Limiting mold liability when working with immunocompromised insureds.
Water and mold remediation efforts in hospitals, surgical facilities, and other health care venues require the highest standard of care in the restoration industry. Professional restoration contractors who accept water damage projects with immunocompromised patients must understand the necessary techniques to isolate airborne contaminants and also the consequences of infection and death when the work is performed poorly. Contractors who accept contaminant-sensitive work may face possible claims of wrongful death, breach of contract, negligence, and misrepresentation.
Let’s look at a claim in the home of an insured whose daughter was diagnosed with bone cancer. Chemotherapy that preceded bone-marrow transplants had eliminated her immune system, making her prone to infection. Community and corporate financial support transformed the insured’s home into a contaminant-free bubble that allowed the mother and daughter to live together comfortably (Photo 1).
During a scheduled doctor’s visit following a bone-marrow transplant, the washing machine in the home overflowed and discharged gray water (Category 2) inside the protective bubble. This created a moisture source for fungal contaminants ideally suited to infect an immunocompromised person.
The scope of work required a hybrid approach that blended commonly employed asbestos techniques with mold remediation. Restoration contractors may wish to consider these suggestions to lessen their liability. Alternatively, plaintiff and defense attorneys may recognize elements to defend or attack restoration contractors who accept this type of loss.
Conducting the Restoration Phase
With no alternative living arrangements available, the mother and daughter have to stay within the protective bubble during the remediation process. Remediation was conducted in accordance with ANSI/IICRC S500 water damage restoration criteria with five differences: (1) collection of viable and nonviable microbial samples; (2) pressure monitoring; (3) temperature and relative humidity monitoring; (4) installation of double containment walls; and (5) swab testing of replacement building materials.
The work was conducted in four stages: planning, remediation, restoration, and testing. Among these stages, the planning stage was most critical because of the time-sensitive nature of the loss and the need for prompt agreement between all parties. The planning stage comprised a discussion about the daughter’s susceptibility, identification of the water-damaged area, and preparation of a detailed timeline listing the contractor and consultant responsibilities. All visits were conducted in Level C personal protection (e.g., booties, Tyvek suit with hood, surgical gloves, and air-purifying respirator).
Pressure measurements were maintained at five pascals positive (clean) and five pascals negative (contained) throughout remediation and restoration tasks. The average temperature of 72.5 F and relative humidity of 50 percent were reported throughout the remediation and restoration efforts.
One favorable design attribute in the home was the introduction of filtered and conditioned fresh air that placed the bubble, or clean area, under a slight positive pressure. The contaminated area comprised the laundry room, a portion of the kitchen, the dining nook, and the foyer (about 300 square feet). The initial remediation tasks were to remove the contents and install a double containment barrier that separated the clean from the contained (contaminated) area. Dehumidifiers and fans accelerated drying and arrested fungal growth. Five tasks distinguished the effort from a typical water loss and are intended to protect all parties from potential liability.
Viable and Nonviable Microbial Testing. Air sampling of both viable (Anderson, MEA) and nonviable (Air-O-Cell) microbial constituents was conducted frequently. Viable sampling identifies the living fungal population that might infect an immunocompromised person; nonviable sampling does not. This task was necessary to defend whether the containment method prevented the introduction of airborne contaminants into the clean living space. Six rounds of air sampling were conducted throughout the four-month project with samples obtained inside and outside of containment and two outdoor control samples with each round.
Pressure Monitoring. A pressure gradient was created to ensure that air movement flowed one way from the clean area to the contained area. Although the clean area was under positive pressure, a small blower was placed in the contained area to discharge a small volume of air out the window to ensure a one-way flow. The blower was controlled using a restrictor plate that limited the discharge rates to less than five cubic feet per minute. A pressure gradient of negative five pascals was established and monitored between the clean and contained area using a magnahelic gauge. Positive pressure measurements in the clean area were monitored using a micromanometer (Alnor).
Temperature and Relative Humidity Monitoring. Temperature and relative humidity in the contained and clean areas were monitored using data loggers (Onset HOBO U12). Stable humidity and temperature measurements would substantiate efforts to maintain comfortable temperatures and monitor the introduction of unconditioned air.
Double Containment Walls with HEPA filters. Two containment walls were constructed about one foot apart between the clean and contained areas (Photo 2). Two walls were installed, each made of six millimeter plastic sheeting, to serve as backup if one containment barrier failed. HEPA filters were installed in each containment wall to allow air movement created by the pressure gradient across the containment walls.
