Our population has grown extremely worried regarding electromagnetic pollution over the past few years. There is real issue about how ElectroMagnetic Fields (EMF) affect people's health. Currently, the main reason of anxiety regarding EMF is the consequences of cellular phones, specifically the development of cell towers near residential areas.
In the world of science, there is a great deal of disagreement over how low-level EMF affects people. There seem to be scientific studies that suggest the possibility of health consequences for humans as a result of the body reacting with electromagnetic waves, whereas other study refutes this data and says that the initial studies are biased and unreplicable. This article's objective is not to provide scientific data in favor of either claim, instead it seeks to "articulate" both viewpoints quickly and to assist readers in determining the most likely indoor EMF sources.
Health Effects of EMF
Research that relate the consequences of electromagnetic fields on people's health are based on the generation of tiny currents that alter the body's normal ionic balance. For instance, researchers claim that a 2.5 kV/m electrical field operating at 60 Hz generates around a billionth of an amp per square centimeter.
This current level is less than the human perception threshold, which is considered as the smallest amount of current that humans can experience flowing through their bodies. Nevertheless, many experts believe that these incredibly tiny currents have the potential to interact with human cells, changing their normal protein synthesis and thus elevating the risk of contracting many illnesses.
On the other hand, many researchers claim the conclusion is purely baseless because the results have not been verified by laboratory testing as required by science. The latter scientists think that there is no need for concern because there is no plausible and testable theory for how low-level EMF affects human cells (referred to as bioeffects in scientific literature).
In either scenario, various research organisations believe that, even if there is no scientific evidence associating low-level EMF with health impacts, it is advised that we strive to avoid electromagnetic fields wherever necessary.
What we will Discuss
In this post, we'll discuss low-level EMF, as opposed to higher-level EMF, which may cause well-known consequences like electrocution when a live electrical connection is touched. We'll additionally look at the most typical EMF sources and provide some approximate EMF values that we could come across in our daily life. It is crucial to remember that the field strength detected in a typical American home is significantly below the safety standard set by many organisations.
However, if we become aware of the "hot spots" within the home, we may redesign the space to make it less vulnerable.
The electric and magnetic field strengths that are shown in this article were measured using a TriField metre, which also analyzes radio and microwave leaks and electric and magnetic field strengths individually.
It is crucial to note that the TriField metre is a basic, inexpensive device that most likely wouldn't meet the requirements established by regulatory bodies on acceptable exposure limits to EMF. In spite of this, the tool serves our needs much beyond expectations.
Technical Information Regarding EMF
Whenever there is a voltage difference across two conductors, electric fields are produced. On the contrary, when the amount of electrical current increases, larger magnetic fields are produced by the passage of electrons generated in electrical current.
Since we want to measure field strengths just around the EMF sources (such as a household appliance), we are within a region which is referred to as "near field". The electric and magnetic fields are distinct and function independently in "near field" (meaning, there can be a magnetic field in the absence of an electric field or an electric field in the absence of a magnetic field). In contrast to near field, electric and magnetic fields are interconnected together in far field.
Electric fields could be effectively insulated by a conductive material or even by the human body. Magnetic fields, on the other hand, can enter the human body and buildings.
Compared to electric fields, magnetic fields are more challenging to protect against, necessitating the employment of pricey ferromagnetic materials that are mostly not employed in building or everyday applications.
Magnetic fields are most frequently encountered in homes due to their difficulties in shielding and the fact that high-current consuming equipment produce them.
The units for measuring electric fields are kV/m or kV/cm (1 kV/cm = 100 kV/m). Teslas (T) or Gauss (G), are used to measure magnetic fields. The following equation represents their relationship.
1T = 10,000 G
Due to their relatively small magnitude, magnetic fields in residential areas are calculated in milligauss (mG). When electromagnetic fields produced by voltages and currents come into contact with conductive materials, they spread similarly to radio waves and cause currents to flow. Based on their wavelength characteristics, electromagnetic fields may be broadly divided into the following categories.
DC Static Fields
Static magnets or the magnetic field of the Earth, for instance, can produce static fields. Their association with the human body is believed to be safe at medium and even moderate strength levels since they are DC and operate at a zero frequency and therefore do not force electrical currents to flow in the body.
Examples of these fields include the Earth's magnetic field, which has a strength of 500 mG; industrial magnetic fields, where some workers can be subjected to fields of up to 500 G without harm for extended periods of time; and magnetic resonance imaging (MRI), where patients can be exposed to fields of up to 40,000 G without harm, albeit for short time intervals.
Electromagnetic Fields with Low-Frequency
EMFs with frequency levels lower than 3 kHz are considered low-frequency fields. The electrical distribution network, which produces fields at 60 Hz as well as harmonics at 120 Hz, 180 Hz, etc., is the principal source of these fields in residential and industrial locations. These are the EMF fields which are monitored inside a house.
EMF Fields with High Frequency
High frequency EMF fields are those that have frequencies over 3 kHz. These are mostly produced through emissions across all spectral bands, including 2 -way radio, commercial AM and FM radio signals, etc.
