Residential toxins in old prefabricated house

prefabricated house real estate check

prefabricated house real estate check

Building biologists are regularly asked for advice

Prefabricated houses from the seventies are part of the fixed portfolio of real estate agents. Mostly, the offers are tempting for young families. The most important plus points are considered to be a prime location, a relatively large plot of land, a good room layout and, ultimately, a favorable price. Too often, homebuyers suppress the problem of pollutants in older prefabricated houses. Even fifty years after completion, certain groups of pollutants have not yet been aired out.
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Pay attention to the dew point

Mold experts use a dew point calculator

The focus is on room air temperature and relative humidity

Visible mold growth in the apartment always causes discomfort for those affected. After all, no one wants to have the unloved co-inhabitant in their neighborhood. To analyze the causes, it is essential to take a look at the physical relationships in the building. The focus is on room air temperature and relative humidity as well as on the surface temperatures of the surrounding surfaces. Mold always grows when it finds enough food and sufficient moisture in its environment. The fungus is not choosy about its “food”. A little house dust is enough, as it can be found in every apartment. In the most frequent cases of damage, condensed water vapor from the air in the room is responsible for the influx of moisture. Mold experts use the dew point calculator to determine cause and effect.
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Using the ACI value to assess the radioactivity of building materials

gamma rays in building materials

Gamma rays in building materials endanger health

The European Union (EU) has developed the Activity Concentration Index to assess radiation exposure

The large-scale installation of radioactive building materials indoors can endanger the health of the occupants. Granite, tuff or pumice are building materials with radioactive potential. However, sand, gravel, limestone and natural gypsum can also be radioactively contaminated under certain circumstances. The builder does not always know which rock is in a product. For example, a masonry block is offered under the brand name “Liapor”, without the buyer knowing that pumice rock is hidden behind it. The European Union has therefore developed the Activity Concentration Index (ACI) to assess radiation exposure from building materials indoors. The Institute for Building Biology in Rosenheim (Germany) recommends an ACI value of less than 0.75 for health protection.
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Boundary conditions for mobile room air cleaners

Air cleaner Dustcontrol

Air cleaner Dustcontrol


Mobile air purifiers are booming in times of pandemics. Manufacturers of these devices outbid each other with superlatives. The German statutory accident insurance (DGUV) sees the use of the air recirculation units in a much more differentiated way. For example, the accident insurer points out important boundary conditions that must be observed when using the devices in classrooms.
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Strong smell after sanding the floor

strong odor form cresols

Renovating a house from the 1960s

A young family in Thuringia (Germany), full of enthusiasm, renovated a house from the 1960s. They wanted to keep the floorboards on the first floor and started sanding off the top layer. But after a short time the Stickler family was very sober. During the work it started to stink terribly. Ms. Stickler also worried about her child’s health. A building biologist should investigate the process to find the reason for the unpleasant smell. The expert sampled the room air using the TENAX method (2 liters of air at a volume flow of 100 milliliters per minute). As a precaution, he took a material sample from the flooring.
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Tar cardboard containing PAH caused odor problems and headaches

naphtalene found in the air of two classrooms

Naphtalene found in the air of two classrooms

Measurement results showed a pollution with naphthalene

In a primary school in Saxony (Germany), odor problems had arisen in two classrooms and in the staff room since the building was renovated. When a new rector took office in 2018, the matter really got going. Ms. Rubens (name changed) not only had a sensitive nose, but increasingly complained of a headache as soon as she was in the staff room. The school administration informed the city administration as the responsible cost bearer. The local building authority then commissioned an engineering office to investigate the indoor air. The measurement results showed a clear pollution of the room air with naphthalene. Since even the guideline II of the German Federal Environment Agency was exceeded with 20 µg / m³, no lessons were allowed to take place in the rooms from now on. A review of the construction plans showed that the school was built in 1964. Therefore, the experts consulted assumed that the building was contaminated. The energetic renovation in 2017 had obviously exacerbated the smell problem. The airtight facade and the lack of controlled ventilation ensured that the pollutants in the indoor air could accumulate more.
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Too many pollutants in the carpets

Carpets may contain toxins

Carpets may contain toxins

People love their carpets – 1.8 million tonnes are sold in Europe year after year. This is also the second largest carpet market next to the USA. The market leader today is Tarkett in France, followed by the Balta Group from Belgium. The production of a carpet takes place in several production steps. Each of the work stages uses a wide range of chemicals. The toxins contained therein later exhale into the room air or they are inhaled by the inhabitants as dust particles. Toxic chemicals are also the main obstacle to environmentally sound disposal. That’s why 1.6 million tons land in the waste incineration plant every year.
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A bright screen reduces the flicker effect

building biologist measures light quality

Building biologist measures lightquality of a computer screen

Building biologist Jens Rudloff (Germany) regularly measures the light quality of his computer screen with a professional measuring device. The “Eco-Mode” of the LED monitor from Fujitsu has a brightness level of 55. For comparison, Rudloff sets the brightness level to 95 and measures whether there are any differences in terms of flicker or blue light for the user. In addition to the light from the ceiling light, the building biologist adds a bright halogen desk lamp during the experiment. As usual in building biology, he uses natural sunlight as a guideline.
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Molds endanger people with weakened immune systems

The fungus Aspergillus fumigatus blocks messenger substances in the immune system

For healthy people, mold spores in the indoor air are normally no problem, since the pathogens are successfully controlled by the immune system. For certain groups, however, caution is required. The guideline of the Scientific Medical Societies (AWMF) includes people with a weakened immune system due to chemotherapy, stem cell transplants or HIV infections. Other risk groups include people with cystic fibrosis and bronchial asthma. The German Robert Koch Institute (RKI) divides the symptoms of immunosuppression into three groups and speaks of moderate, severe and very severe immunosuppression. In a recent study, scientists from the Friedrich Schiller University in Jena (Germany) have now found out in what way the mold can turn off the immune system.
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Power line too close to the house

power line magnetic fields

Young family is looking for a property

Iris Graustein (Germany) has been looking for months a residential building in the suburban area. Finally, the broker reports with a financially appropriate offer. After inspecting the property Iris is in doubt. Because at a distance of ten meters leads a power line with two conductors to garden and house over. The utility company tells the family that it is a 20 kilovolt line. Contradictory information about magnetic fields near power lines can be found on the Internet. Even the called building biologist can not provide remote diagnosis. On the one hand, a much lower current flow is to be expected with the 20 kV line than with a large 380 kV line; On the other hand, the cables are very close to the house. The building biologist advises a long-term measurement over 24 hours to obtain certainty about the magnitude of the magnetic field in the apartment.
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