Flooding is a natural event that occurs in our world. Flooding is a welcome event in some parts of the world, especially where water is scarce, and the animals and plants have adapted to living in flood-prone areas. Flooding can enrich the soil, improve wetland conditions, disperse seeds and other nutrients for both plants and animals, and provide new homes for aquatic creatures. However, flooding can have devastating effects on some environments, especially on the animals, humans, and structures that inhabit and man built in the path of the flood. Loss of life, destruction of property, water sources contaminated by sewage and debris, and lack of life-sustaining supplies such as medicine and food are commonly a result of floods.
The causes of floods – as well as the severity of the flooding – varies greatly. The most typical natural floods are river flooding, coastal floods, and heavy rainfall or monsoons. Recently a fourth type of flooding is increasing. The Office for Coastal Management within the National Oceanographic and Atmospheric Administration (NOAA) reports that high tide flooding has increased 300 to 925 percent since 1960. Natural events cause floods; however, some are due to the actions of man. Human-made floods may involve sewer and drain systems breaking, burst pipes, or making changes to the topography of an area. In the United States, the areas hardest hit are those on the coast and those close to large water bodies such as bays, lakes, and rivers, and their tributaries. Residents in some areas are affected by both oceans and other inland water bodies. For example, barrier islands and cities built on low lying peninsulas. One example of such an area would be Charleston, South Carolina, with its neighboring cities and its barrier islands: Folly Beach, Kiawah, Isle of Palms, Johns island, James Island, and Sullivan’s Island, to name a few. A recently published list of the ten states most prone to flooding in the United States shows eight of the ten on the east coast, one on the west coast, and one on the Gulf of Mexico. Regardless of the cause or the extent of the flooding event, one of the adverse effects of water damage – no matter what scale it is on – can be mold growth. Indeed, the CDC, EPA, FEMA as well as other sites indicate that the development of mold is directly tied to water intrusion.
Molds, and there are thousands of mold species, are a multi-celled fungi that can be both beneficial and harmful to our ecosystem. They have been called biological pollutants. Mold exists both indoors and outdoors and has always been a part of life on earth anywhere there is moisture. Some mold can live year-round. Different molds can tolerate different levels of what they need to survive in addition to nutrients – amounts of aeration, light, sugar, salt, water, PH, and temperature. It can enter a home via a pet, clothes, something being carried in, shoes. Mold can come in through windows, doors, vents, air, and heating systems.
The basic structure feature of mold is its hyphae, threadlike structures that spread out like tree or plant roots into the organic material on which they live. Their color can be affected by the environment that they live in, and some researchers theorize that fungi use their ability to change color as a type of survival skill. They rely on the proper moisture and temperature range for survival. Reproduction takes place through the release of spores – analogous to seeds- into the air. These spores find a host nutrient and colonize. Mold grows on organic material, often decaying, which they use as a food source. This growth into colonies will continue to take place until the source of moisture is eliminated, the mold remediated, and all unsalvageable items removed from the home. They take in nutrients from organic material, storing the nutrients into their cells. Fungi have also adapted to use dust as a food source.
Though mold is microscopic and not always seen by the naked eye, mold colonies can often be observed in damp areas on the organic material on which they live. Mold flourishes in temperatures ranging anywhere from as low as 2 degrees to as high as 90 degrees Fahrenheit. Temperature affects humidity with warmer air capable of holding on to more moisture or water vapors. Mold tends to prefer dark living conditions. However, even if the conditions for survival are not optimal, mold can remain dormant only to resurge in growth if and when the proper conditions return. As mentioned earlier, mold thrives in areas of high moisture. An excellent example of a high moisture area is the basement, where moisture from the ground can seep through the walls causing high humidity. Crawl spaces without covering on the exposed ground or uneven sloping and other areas with drainage issues can host mold colonies. The Center For Disease Control reports that there is some evidence to show that mold spores can move from crawl spaces into the living spaces above. Areas where crawlspaces and flooding are common, such as the Charleston, South Carolina area, may experience mold problems in their crawlspaces. Condensation from HVAC and other equipment, unvented clothes dryers, and leaky pipes can cause buildup of moisture and high humidity. Kitchens and bathrooms or attics/roofs are other areas of the home can experience problems with dampness and or leaks.
