Mould Investigation

Mould sampling and investigation may be required for any of the following reasons:

• Where water damage has not been remediated promptly and hidden areas such as ceiling, wall or floor cavities may have been wet for some time.
• Where mould odour is present but there are no visible signs of mould or where several suspect areas may be involved
• Where health issues cannot be explained or where water damaged buildings have envoronmental conditions contusive to biological activity, typically following flooding or long term water damage.
• Where complaints against landlords or builders have resulted in lack of action
• Where Local Authority Environmental Health Officers have no evidence of visible mould and cannot assess hazards under the Housing Health and Safety Rating System and where although mould is recognised as a Class 1 hazard they require scientific evidence to substantiate action.
• Where litigation against contractors, builders and landlords is considered
• Where landlords or tenants require evidence of causation in respect of lifestyle
• To enable clearance following mould removal or decontamination

When the property has typical mould symptoms such as known or suspected health effects or water damage issues such as leaks, flooding or condensation which have been long standing or in any event more than a week, mould growth can be expected. If its not visible it may be hidden in cavities or behind decorative finishes such as wall paper, paint, carpet etc.

Mould investigation should always be preceded with a n assessment of visible water damage, history of building events and detailed investigation of moisture sources which may encompass the use of specialist equipment such as infra thermography and non penetrative ultrasonic meters.

Several sampling techniques are available and all have benefits and drawbacks and it is therefore imperative that the correct sampling protocol is chosen or the report may not provide the detail or answers required.

Types of mould sampling

Table 1 provides a very broad assessment of sampling techniques which Building Forensics use:

Ref	Type of sampling	Application	Benefit	Shortfall
1	SAS culture plate	Air sampling	Limited identification	Cannot detect heavier spores, or dead non viable spores.
2	Total Spore Counts Cassette collection	Air sampling	Identifies both live and dead mould with fragments	Can be overwhelmed by debris.
3	Anderson single stage Cultureable	Air sampling	May identify some genus and species	May not collect representative sample of contaminates present and
4	PCR –DNA	Air sampling	Identifies all usually recognised indoor moulds and is not affected by debris	A little more costly
5	Tape lift	Surface sampling	Identification of visible mould from surfaces	Limited to visible mould
6	Bulk	Material sampling	Assessment of genus and speciation	Only identifies what can be seen

Note

Culture type sampling as seen in 1 and 3 is known to provide very limited results as many spores may not carry in the air due to aerodynamics, they may not accept the culture media as a suitable growth food. Often the mould active growth of some moulds will overpower the slower growing moulds and therefore a complete range of toxic moulds may be missed.The World Helath Organisation stated in 2009 that this type of sampling is generally unsuitable for investigation purposes, preferring total spores counts and PCR-DNA (2 and 4)

It should also be recognised that culture plates require live, viable spores to grow whereas dead or non viable pores and fragments may be as greater health risk and only total spore counts and PCR will assess these issues.

Typical reports

The following is a basic report which shows comparison between two bedrooms, a lounge and outside air. Following a visual survey no mould was apparent in this well decorated apartment and landlords were unaware of the serious nature of mould and decay and the likely cause of the tenants asthma and other health issues which had developed since moving into the property.

Report for Mr. Smith provided by :

Jeff Charlton
Building Forensics
10 Osbourne House, St Martins lane,
Kent, BR3 3XS
Phone 08700 789 999
forensic@999team.org
www.buildingforensics.co.uk

Regarding: Project: Smith NA

Approved by:

Dates of Analysis: Spore trap analysis: 07-23-2011

Service SOPs: Spore trap analysis (1038)

For clarity, we report the number of significant digits as calculated; but, due to the nature of this type of biological data, the number of significant digits that is used for interpretation should generally be one or two. All samples were received in acceptable condition unless noted in the Report Comments portion in the body of the report. Due to the nature of the analyses performed, field blank correction of results is not applied. The results relate only to the items tested.

