Mould risk minimisation: Inspection and assessment
Mould inspection guidelines are shared, and the mould assessment and grading process is explained by DR HEIKE NEUMEISTER-KEMP, DR PETER KEMP, CEDRIC CHEONG and KEVIN WHITE from Mycologia.
Over the last couple of years, there has been renewed interest in the topic of mould and indoor air quality (IAQ) due partly to heightened public and media interest in the health effects associated with mould exposure, the impacts of bad IAQ on occupants and the legal liabilities associated with these hazards. It is, therefore, crucial that risk minimisation techniques and procedures are engaged to manage these risks.
Mould can damage building materials, make a building unhygienic with foul odours and cause adverse health effects in susceptible individuals, such as those with impaired or immature immunological or respiratory systems, the very young or elderly and individuals with a predisposed genetic predisposition.
The hazards associated with exposure to mould are often dismissed because of a lack of understanding. This lack of education and awareness has seen many individuals exposed needlessly to potential allergens, pathogens, toxins and mycotoxins, which can result in adverse health effects and costly litigation.
IAQ problems arise in non-problem buildings (no leaks, no structural damage) when there is an inadequate quantity of ventilation air being provided for the amount of air contaminants present in that space. In problem buildings, structural damage, lack of maintenance, occupant behaviour and activities, degrading infrastructure and external water ingress all contribute to increasing risks from microbial off gassing and other IAQ hazards. Health problems occur in occupants when one or several species become established indoors, which presents our bodies with an ‘abnormal’ exposure.
KEY UNDERSTANDINGS REQUIRED
Part of the reason why there is a lack of understanding about the potential harmful effects of mould exposure is that facilities managers, cleaning and maintenance staff, and consultants don’t have sufficient awareness or guidance about the risks of mould exposure. This can be attributed to the lack of any formal Australian industry body to offer accredited training programs on mould.
Currently, there are a range of training providers offering training on mould remediation techniques; however, most are currently based on US systems and aren’t well-suited to Australia because of differences in legislation, building codes and metrics. The key understandings managers, service staff and consultants should possess, as a minimum, when dealing with the management of mould are the following:
- Managers need an understanding of potential exposure pathways and health issues. With this knowledge they can then ask the right questions and communicate to stakeholders about potential hazards and mitigation. They need to know the limitations of their own staff and when to call in consultants and the benefits to them of clearance testing.
- Cleaners and maintenance staff who are likely to come into contact with mould during the course of their work need to know what to look for, how to minimise their exposure and appropriate personal protective equipment (PPE). They need to know how to correctly remove the mould so that it doesn’t spread and contaminate other areas, and why bleaches don’t work on mould.
- Consultants and IAQ specialists need to see the big picture and put together the jigsaw puzzle of potential cause and effect. They need to know what to look for, where to look and how to develop an appropriate sampling and analysis plan.
Mould hazard awareness training should be conducted by an accredited trainer who assesses the trainee on their understanding following training. The competencies that should be assessed include:
- mould ecology (what is mould, how does it grow and why)
- health effects (exposure to people, how, why and symptoms)
- PPE (what and how to use)
- microbes (what other microbes are important in water damage)
- morphology of fungi (what does fungi look like, how do we identify them), and
- exposure and mycotoxins (effects and pathways of toxins emitted from mould).
It is essential that cleaning staff and personnel charged with the management of mould receive this level of training. The common thought about mould is it’s everywhere, so why should we worry about a little bit of it on the wall or in a bathroom? The reality is mould is a contaminant and, despite the fact that it is common, it still causes potential health effects, thus exposure to mould should be minimised.
THE MOULD INSPECTION PROCESS
The WHO Guidelines for Indoor Air Quality: Dampness and Mould states that “persistent dampness and microbial growth on interior surfaces and in buildings structures should be avoided or minimised, as they lead to adverse health effects”. The document adds that “thorough inspection and, if necessary, appropriate measurements can be used to confirm indoor moisture and microbial growth”.
From a clinical practice perspective, it is suggested in a report from The American Academy of Pediatrics (AAP) that “extensive documentation of indoor fungal growth may not be necessary, depending on concerns of the occupants. Visible signs of mould growth (for example, discoloured patches, or cottony or speckled growth on walls or furniture, evidence of dampness or water damage, or an earthy, musty odour in a particular area) suggest a damp environment and mould growth”.
According to the AAP, efforts should be focused on clean-up and addressing the moisture problem to prevent recurrence as they believe additional documentation of mould exposure with sampling is not necessary. It is suggested that if environmental sampling is to occur, it is to be conducted by professionals who have expertise in evaluating indoor mould/dampness problems.