Swab Sampling of Replacement Building Materials. Building materials (e.g., gypsum board, base trim, and foil-faced insulation) were swab tested for the presence of viable fungal contaminants. The swab-sampling effort was intended to defend against the argument that contaminated building materials had been introduced after remediation.
What Problems Emerged?
Every project experiences technical issues. This project was no different. Here are some of the issues that came up.
- The remediation effort did not include the complete baseboard removal in the contained area.
- The initial placement of the containment walls did not encompass all of the water-damaged flooring.
- Drying of the concrete foundation took longer than expected because of sensitivity to meeting the flooring manufacturer’s installation recommendations. This task extended the project schedule by two months (Photo 3).
- Clearance testing failed twice because the cleaning effort was not comprehensive and small amounts of waste debris and microbial growth structures remained within the contained zone.
- Negative pressure in the contained area introduced outside air contaminants whenever the front-entry door was opened.
What Did the Monitoring Results Show?
The nonviable fungal spore results closely paralleled the viable spore results by reporting the highest concentrations outside and lowest inside the clean or bubble area. The viable results are shown in Figure 1.
Colonies of the genus Penicillium spp. were most common and reported at the highest concentrations. Five Aspergillus species (A. fumigatus, A. carbonarius, A. calidoustus, A. sydowii and A. versicolor) were identified. One colony of A. versicolor was identified from a sample volume (0.0566 m3) collected from the clean area. This species is occasionally associated with aspergillosis (DiSalvo, 2014).
Swab samples obtained from aluminum-faced insulation panels and base trim reported the absence of fungal contaminants. Gypsum board samples contained one concentration colony of yeast (Candida sp.). Within the genus Candida sp., the fungal species Candida albicans is considered an opportunistic species.
When a plaintiff alleges to have developed an illness from mold exposure, the case will center on the cause of the mold. Not only must a plaintiff establish that the defendant negligently failed to prevent the mold exposure or improperly performed mold remediation, but also that the defendant’s negligence created a dangerous mold condition that directly caused the claimant’s illness.
In Cummo v. Children’s Hospital of New York, et al., a couple filed suit against a New York hospital and its contractors alleging that the couple’s immunocompromised daughter died from a fungal infection acquired at the hospital. The plaintiffs asserted that their daughter’s death resulted from exposure to fungus, toxic airborne particles, bacteria, Aspergillus, and Legionnaires’ disease, and that the hospital knew of, but failed to correct, the unsafe conditions. The hospital countered that there was no evidence of any dangerous Aspergillus contamination at the hospital, and the hospital took the necessary actions to reduce the threat of acquiring an infection by daily cleaning, maintaining positive pressure, using HEPA filters, and implementing an air-sampling program. Further, the hospital argued that the child died because she was immunocompromised from the side effects of chemotherapy and an infection secondary to her severe aplastic anemia and it is impossible to completely prevent fungal infections in immunocompromised patients.
The question for the court was whether the girl’s infection was contracted because of an unsafe condition at the hospital. Ultimately, the court found in favor of the hospital because the plaintiffs showed no evidence that there were dangerous levels of mold in any room occupied by the child and that the child could have contracted a fungal infection only as a result of the defendants’ negligence.
The authors would like to thank the following reviewers for their comments and suggestions: Chin Yang, Ph.D., Nicholas Albergo, PE. DEE, John Marquardt, P.E., Jeff Steger, P.E., Chris Martinez, EIT, Rick Price, Jeff Wilemon, Michael Bass and Sam Montgomery.
ANSI/IICRC S500 Water Damage Restoration, Standard and Reference Guide for Professional Water Damage Restoration
DiSalvo, A. Mycology- Chapter Seven Opportunistic Mycoses, Microbiology and Immunology, University of South Carolina on-line. Pathmicro.med.sc.edu/mycology/opportunistic.htm
Joshi, A,Y., Iyer, V.N., Hagan, J.B., Sauver, J.L. and T.G. Boyce, 2009. Incidence and Temporal Trends of Primary Immunodeficiency: A Population-Based Cohort Study, The Mayo Clinic Proceedings, January, 84(1)16-22.
Gogate, S. Immune Deficiency Disorders, Types, National Jewish Health, www.nationaljewish.org/healthinfo/conditions/immune-deficiency/types
National Institute of Allergy and Infectious Diseases, Primary Immune Deficiency Diseases. www.niaid.hih.gov/topics/immunedeficiency/Pages/Default.aspx