Healthy Indoors Magazine
Issue link: https://hi.healthyindoors.com/i/815664
COVER STORY—March/April 2017 10 leased into areas outside the containment area. Furthermore, the Environmental Protection Agency requires air sampling after abatement (clearance, in other words) to ensure that the air within the con- tainment is not contaminated with residual asbes- tos and that the containment can be removed and remaining remodeling, demolition, or re-occupancy can occur. Air sampling should be adequate to iden- tify any airborne asbestos hazard, but is it enough to characterize asbestos health hazards within the containment? What if the asbestos particles are not airborne at the time of sampling? What if the asbes- tos particles are settled out of the air and are present in settled dust? How would the air sampling techni- cian identify this problem? I would like to specifically address an issue that may be overlooked concern- ing asbestos contamination. QuanTEM has been involved in several proj- ects where the consultants chose to collect set- tled dust samples in addition to air samples. The interesting thing about these projects was that NO asbestos was detected in the air samples. However, hundreds of thousands to millions of as- bestos fibers per square centimeter were present in the settled dust. What does this mean? What conditions could promote this outcome? Scores of hypotheses could be made if all of us were to sit down and think back on all the containments we've been in and what we've seen in those ar- eas. However, let's discuss two possible causes. Is the containment visually clean? Visual inspection of the containment after detail cleaning and prior to air sampling needs to be im- proved. More thorough investigation of surfaces in the containment is warranted. So how do consul- tants do a more thorough investigation? Hard work. The inspector's visual inspection needs to be com- prehensive—including areas the abatement crew may have overlooked during their detail cleaning. I can't remember how many times I went into contain- ment and crawled around in hard to reach places and found pockets of asbestos-containing debris ly- ing about. Many of my colleagues in various areas of the country have found similar conditions. So, if you have raw asbestos-containing material debris of the moldy materials may involve breaking, abrad- ing, or otherwise damaging asbestos- or lead-con- taining materials. In our litigious society, the issues of lead-containing materials and asbestos-con- taining materials are still hot topics and should be addressed in addition to any primary mold issues. The suspect materials should be addressed in an inspection report. Sample the materials yourself, get the materials sampled by another certified par- ty, or disclaimer your mold report and recommend the materials be sampled by a properly certified and licensed inspector prior to being disturbed during mold remedial activities. Also, make sure that if you do the sampling yourself, you have the proper lead or asbestos certifications and/or licenses in your state to avoid any encounters with your local envi- ronmental regulatory agency. As a reminder, prior to 1978, lead was com- monly added to paints, varnishes, ceramic tile, and ceramic tile glazes. Even today, some import- ed ceramic tiles and glazing contain lead. Asbes- tos, however, was at one time or another put in just about every building material produced. A long list of materials has been found to contain asbestos, including gypsum wall board, joint compound, tex- ture (surfacing) materials, plasters, vinyl floor tiles, sheet flooring, tile adhesives, grouts, caulks, pipe wrap, block pipe insulation, sink insulation coat- ings, heat shields in light fixtures, vermiculite attic and wall insulations, acoustic ceiling tiles, light- weight acoustical ceiling textures, cement sheet- ing (transite), roofing (shingle, rolled, tar paper, built-up), roofing tars, penetration sealants, alumi- nized paints, stuccos, and wire insulation. The asbestos process has been defined for over thirty years now and involves the following phases: inspection and sampling, abatement, and clear- ance. During the inspection and sampling phase, each suspect material is identified, sampled, and analyzed utilizing a bulk analysis technique such as Polarized Light Microscopy (PLM) or Transmission Electron Microscopy (TEM). During abatement and clearance, air samples are collected. Air sampling is used during abatement to determine asbestos concentrations for worker exposure purposes and to ensure that asbestos fibers are not being re-