If you’ve ever asked yourself, what are the dangers of black mold, you should know that black molds are a potential danger to both:
- Your health
- The structural integrity of your home.
In order to understand what makes black mold so dangerous, you must first understand what black molds are.
Molds are a member of the Kingdom Fungi, which is an extremely diverse kingdom containing over 1 million species of mushrooms, molds and yeasts. Fungi obtain their nutrients from dead organic matter, which is digested by the release of enzymes into the environment to break down the organic matter, which is then absorbed. Fungi are not classified with plants since they contain no chlorophyll. This lack of chlorophyll accounts for their diversity of color, ranging from white to black. In general, molds are commonly known as a fungus, mildew, black mold, or even toxic mold, but the names themselves typically do not refer to any single species of mold.
What is black mold and what does it look like?
In the United States, black mold (sometimes referred to as toxic black mold) is a generic term that is used to describe several species of molds (especially Stachybotrys) that produce mycotoxins. A mycotoxin is a toxic chemical byproduct of the mold’s digestion process. As individual black mold spores proliferate into colonies, and the concentration of mycotoxins increases, the risk of danger also increases. Molds, and their mycotoxins, are a danger to both your health and the structural integrity of your home, but the severity of the danger is directly associated with the types of black mold that are present.
Types of Black Mold
There are literally thousands of different species of molds, each of which is uniquely identified by its scientific, or binomial, name – which are typically difficult to pronounce as they written (in italics) in the Latin grammatical form.
As impressive as it might be to compile a list of the thousands of known mold species, it would not only take an inordinate amount of time, but it would also add virtually no value, or useful information, to this site. In addition to the list being extremely long, only a small percent of the molds listed would even be considered as black (or toxic) molds. This is because molds exist across virtually all ecosystems, thriving on dead organic matter everywhere in nature.
What follows then, is a list of the most common types of black mold, and a brief description of each:
- Alternaria: A natural part of the fungal flora found most everywhere, there are 299 species which are agents of decay and decomposition. Alternaria spores are airborne and easily spread indoors, where they can grow into thick colonies. They are common allergens in humans and can cause hay fever or asthma (in hypersensitive persons). This type of mold produces a variety of toxic compounds which is why allergies are common upon exposure. More serious health effects are possible in persons with compromised immune systems.
- Aspergillus: Found in almost all oxygen-rich environments, Aspergillus species commonly grow as molds on carbon rich surfaces, such as sugars and starches, and also grow in or on many plants and trees. Aspergillus is also capable of growing in nutrient-depleted environments. The species Aspergillus niger can be found growing on damp walls, and as a component of mildew. Surprisingly, A niger has commercial importance as the major source of citric acid, accounting for over 99% of the world’s production (mainly in bioreactors).
- Cladosporium: Includes some of the most common types of indoor and outdoor molds. Indoor species are known to grow in surfaces where moisture is present. Cladosporium species are rarely pathogenic (causing disease) to humans, but have been known to cause skin, toenail and pulmonary infections as well as sinusitis. Airborne spores are significant allergens that can severely affect asthmatics and people with respiratory diseases. Cladosporium species produce no major mycotoxins, but do produce VOCs (volatile organic compounds) which are associated with ‘moldy’ odors.
- Penicillium: A mold of major importance due to its use as an antibiotic. Commonly known as molds, many species produce highly toxic mycotoxins and have a propensity to thrive in low humidity environments and and colonize rapidly via aerosol dispersion. Aerosol dispersion is the reason that Penicillium species are present in the air and dust of indoor environments of homes and buildings. Penicillium growth occurs indoors, even in low relative humidity, using building materials to obtain nutrients for growth. Of all the known types of mold, spores of the Aspergillus- and Penicillium-type species are the most prevalent in the indoor air of residential properties.
- Stachybotrys: First identified in 1837 and now containing approximately 50 species, Stachybotrys has a very wide spread distribution and inhabits materials that are rich in cellulose (wood). The two most infamous species are Stachybotrys chartarum and Stachybotrys chlorohalonata, more commonly known as black mold, or toxic black mold and is widely associated with poor indoor air quality due to mold growth on water damaged materials. Exposure to the mycotoxins released by the Stachybotrys chartarum or Stachybotrys chlorohalonata can have a wide range of health effects on humans, depending upon the length and concentration of exposure.
Is all mold that is black toxic?
Most well known, and most commonly reported in the news, are the dangerous health effects of black molds. The severity of a human’s reaction to mold exposure is dependent upon:
- The type of mold (the specific species),
- The dose (actual concentration of mycotoxin)
- The route of entry into the body (inhalation, ingestion or contact).
What Color is Black Mold?
