Healthy Indoors Magazine - USA Edition

26 | February 2019 industry. Equipment and techniques which improve the effi- ciency and effectiveness of the work are being added to the mold remediation field every day. Proper use of these sup- plies and work practices means that the surfaces and air in mold remediation containments can be thoroughly cleaned. Honest Reporting One of the significant concerns which arise when discussing low levels of target spores recovered from post-remediation air samples is how often professionals in the mold remediation field will change their terminology without justification. Labora- tory results for spore trap air samples contain both raw counts and extrapolated levels. The raw counts represent what was identified under the microscope. However, those are convert- ed to counts per cubic meter of air (c/m3) because the ana- lytical process uses a mathematical formula to determine the concentration of spores in the air. Since airborne concentration is the subject being evaluat- ed, most of the discussion regarding post-remediation results centers around the values represented in counts per cubic meter of air. Oddly enough, when individuals point to the low levels of target spores that they are trying to ignore or down- play in a post-remediation sample, they will often switch to the raw counts to make it sound less significant. This duplicity in terminology undermines the scientific process being utilized to come up with the spore concentrations. How Much Is Too Much? The biggest difficulty in taking a position regarding certain levels of target spores which are acceptable following a re- mediation activity is determining what actual, and numeri- cal levels are appropriate to have in a home or commercial building. If 24 counts per cubic meter of air of Stachybotrys is acceptable (which may equate with one spore on the raw count), then what about 48 c/m3? And, if 48 c/m3 is okay, then what about 96 c/m3? Where does it end and what is it based on given that such spores are rarely seen in build- ings that are not water-damaged? Individuals who advocate that low levels of target spores are acceptable for post-remediation needs to contemplate the client difficulties when professionals in the mold remedi- ation field are telling the homeowners it is suitable to leave "toxic" spores behind. How does such a position reduce the long-term liability of the contractor or consultant when there currently is no validated medical evidence which indicates an acceptable threshold for such exposures? Zero Tolerance of Target Spores Is Achiev- able and Reasonable As an advocate of zero tolerance of target spores in post-re- mediation spore trap samples, I have had hundreds of discus- Even so, the interpretation of the analytical data needs to be framed by the common sense understanding that the world is not spore-free. Therefore, some residual spores af- ter remediation are to be expected. However, the argument is that certain types of spores are not acceptable; even at extremely low concentrations. What Are the Spore Types of Concern? Many types of mold are considered to be part of a "normal fungal ecology" inside the building. While the specific mix of spores in a building will vary by location, season, time of day, and amount of infiltration of outside air, there are certain fungal types typically not found in buildings unless they are water-damaged. At Wonder Makers, we use the term "Target Spores" to reflect the five types of mold that are unacceptable in terms of post-remediation air sample results: Stachybotrys, Chaetomium, Memnoniella, Fusarium, and Trichoderma. This list was not developed randomly, but reflects a number of specific characteristics shared by these target spores. First and foremost, the identification of these types of spores inside buildings correlates closely with the struc- ture being water-damaged. None of these five target types are common in indoor air samples in well-maintained, clean buildings. Indeed, these target spore types are rarely seen in outdoor air samples. This is because airborne distribu- tion of the spores for reproductive purposes is a secondary method for such fungal organisms as compared to distribu- tion by flowing water, foot traffic, etc. Another reason that certain types of mold have been desig- nated as target spores is because there is ongoing discussion regarding the fact that certain molds may produce more sig- nificant health effects upon exposure than others. Both medi- cal data and public perception about certain mold types being "worse" than others is now frequently tied to the fact that the list of target spores typically produce more dangerous myco- toxins than other types of fungal organisms. Post-Remediation Is Designed to Gauge the Effectiveness of the Work When using a strict criterion for review of analytical data, it is important to remember the overall purpose of the remediation effort. For the area of structure under the contractor's control, the ultimate goal is to return the building to a pre-loss condi- tion. Given the previous discussion that target spore types are not typically found in air samples in buildings with a normal fungal ecology, allowing "small" concentrations in post-reme- diation air samples to be acceptable is not logical. The argument that contractors should get a "pass" on a small number of target spores also tends to diminish the ca- pabilities of the contractors working in the mold remediation

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