Over the past decade, scientists have greatly increased their understanding of molds and mildew. Specifically, the potential health risks associated with molds. Little has been done to educate the general public. Understanding this fungus can greatly help with the removal of this micro-organism and, thus, reduce health risks to humans.

All molds need three things to be able to grow—a food source, moisture, and a certain temperature range (Click image to enlarge).

The first question that should be answered is, "Are mold and mildew different?" If you were to ask an expert, he would tell you that they are different. A mycologist—a scientist that studies fungi—classifies mildew as fungi that grow on plants and is usually white. The non-expert typically refers to molds and mildew interchangeably, depending on the contextual circumstances. A piece of fruit is usually referred to as moldy, while clothing would be said to have mildew. It can be said, then, that what the non-expert refers to as mildew in most cases is actually mold, but a scientist only uses mildew to speak of fungi growth on plants. For the sake of this article, we will only discuss molds.

Conditions for Growth
All molds need three things to be able to grow—a food source, moisture, and a certain temperature range. If these three conditions are present, molds will be able to germinate and grow rather quickly.

The role of molds in nature is to break down dead and decaying plant matter. Molds are able to digest just about anything that they grow on, with water being the single biggest factor that limits mold growth. Mold spores can germinate in as little as 12 hours and can colonize in one to 12 days. There are many ample food sources in the average office building or home that fall pray to mold very easily with the right amount of moisture. The most common include drywall, wood, insulation, and paper.

Many believe that molds need physical water to be able to grow, but that is not the case. Mold’s only moisture requirement is that the humidity be between 65% and 99% on the growing surface. Keeping the relative humidity below 50% will deter mold growth.

Prevention
Preventing mold growth can be a taxing undertaking, especially in humid climates. Molds gradually destroy the things they grow on, so it is important to remove them as soon as possible to save the building materials. There are a few guidelines that will help reduce mold growth:

• Humidity levels should stay relatively low, below 50% is optimum;
• an air conditioner or a dehumidifier should be used during the hot, humid months;
• exhaust fans in kitchens and bathrooms should be used to provide adequate ventilation to help keep humidity low;
• use paints with mildewcides to help protect against growth;
• clean infected areas with mold-killing products;
• areas that are constantly exposed to moisture should not be carpeted;
• and porous materials should be removed and replaced, such as drywall and carpet.

Removal
The removal of mold and mildew is a strenuous task because they repopulate with such efficiency and ease. When molds are killed, they release spores to help the continued survival of the species. Mold spores can almost always be found on the exterior and interior of homes and buildings. One of the biggest problems when treating molds is avoiding regrowth from these spores soon after the cleaning has taken place.

Table I: Properties of Popular Mold Killers

There are a number of products on the market that will kill mold (see Table I). One of the most popular is a mixture of bleach and water. Bleach is an effective killer but is very toxic and can harm the surfaces you are treating. Many times, this creates a better host environment for molds to repopulate. Additionally, bleach will etch many surfaces, harm wood, take the sheen off paint, and kill plants and animals. Many other chemical products must be mixed with bleach to be effective. These products can be effective but can also be difficult to use, smell bad, and produce toxic fumes—and will harm other living organisms in addition to killing the mold.

There are also biodegradable solutions on the market. Many will help remove molds without harming the surfaces being treated or other living creatures, such as plants, animals, or marine life. Some commercially available products on the market are biodegradable and do not contain phosphates, ammonias, or bleach. This type of product not only effectively removes mold but destroys the mold’s food source so that spores cannot recolonize soon after cleaning. When looking for a product to remove molds, it is important to consider the effects of the products you are using and to see if they are treating the symptom or the
cause of the problem.

After molds have been removed, it is important to fix the reason they were there in the first place, and usually that entails eliminating the source of moisture and food. If a product was used that eliminates the food source, and you fix the moisture problem, you should be fairly well protected against mold regrowth.

Hazards
Besides the overall distasteful appearance of molds, there are other hazardous effects associated with them. Numerous species of molds, and the mycotoxins they produce, can cause or aggravate many different ailments. According to the experts at www.startremodeling.com, the large number of mold species, such as stachybotrys atra, penecillium, cladosporium, and many types of aspergillius, cause many of these problems. They also add that some of the effects caused by these molds are asthma, pneumonitis, upper respiratory problems, sinusitis, dry cough, skin rashes, upset stomach, headaches, disorientation, and bloody noses.

There are a number of other types of mold that are toxic and that carry mycotoxins that are known carcinogens. Prolonged and severe exposures can lead to internal bleeding, kidney and liver failure, and pulmonary emphysema. These health risks are serious and, therefore, builders, homeowners, landlords, and property management personnel should take steps to clean all mold when it is discovered to reduce exposure to it.

Summary
With the increased knowledge gained by scientists over the past 10 years, we can better clean and protect ourselves against molds. They pose many problems for both the substrates on which they grow as well as for the people that are exposed to them. When molds appear, take action immediately to remove them. Use products that won’t harm yourself or the surfaces you are cleaning, and try to use something that has a residual effect against re-growth. Molds serve a valuable roll in nature, and that is where they should stay.

References
www.cdc.gov/mold/faqs.htm-CDC Website
www.mold-help.org/
www.startremodeling.com

For more information, contact the author at (e-mail) mryad7@hotmail.com.