On the positive side, molds can be used to create antibiotics (such as Penicillin) and foods (e.g., cheese, soy sauce). They help break down dead organic material, thus allowing for the decayed materials to be reintroduced into the environment and used by plants to thrive through the enriched soil provided by the decaying process.
The adverse effects of mold are usually associated with higher levels of spores being present. Their ability to break down and destroy organic materials can also lead to their negative impact on building structures, elements within those structures, and the health of humans and animals. Some examples of sources of organic material in structures are carpet, drywall, paint, wood, paper, dust, soap. When the humidity rises above around 60 percent or water or moisture is present, mold colonies can thrive. Mold can grow – given the proper conditions – in as little as 24 hours. It is impossible to remove mold from very porous material such as drywall, carpet, and wood requiring disposal of those materials.
What makes the mold problematic in terms of health is their release of mycotoxins. The effects of mycotoxins were recorded as early as the 17th century when outbreaks of what was then called Saint Anthonys Fire (the disease is ergotism) caused by ingestion of the spores of the fungi when workers handled the moldy rye. Mycotoxins can affect both animals and humans, especially the health of those who are susceptible (those with weakened immune systems, for example). Symptoms associated with someone having been exposed to mold include: irritated skin, respiratory infections such as wheezing, coughing, congestion, painful eyes, aches and pains, headaches, mood swings, and other cognitive function loss or confusion. More serious health issues associated with specific fungi will be discussed further in this article. These mycotoxins often cause a musty and unpleasant smell, which is sometimes an indication of the presence of mold.
The four most common molds found in homes are Aspergillus, Cladosporium, Penicillin, Alternaria, and Stachybotrys. There are many other molds found to affect structures and health as well: Acremonium, Aureobasidium, Chaetomium, Fusarium, Mucor, Trichoderma, and Ulocladium. Though this list is not exhaustive, it is comprehensive, and each of the above molds will be discussed briefly in this article.
Aspergillus is a mold most commonly found in both soil and the air. According to the CDC (Center for Disease Control), there are rougly180 species of Aspergillus, with under 40 being considered by scientists a cause of infection to humans. Under the proper conditions – a combination of temperature and moisture- mold can grow on any organic surface, including clothing and furniture, as well as materials identified above as part of the building structure. This mold is especially dangerous if it enters the lungs or affects the immune system of humans and animals. Symptoms of aspergillosis (infection or allergic reaction to Aspergillus) range, depending on the exact infection, include weight loss, headache, fever, fatigue, coughing, skin sores, pain in the chest, and vision problems. Aspergilloma, basically a fungus ball or growth in the lungs, may occur in those who have had past health lung issues.
Aspergillus Versicolor is a slower growing fungus that was identified in 1903 by scientist John-Pierre Vuillemin, a French mycologist. A few years later, in 1908, another scientist named Carlo Tiraboschi placed the fungi in the Aspergillus genus and gave it its binomial name of Aspergillus Versicolor. It is a highly resistant fungus which can survive in temperatures anywhere from 39 to 104 degrees Fahrenheit and a wide range of PH, sucrose, and salinity levels. This mold, though present in a large variety of environmental conditions, is found most often indoors in consistently wet, damp, moisture-laden structures and in foods and grains with high concentrations of sugar. It has been found anywhere from the Arctic to the Dead Sea. Aspergillus has been identified in peat bogs, the Mir space station, and Uranium mines.
The use of the word Versicolor fits for this fungus. When it present, it usually starts white and then morphs into shades of yellow, green (both vibrant and pale shades), pink, orange, and beige in varying color combinations and concentrations. Colors may often reverse themselves as well if the colony exists for longer durations of time, perhaps in as little as two weeks. The reproduction of the Versicolor is asexual, meaning that it reproduces from a single organism, producing feathery spores that spread to other areas to colonize and establish growth. To the touch, it feels like a powdery substance.
