In each sixth German dwelling it molds visibly. But most fungi bloom in secret. If they remain undetected for a long time, they can cause allergies and make the inhabitants ill.
B urn-out. That's what he thought of first. Had he slept at all? Tiredness weighed on him like lead when the alarm clock rang in the morning. He had a hard time getting up, dragging himself to the shower, to the car, to work. Nothing seemed to help against this feeling of not moving from the spot. Coffee, another coffee, at some point he just felt sick from it. If only he could concentrate.
Johannes Teska* is a medical engineer, develops high-tech for hospitals. He must be on the case. But Teska didn't even remember what his girlfriend had said to him on the phone the night before the next morning. Maybe it was just too much – the job, commuting to the other city to the shared apartment. Burnout, it felt like?
On weekends, when he slept in the shared apartment, he felt better. As if the change of location relieved him of all the stress. And he liked his job. If Teska was honest, he didn't feel stressed at all – neither by work nor by the long train rides home.
And then he noticed that strange smell. Musty, kind of like sewage. Under the sink in the open kitchen, he found an old rag, pitch black, bursting with mold. He must have fallen for it when a plumber fixed a pipe some time ago. Teska threw away the rag. But the smell stayed -. With him the fatigue. For weeks he was tormented by allergic symptoms. He knew them well, he suffered from hay fever anyway. Just not actually in November. Whether the rag had "rubbed off" onto the wall behind the sink? Was it possible that mold was to blame for his condition?
Airtight rooms favor mold infestation
With alcohol against the mold
Annoying mold stains on the walls can be fought with high-proof alcohol. It is important to ventilate well afterwards and not to light a fire.
Aspergillus, Cladosporium, Penicillium or Stachybotrys – mold is everywhere. They live on the earth, on food, animals, even people, and their spores are constantly flying through the air. You can breathe them in without any problem. But when they proliferate in an indoor environment, they can make you sick.
There is moisture damage in every fourth German apartment. Visible mold in one in six homes. This is the result of a survey by the housing portal Immowelt. Experts ame, however, that most damage is not even visible. The number of unreported cases is therefore probably much higher. In the airtight new buildings, there is too little heating and far too little ventilation.
Once mold has spread, it can cause a myriad of symptoms – from watery eyes to asthma, fatigue to respiratory infections. But the signs are diffuse and often the infestation can be traced only with different measuring methods.
Proper ventilation prevents mold
"The inquiries because of mold have multiplied in the last years," says Olf Herbarth, university professor at the medical faculty of the University of Leipzig. Like many other experts, Herbarth also sees the problem in the ventilation of living spaces. "Windows used to leak," he explains. "There the room air was exchanged two to four times daily completely."Today this value is still around 0.01.
An air exchange does not take place thus actually any longer. The current DIN standard for thermal insulation of buildings also prescribes "sufficient air exchange". At least half of the room air should be exchanged per hour according to this regulation. "In fact, many air only once a day," says Klaus-Peter Boge, expert for mold and residential toxins.
But if too little fresh air gets into the rooms, the relative humidity rises – and fungi grow particularly well in humid environments. Even those who heat too little risk the spread of mold. In cold bedrooms, for example, the warm air breathed condenses on the walls. "That's why mold is often found behind the bedroom curtain or the closet," explains toxicologist Thomas Schupp of Munster University of Applied Sciences. Even hidden water damage. Building defects often lead to mold infestation. They often remain undetected for months. Only when the inhabitants feel really ill, they come on the idea to look for mold.
The so-called watering-can mold Aspergillus forms white, green, brown, black, gray or yellow fungal turf. Almost all of the 350 Aspergillus species can cause allergic reactions . cause ones. In addition, aspergilli can secrete toxins that thrive on food such as fruit or grain.
"I've basically known 'burnout' for 30 years," says Boge. So long the learned engineer already examines mold damage in interiors. "I often experienced that humans were constantly tired, to nothing aufraffen could, preferably only at home remained."Most of the time, he found mold in their apartments. "Once that was gone, people felt better all of a sudden."These people had not suffered from stress or chronic exhaustion, but from the mold on their walls or in the floor.
This was also the case with Johannes Teska. The musty smell, it came from the wall behind the sink. Teska was sure of this. Only to see there was nothing. An assessor first looked for wetness, the most common cause of mold infestation. But she found nothing. Only a detailed examination of that wall behind the sink revealed: mold, extensive, on the entire wall.
It was not visible to the naked eye, but easily visible under a magnifying glass. The young man wanted to know whether he could stay in the apartment. No problem, said the expert, an allergy is unpleasant, but not dangerous. Only the mold would have to be removed.
Mold can cause allergies, experts agree today. After pollen, house dust and animal hair, the spores with which molds reproduce are among the most important allergens in the environment. Over 100.000 different species of molds live in the world, about 100 are known to be allergenic. People who suffer from an allergy anyway are particularly susceptible.