An American Industrial Hygiene Association (AIHA) document on indoor mould titled Recognition, Evaluation and Control of Indoor Mould details essential steps and principles for a building walkthrough. The publication goes on to detail areas for interior and exterior evaluation, moisture measurements, and inspection for hidden mould and content/furniture considerations. The suggested steps include:
- examine the physical structure, maintenance activities and occupancy patterns of the building
- look for potential sources of biological agents
- look for evidence of current or past water damage or excess moisture
- note sources of other indoor air contaminants, and
- as needed, formulate plans for an in-depth investigation or for control and remediation of noted problems.
According to an Institute of Inspection Cleaning and Restoration Certification (IICRC) document titled S520: Standard and Reference Guide for Professional Mould Remediation, the inspection and preliminary determination process includes, but is not necessarily limited to, “gathering information, and conducting a physical inspection of the affected premises for moisture problems and potential mould contamination”.
The document lists areas to inspect to include, but not be limited to: water intrusion or condensation, water stains, structural damage, HVAC operations, odours, construction type, previous repairs or remodelling and structure defects. When conducting a visual inspection, the use of a checklist is recommended. Include:
- signs of mould or water damage
- the location of damage
- changes in the colour and integrity of the surface material, and
- the size of the damaged surface.
Australian Mould Guideline (AMG) states that a “methodical approach should be used when undertaking mould related work to ensure personal safety, duty of care and legal requirements are adequately covered”. The guideline suggests a three-step process:
- gather information from the client on the situation being investigated
- undertake a site visit and inspection, and
- establish what procedures are required to deal with any moisture or mould damage problems identified.
The document describes the visual inspection of mould damage as “the most important step in identifying the type of mould problems that will be encountered and helps determine the type of mould remediation strategy required”. It adds that “the most important surfaces to inspect are made from porous materials” and “it is also important to inspect for hidden growth behind furnishings or in building cavities”.
When looking for evidence of damage the guideline suggests looking for evidence of “visible mould growth, surface condensation, flooding events and accidental spills, and impact of high humidity”. It adds that “in situations where it is not possible to perform extensive inspection, there may be a ‘discovery’ of hidden mould damage at a later date; it is important to ensure that all parties should be made aware that, if this occurs, an additional inspection may be required, and discovery of hidden damage should be documented”.
The first suggested measurement to be undertaken is that of moisture measurements. AMG states that “the aim of taking moisture measurements is to establish the extent of moisture damage, to provide an indicator of hidden mould damage and for quality control”. Other measurements that may assist in the assessment and evaluation process are surface, bulk dust, material and airborne samples. IAQ parameters, such as temperature, relative humidity, dew point temperature and total volatile organic compounds (VOCs) concentration, also provide valuable data for evaluation.
The Mould Worker’s Handbook: A Practical Guide to Remediation provides more practical and detailed instructions on inspection and determining the cause of mould damage. The document describes the process of visual inspection, moisture sampling, surface sampling, bulk dust and material sampling, airborne sampling (with attached case studies, photographs and scientific reports showing the entire process from initial client enquiry through to inspection), remediation and post-verification clearance sampling.
MOULD ASSESSMENT AND GRADING
Following the initial inspection, the next step involves the assessment and building contamination grading such that the most appropriate remediation strategy can be selected. In general, most published guidelines suggest similar criteria for the selection of remediation strategies.
The level of containment and PPE is generally based on the area of visible mould contamination. AMG uses the international system of categorisation for the purposes of determining remediation strategies and the use of respiratory personal protective equipment. Seven categories were created based on the extent of visible mould growth. The mould damage classification system includes the various types of mould damage. These are described in a table in the Jun-Jul 13 edition of Facility Management magazine.
ARMED TO MANAGE RISKS
By gaining a better understanding of why and how mould grows, its impact on buildings and upon occupants, and its relationship with IAQ and the building envelope, you can better understand potential health risks, risk minimisation and management methods. Armed with such knowledge, you can more competently manage such risks and make more informed decisions on behalf of property owners.
The second half of this article covers mould remediation and removal of contaminated materials.
Dr Heike Neumeister-Kemp is the chief executive officer and mycologist at Mycologia. Dr Peter Kemp is a director and IAQ and SBS (sick building syndrome) consultant at Mycologia. Cedric Cheong is a director and the operations manager at Mycologia and Mould Worx, and Kevin White is a consultancy and training manager at Mycologia.
Dr Neumeister-Kemp and Dr Kemp are co-authors of Australian Mould Guideline (AMG), which was developed specifically for the Australian market and links key international standards and guidelines, particularly the IICRC S520 Standard. The duo also co-authored The Mould Worker’s Handbook: A Practical Guide to Remediation.