As in the earlier discussion of molds in general, Aspergillus Versicolor can operate in both positive and negative ways. It can help with the removal of lead ions and reduce xylan in waste materials produced from the processing of hardwoods as well as other agricultural industries. Further, a substance from the hyphae of the Versicolor is potentially toxic to cancer cells in the human breast and colon areas.
On the other hand, there are many possible health problems associated with Aspergillus Versicolor. Scientists have linked over 20 allergens to Aspergillus Versicolor. Also, its mycotoxins (toxic compounds released by the mold ) may suppress the immune system, potentially leading to serious health issues for those with compromised or weak immune systems. Children, especially toddlers and infants, and the elderly are also susceptible to the harmful effects of Aspergillus Versicolor. This mold causes digestive problems through the release of Sterigmatocystin and Cyclopiazonic acid. Such digestive problems include upset stomach and diarrhea have been noted in humans who have consumed even small quantities of this fungus. Sterigmatocystin has been identified as a carcinogen (Class 2B) – potentially carcinogenic to humans, proving especially damaging agent to the liver and kidneys when tested in rodents. When a high number of spores (produced as a result of asexual reproduction) enter a body, it has been reported to have grown as a mold in the lungs and ultimately may release its poison directly into the bloodstream. Onychomycosis is a condition causing fungal infection in the nails of a person’s feet (which is most common) and hands. This condition can lead to loss of a toe or fingernail after a bout of thickened yellow or white nails. A connection between Aspergillus Versicolor and pneumonia has been suggested, sometimes with deadly consequences. It should be noted here, however, that the length of exposure, the number of spores, and the health situation of the individual are a factor in any development of effects. This is a very robust fungus that has been shown to survive in a wide range of environments. As with other molds, It can remain dormant even if the conditions are not conducive to growth. It can stay airborne for long periods. It has a survival system and survival instincts. When attacked the spores may take to the air to find other spots to colonize. The best steps taken would be not to allow abnormal concentrations of this fungus, or any mold, to exist in our homes and other building structures. Remember that water damage is the crucial factor in the development and survival of Aspergillus Versicolor, so being diligent in controlling humidity and repairing leaks is essential.
Stachybotrys Chartarum, commonly referred to as just Stachybotrys, is another dangerous slow-growing mold that flourishes in situations and areas where there is a constant and abundant supply of moisture present. The presence of Stachybotrys was first was reported in 1837 when a mycologist in Czechoslovakia, Joseph Corda, found the fungi on wallpaper. Initially, the effects of Stachybotrys were noted in farm animals and in the farmers and farmworkers who handled the various grains, hay, and straw associated with farms, and especially those farms with horses. A significant outbreak of illnesses in Russia in the 1930s and 40s led Russian scientists to identify the mycotoxins related to Stachybotrys. This case also highlighted the progression of this disease’s movement to humans. Stachybotrys can thrive in a wide range of temperatures and can survive through the winter. The spores produce viscous masses are generally stay on the organic material of their host until dry or disturbed, in which case they can go into the air and move to other food sources. Stachybotrys most often found co-existing with other molds/fungi and prefers materials high in cellulose: grains, plant debris, fabrics, wallpaper, wood pulp as examples. Its color ranges from brown to black to grey or even a greenish-black with the specific color depending upon age and moisture content. This mold is of particular concern to those who live in areas where coastal flooding, inland flooding, high tides, heavy rain, and tropical storms occur – Charleston and Mount Pleasant, South Carolina, and the surrounding barrier islands for example. Not only does the intrusion of direct water cause damage, the high humidity associated with these disasters exacerbates mold problems for those living in Charleston and surrounding areas. Again, Stachybotrys thrives on many of the building materials used to build homes (paper backing of drywall, insulation backing, glue used for carpet backing, paper vapor barriers, ceiling tiles, wood). Since some of the source materials are most exposed, the fungi may grow without the homeowner being aware. Standing water in the home from drip pans for appliances or HVAC systems are a possible source of growth with Stachybotrys mold colonies have been reported by homeowners and service workers in air ducts.
The focus on Stachybotrys in recent times occurred when there were infant deaths due to pulmonary hemorrhage in Cleveland during the years from 1993-1996. The Center for Disease Control was called in but found that linking Stachybotrys (which had been found by investigators in the homes of the ill infants) was not conclusive and that more research was needed.