That is why it is often difficult to tell whether it is actually the mold that is causing the symptoms. "Mites, for example, like to eat mold," explains Thomas Schupp, the toxicologist. With a house dust allergy sufferer one can hardly differentiate whether he reacts to the mites or the mold.
Experiments on mice, however, have shown that the mold spores themselves can also cause asthma-like symptoms. Around five percent of Germans suffer from mold allergy. It can also develop in someone who has not had an allergy before.
Symptoms of illness caused by mold
The typical symptoms of a mold allergy include watery eyes, a runny nose and an asthmatic cough. A test shows whether you suffer from such an allergy. "Doctors can order the spores of certain types of fungus and then test specifically for them," explains toxicologist Schupp – for example, with the so-called prick test. This involves scoring the skin on the patient's forearm and applying the allergen directly. If an allergy is present, the skin becomes red and swollen.
"Unfortunately, the prick test does not work for one of the most common allergenic molds," Herbarth, an environmental medicine specialist, cautions. Aspergillus versicolor cannot be detected with the prick test so far. "Most test for Aspergillus fumigatus. Then the test is often negative, because this fungus rarely occurs indoors." Those who have severe symptoms should therefore rather have a blood test done. The blood is analyzed for certain antibodies. This is how the doctor can safely determine whether someone has developed an allergy.
As with all allergies, it is important not to expose oneself to the allergen anymore. This means that the fungus must be removed, if possible professionally. "Up to a size of 0.5 square meters, you can still remove a mold yourself," says Herbarth. In its "Mold Remediation Guide," the German Federal Environmental Agency recommends treating such small mold spots on smooth surfaces with a household cleaner and then disinfecting the spot with 80-percent alcohol.
"Under no circumstances should you simply brush over the mold with wall paint," warns the physician. Because this removes the smell in the short term, but the mold continues to spread under the paint. Those who are allergic or have a weak immune system should not remove mold themselves.
In Teska's apartment, an area of more than 0.5 square meters was infested. "In such a case a specialist should rather ran", says Heinz-Jorn Moriske, director of the advisory board environmental hygiene with the Federal Environment Agency. Teska's landlord had the infestation removed by a specialist painter and the wall repainted. The damage seemed to be repaired, but the young man did not feel any better.
Shortly before Christmas, on his way to work, his heart suddenly began to race; on the treadmill in the gym, the athletic young man could barely stand it for another ten minutes. He coughed constantly. That already for weeks. "The contrast between weekends at home and the first night in my apartment became increasingly stark," he recalls. From Sunday to Monday he slept the worst. Sometimes he coughed all night long. He contracted bronchitis that he simply could not get rid of.
In addition to allergies, molds can also trigger infections. However, this actually only occurs in people whose immune system is weakened – for example, after an organ transplant or during cancer treatment. Particularly dangerous is aspergillosis, an infection with the mold Aspergillus, which can be fatal.
Penicillium, the "brush" mold, is known to many as a producer of the antibiotic penicillin, which is used to treat bacterial infections. With the mold, however, a . uch blue cheese as Camembert or Roquefort is produced. Penicillium can cause allergies. Secretes toxins under certain circumstances.
Mostly the fungi affect the lungs, sometimes also the central nervous system. About 5000 people are currently affected by a mold infection in Germany each year. About half die from it. "With healthy humans there are mold infections in the domestic surrounding field however normally not", says Herbarth, the environmental physician.
The fact that Johannes Teska constantly had respiratory infections was probably related to the fungus anyway. "Molds affect our health in three different ways," explains Herbarth: In addition to spores, many fungi also secrete toxic substances called mycotoxins, and they release volatile organic compounds into the surrounding air. These substances irritate the mucous membranes. "In a sense, they break the barrier between what is outside the body and the body itself."
In addition, molds can weaken the immune system, adds toxics expert Schupp. Both make people more susceptible to colds and respiratory infections.
Because Teska's symptoms did not subside, the medical technician insisted that further research be done to find the actual cause of the mold infestation. Even if nothing was visible; he was sure that something was still in the air. "We experts ame that around 85 percent of mold damage is not even visible," says Klaus-Peter Boge.
They hide under the floor, behind cupboards, mirrors or wallpaper. It is often building defects that are behind the infestation – improperly dried screed, improperly installed insulation, leaking exterior walls or an incorrectly installed water pipe. In the poor indoor climate of many houses, the fungi can then multiply quickly.
In Teska's case, it was an adventurously installed sewer pipe under the bathtub that had caused the damage. When the young man took a shower, several liters of water ran into the floor right next to a heating pipe. The heat ensured that the surface of the soil dried again immediately. But in the deeper layers the water collected. Offered equal several mold types paradisiacal conditions. "The mold grew out of the ground, so to speak," says Teska – to an extent that he himself had not anticipated. For months he had been exposed to the outgassing of the fungus. Not an isolated case, warns mold expert Boge.