Effects of Fluorescent Lighting in the Basement
The mudroom, which is often found in a basement, has a lot of electrical items and is vast, making it the place with the maximum magnetic fields. At the operator's shoulder height in the basement, the ambient magnetic field intensity was determined to be 2 mG, while it was 3 mG at the operator's head height (with all appliances switched off).
The electrical wiring arrangement in our home that connects the basement ceiling to the upper floor is really what enabled the magnetic field to grow when the detector was raised higher towards the ceiling.
Fluorescent lighting, which is frequently found in laundries, basements, and garages, is a strong generator of both electric and magnetic fields. After turning on the fluorescent lights, the background magnetic field in the same space was examined and found to be 2 mG at chest height (the very same reading as when the lights were switched off) and 5 mG at head height.
The extra current flow in the fluorescent lamps may have been what caused the second measurement to spike. The magnetic field is substantially stronger at a distance of 6 inches from the lighting system, despite there being only a slight background increase, as seen in Fig. 1 below.
The strength of the electric and magnetic fields across a 55 inch florescent tube fixture is depicted in Table 1 below. The concentration of the EMF produced by the fluorescent lamps is apparently very disproportionate when the numbers provided in Table 1 is compared to those shown in the graph of Fig. 1. However, the areas with larger magnetic fields also have powerful electric fields.
The area having the maximum electric field was found to be 10 inches from the fixture's end. The graph in Fig. 2 shows how the electric fields weaken as one gets farther away from the source.
The EMF device was moved away from the fluorescent lamp after maintaining a consistent distance of 10 inches from the end that produced the greatest electric field for the EMF level measurements shown in Fig. 2. It was observed that when the detector travels away from the source, the initial field strength reading drops dramatically.
EMF Radiations from Big Appliances
As stated earlier, whether the fluorescent lights were on or off, the magnetic field measured at the shoulder height in the basement was 2 mG. The washer and dryer were switched off while the measurements were collected at a position adjacent to them. At shoulder height, 2 feet away from the washer, while the washer was switched on, the magnetic field was 3 mG.
The hairdryer (and other such equipment) have a magnetic field that is stronger at the location where the mains cord enters the device. This was found to be 15 mG for the washing machine. However, because of the placement of the high-current-consuming motor, the appliance's bottom had the greatest magnetic field as measured.
Table 2 displays the magnetic field strength measured somewhere at washing machine's front at different elevations above its bottom.
Because the strength of the magnetic field completely depends on the operation of the machine, the former are maximum numbers, — meaning, the strongest magnetic fields observed. In any event, it demonstrates that magnetic fields produced by washing machines are powerful. When the electric dryer was turned on, the location where the power cable enters the device and the power cord itself produced the strongest magnetic fields, both measuring 100 mG.
The magnetic fields produced by the electric dryer, in contrast to the washing machine, remained constant when the testing instrument was lowered toward the ground. It is reasonable to believe that the magnitude of the EMF is equal to the total of the individual contributions whenever two or more appliances are switched on at the same time.
The Effects of Radiations from Small Appliances
Strong magnetic fields are not just produced by large electric equipment. Small, portable electrical devices too can release EMF at magnitudes similar to those of a washing machine. A steam iron produces a 40 mG magnetic field around the power cable and around the handle.
As seen in Fig. 3, the most powerful fields are found on the sidewalls, where they may reach values of up to 100 mG before weakening as we move away from the iron. The essential magnetic field strength generated by an electrical light dimmer was observed to be 20 mG, with peaks that might reach higher than 100 mG depending on its orientation.
EMF from computers and televisions
Another potential cause of both electric and magnetic fields are televisions and computers. The electric field was measured to be 5 kV/m and the magnetic field was 15 mG at a distance of 2 feet from a normal Tv set. Fields dropped by up to 5 mG and 1 kV /m at a distance of 3 feet.
The magnetic field intensity measured at a distance of 20 inches from a computer monitor, which is standard for most consumers, was 35 mG. Surrounding the different components of the computer, including the CPU, keyboard, speakers, etc., it was observed that the magnetic field remained pretty consistent.
EMF outside of the house?
Contrary to common opinion, despite the enormous amounts of current they can carry, pole-mounted high-voltage transformers produce a very weak magnetic field. The magnetic field strength was found to be just 3 mG close to the transformer.
These transformers are particularly well protected to reduce energy losses since radiating electromagnetic fields signify energy waste for the power companies.
Thus transformers contribute very little to the electromagnetic pollution within an apartment due to their low EMF concentrations and their position. Magnetic fields of 100 mG was induced on the body of the external electric meter by the main electrical wiring. It detected a 100 mG magnetic field at a distance of 3 inches from the meter, but no electric field.
A Few Closing Remarks
As discussed, the objective of this article was to provide a summary of how and why electromagnetic fields are produced and to provide a relative measurement of the field intensity produced by several typical household equipment.
When installing equipment inside a house, it is necessary to keep in mind how rapidly electric and magnetic fields weaken as we move away from these sources. Viewers are recommended to make their own judgments and get enlightened by reading the most recent research and scientific results in this contentious field because the correlation between EMF and health consequences has not been confirmed in the scientific community.