WATER DAMAGE INVESTIGATIONS

MORE THAN SUCKING AIR

Connie A. Morbach, M.S., CHMM, CIE, ASCS

Sanit-Air, Inc.

1311 North Main/ Clawson, MI 48017

248 435-2088

connie@sanit-air.com

IS Mold New?

• Mold is not new, awareness has increased

• Changes in building construction Tighter Porous Materials =Good Nutrients Construction to allow high moisture

Better testing methodologies Physician Awareness

Link previously unexplained illnesses

Tight Construction• Focus on energy conservation resulted

in tighter buildings with less natural ventilation– 75 years ago, cracks in the building envelope

allowed for 5 - 10 air changes per hour (ACH)– Now building codes permit 0.35 ACH

• Contaminants are not diluted out

• Higher concentration results in greater exposure and opportunity for amplification on building materials

• The solution is to build tight / ventilate right

New Building Materials Are Good Nutrients

• Materials high in cellulose content that are porous retain moisture and provide good nutrient material for mold amplification– Drywall– Oriented Strand Board (OSB)– Plywood– Ceiling Tiles

• Hasty construction with less detail to preventing water intrusion and providing mechanisms for removal

MOLD IS NOT NEW

Leviticus 14:33-48This passage describes mold contamination .

Instructs priests to inspect homes and scrape off mold if it is present. After 14 days, the home should be inspected again, if the mold returns, its a “destructive mildew” and the house must be torn down - its stones, timbers and all plaster - and “taken out of town to an unclean place”.

MOLD FACTS

Mold Spores are Ubiquitous in Nature

Indoors, Mold is not a Problem Until it Amplifies

Mold Requires Water to Amplify (colonize)

During Periods of Growth and Metabolism, Mold Cells Produce Volatile Organic Compounds and Mycotoxins

Under Stress (Drying Out), Mold Produces Spores

Spores Become Airborne When Disturbed by Airflow, Disruptions, Pressure Differentials

Mycotoxins Become Airborne by Attaching to Spores

ASPECTS OF A MOLD EVALUATION

• Visual Evaluation

• Moisture Measurements

• Environmental Parameters

• Development of Hypothesis

• Development of Sampling Plan

• Sampling

Visual Evaluations

• Most important aspect of investigation

• Evaluate water stains and visible growth– Ceilings, walls, floors, floor coverings

• Hidden damage is often more severe than damage on the outer surfaces

• Access ports, boroscopes, and other invasive techniques might be necessary

– Ventilation systems• filters, duct lining

Surface Moisture Measurements

• Non-penetrating– Calibrated for different materials

• Drywall

• Wood

• Concrete

• Probes– Hard to reach areas– Sub-surface with long probes

Aw: Minimum water activity level at 25°C

ERH: Equilibrium relative humidity

Aw < 0.80, ERH <80%

Aw < 0.80-0.90, ERH <80-90%

Aw >0.90, ERH >90%

water

Aw: Minimum water activity level at 25°C

Aspergillus versicolor Aw 0.74-0.79

Ulocladium chartarum Aw 0.89

Stachybotrys chartarum

Aw 0.94

Evaluate Hidden Damage

• Mold that is hidden and visible is equivalent to visible mold and must be evaluated

• US EPA cautions that mold on the backside of walls and behind wallpaper is frequently more severe than mold on the painted side of walls

• Precautions must be taken to prevent cross-contamination during invasive evaluation

Environmental Parameters

• Temperature

• Relative Humidity

• Carbon Dioxide

• Air flow– Smoke pens

• Pressure relationship

Carbon Dioxide• Produced by people and combustion

appliances

• OSHA PEL 5000 ppm

• Previous recommendation of 1000 ppm

• Outdoors in MI typically 350 - 450 ppm

• Can provide information on tightness of a building

• Can provide information on ventilation relative to industry guidelines

When is Testing Indicated• Illnesses associated with biological

contaminants– Aspergillosis– Hypersensitive diseases

• Diagnostic tool to assist in the development of a remediation scope

• Baselines before remediation

• Verify remediation effectiveness

• Litigation support

Interpretation of Data

• No regulatory limits (PELS, TLV’s)