Although mold is often referred to as either toxic mold or black mold, mold can actually be found in a wide variety of colors. In no particular order of occurrence, mold colonies can be found in one or more of the following colors:
Although molds can be found in many colors, it is not possible to identify individual species of molds by color alone. One simple reason is that there are tens of thousands of species of mold, many of which will be the same color. Also, when molds first begin to grow, they may start out as one color, then change to another as the colony grows and expands.
What does Black Mold Look Like?
Since there are thousands of different species of mold, trying to describe what black mold looks like is no easy task.
Knowing how to properly identify the many different types of mold is the first step in assessing the dangers of black mold if in fact it turns out that black mold is what happens to be growing in your home. Any attempt to identify black mold by providing descriptions of the many different species would be extremely tedious to read and still end up not being very helpful. The best way to find out what black mold looks like, is to simply skip the explanations and provide a guide of images. This will allow you to make a direct comparison to whatever discoloration, or growth, that is causing you concern.
Health risks can include allergic reactions (ranging from simple coughing and sneezing to chronic conditions such as sinusitis and asthma) and irritations (ranging from skin rashes to irritations of the central nervous system – leading to dizziness and/or headaches). Reactions will also vary with the sensitivity of the person exposed, young children, the elderly, and other immune compromised persons are at the highest risk.
In the home, high concentrations of mold can lead to not only cosmetic, but serious structural damage. The reason that mold is so dangerous to your home is that they obtain their nutrients by consuming organic materials. Unfortunately, your entire home is built from, and contains, a wide array of organic materials, such as:
- and much more.
What is the cause of black mold?
When the appropriate combination of temperature, humidity and light exist in the presence of organic nutrients, mold spores will begin to rapidly germinate and reproduce. As the mold colony expands, it requires more nutrients to continue to thrive and the longer the mold is left unchecked, the more damage it is capable of causing.
One of the keys to preventing extensive damage is to prevent any black mold colonies that do happen to form, from expanding. This may require you to inspect hidden areas (such as crawl spaces and attics) for moisture, or install ventilation However, this short inspection time can potentially save you thousands in cosmetic and/or structural repairs.
Black molds, and the mycotoxins they produce, represent a danger to both your health and the structural integrity of your home, but by knowing the conditions that molds thrive in, and how to prevent them, you can make your home safer and healthier.
What are the symptoms of mold exposure?
Mold exposure has been linked to a variety of health issues, so it is important to be able to recognize the symptoms of toxic mold exposure. Both the growing mold, and the airborne spores, are allergens, so the symptoms of black mold exposure are similar to the allergic reactions which occur in sensitive individuals.
The severity of the symptoms associated with a mold allergy will vary with the persons sensitivity, the most common symptoms being;
- runny nose
- irritated/watery eyes
- skin rash
Some black molds (such as stachybotrys) are also referred to as toxic molds, because during their growth phase they generate mycotoxins, a toxin which causes irritations on the skin and in the airways of sensitive individuals. So just as some people have allergic reactions to pollen, ragweed and dust, certain individuals have a similar sensitivity to molds and/or their toxins.
As with all allergies, the severity of the symptoms associated with black mold exposure will vary greatly. While most people will have mild reactions, there are also those that will have severe reactions, such as those who have asthma. Exposure to mold toxins or mold spores can trigger an intense reaction resulting in a fever and difficulty breathing. Although it is very difficult to anticipate how an individual will respond before they have been exposed to mold, there are several factors that are useful in predicting a persons susceptibility to the adverse health effects of black mold exposure. The following groups of people would be at an increased risk of a severe response to mold exposure:
- infants/young children
- the elderly
- the immune compromised
This by no means implies that these are the only factors that will determine the severity of adverse health symptoms displayed by a person who is exposed to black mold toxins or mold spores.
Also of great importance is the type and quantity of mold present. It is very possible for an otherwise healthy person with no history of allergic reactions to be effected in the presence of a high concentration of toxins or spores. Severe reactions have been known to occur among workers who are regularly exposed to large quantities of mold in occupational settings (such as farmers working around moldy have, or contractors working in moldy, flood damaged homes).
In addition to the dose, or level of exposure, the route of entry into the body will also play a role which health symptoms develop. The most common routes of entry are breathing and external contact, which lead to the well known symptoms of sneezing, runny nose, wheezing, and watery eyes (due to inhalation) or itching and/or skin rashes from contact. Less common is ingestion, although this has been known to happen when people (unknowingly) consume moldy foods.
Black mold health symptoms are caused by the body’s allergic response to mold toxins or spores, and the severity of the response will vary based on the sensitivity of the individual and the level of toxins.
Treatments For Black Mold Exposure
There are a number of different treatments available to help with black mold exposure:
- hyperbaric oxygen treatments for toxic mold exposure.
- prescription medications
- treatment to environment’s air quality