February 2004 - Mold

Safety Concern:

Toxic Mold

The most potentially dangerous bio aerosols are :Bacteria like Anthrax, TB and Legion Ella: viruses like colds, influenza, mumps, measles, SARS, West Nile; and fungi such as mold and yeast.



Over 100,000 varieties of mold exist (a subset of fungi) and another 100,000 yet to be identified. Molds can survive temperatures ranging from 40-100 degrees and need food and water to grow and amplify. One hundred species have been identified as causing human infections.



Mold likes cellulous and any paper or wood products. Water is the element you can control – relative humidity over 60% can be a problem. Problems occur with new tight construction and building materials that are cellulous base. A second problem is 21% of our population now has asthma or allergies; people are more sensitive to mold and other environmental factors.



Mold is found in soil, decomposing plant matter, household dust, building materials, ornamental plants, items of food and water. Industries use mold for enzymes, chemicals and foods (soy and citric acid). Industries use 170+ species, 16 toxic species of mold. They range from infectious to carcinogenic.



Penicillin is a hazardous mold commonly found in soil, food, cellulose and grain. Common uses of mold are penicillin and cheese.



Black Mold – Stachybotrys Chartarum – generally has low indoor levels. Black mold favors building materials and is often found of the backer paper on drywall. Human reactions can include allergic reactions, skin irritations, sinus infections, pink eye and fatigue. In some rare cases, brain damage and memory loss may occur. Sixteen species of black mold have been identified.



In the next ten years, the big issue will be if the mold produces mycotoxins. The mycotoxins can produce adverse health affects.



Is mold a real concern? There is data that shows people are affected by mold and mold spores. Whether or not problems are related to a high order of mold toxicity is not known. Legal cases will probably move ahead of science and future cases will be based on case law, not science.

EVALUATING MOLD

There is no simple way to sample and test. Indicators can be visual, odor, and symptoms in occupants, evidence of water intrusion, sampling and testing. Testing always needs to compare inside and outside levels. An inside test alone means nothing. Guidelines are not great (“they really suck”) and are primarily for viable or living mold spores.

SAMPLING

The intention is to confirm the “obvious”, or test a portion of the “obvious” for the type of mold. Three methods of sampling are used.

1. Surface sampling such as tape lift, swab or wipe. Samples are sent to a lab for microscopic evaluation.

2. Air samples can be taken via an “Air-O-Cell” which pulls air through a controlled opening and the spores are caught on a sticky surface. A lab then analyzes the sample.

3. Wallchek™ Sampler is used with an Air-O-Cell to take a sample from inside a wall to check for contamination.



If there is a problem, there must be a written abatement plan to detail how removal will be done – containment, dehumidify, and air scrubbing and HEPA vacuuming. The typical approach is to clean visible mold-scrub, scour or sand if feasible. It is important to remove and dispose of porous materials – carpet and pad, drywall, etc. Cleaning can include diluted bleach, quaternary ammonium chloride and biocides. Do not apply materials in ducts (fogging). Many problem materials have been used for duct fogging and further problems have been created. Surfaces can also be protected with a special coating.

Most problems show up in attics and basements. Concerns will be water flow toward a structure, slab on grade construction, roof systems using bottom of roof trusses for ceiling, fires and floods, humidifiers, window and sliding glass door installation and flashings, flat roofs, balconies and porches over the structure, bottom of roof decks, floor decks, basement walls, around plumbing, behind bathroom tile, behind bathroom fixtures, on drywall. Water intrusion is the controlling factor.

Mold is everywhere and many are toxic. No definitive regulations are in effect now nor will they be soon.