• Case by case basis

• Build your own database

• Rely on published studies

Air Sample Interpretation• Indoor vs. Outdoor

– Predominant indoor organisms different than outdoors

• Complaint vs. non-complaint

• Indicator organisms– Stachybotrys, Memnoniella– Penicillium– Aspergillus

• Persistent and consistent presence of organisms

Source Sample Interpretation

• Do predominant surface contaminants match air contaminants

• Affected vs. non-affected

• Are hyphae present

• Do post cleaning samples improve

Common Testing Mistakes

1. Too little emphasis on visual evaluation

Essential to establish test sitesMoisture metersStainingDeteriorationVisible growthEvaluation of hidden growth

Common Testing Mistakes

2. Poor Quality Control• Sterile techniques not implemented

• Inaccurate calibration

• Mislabeling of samples

• Media not subjected to QC

• No temperature control during shipping

Common Testing Mistakes3. Too Much Emphasis on Total

Concentrations• No PEL’s TLV’s - dose response too

complex to establish

• Interpretation should be based on:– Types and relative concentrations compared to

outdoors or non-complaint/non-affected areas– Identification of “signature organisms” for

water damaged building materials

Common Testing Mistakes4. Too Little or Too Much Concern

Relative to “Signature” Organisms • Fungi associated with water-damaged building should

incite remediation and/or additional investigation• Examples

• Stachybotrys• Penicillium• Aspergillus• Acremonium• Trichoderma

Common Testing Mistakes

• Two Common Methods for Air Samples– Spore trap

• Measures Countable spores

• Example: Air-O-Cell cassette

– Culturable• Measures organisms that will grow in a selected

culture media

• Example: Andersen impact sampler

5. Reliance on One Type of Air Sample

Air SamplesCulturable Fungi

and Bacteria• Enumeration• Identification of genus

and species• Necessary for profile

comparisons• Can underestimate• Selective media• Samples must culture

Countable Spores• Enumeration only• Identify some genera• Cannot differentiate

species• Can identify some

particles and pollen• Can underestimate if

high particulate matter present

• Immediate results

Example of Inconclusive Testing• Spore trap results

– Inside• 2000 c/m3

Penicillium/Aspergillus

– Outdoors• 2000 c/ m3

Penicillium/Aspergillus • Do not know if Penicillium or

Aspergillus is present

• Could have Penicillium inside and Aspergillus outside, which would indicate an indoor source

• Could be the same indoors, which would suggest outdoors is the source

• Culturable Samples– Inside

• 500 cfu/m3 Aspergillus versicolor

• 1500 cfu/m3 Penicillium chrysogenum

– Outside• 500 cfu/m3 Aspergillus versicolor

• 1500 cfu/m3 Aspergillus fumigatus

• Apparent indoor source of Penicillium chrysogenum

Common Testing Mistakes6. Failure to Collect Air Samples

Under “Normal” Operating or Living Conditions

• Can produce ‘false negative”

• Documentation of normal conditions could include:

– Quiescent sampling– Semi-aggressive– Aggressive

Common Testing Mistakes

7. Failure to design a well thought out sampling strategy

• Testing should be conducted to answer a question (hypothesis)

• Sufficient samples must be collected to evaluation the hypothesis

• A poorly designed sampling plan with too few samples can raise more questions than it answers

Summary• Indoor mold amplification is undesirable

and should be avoided.

• Air sampling for mold is prone to false negatives and should only be conducted if a well designed plan is developed to answer a specific question

• Sampling is only one piece of the puzzle. Visual inspection, building history, and patient history are important to a case.

CONSENSUS DOCUMENTS• Bioaerosols: Assessment and Control

American Conference of Governmental Industrial Hygienists (ACGIH), 1999

• Guidelines on Assessment and Remediation of Fungi in Indoor Environments

New York City Department of Health, 2,000• IICRC S500, Standard and Reference Guide for

Professional Water Damage RestorationInstitute of Inspection Cleaning and Restoration Certification, 1999

• Mold Remediation in Schools and Commercial BuildingsUS EPA, 2001

New Testing Methodologies

• VOC (Volatile Organic Compounds

• Mycotoxins

• Endotoxins

• Particle Counters

• PCR

RESOUNDING CONCLUSIONS

A Poorly Developed Sampling Plan Can Raise More Questions Than It Answers

An Investigator Can Not State That Something Is Not Present Unless Appropriate Testing Is Conducted