wave Wave length (λ). It Period (T). Frequency (f). is the distance between two It is the time required for It is the number of complete consecutive peaks. It is the oscillation movement cycles elapsed per unit of measured in units of length of the wave to describe a time (in a second, for (meters, for example) complete cycle example)
Electromagnetic waves Electromagnetic radiation is a combination of oscillating electric and magnetic fields, which propagate through space, transporting energy from one place to another. These waves do not need a material means to propagate (they can do it in a vacuum)
Laws and equations
Sources of EMF The number of sources of EMFs has grown significantly over the past 30 years
Index 1 Introduction to EMF 2 EMF health effects 3 Standards and normative 4 Applications and sectors 5 Wavecontrol solutions: EMF assessment 6 Measurement in the field - examples 7 Measurement demo
Who is taking care of EMF? ICNIRP: International Commission on Non-Ionizing Radiation Protection WHO: World Health Organization IEEE: Institute of Electrical and Electronics Engineers
Low frequencies (1 Hz – 100 kHz) – biological effects Neurobehavior Perception of surface electric charge • • Stimulation of myelinated nerve fibres of the human peripheral nervous system (PNS) Stimulation of myelinated nerve fibers of the central nervous system (CNS) • • Stimulation of muscle tissue Induction of phosphenes in the electrically excitable cells in the retina • • Indirect scientific evidence that brain functions such as visual processing and motor co-ordination can be transiently affected by induced electric fields
Low frequencies – biological effects Neurodegenerative disorders Some reports suggest that people employed in electrical occupations might • have an increased risk for ALS (amyotrophic lateral sclerosis) • So far only one residential study is available, indicating an increased risk for Alzheimer’s disease after long -term exposure, but based on very small numbers of cases Overall, the evidence for the association between low frequency exposure and • Alzheimer´s disease and ALS is inconclusive.
Low frequencies – biological effects Cardiovascular disorders hazardous cardiovascular effects associated with low frequency fields are • unlikely to occur at exposure levels commonly encountered environmentally or occupationally.
Low frequencies – biological effects Cancer Research has suggested that there may be a weak association between the • higher levels of exposure to residential 50-60 Hz magnetic fields and childhood leukemia risk, although it is unclear whether it is causal. Overall, in contrast to the epidemiological evidence of an association between • childhood leukemia and prolonged exposure to power frequency magnetic fields, the animal cancer data, particularly those from large-scale lifetime studies, are almost universally negative.
Low frequencies – Summary Accute effects • There are a number of well established acute effects of exposure to low- frequency EMFs on the nervous system: the direct stimulation of nerve and muscle tissue and the induction of retinal phosphenes. There is also indirect scientific evidence that brain functions such as visual processing and motor co- ordination can be transiently affected by induced electric fields. Chronic effects WHO’s cancer research institute, IARC (International Agency for Research on • Cancer), evaluated low frequency magnetic fields in 2002 and classified them in category 2 B, which translates to “possibly carcinogenic to humans”. The basis for this classification was the epidemiologic results on childhood leukemia.
High frequencies (100 kHz – GHz) Biological effects • Exposure to electromagnetic fields at frequencies above about 100 kHz can lead to significant absorption of energy and temperature increases.
High frequencies (100 kHz – GHz) Regarding absorption of energy, EMF can be divided into four ranges: From about 100 kHz to less than about 20 MHz: absorption in the trunk • decreases rapidly with decreasing frequency, significant absorption may occur in the neck and legs. From about 20 MHz to 300 MHz: relatively high absorption can occur in the • whole body, and even higher values if partial body (e.g., head) resonances are considered. • From about 300 MHz to several GHz, at which significant local, nonuniform absorption occurs. Above about 10 GHz: energy absorption occurs primarily at the body • surface.
Static fields (0 – 1 Hz) Direct effects: Induction of electrical ‘flow’ potentials across blood vessels due to the • movement of electrolytes in the blood • Forces on paramagnetic and diamagnetic components of tissues Changes in chemical reactions due to altered spin chemistry • • Deflection of ionic currents due to magnetic (Lorentz) force.
Static fields (0 – 1 Hz) Movement-induced effects: When the static magnetic field exceeds 2 T, the movement-induced electric field in the head may be high enough to: • Evoke vertigo Nausea • • Visual sensations (magnetophosphenes) • Metallic taste in the mouth Possibility of acute neurocognitive effects, with subtle changes in attention, • concentration and visuospatial orientation
Indirect coupling mechanisms Two indirect coupling mechanisms have been reported: Contact currents that result when the human body comes into contact with • an object at a different electric potential. • Coupling of EMF to medical devices worn by, or implanted in, an individual.
Index 1 Introduction to EMF 2 EMF health effects 3 Standards and normative 4 Applications and sectors 5 Wavecontrol solutions: EMF assessment 6 Measurement in the field - examples 7 Measurement demo
ICNIRP • ICNIRP: International Commission on Non-Ionizing Radiation Protection. • It aims to protect people and the environment against adverse effects of non-ionizing radiation (NIR). ICNIRP develops and disseminates science-based advice and guidelines on limiting exposure to non- • ionizing radiation.
ICNIRP guidelines ICNIRP 98 and 2010 guidelines for Electric field ICNIRP 98 and 2010 guidelines for Magnetic field
European Union EMF framework General public Occupational safety Council Directive 89/391/EEC (Framework Directive) Council Recommendation 1999/519/EC of 12 July 1999 20th directive EMF Directive 2013/35/EU ...
EMF Directive 2013/35/EU
Not only Europe ✓ United States: IEEE, FCC, OSHA ✓ China ✓ Russia ✓ Japan ✓ Australia ✓ Rest of the world: usually ICNIRP
Recommend
More recommend
