B. Kollmeyer, M. Canright, Forensic Analytical, Rancho Dominguez Hills, CA; D. Kahane, Forensic Analytical, Hayward, CA.
This case study discusses a litigated personal injury matter involving alleged mold growth and contamination in carpet where the primary evidence presented was carpet microvacuum results. When visible evidence of mold growth is limited, hygienists frequently rely upon interpretation of sampling data collected through a variety of nonstandardized sampling methods. As such, there is frequently a large degree of variability amongst hygienists in how such data is collected, interpreted and used in reaching conclusions. This case study focuses on how carpet dust microvacuum data was used by various hygienists to support different conclusions. Issues encountered include the method of collection, how results were quantified, how interpretations were supported, and how they were related to causal factors. This case study shares the approach taken to integrating various data related to microvacuum results to arrive at sound and supportable conclusions. A review of current studies involving the collection of carpet microvacuum samples is presented as a basis for supporting the approach taken. This case study will provide hygienists with perspectives and approaches to how microvacuum data is utilized in developing supportable conclusions. It will further provide perspectives on the variability of how such data is collected and used within the industrial hygiene community. By presentation and discussion of these issues, hygienists can continue to move toward greater consistency and more sound methods for collecting and interpreting data.
K. Ong, R. Lewis, A. Dixit, M. MacDonald, D. Backer, S. Condoor, Saint Louis University, St. Louis, MO.
A study was conducted to evaluate the growth of fungi and its removal in wetted carpet over time using newly designed or emerging technologies that rely on physical principles of steam or heat and fluid flow. Sixty samples of carpet were imbedded with heat-treated house dust, followed by imbedding, wearing with a hexapod, wetting and inoculation with a liquid suspension of Cladosporium sphaerospermum prior to placement over a water-saturated foam pad and incubated for 24 hours, 7 days, and 30 days. Cleaning was performed using three methods; high-flow, hot water extraction, hot water and detergent, and steam. Fungal loading increased from approximately 1,300 colony forming units (CFU) per square feet in 24 hours to a maximum of approximately 9,200 colony forming units per square feet after seven days with a slight decline in growth after 30 days incubation. Significant differences were found among all three methods for removal of fungi over time (p < 0.05). Steam was significantly better than the other two methods (p <0.001) with 99% efficiency in removal of Cladosporium sphaerospermum from wetted carpet after 24 hours and 30 days incubation time, with 92% efficiency after seven days. The other two methods had declining efficiencies of fungal removal over time, from a maximum of 82% and 81% at 24 hours down to 60% and 43% at 30 days for detergent and high-flow, hot water extraction, respectively. The net effect of the mold management study demonstrates that while steam has a nearly constant fungal removal rate, the detergency and high-flow, hot water methods decline in efficiency with increasing fungal growth.
J. Furman, Wild Apple Enterprises, Ltd., Columbia, NC.
Crawlspaces in hot and humid environments are targets for moisture and mold issues. A brand new home, just built and never lived in, had a major moisture problem, with water dripping “like a rain forest” and pools of water forming on the ground. Wood moisture was 25–30%. Within two months mold had covered all of the floor joists and insulation. Developing a protocol to remediate the mold and clean the crawlspace had to coincide with removing the moisture from the wood to stop mold re-growth. There were many useful lessons learned in this phase. Once control of the moisture and mold growth was achieved, an enclosed or sealed off crawlspace was chosen as a permanent solution. This solution, recently code approved, is straightforward in approach, but needs a number of important details to be observed in installation. All of this and keeping the house above from becoming contaminated. Did it work? What to do differently? This use of building science technology is really currently evolving as a very useful tool in mold remediation.
S. Evans, MDE Inc, Seattle, WA.
When industrial hygienists are evaluating mold in a building in conjunction with a mold remediation project, a key element in the remediation process is correcting any water leaks or water infiltration. What tools and methods can industrial hygienists utilize to determine the source(s) of water infiltration in buildings? Visual observations of mold growth patterns and characteristics, along with relative moisture measurements can often be utilized to identify likely sources of water infiltration. When information suggests the generalized area of infiltration but not the specific material, installation or design that permitted the water to infiltrate, these techniques can be used to support the need for destructive evaluation of the generalized area so that the specific cause of water infiltration can be identified. Examples of mold patterns/characteristics and relative moisture measurements will be shown to illustrate how water infiltration sources can be distinguished in residential and commercial building envelopes including walls and windows and in occupied areas such as walls, baseboards, floors, and ceilings. In residences, these practices will be illustrated additionally for kitchens, bathrooms, attic areas, and crawl spaces. These techniques can be used to ascertain whether the water infiltration is linear, such as at horizontal or vertical joints or seams, or along the length of pipes. They can also be used to assess water infiltration through walls, ceramic tile, or in concrete slabs.
D. Jerger, Shaw Environmental and Infrastructure, Inc., Knoxville, TN; J. Duffy, CCI Environmental Services, Inc., Suwanee, GA.
