HPmag | Magazine | Show 2007 | Guest Editorial

GUEST Editorial

Mold Remediation
A threat to health and property, mold is a strong contributor
to poor indoor air quality.

by Cari Haerther
The Environmental Protection Agency (EPA) states that poor air quality is now one of the top five environmental threats in the United States. A strong contributor to poor air quality is mold; a health-threatening fungus that flourishes in hot, humid climates. Areas that are susceptible to hurricanes are consequently susceptible to mold. Extensive water damage after major hurricanes and floods increases the likelihood of mold contamination in buildings.

Following Hurricane Katrina, a team of scientists led by researchers at Columbia University’s School of Public Health conducted a study to assess flood clean-up procedures in New Orleans, LA. This study is the first comprehensive report documenting levels of mold and bacteria in homes that received sustained flooding and major water intrusion. They reported that household levels of mold and bacterial endotoxins in three single-family homes were so considerable that they equaled or surpassed those in wastewater treatment plants, cotton mills, and agricultural environments.

In the aftermath of major hurricanes or floods, buildings wet for more than 48 hours will generally support visible and extensive mold growth and should be remediated. Excessive exposure to mold-contaminated materials can cause adverse health effects in susceptible persons regardless of the type of mold or the extent of contamination.

VISUAL INSPECTION
Visual inspection is the most important step in identifying possible mold contamination. This assessment is particularly important in determining remedial strategies and the need for personal protective equipment (PPE) for persons in the contaminated area.

Ceiling tiles, gypsum wallboard, cardboard, paper and other cellulosic surfaces should be given careful attention during a visual inspection. Not all mold contamination is visible—with a flood, contamination in the interior wall cavities or ceiling is common. A professional judgment will necessarily play an important role in the visual inspection because less quantifiable factors (e.g., location of the mold, building use and function) and exposure pathways also are very important in assessing potential human exposure and health risks.

Ventilation systems should be inspected, particularly for damp filters, damp conditions elsewhere in the system, and overall cleanliness. To avoid spreading microorganisms throughout the building, HVAC systems known or suspected to be contaminated with mold should not be run.

TESTING EQUIPMENT
In addition to visual inspection, there are several tools that are useful in determining possible mold contamination or identifying circumstances that can create a mold-friendly environment.

Moisture meters, available from contractor tool and supply outlets, provide qualitative moisture levels in a variety of building materials (e.g., carpet, wallboard, wood, brick and concrete) following water damage and can also be used to monitor progress in drying wet materials. Damaged materials should be removed and discarded.

Humidity meters can be used to monitor indoor humidity and inexpensive (less than $50) models that monitor both temperature and humidity are available. A borescope is a hand-held tool that allows users to see hidden mold problems inside walls, ceiling plenums, crawl spaces and other tight areas without major drilling or cutting of drywall.

SAMPLING
Sampling for mold is not part of a routine building assessment. In most cases, appropriate decisions about remediation and the need for PPE can be made solely on the basis of visual inspection. If visible mold is present, then it should be remediated regardless of what types of microorganisms are present, what species of mold is present, and whether samples are taken.

Other than in a controlled, limited, research setting, sampling for biologic agents in the environment cannot be meaningfully interpreted and would not substantially affect relevant decisions about remediation, occupancy, handling or disposal of waste and debris, worker protection or safety, or public health.

If sampling is being considered, a clear purpose should exist. For example:

• To help evaluate a source of mold contamination. For example, testing the types of mold and mold concentrations indoors versus outdoors can be used to identify an indoor source of mold contamination that might not be obvious on visual inspection.

• To help guide mold remediation. For example, if mold is being removed and it is unclear how far the colonization extends, then surface or bulk sampling in combination with moisture readings might be useful.

CLEAN-UP
A series of actions is required in order to properly remediate mold infestation. The order of these actions is important, but can vary on a case-by-case basis. Typically, the following actions are taken regardless of whether a problem is small and simple or large and complex:

• Take emergency action to stop water intrusion, if needed.
• Determine the extent of water damage and mold contamination.
• Plan and implement remediation procedures.
• If needed, establish containment/protection for workers and occupants.
• Eliminate or limit water or moisture sources.
• Decontaminate or remove damaged materials.
• Dry any wet materials.
• Evaluate whether space has been successfully remediated.
• Prevent or limit potential recurrence by controlling sources of moisture.

For small, simple problems, the entire list of tasks can be done by one person. Large, complex problems might require many persons from different professions and trades. For circumstances that fall between those extremes, some combination of occupant action and professional intervention will be appropriate.

Cari Haerther, Florida Mold Consultants, LLC, Boca Raton, FL 33434; www.flamold.com.Florida Mold Consultants is a leading authority on mold testing and remediation in the state of Florida and provides these services for single family, multi-tenant residential and commercial buildings.