About Mold at Home

What exactly is this mold anyway?

Mold are microscopic fungi, or micromycetes. It’s an extremely diverse group of microbes and it covers far more than just stains on walls.

Among micromycetes there are many important species of mold used industrially: antibiotic producers (penicillin, cephalosporin, and so on), producers of organic acids, enzymes, starter cultures for cheese production with mold, and a special fungus (Botrytis cinerea) that gives Tokaji wine its distinctive taste. Preparations based on fungi of the genus Trichoderma are used as a biological protection for plants against certain phytopathogenic fungi.

Micromycetes are powerful participants in biodegradation and soil formation. They participate in the decomposition of polymeric materials (for example, rubber from car tires) and various building materials (concrete, plaster, drywall, wallpaper, paints, etc.).

There are also pathogens of various mycoses, including fungal infections of nails and skin. And, of course, what scares us all and becomes the subject of numerous myths — producers of mycotoxins, which we will mention a little later.

Why do walls mold?

In reality, mold does not have malicious plans to take over your home. However, when humidity rises, mold spores, which are constantly drifting in the air and are present on almost all surfaces to some extent, begin to germinate. It’s as simple as “just add water.”

Can mold on a wall be dangerous?

Not beneficial — certainly not. The presence of mold in a room leads to an increased number of its spores in the air. And this, in turn, is a factor of air pollution and places a load on the respiratory system.

Respiratory symptoms may appear, the body tries to rid itself of foreign particles — by producing mucus, coughing, sneezing.

With prolonged contact with mold, fungal metabolites can lead to allergies and act as a trigger for the development of asthma.

More vulnerable may be young children, the elderly, and those with immunosuppression and bronchial asthma. In case of an allergy to antibiotics, an exacerbation of allergic manifestations is possible if a mold that can produce these antibiotics grows on the wall.

Against the backdrop of severe immune suppression and a high concentration of mold spores, there can even be mycosis of the lungs.

Is black mold really dangerous?

A popular belief is that black mold may be more dangerous than mold of other colors. Perhaps this view arose because of the black color of one of the not-too-friendly molds in the genus Stachybotrys, which is associated with acute lung injuries in infants.

However, the mycelium not only of this fungus can be black; it can be other species as well, which are difficult to distinguish by eye. And many fungi that are not black can also be dangerous, for example Aspergilli, known as the most common causes of pulmonary mycoses, Chaetomium, which can sometimes be a cause of onychomycosis, and others.

Moreover, black coloration of fungi is due to the pigment melanin (well, almost like us), and the amount of this pigment can increase when the fungus is subjected to oxidative stress. Therefore, do not be surprised if, for example, after using a whitening product on the wall, mold begins to grow again, but now black rather than green.

How to get rid of mold?

The key technique in fighting mold is moisture control. It is desirable to keep it within 40-60%. If humidity is too low, the mucous membranes of the nose, eyes, and skin suffer, and if higher, mold will not be long in appearing.

This most often happens on the first floors of buildings or as a result of emergencies, when, for example, there is a water leak somewhere.

Proper ventilation and insulation of facades are important so that condensation does not form on cold walls. It should be remembered that sources of mold spread can be air conditioners and humidifiers. Their filters often harbor entire colonies of fungi, so they should be changed in time. The soil in plant pots is also a potential source of mold spores. Therefore, monitor the condition of soil in pots, transplant if there is a bad smell, use drainage, clean plant leaves from dust, and remember to ventilate the room.

A common construction mistake that brings mold into the home is the use of drywall materials in places where there may be increased humidity. Drywall is very susceptible to moisture, dries poorly, and mold grows through it. In such a case, only dismantling such walls will save you.

Today there are building materials with antifungal components — primers, paints, etc. Therefore, in places where there may be increased humidity, they should be used.

You should ensure that nowhere water stagnates (for example, in the bathroom), always thoroughly dry things before putting them away in a cabinet, hang things to dry in time, not leaving them in the washing machine, thoroughly drying sports equipment, kitchen towels, etc.

If mold has already appeared, in addition to moisture control, you should also as carefully as possible clean the place of its appearance. For this you can use chlorine-containing cleaning agents, as well as treat with special anti-mold preparations — fungicides — and monitor the spot subsequently. If mold appears on wallpaper or drywall, such materials are replaced, and the wall under them is treated with a fungicide. If the affected area is quite large, there is sense in consulting with professionals.

If bread has mold?

Eating products infected with mold is not advisable, because the dots we see on the surface are only small parts of the entire mold mycelium. The mold-infected portion of the product is significantly larger. Also, if, for example, jam has molded, you should discard the entire jar. Fungi can produce toxins that are dangerous when consumed.

And what about cheese with mold?

As we mentioned earlier, for industrial production of mold-cheeses, they use special industrially studied strains that do not have genes for antibiotic or toxin production. However, it’s worth remembering the risks of consuming soft cheeses, such as increased probability of listeriosis and salmonellosis, as well as a fairly high content of salt and saturated fats. It is advisable to prefer cheeses made from pasteurized milk. How to understand that a cheese with mold has actually spoiled — here.

About mycotoxins and zombification

Many fungi do indeed produce toxins. And if they simultaneously suppress bacterial growth, we politely call them antibiotics. Just by looking at your wall, it is practically impossible to determine whether your mold produces toxins.

The authors also claim that simply inhaling air in a room with mold cannot cause so-called microtoxin exposure, since toxin concentrations are too low.

In most cases, intoxication can occur when consuming spoiled products. The effects of mycotoxins mainly manifest as general malaise and weakness and do not exhibit some very specific effect on the human brain.

Of course, there are well-known mycotoxins such as aflatoxin, which Aspergilli can produce in grain when it is overly moist, or ergotamine, which also has a psychoactive effect; poisonings from them were widespread mainly in past centuries when consuming spoiled grain. Now such outbreaks occur quite rarely; one occurred here in Kenya in 2004.

In scary mold films, there is always a story about zombie ants, under the influence of which the poor creatures climb onto leaves, latch onto a edge with their jaws, and die, while a fungal hypha grows from their heads. It looks really creepy and can lead to the idea that fungi are so treacherous they can turn us into zombies as well. However, this example of parasitic interaction is very specific and “designed” only for a certain ant species.

It’s fair to note that not only cordyceps can do this to ants. For example, there is a disease called dystrocoeliosis, caused by a flatworm that parasitizes herbivorous animals, but is occasionally found in humans. Intermediate hosts are snails and ants. Affected ants infected by this worm behave somewhat the same way as those infected by cordyceps: climb onto a blade of grass, anchor their jaws, and wait to be eaten by some sheep. Thus, it is quite possible that there is some “button” in the nervous system of ants that can force them to behave this way.

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