Mold Matters

Make way for mold. A growing body of evidence indicates the air we breathe in our homes and offices contains more pollutants and dangerous toxins than the outdoor air in large, industrialized cities. This is a serious matter because the average person spends about 90 percent of his or her time indoors.

Have you had water damage because of leaking pipes or flooding? Do you have stained or discolored walls, ceilings, or floors? Is mold visible on walls or other surfaces? Was any area of the building wet or damp for a period exceeding 48 hours? Have you noticed a persistent, musty odor? Have you noticed water collecting (or areas that are chronically damp) in your basement or attic? Do your windows or roof leak? If you answered "yes" to any of these questions, you may have a mold problem requiring immediate attention.

Mold, which is a type of fungus, has a purpose in nature: it causes wood and other dead natural materials to decompose. Without mold, dead trees, plants, and leaves would never decay. Mold serves an important ecological role outdoors but these attributes are not desirable or beneficial indoors.

In order for mold to grow, several conditions must exist. Mold spores must be present, there must be a source of food (such as cellulose or wood products), and there must be water or high moisture present. Mold spores and cellulose exist naturally in most building products (e.g., wallboard, ceiling tile, carpet, wood flooring). So, when these materials stay wet or damp for more than one or two days, mold can grow.

Mold can appear indoors wherever there is flooding, leaking pipes or roofs, standing water, or moist surfaces. You may find mold in places where water collects, such as dehumidifiers, air conditioner drip trays, and refrigerator collection pans, highly humid areas such as bathrooms, laundry rooms, basements, and crawlspaces, and places where moisture can enter the building because of incorrectly installed vapor barriers, insulation materials, and windows.

Signs of mold and its causes are not always obvious. Sometimes people experience vague, persistent symptoms when mold growth is not visible. In such cases, mold could be growing behind walls, under floors, or above ceilings. Indoor air testing is usually the best way to detect spores coming from these hidden sources.

Other molds are allergens, which is why people may experience the onset or exacerbation of allergy symptoms when mold is present. Viable spores can grow, increasing the production of mycotoxins. But non-viable spores can also cause allergic reactions even though they are "dead." These can remain biologically active for years after mold growth has ended.

At the very least, mold is a nuisance, in terms of its unpleasant appearance and odor. At its worst, mold can cause serious health problems and irreparable damage to buildings and property. Once a mold colony is established, it generates mold spores that float through the air, land on other surfaces, and form new colonies. Spores can be dispersed fairly quickly in a variety of ways including normal air currents, HVAC systems, humidity control appliances (e.g., humidifiers), and improper cleaning of mold-affected areas. By the time the fungi become visible to the naked eye, millions of reproductive spores can be spread throughout your home or office.

These dangerous microorganisms remain airborne and are consequently inhaled as we breathe. In this way, spores introduce toxins into your body, causing adverse health effects, such as allergic reactions, fatigue, shortness of breath, dizziness, rashes, headaches, runny nose, watery eyes, sneezing, and coughing.

The type of mold in a building will determine the appropriate course of action. A conscientious building manager or homeowner can usually resolve minor mold problems. Small areas of mold on nonporous surfaces (e.g., hard plastic, metal and glazed tile) can be cleaned with a solution of bleach and water. Porous surfaces (e.g., fabric, wallboard and wood) that are infected with active mold must be replaced. The individual attending to the mold should wear appropriate personal protection, make sure there is adequate ventilation, and keep others out of the work area. Scrubbing large areas of mold can release dangerous particles, risking health problems. So, for areas of mold larger than a few square feet, seek the assistance of a professional.

Significant mold problems (in terms of quantity and/or persistence) generally require a four-step process to resolve them: investigate the problem, stop the cause, remove damaged materials, and restore the environment.

The first step is to determine if mold is the problem and, if it is, find the source and type of mold. This is accomplished by a combination of visual inspection and scientific testing. Testing can determine or confirm the existence of mold (which may or may not be visible), and the type(s) of mold present. Results will also indicate potential health problems and the degree of safeguards and skill needed to correct the problem. The collection and analysis of samples can take a week or more, so it is important to proceed with the next two steps while awaiting test results.

Mold is almost always caused by excessive moisture. Therefore, it is critically important to find the water source and to stop any further water ingress.

Once the moisture problem is corrected, the contaminated materials must be removed and all affected areas must be dried thoroughly as soon as possible. As a rule, all affected porous materials (such as paper, wallboard, and fabric) are discarded rather than cleaned. Affected nonporous items (such as plastics and metals) and semiporous items (like wood) should be thoroughly and professionally cleaned. Anti-microbial, encapsulating coatings may also be applied as a last resort if materials cannot be removed (i.e., structural beams).

If parts of the building or furnishings have been removed, they are now replaced and the environment is restored to its previous functionality. This phase may include tasks such as recarpeting, replacing walls, or repainting.

More serious problems may require professional intervention. Those professing to offer these services should be questioned closely. In addition to asking about the company's experience in solving similar problems, ask about the training and experience of the staff that will be performing the work. There are no federal regulations covering professional services for mold and indoor air quality, but there are certifications offered which require classroom training and passing a test on the related subject matter.

When selecting professional help, be aware of potential conflicts of interest. For example, someone who works for a remediation company may have difficulty conducting an objective investigation since his company can benefit from his recommendations. For best results, get an objective party to conduct the investigation and manage the project. Select a professional whose future income is not related to his findings and recommendations.

Finally, the consultant should estimate the cost of services to be performed. Be aware that some vendors price their initial visit very low and, once on-site, bill for additional services such as extra testing. This can easily add hundreds of dollars to your bill. So, be sure to ask the vendors what charges beyond their initial quote might be incurred.

Robert I. Leighton is the president of Leighton Associates, a Forest Hills environmental consulting company specializing in indoor air quality, environmental investigations, and mold remediation.