Stachybotrys can release trichothecene mycotoxins capable of causing a wide range of harmful side effects in humans, referred to as Trichothecene Mycotoxin Poisoning. Length of exposure, the number of spores, and the health of the individual are all significant factors in the severity of symptoms. Exposure to the skin may result in sores, pain, and redness. Internal exposure can cause neurological problems such as vision, mood, orientation, balance, memory, and personality. Respiratory issues such as coughing, sore throat, difficulty breathing, and runny noses can occur. Digestive problems with vomiting and diarrhea may develop. In extreme cases, death.
Chaetomiun is another multi-species fungus that often grows alongside Stachybotrys. When this occurs, it is most often a strain called Chaetomiun Globose. Though not common, this strain can affect various systems in the body, including the brain and the skin and nails (Onychomycosis). Other species have been seen in bone marrow transplant recipients getting infections while in the hospital. This fungi releases mycotoxins, which can produce allergic reactions in those affected by the spores. Like Stachybotrys, it thrives on materials composed of cellulose. When it is present, it has the power to degrade its host-especially when it is paper or other materials made of cellulose. Its ability to destroy is enhanced the more that moisture is present. The Chaetomiun mold can be found both inside and outside of structures. Outside it may be found in the soil in decayed plants, dung from animals, and compost. Additionally, these fungi can be found worldwide. It is a rapidly growing mold that starts white, moving to a greenish-gray as it matures. Like Stachybotrys, its spores are bound together with a mucous, making it is less likely to be ejected into the air.
Alternaria is a prevalent fungi that can exist alongside other fungi and is most often associated with allergic reactions that can occur both in inside and outside environments. It is commonly found from spring to fall and is easily airborne, especially when there are warm to hot temperatures and windy conditions. The colonies increase in size, sometimes in less than a week, with the amount of its growth dependent on the amount of moisture present and the proper conducive temperature (anywhere from 30 to 80 degrees Fahrenheit). Alternaria fungi occur naturally in soil, trees, and plants. Some figures suggest that over 4000 divisions of plants are hosts to these fungi. Alternaria is responsible for decay and degeneration in plants and various crops (fruits, oilseeds, vegetables, grains), often negatively impacting a farmer’s crop production. The mold’s effect on animals is not well studied yet. In humans, mold growth occurs most often in parts of the body where mucous secretion is present – the lungs, eye as examples. Its spores can enter into an indoor space, and if the right conditions exist, the spores can quickly colonize on wood, carpet, tiles, food, wallpaper, drywall paper, furniture, and even the plants in your home. It can invade unseen in the walls, under the carpets, basements, and attics. The effects on human breathing can be as severe as asthma. Usually, however, the allergic reactions of itchy eyes, runny nose, headaches, and sore throat are most often the result of exposure.
Perhaps one of, if not the most, recognized mold is penicillium because some of its subgroups are used to produce the antibiotic Penicillin. Penicillin exists around the world in both the soil and the air. It is a dry chain of spores which are easily airborne. It reproduces in both asexual and sexual ways. Penicillin as a medicine (mould juice) was an accidental discovery made in 1828 by Alexander Fleming at St. Mary’s Hospital in London from the strain called Penicillium Chrysogenum. This strain was referred to as Penicillium Notatum during that time. He noticed a green mold in his samples, and where it grew the bacteria he was working with at the time – Staphylococcus – would not grow. Staphylococcus is a bacteria that was the cause of many diseases and conditions in humans. Fleming removed the mystery mold and produced numerous samples of it in a solution and used it the resultant solutions to experiment with its effect on different bacterias. Through his investigations, scientists and doctors learned that this mold – named Penicillin – was able to destroy various bacteria harmful to humans by weakening its cell walls. For his work and the work of other scientists, Fleming (along with Ernst Chain and Sir Howard Florey) was awarded the Nobel Peace Prize in 1845.