Hurricane Katrina forced numerous people to evacuate the Gulf Coast. Ft. McClellan, Anniston, AL was selected to supply long-term housing needs because the facility had available space for offices, residences, recreational facilities, and a clinic. Shaw was contracted to assess and prepare those facilities with seven days. Two buildings designated for residences contained 32 dormitory-style barrack rooms for a total area exceeding 100,000 square feet. The plan was to convert these rooms into individual apartments to house the evacuees. Each building also had a kitchen, two food serving areas, and two dining areas. Mold growth was observed in all the buildings since the base had been closed for seven years. Remediation of the mold was the critical path item for renovation of the facilities. The overall challenge was to assess the extent of mold growth and develop and implement a mold abatement plan including clearance guidelines to allow construction workers to immediately enter the facilities to prepare for the new residents. The visual assessment indicated visible fungal growth on both porous and nonporous surfaces from water intrusion and condensation in all the facilities. The mold abatement plan included cleaning and/or removal of porous materials and cleaning of nonporous materials. The clearance guidelines consisted of visual inspections for dust, debris, mold, and moisture to permit construction workers to enter the facility. Aggressive spore trap samples were collected and analyzed within 24 hours to assess the residual spore load prior to the occupation by the new residents. Viable culture samples were collected to determine fungal species of in the dining areas and clinic. The application of “emergency response” planning allowed Shaw and CCI to meet a very aggressive schedule, including mobilization of over 300 workers, equipment and supplies within 24 hours to provide immediate long-term housing for hurricane victims.
B. Kollmeyer, Forensic Analytical, Rancho Dominguez Hills, CA; D. Kahane, Forensic Analytical, Hayward, CA.
This case study discusses experiences and challenges related to the fungal assessment and remediation of several hotels impacted by hurricanes Rita and Katrina. In the aftermath of a catastrophic hurricane, professionals involved in mold and moisture assessment and remediation activities are faced with significant challenges not normally encountered in typical investigations. Investigators must contend with logistical constraints, lack of information, expedited timetables, lack of infrastructure, security concerns, limited communications, and a rapidly changing set of parameters and direction from property owners. Hygienists must navigate these challenges quickly and efficiently in order to develop sound data and conclusions to support decision-making. This case study shares approaches taken to overcome the aforementioned challenges and discusses the various dynamics of moisture intrusion and mold growth encountered in seven different hotels located in coastal Louisiana and Mississippi. It recounts the evolution of the projects from an industrial hygienist’s standpoint and how each issue was navigated as it arose. The data and lessons learned from this case study will help hygienists to be better prepared for responding to large catastrophic events and specifically the dynamics of mold and moisture related to hurricane impacts on large buildings. By sharing and digesting these experiences, hygienists will be better prepared to make sound decisions in an unstable environment and more effectively support recovery efforts.
B. Cortes, EMSL Analytical Inc., Orlando, FL.
Following the worst natural disaster to hit the Gulf Coast states, 209 spore trap samples were analyzed from September 1 to October 1 from Louisiana and Mississippi. The aftermath of Katrina left Mississippi in shambles and New Orleans under water. This study looks at fungal genera and concentrations of spores per cubic meter in order to assess water damage and/or mold amplification in standing buildings affected by Katrina, using indicator genera such as Epicoccum, Chaetomium, Stachybotrys, and Ulocladium. Outdoor fungal variability in Mississippi was greater than in Louisiana (24 genera vs. 13). In both states, the major source of contamination was Aspergillus/Penicillium spores although there was a 10-fold difference in the concentration of these spores, with Louisiana reporting 789,000 to 7 million spores/cubic meters reported in Mississippi. Water damaged indicators were detected in both states. In Louisiana the indicator genera was comprised by Epicoccum, Chaetomium, Ulocladium, and Stachybotrys and concentrations did not exceed 2000 spores/m3. In Mississippi, significant amplification was observed for Paecilomyces (3,726,789 spores/m3), Memnoniella (292,423 spores/m3) and Scopulariopsis (283,572 spores/m3). Epiccoccum concentrations were similar in both states. While there are marked differences in the type, number of genera and total concentrations between the two most affected states, the fact remains that mold proliferation is a reality that the Gulf Coast states will need to address. We can only speculate that the amplification seen in just one month will worsen with time as the extent of water damage increases due to a very slow recovery process.
W. Sothern, Microecologies Inc., New York, NY.
Our group, from the Little Sisters of Assumption Family Health Service (a Catholic charity organization), was requested by a concerned group of New Orleans’ citizens to assess the mold problems in New Orleans in the aftermath of Hurricane Katrina, and to provide practical advice to residents concerning their mold problems. We arrived in New Orleans on October 1, 2005, one month after the storm. The city was still under curfew, and only a small percentage of the evacuated population had returned. The majority of homes in New Orleans had been submerged in two to eight feet of fetid flood waters. We inspected 20 homes across the city, and in each home the furnishings and walls were covered with severe levels of visible mold growth. We took surface samples for laboratory analysis, and results will be presented. Residents needed advice about: How to safely inspect their homes and remove salvageable possessions; Where to draw the line on what work they could safely perform themselves, and how to protect themselves; and How to select and deal with a mold remediation contractor. The State of Louisiana Department of Health and Hospitals had issued very good basic advice to residents concerning mold issues. We provided a supplemental pamphlet with detailed “How-to” advice for residents, and we produced a “How-to” video which was distributed to residents through the American Red Cross and other organizations. We also conducted training and discussion sessions for residents.
M. McGowan, Malcolm Pirnie Inc., White Plains, NY.
When a large county in southern Mississippi was devastated by Hurricane Katrina, our firm was asked to assist the county with recovery operations. These activities included: the oversight of document recovery/ restoration; wind, water, and mold damage assessments of over 80 county buildings; oversight for remediation and removal of water and mold damaged building materials and contents; and, reconstruction design and oversight. The purpose of this paper is to describe the conditions that we encountered; how we assessed the damage to buildings and property; and, how we provided for the health and safety of our workforce during the process. The information provided in this paper will assist others in planning and executing similar operations.
Posted May 30, 2006