Building Forensics shall have no liability to the client or the client's customer with respect to decisions or recommendations made, actions taken or courses of conduct implemented by either the client or the client's customer as a result of or based upon the Test Results. In no event shall the Company be liable to the client with respect to the Test Results except for the Company's own willful misconduct or gross negligence nor shall the Company be liable for incidental or consequential damages or lost profits or revenues to the fullest extent such liability may be disclaimed by law, even if the Company has been advised of the possibility of such damages, lost profits or lost revenues. In no event shall the Company's liability with respect to the Test Results exceed the amount paid to the Company by the client therefor.

Typical lab analysis of hidden mould sampling. Despite no visible mould a reading of 17,000 "Toxic Mould" spores was recorded in lounge against outside air count of only 300

Introduction

Molds are a natural and important part of our environment. They are ubiquitous and are found virtually everywhere. Molds produce tiny spores to reproduce. These spores can be found in both indoor and outdoor air and on indoor and outdoor surfaces. When mold spores land on a damp spot, they may begin growing and digesting whatever they are growing on in order to survive, leading to adverse conditions. In response to increasing public concern, a number of government authorities, including the United States EPA, California Department of Health Services and New York City Department of Health, have developed recommendations and guidelines for assessment and remediation of mold. Websites for these organizations can be found at the end of this report. While it is generally accepted that molds can be allergenic and can lead to adverse health conditions in susceptible people, unfortunately there are no widely accepted or regulated interpretive standards or numerical guidelines for the interpretation of microbial data.    Sampling cavity for hidden mould  through removed light switch

The absence of standards often makes interpretation of microbial data difficult and controversial. This report has been designed to provide some basic interpretive information using certain assumptions and facts that have been extracted from a number of peer reviewed texts, such as the American Conference of Governmental Industrial Hygienists (ACGIH) and WHO Dampnes and Mould Guidelines 2009 In the absence of standards, the user must determine the appropriateness and applicability of this report to any given situation. Identification of the presence of a particular fungus in an indoor environment does not necessarily mean that the building occupants are or are not being exposed to antigenic or toxic agents.

None of the information contained herein should be construed as medical advice or a call to action for evacuation or remediation. Only a qualified physician should make any decision relative to medical significance.

Building Forensics primary investigation, was to provide consulting and collect the sam ples referenced in this report. The laboratories p rimary involvement in this project is to provide analytical results for the samples submitted. The data presented in this report are based on the samples and accompanying information provided and represents concentrations at a point in time under the conditions sampled.

Building Forensics standard terms and conditions govern all aspects of this report.
Please refer to the chain of custody included with this report.

Methods

1. Surface Samples – Swab, Dust, Tape and Bulk Samples

Swab, Dust and Tape samples are mounted on a glass slide and observed under a bright field microscope for either Qualitative or Quantitative Examination. A bulk sample is also simultaneously observed under a stereomicroscope to look for signs of any visible discoloration or fungal growth, which is then mounted and observed under a bright field microscope for either Qualitative or Quantitative Examination. The samples are analyzed at a Doc. # 800122 Rev: 00 Revised: 7/6/09 Page 2 of 6, QAD minimum of 200X magnification and up to a 1000X magnification. In the qualitative examination, the prepared samples are observed for the presence of any structures or skewing of spore distribution that may indicate growth in the sample being analyzed. In the quantitative examination, the mold spores detected in the sample are counted and reported as spores per cm2, spores per gram (or 1000mg), or spores per swab/wipe, etc depending on the sample type. These methodologies do not differentiate between viable and non-viable fungal spores.