Penicillium as a fungi is considered a sac fungi and is regarded as an ascomycete. That said, its physical appearance is much like that of a paintbrush (coming from the Latin word for paintbrush – penicillium). Its color ranges from yellow to green to blue. The genus was identified in 1809 by Johann Heinrich Friedrich Link, a German scientist. Penicillium species can be used to produce food. Some cheeses are made with penicillium (blue cheese, for example, with the blue from the spores used in the production of the cheese itself). The meat (ham and sausage, for instance) and beer (aids in fermentation) industries also use the fungi. It can spoil food – most often affecting foods that have been stored, having even low levels of moisture. It is considered one of the leading causes of spoilage in fruits and vegetables. However, it also can have detrimental effects on animals and humans. If moisture is present on the surface of a host, this fungi can thrive. Indoors it can live on walls, carpets, furniture, mattresses – even the dust created by those materials. Of the over 200 species of this mold, the most common indoor variety is called Penicillium Chrysogenum, earlier identified as being described as the species from which Alexander Fleming discovered Penicillin. Penicillium is considered a contaminant. Certain strains of its mycotoxins have been called the worst of the opportunistic infectious agents for persons with HIV. The mycotoxins released by Penicillin can be allergenic and even carcinogenic to various systems of the body, especially affecting those with compromised immune systems.
There are roughly 150 species of the fungi Acremonium, a slow-growing and yet abundant mold. One is often warned to presence by the foul smell that can emit. The physical characteristics of this mold are that they form a structure that almost appears to be like a string of Christmas tree lights. At the earliest stages, it is more tightly packed together and moist. As it ages, it moves to a less dense profile which dries to a powdery, dusty finish. Its color may be pink, orange, or white. Acremonium is an organism that lives off of organic material – especially those composed of cellulose. Originally called Cephalosporin, this mold was discovered in the late 1930s by Italian researcher Guiseppe Brotzu while working with samples from sewage. Some of the species confines themselves to living and helping decomposing material and thus providing nutrients.
Acremonium is a species considered as a pathogen to mammals. It is opportunistic in that it affects those with or recovering from some health affliction or in those very young or old. As with all molds, this fungi require moisture and is associated with water damage in a structure. Acremonium, however, requires a high amount of water to develop, making it logical for it to be present in HVAC systems or other cooling units, drain pans, window and door seals, humidifiers, bathrooms, basements, laundry rooms, kitchens. This affinity for water means that it often grows with another fungus, Stachybotrys. The adverse health effects can range from skin or nail lesions or infections (forms of Mycetoma), eyesores, vomiting, and diarrhea if ingested, and allergies. There can be more dangerous results from exposure as well – usually related to high exposure. If the mold enters the bloodstream, it can lead to infection of any of the organs. Invasion most typically occurs when an individual has had transplants or surgery or has leukemia, HIV/AIDS, or diabetes. Pneumonia, peritonitis, arthritis, and meningitis may also occur.
Aureobasidium is a fast-growing mold that has only about 14 species – a relatively low number compared to the other fungi previously identified and discussed in this article. Pullulans is the most well studied of the species of Aureobasidium. It grows to maturity in a week. As with so many other molds, it is moist when it is young. It has been described as having a yeast-like appearance. With maturity, it turns from whites, creams, pinks, and yellows to brown and then black with gray edges. With the dark color change, the hyphae become visible. It resembles a twig with little buds forming. Its spores leave scars when they are released. Its structure is, however, dependent on the temperature, light, and humidity (it loves water) it is exposed to as it develops. One exciting feature of this mold is that it can morph itself due to some genetic instabilities making it hard to classify the species.
It is found to live in coexistence with plants on the plant itself without showing signs of disease. It has been used to help control some diseases in plants that are stored frequently – onions, for example. It lives in many environments – in the soil, the air, wood, fish ponds, water, and stones. Old stone building can turn black over time when this fungi is present. It can colonize inside a structure on wood, grout, air conditioning units, and textiles. Aureobasidium can grow anywhere in a structure where there are extremely moist, humid conditions. Aureobasidium also can develop colonies on foods: seeds of grains, vegetables, fruits, nuts. Though not considered a primary human pathogen, it can produce reactions such as allergies, hay fever, inflammation of the eyes, nail infections, humidifier fever and peritonitis. It can even grow in hair. Sometimes there are more severe reactions with exposure for those that are sensitive, especially trouble breathing with a tightening throat. Doctors have reported spleen and kidney infections. Perhaps the most severe illness associated with this fungus is humidifier lung, which is a chronic condition that sometimes requires surgery.
