Electric, magnetic and electromagnetic fields (EMF)

Indoor electrosmog

Electric, magnetic or electromagnetic fields (EMF) are colloquially referred to as electrosmog (e-smog) and describes the sum of existing electric or magnetic fields as well as electromagnetic radiation and their possible interactions the effects on humans.

Electric or magnetic fields are generated e.g. by the A/C 230V (50Hz) power supply in electrical installations, numerous electrical household appliances, lighting, office equipment, computers or consumer electronics as well as by railroad current (16.7 Hz). In Germany, electromagnetic fields include e.g. DVB+/DVB-T, W-LAN, Bluetooth, Tetra or mobile radio services such as GSM, UMTS, LTE, 5G.

WLAN or Bluetooth has arrived today in almost every office or household up to the children’s rooms their application can be found in numerous devices such as smartphones, tablets, laptops, computers, smart home or home entertainment. The sum of the possible sources can influence the well-being or health. Due to the permanent influence of electromagnetic fields, negative health effects can occur in people. This can lead from single symptoms to complex diseases such as headaches / migraines, chronic fatigue, loss of performance, nervousness, sleep disorders, weakening of the immune system.

In recent years, an increase in electro-hypersensitive people has been registered. (Electro-hypersensitivity EHS). EHS has been classified as a multi-system disease by the European Academy of Environmental Medicine (EUROPAEM). Many sleeping places often have too high values of technical fields from a building biology point of view . Effects of electrosmog are usually the sum of many sources that affect the organism. For particularly sensitive areas such as the sleeping place, according to the recommendations of building biology, at best there should be no EMF fields or, if possible, only very low EMF fields.

 

Health risk from artificial mineral fibers

Artificial mineral fibers (KMF) usually consist of glass, rock and mineral wool as well as binders. KMF insulation materials are widely used, for example, in the thermal insulation of buildings or pipelines and in sound insulation. KMF fibers manufactured before 1995 can be carcinogenic. A health risk from KMF fibers was proven as early as 1972. Artificial mineral fibers are classified according to the Ordinance on Hazardous Substances via the so-called material composition into three groups, the carcinogenicity index* (KI index).

KI>40 not carcinogenic
KI 30to 40 possibly carcinogenic -> K3
KI <30 carcinogenic -> K2

In the period from 1995 to 2000, when the industry switched to mineral fibers, which are more biosoluble, there was no corresponding labeling, so that it is not possible to distinguish whether a mineral wool used in a building poses a health risk.

The smaller the fiber, the higher the risk that the KMF fibers are carcinogenic. Since the late 1990s, only biosoluble KMF insulation materials have been commercially available. Biosolubility of KMF fibers means that in a given period of time the fiber must have degraded in the body by a certain amount.

If the harmlessness cannot be clearly determined before the start of remediation or demolition work, it must be proven by a suitable test procedure.

The Technical Rules for Hazardous Substances (TGRS) describe the protective measures that must be taken during demolition, renovation and maintenance work involving old mineral wool.
In addition, some KMF insulation materials contain binders containing formaldehyde. Because of its toxicity, special legally specified indoor concentrations apply to formaldehyde. Neither fibers from mineral insulation materials nor formaldehyde should be present indoors, if possible.

Good alternatives to artificial mineral fibers are offered, for example, by wood-fiber insulation materials for the energy-related renovation of buildings. Wood fiber insulation materials are sustainable and have a good life cycle assessment.

(* The carcinogenicity index KI, which is the difference between the sum of the mass contents (in %) of the oxides of sodium, potassium, boron, calcium, magnesium, barium and twice the mass content (in %) of aluminum oxide, is at least 40 for artificial mineral fibers. Source: BBSR report 1/2011).

Spectrum analysis of high frequency

Frequency-selective measurement of high-frequency (HF) immissions

In the generally more frequently used method of RF imaging, the so-called broadband measurement, the sum of all RF immissions present at the time of measurement can be recorded, as well as an acoustic signal characteristic of the respective mobile radio service.

Depending on the task for investigating a residential or sleeping area, it may be necessary to record detailed information on the high-frequency immissions, e.g. which radio service is involved, what signal strength is present and what permanent minimum and maximum RF immissions can be expected at the measurement point. This information can be collected by the so-called frequency-selective spectrum analysis, in which all mobile radio services present at the time of the measurement are determined separately.