2. Air Samples- Spore Trap Device

Spore traps are a unique sampling device designed for the rapid collection and analysis of a wide range of airborne particulates, including fungal spores. While analyzing the sample, the analyst takes a number of variables into account to select the proper analytical method to accurately determine the densities of the various spores on the trace. The densities of the debris and the spores on the trace will determine the approach to analyzing the sample. In general, the sample is directly mounted under the microscope and the various airborne particles detected are counted at a minimum of 200X magnification and up to 1000X magnification, with the entire trace (100% of the sample) being analyzed at 200X or 600X. This method does not differentiate between viable and non-viable fungal spores. This technique does not allow for the differentiation between Aspergillus and Penicillium spores. Additionally, depending on morphology, other non-distinctive spores are reported in categories such as ascospores or basidiospores. All slides are graded with the following debris scale for data qualification.

a. Total Fungal Spores

According to ACGIH, “.... differences that can detected with manageable sample sizes are likely to be in 10- fold multiplicative steps (e.g., 100 versus 1000...)”. Following this logic, if total fungal spores are ten (10) times greater in the sample from a suspect area than in the negative control sample collected from a non-suspect area, then that sample area may be a fungal amplification site.

b. Mycelial Fragments

Mycelium is a fungal mass that constitutes the vegetative or living body of a fungus. Following the same logic above, if total mycelial fragments are ten (10) times greater in the suspect sample than in the negative control, then the sample area is considered to be a fungal amplification site. The presence of mycelial fragments provides evidence of microbial growth.

c. Mycotoxins

Molds can produce toxic substances called mycotoxins. More tha n 200 mycotoxins have been identified from common molds, and many more remain to be identified. Some of the molds that are known to produce mycotoxins are commonly found in moisture-damaged buildings. Exposure pathways for mycotoxins can include inhalation, ingestion, or skin contact. Although some mycotoxins are well known to affect humans and have been shown to be responsible for human health effects, for many mycotoxins, little information is available, and in some cases research is ongoing. Some molds can produce several toxins, and some molds produce mycotoxins only under certain environmental conditions. The presence of mold in a building does not necessarily mean that mycotoxins are present or that they are present in large quantities.

d. Water Indicator Molds

Certain authorities identify certain molds whose presence indicates excessive moisture. The presence of a few spores of indicator mold should be interpreted with caution. Additionally, it should be recognized that these named molds are not necessarily the only ones of potential significance.

e. Mold Glossary

Specific characteristics of the individual molds listed in the report are presented in Table 1.




  Potential Water Intrusion/Indicator Mold
  Potential Water Intrusion/Indicator Mold Capable of Mycotoxin Production

Extended Outdoor Comparison

Outdoor Location: 1, Ambient

Spore Trap Report

Spore Trap Report

Spore Trap Report

*The spores in this category are generally capable of growing on wet building materials in addition to growing outdoors. Building related growth is dependent upon the fungal type, moisture level, type of material, and other factors. Cladosporium is one of the predominant spore types worldwide and is frequently present in high numbers. Penicillium/Aspergillus species colonize both outdoor and indoor wet surfaces rapidly and are very easily dispersed. Other genera are usually present in lesser numbers.

**These fungi are generally not found growing on wet building materials. For example, the rusts and smuts are obligate plant pathogens. However, in each group there are notable exceptions. For example, agents of wood decay are members of the basidiomycetes and high counts of a single morphological type of basidiospore on an inside sample should be considered significant.

†The spores of Aspergillus and Penicillium (and others such as Acremonium, Paecilomyces) are small and round with very few distinguishing characteristics. They cannot be differentiated by non-viable sampling methods.

††Most of these spore types are not seen with culturable methods (Anderson sampling), although some may appear as non-sporulating fungi. Most of the basidiospores are "mushroom" spores.

‡Rated on a scale from 100 to 300. A rating less than 150 is low and indicates a low probability of spores originating inside. A rating greater than 250 is high and indicates a high probability that the spores originated from inside, presumably from indoor mold growth. A rating between 150 and 250 indicates a moderate likelihood of indoor fungal growth. MoldSCORE is NOT intended for wall cavity samples. It is intended for ambient air samples in residences. Using the analysis on other samples (like wall cavity samples) will lead to misleading results.