Debate surrounds the classification of species of the fungi Fusarium. This sickle-shaped soil fungi can be found worldwide and often lives alongside plants in their temperate environment. It can stay present in soil for as long as ten years. Most of the species are considered saprobes, meaning that they get sustenance from organic material living in standing or turbid water. The colonies proliferate with their color ranging from pastel to bright colors. Some species, however, invade and infect grains and foods eaten by animals and humans. It can destroy crops, its asexual spores transported by wind or rain splashes. Fusarium head blight fusarium, basal rot disease, and fusarium wilt are just a few such blights. Some reports suggest that there are 14 species of these fungi that are destructive to plants. A North Carolina university reports that at one time, Fusarium Oxysporum fungi was responsible for Fusarium wilt, almost destroying tomato crops in the southeastern part of the United States. Infection in humans is called Fusariosis, and it can affect the lungs, sometimes causing pneumonia, skin infections, and tissue inflammation. Infections of Fusarium can prove to be difficult to cure as the fungi is resistant to many antifungal agents. This infection can prove fatal in patients with severely compromised immune systems.
Another fungi found in soil, plants, and decaying ground material is Mucor. It is a fast-growing, circular mass with its hyphae growing out at wide angles. Resembling cotton as it grows – some have dubbed it a cotton-candy mold – its coloring ranges from white to yellow, moving to dark gray, brown, and often black as the colony matures. Some of its fifty species increase in temperatures that range from around 75 -85 degrees Fahrenheit, with other species able to survive in temperatures of over 100 degrees Fahrenheit. The fungi species that thrive in higher temperatures are then ones that can affect the health of both humans and animals, even some amphibians. The specific infection associated with Mucor is called Mucormycosis, a collection of infections that most often involve the mucous membrane in the mouth, nose, sinus, lungs, and brain. Though in truth, any part of the body may be compromised by exposure to this mold. Mucormycosis is considered opportunistic and affects those who are unable to fight off infections and can enter the body through cuts in the skin or by breathing in the spores. Just as so many of the other molds, the fungi attacks those with weakened immune systems – people recovering from surgery, injury, or on certain medications. These infections, though not universal, can be fatal.
Mold is universally present in our world – found in both the natural and human-made environment. With its ability to have both positive and negative effects on those environments, mold will continue to be a part of our world. One of the essential elements needed for mold to grow and colonize is moisture. And so flooding – whether it be minor or significant – whether it be man or nature caused – becomes a concern when mold is allowed to grow to an abnormal concentration. This article has discussed several of the most common molds that humans will encounter as a result of water damage. Possible health effects are highlighted for each as well.
There are several fundamental pieces of information that are important in understanding mold. Mold needs moisture, the proper temperature, and nutrients to colonize. The health effects of mold can impact anyone but most often attack the systems of those recovering from surgery or injury, the very young, the old, and those with a compromised immune system. Not everyone will react the same way to exposure to mycotoxins. Some people are highly allergic, and some do not experience symptoms at all. Mycotoxins may cause unpleasant odors, but there may be no smell at all. Mold can grow at alarming speeds given the right conditions, and some mold growth occurs in unseen areas. Mold can grow behind walls, under cabinets, on the back of books on a library shelf, a shower curtain, grout seams, wood joists and beams, or sump pump holes. Any moist, dark space where there is a food source, a mold colony can safely reproduce and multiply. Even if microbial growth is seen, trying to determine what type of mold it is not a textbook task, several of the molds discussed can have the same coloring. Not all black mold is Stachybotrys, the commonly feared and infamous black mold. Mold can vary its color, size, and texture depending on its nutrient host, the amount of light is exposed to, and temperature. Mold spores can enter a structure via so many routes, unseen by its host transporter or in the air. If disturbed, the microscopic, invisible spores can travel silently and move to other areas to colonize and thrive. This tiny creature -like all living creatures, wants to survive.