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When the word “mold” is mentioned, one does not conjure up images of anything threatening. Sure, if left in the pantry long enough, that loaf of bread will start turning green with mold; or, if you ignore scrubbing your shower stall long enough, mildew, which results from mold, will surely pay a visit. Mold, at least as a serious health threat, is not something that has concerned most people in their daily lives. Until now.

Prior to 1990, only a handful of lawsuits alleging exposure to toxic mold were filed. During the 1990’s, however, mold litigation began gaining momentum and in the last few years the number of lawsuits filed alleging injuries and/or damages caused by toxic mold has exploded.

Stories of homeowners, office tenants and even school children being forced from their homes or buildings occur daily in the print and television media. Contractors, subcontractors, construction managers, property managers, architects, construction component suppliers and building owners have all been targeted in toxic mold litigation. Some even believe that mold litigation over the next twenty years could eclipse asbestos litigation which reigned in the last two decades.

Molds are microscopic fungi that grow on surfaces of objects, within pores, and on deteriorated materials. Molds are commonly found everywhere– both inside and outside, on surfaces and in the air. Given the proper conditions, molds can easily thrive in an indoor setting. Most indoor molds, however, originate from the outside. For example, more spores can enter a building by air circulation through open doorways, windows, heating, ventilation and air conditioning units. They can also be carried indoors by attaching to clothes or shoes worn by people or to the fur of animals.

Feeding Mold

Once inside, and given the proper conditions, some molds can get a foothold in a structure in less than 48 hours. In order to grow, molds require temperatures above 40 degrees and below 100 degrees Fahrenheit, a food source, and moisture. Many common building materials are suitable as food for the growth of molds.

Water-damaged cellulose materials are good hosts for molds. Some paints, wallpapers, insulation materials, carpets and fabric – when wet – foster mold growth. Mold problems involving these materials are generally traced to construction defects or faulty maintenance such as roof leaks, improperly sealed windows and doors, balconies and decks, air conditioner and plumbing leaks, flooding, and damp basements or crawl spaces.

They also can be caused by faulty landscaping, sewer backups, excessive humidity, humidifiers, HVAC systems, combustion appliances that are exhausted to the outdoors (i.e. furnaces, stoves, water heaters, dryers and fireplaces), and wet or water damaged building materials such as wet cellulose materials (i.e. paper, paper products, ceiling tiles, wood, and wood products).

Indoor mold exposure does not always cause health problems. In fact, people are exposed to molds on a daily basis and few suffer adverse health problems as a result. Different people will react to mold exposure in very different ways. For some, exposure to a relatively small amount of mold can result in health problems.

Some individuals may experience allergic reactions from inhalation of mold spores, which can be an allergen. These reactions, including hay fever, asthma, hives, or hypersensitivity pneumonitis, are the most common health problems associated with mold exposure.

Others inhaling some mold spores may suffer infectious responses such as aspergillosis or histoplasmosis. These kinds of responses are rare and occur primarily in those who suffer from compromised immune systems (i.e. chemotherapy patients, HIV/AIDS patients, the elderly and infants).

Finally, some believe that inhalation of spores from certain molds (i.e. Penicillium, Aspergillus and the infamous Stachybotrys) can produce toxic responses such as disruption of cellular function and interaction with DNA in individuals. Unfortunately, there is little research on the potential toxic effects resulting from exposure to indoor mold.

Molds May Produce Toxins

According to the Centers for Disease Control, there are approximately six varieties of household molds common in homes and buildings in the United States, and three can produce toxins.

Unfortunately, it is impossible to distinguish between toxic and benign molds just by looking at them. They all look like black or gray sooty patches and a professional sample is needed to specifically identify the type.

One strain, Stachybotrys Chartarum, also known as Stachybotrys Atra, is at the center of many recent lawsuits and therefore commonly referred to in the news. Stachybotrys is relatively uncommon and requires areas with excessive humidity and fluctuating temperatures. Stachybotrys also likes wood and paper products such as fiberboard, drywall, ceiling tiles wallpaper, gypsum board, sheetrock wall board, paper, lint, dust, hay and straw.

Stachybotrys can produce the chemical trichothecene, whose toxic effects have been documented with respect to animal studies. Some human studies have focused on bleeding lungs in infants. However, the results from these studies are inconclusive at this time and as a result, the effects of human exposure to Stachybotrys are relatively unknown.

Although various health officials and agencies have issued policy statements and guidelines regarding the toxic effects and remediation of indoor molds such as Stachybotrys, they have not yet established objective exposure guidelines due to the lack of sufficient epidemiological research.

Avalanche of Lawsuits

Although most of the current fear over Stachybotrys and other common indoor molds is likely unsubstantiated, detection of these molds in homes, office buildings, and schools and other public buildings has resulted in an avalanche of insurance claims and lawsuits.

Most lawsuits focus on the contractor or architect of the structure. These claims generally include negligent design of the structure or its mechanical infrastructure in such a way that fostered mold growth, created “dead zones” or did not allow for sufficient air exchange to prevent the growth of mold inside the structure.

Claims against contractors generally allege that the contractor failed to allow for sufficient time for interior woodwork or other cellulose material to dry before it was sealed. Mold claims associated with installation of EIFS sidings are also becoming more common.

Claims against reconstruction contractors are also common since any water loss associated with broken pipes, snow/ice damage, sewer systems and fire sprinkler systems can be conducive to mold problems. Condominium associations can also be targeted for claims because most condominium bylaws impose on the association the duty to maintain common elements (crawl spaces, attics, etc.) where mold can grow. If these areas are not maintained or sanitized, owners who become ill frequently look to the association to cover their expenses. Landlords, commercial and residential, are subject to claims from tenants for similar reasons.

Mold litigation is often highly problematic from an evidentiary perspective and from the shear costs involved. Mold can grow so rapidly that sometimes it is difficult to determine a single specific cause. Normally, there is an event that introduces water or moisture to interior of the structure that allows the mold a foothold and then general ambient conditions permit the mold to grow and spread.

Mold lawsuits also typically involve multiple parties. A disgruntled home or building owner may sue the general contractor. The contractor then joins other subcontractors, architects and any other party who may have had any involvement at all in the construction project. It is not uncommon to have 50 to 100 individuals or entities involved in the lawsuit if the losses are significant.

Toxic mold claims can also require a significant number of experts, which can also make the case expensive. On the environmental side, environmental specialists such as industrial hygienists or toxicologists are needed to test for mold by gathering samples and sending them to a microbiological lab to determine which type or strain of mold is present.

On the construction side, experts needed include engineers and others in the construction field who can pinpoint the level of water penetration and its origination point.

Remediation contractors will also be needed for removal of the mold and how much it costs. Remediation costs can easily be $150 per square foot, and in some cases involving large buildings, damages for remediation of the mold can cost tens or hundreds of millions of dollars. Sometimes, remediation is not possible (or is too expensive) and demolition of the structure is necessary. Finally, on the medical side, depending on the injuries, experts needed range from environmental medicine physicians to ear, nose and throat physicians to pulmonary physicians to neurologists.

As people spend more and more time inside, and as construction techniques improve so that structures become more airtight, the potential for the growth of interior mold will increase. Claims arising from mold exposure will also increase as a result of increased knowledge on the part of the general public and aggressive advocacy resulting from the current lack of evidence linking mold exposure to illness.

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Harrison H. Yoss

Harrison H. Yoss


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