In a first overview measurement of the spectrum analysis, it is shown in which frequency ranges an RF-immission is present. Subsequently, the respective radio service is measured in frequency and signal strength (detailed spectrum), from which the permanently existing base load (minimum load) as well as the maximum full load (max peak or worst case) of the transmitter can be determined. With the help of predefined correction factors, the different bandwidths of the respective mobile radio services are taken into account and extrapolated to the maximum power. From the maximum transmission power (MaxPeak), the minimum load can now be calculated (base load).

The total immission of all mobile radio services determined at the measuring point is formed from the sum of the detail spectra and specified in the radiation density (power flux density) in microwatts per square metre (μW/m2). A frequency-selective spectrum analysis is generally recommended for the planning of a remediation measure for the shielding (attenuation) of high-frequency immissions.

The broadband measurement technique

Sum measurement of high-frequency immissions

Unlike spectrum analysis, broadband measurement is only sum-based, i.e. only the total sum of the high-frequency immissions detected by the device is indicated. The problem here, however, is that a broadband device cannot distinguish between the respective radio services, but these can be present with very different bandwidths in the same frequency range (GSM/LTE).

However, the bandwidths of the respective mobile radio service must be taken into account to determine the high-frequency immission. Thus, when measuring an RF immission by means of a broadband measuring device, an underestimation can occur, which can amount to a factor of 100. Therefore, broadband measurement is not suitable for determining an RF immission caused by different mobile radio services or for planning a remediation measure to shield radio frequency.

The broadband measurement technique is well suited for “in-house” source detection, but can also be used for long-term recording of RF immissions. Long-term broadband measurements can also be useful if the expected RF immissions cannot be detected at the time of a spectrum analysis because the source is located outside one’s own sleeping/living area and may not be transmitting continuously.

For a concept for the shielding of RF immissions, a long-term RF measurement is usually not necessary, since the minimum and maximum exposure determined by the spectrum analysis provides the framework for the shielding effectiveness of a shielding material required to comply with international recommendations.

Property survey / Building biology building check

Healthy building and renovation is gaining importance and offers a variety of possibilities to avoid or reduce pollutants in building materials.

Energy-efficient construction and renovation places high demands on the building envelope and its airtightness. However, airtight construction is often the cause of the accumulation of pollutants or humidity in indoor spaces.

When planning a new home, consideration should be given to the selection of tested building materials, examination of the building site, and shielded electrical installation. A ventilation concept is also mandatory today to avoid moisture damage or the accumulation of pollutants. Contaminated sites such as PCB, lindane, formaldehyde, artificial mineral fiber insulation materials or asbestos are often found in older existing buildings.

Before renovating an existing property, a building biology building check should be carried out. Pollutants, moisture damage or mold or outdated electrical installations must be taken into account during renovation. The building biology building check forms the cornerstone for healthy living, on which a renovation plan can be built. The health precaution begins already in the own four walls with the selection of pollutant-tested building materials and facility objects as well as the avoidance of electrical smog.

After completion of a residential building, in addition to the obligatory air tightness measurement, a room air examination for pollutants, as well as the measurement of technical fields and waves should not be missing as a measure for quality assurance.

Infrared thermal imaging in building biology

Thermography is an imaging method that makes temperature distributions visible. With the help of an infrared thermal imaging camera, the temperature differences on the surface of a building component, such as a wall surface, become visible by means of colour gradients. Thermal bridges or weak points in the building envelope can thus be made visible.

In addition to the energetic analysis of heat losses of a building, thermography also offers valuable support for the building biology investigation of mould infestation in interior rooms. In addition to moisture analyses of parts of the building, infrared thermal imaging can be used to visually depict an area where there is an acute risk of mould growth.

In summary, building thermography offers valuable support:

– For the identification of energetic leaks in the building envelope.
– For quality assurance or leakage detection of airtightness tests of a building project
– Building biology investigations to assess the risk of mould formation

The use of scanner technology for infrared images provides high-quality and informative thermal images.

Example: Entrance area of residential building – risk of mould formation due to thermal bridges

 

Example: Window reveals in residential buildings – risk of mould growth due to thermal bridges

Example: Facade of residential building: Analysis of heat losses

Example of a thermal bridge in the floor area:

Example of a thermal bridge in the area of the floor ceiling:

Example of a thermal bridge in the area of the floor ceiling: