Poorly designed antenna structure at Stockholm
Seven low-level mobile phone antennas are located along the shore road in the Skeppsbron district of Stockholm (Sweden). An international team of researchers led by Mikko Ahonen from Finland and Michael Carlberg from Sweden concluded in a study that the determination of the locations along the shore road serves as an example of a poorly designed antenna structure. A portable exposimeter was used to record electromagnetic radiation at various measurement points. The highest average field strength in one of the defined segments was 12.1 volts per meter (V/m), corresponding to a radiation density of 388 milliwatts per square meter (mW/m²). The peak value in the area studied was 31.5 V/m (2,648 mW/m²), reaching over 50 percent of the internationally accepted limit of 61 V/m at a frequency of 2,600 megahertz.
Architect Florian Hoppe presents the straw bale building
Architect Florian Hoppe knows his way around both building materials. He developed a relationship with clay at a very early age in his father’s company. He learned masonry and plastering by working on several construction sites in Thuringia/Germany. Through a cooperation of different companies it was even possible to use local clay. In the course of his architectural studies, Hoppe became enthusiastic about straw bale construction. One idea in particular from the settler days in America did not let him go: he wanted to realize the load-bearing straw bale without wooden stud construction in Germany as well. After careful preparation and with the support of his family, he was able to move into his spacious straw house ten years ago.
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.
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.
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.
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.
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.
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.
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.
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.