Where does Mold and Mildew come from and What is the best way to remove Mold in the home?

Laundry rooms and wet clothes are famous locations for molds and mildew. What are these things? They’re fungi, plants without chlorophyll, microscopic members of the same family of plants as mushrooms.

And there are lots of them: they make up about a quarter of the earth’s biomass. The fungi can be roughly divided by their morphology into yeasts, mushrooms, and molds.

Molds (“mildew” is a name commonly applied to many different molds) are the ones found in damp places, in bathrooms, cellars, laundry rooms, on rotting food, and even on wet laundry, if you leave it around long enough. Most of them come into damp places inside houses from outside, but some (Penicillium and Aspergillus are two examples) can grow inside buildings that are quite dry. Like bacteria, they’re everywhere, indoors, outdoors, on plants and animals, in piles of dry leaves, in rotting organic material. They come in a variety of lovely colors, black, orange, green, brown, white. Most molds are harmless, and many are useful or essential in living systems.

But when they grow inside houses in sufficient quantity, they smell bad, very musty, take a whiff of a pile of wet laundry that’s been sitting around for a few days. This is because the molds produce a large number of organic compounds that are very volatile (volatile here means not that they are explosive, they aren’t, but that they are easily evaporated into the air, where you can inhale their odor). But their smell isn’t their worst characteristic.

The problem with them is that when certain strains of the fungus are living on certain organic materials, they produce mycotoxins, organic compounds that can poison vertebrates, including humans. It is very difficult to know whether these mycotoxins are actually present. The toxins can be isolated in a laboratory from a sample of the mold, but even this doesn’t prove that they were in the air where the sample was taken. There is one laboratory in Lenexa, Kansas, called the IBT Reference Laboratory, that has developed an isotype-specific enzyme-linked immunosorbent assay (ELISA) method to measure the presence of antibodies to the poisons in blood samples, but the Food and Drug Administration has not evaluated or approved the test.

The necessary work to determine the test’s sensitivity and accuracy has not been carried out, and the test is therefore not useful as a diagnostic tool. Stachybotrys chartarum, a greenish-black household mold less common than some others but not at all rare, has been the subject of a number of press reports that connect it to infant pulmonary hemorrhage cases, but the CDC considers these unconfirmed rumors, not scientific facts.

Still, getting these toxins in your mouth or inhaling them into your lungs can probably cause some unpleasant symptoms, even if they aren’t terribly dangerous. Not all molds produce mycotoxins, and even those that do produce them do so only under certain physical conditions. But poisons called aflatoxins have been isolated in house dust containing Aspergillus flavus and some called trichothenes have been found in Fusarium, Cephalosporium, Stachybotrys, and Trichoderma, all common species of household molds.

No one knows exactly how these toxins make us sick, but they do cause a variety of unpleasant symptoms. Repeated exposure to airborne mycotoxins can cause nose, throat, and eye irritations, allergy, aggravation of asthma, and, particularly in immunocompromised people, pneumonitis, a dangerous inflammation of the lungs. If you find mold or mildew in your laundry room (or anywhere else), it’s a good idea to get rid of it and then eliminate the conditions that allow it to grow.

The easiest and cheapest way to remove mold is with a chlorine bleach solution, one and a half cups to a gallon of water. Just make sure the area is well ventilated, since chlorine itself is not especially healthy to inhale. Mold is easiest to clean up when it is damp, and you should avoid touching it. Wear rubber gloves. Dried-out mold is more likely to release spores, and if you’re cleaning that up you should wear a dust mask. Moldy garbage should be put into plastic bags and tied tightly before being discarded.

Rain and irrigation water should be directed away from exterior walls. Ventilation systems and dehumidifiers can be helpful in places where the source of moisture can’t easily be eliminated, and there are mold inhibitors that can be added to paints. Drying clothes indoors or putting carpeting in laundry rooms or bathrooms are invitations to mildew. If you are tempted to leave wet laundry in the washing machine or dryer, resist. And finally, stop worrying. Toxic molds are commonly found in houses, and although they can pose significant dangers to those who are immunocompromised, they almost never cause serious illness in otherwise healthy people.

In short, there are some things you can do to “sanitize” your laundry and your laundry room, mostly by performing home versions of hospital procedures. But the contribution of such efforts to your physical health is dubious at best. In weighing the costs against the benefits, there are undoubtedly better ways to protect your health than by trying to produce “99.9% germ-free” laundry.