Fungal infestation measure
Finding out whether a room is affected is not that easy: "If there is no mold to be seen, a spore meter is usually used," he explains. Such devices measure the number of spores in the air. It usually ranges from 300 units per cubic meter in November to as high as 3000 in August, when most molds shed a particularly large number of spores.
If a mold has spread in a closed space, clearly more spores would have to fly around – at least theoretically. "However, fungi do not always sporulate to the same extent," says toxicologist Schupp. "Such measurements are therefore not always meaningful."
Several methods should therefore be used to determine whether damage has occurred, Boge emphasizes. MVOC measurements can also be used to determine whether volatile metabolites, such as those usually secreted by molds, are present in the indoor air. MVOC, which stands for "microbial volatile organic compounds," are volatile organic compounds that can affect a person's health just as much as spores do.
If such outgassing or spores are detectable, mold detection dogs are also used today. They locate the fungus – for example, under the floor, in a wall or the ceiling of a room. Then the expert knows where to look and can take samples from the suspicious spots and send them to the lab.
The "Cleveland babies" – death by Stachybotrys chartarum
In Teska's apartment the expert found one of the most feared molds at all. In the U.S., Stachybotrys chartarum is known as "toxic mold". Stachybotrys first came to attention in the early 1930s. Russian farmers told stories of horses that fell victim to the "black straw" in rows.
As it turned out, the bales had become damp and were infested with a black, slimy mold. Animals that had eaten the stalks developed high fevers, had inflamed eyes and severe diarrhea. Eventually they died from infections and internal bleeding. The farmers themselves complained of skin rashes, coughs and bloody colds.
In the 1990s, several infants in Cleveland in the U.S. state of Ohio were admitted to a children's hospital with pulmonary hemorrhages. They were exposed to the "toxic mold" in their homes for extended periods of time. Some of these "Cleveland babies" died – possibly from toxins from the stachybotrys that had attacked their lungs. But it could not be conclusively proven.
Stachybotrys chartarum forms a black turf of mold, has a slimy consistency and thrives on damp ground. If it's found indoors, it points to wasse . rdamage. The fungus secretes dangerous toxins, called mycotoxins, under certain circumstances.
Although the cases of the dead babies made big media waves, the body of studies on mycotoxins is thin. It is still not known how exactly the toxins work when they are not eaten, but "only" inhaled. Rats that ate tiny amounts of the toxins over three months showed severe damage to blood-forming organs after a short time, and their lungs and immune systems were attacked by the toxins.
Similar results were obtained in an inhalation study in which rats and mice were exposed to aflatoxins, the toxins of some Aspergillus species, for two hours. The toxins attacked the liver cells of the animals. Also inhibited the immune system. And mice that inhaled the toxins daily for a year were significantly more likely to develop lymphocytic leukemia.
"Animal experiments cannot simply be transferred to humans," says toxicologist Schupp. But that mycotoxins are dangerous when ingested through food is undisputed, he said. "I ame that they can also make you sick if you inhale them."Of course, it always depends on the quantity: "The dose makes the poison."
Toxin-forming molds pose a particular risk, confirms Heinz-Jorn Moriske of the Federal Environment Agency. "Precisely because we don't know what effects they have on humans exactly, molds should always be removed – preferably before they affect the health of the occupants."
If clothes are properly infested because they are exposed to an off-gassing stachybotrys for weeks, then you can throw them away
In three days he has to go again, to the apartment that he would prefer not to enter at all. Johannes Teska had moved out when he knew what fungi had spread in his home. It took a few weeks, then he was much better. Today he has no symptoms at all. "I underestimated it," he says in retrospect. Unnecessarily long he had exposed himself to mold, because he simply could not believe that it was the reason for his condition.
After he moved out, a battle of experts began over the necessary remediation measures. In the meantime, everyone agrees, but the apartment has been closed since February. This also means that Teska's furniture, his clothes, the entire inventory have been exposed to the mold for a good year now.
"The last time I was there, everything was infested. On my bed, the closet, the chests of drawers – black spots everywhere," he says. And that no one can tell him exactly from which materials the spores and toxins can really be removed. Smooth surfaces can be cleaned, "but if clothes are really infested because they have been exposed to off-gassing stachybotrys for weeks, then you can throw them away," says Klaus-Peter Boge, the expert witness.
That's how Teska wants to handle it, although he's actually attached to some of the pieces. "I'm throwing it all away," he says. "I am disgusted by the very idea that I have to touch the things again at all."
Teska's new abode, a furnished room in a modern new building, seems a bit sterile. The floor is tiled, the walls spackled, the furniture smooth and white. "I wanted it that way," says the young man. "May not be as comfortable, but mold can't hide as well."
In a new building, moreover, there are usually no leaks. There is also less chance of a pipe burst. Teska has to air more now. "Doesn't matter," he says.