Understanding Mould: Impact of Moisture, Identification, and Assessment
Understanding the Impact of Mould on Health
Mould is a common problem that can have detrimental effects on both the health of individuals and the structural integrity of buildings. It is classified as a type of fungi and is an organism that can occur naturally in any part of the environment, including both indoors and outdoors. Capable of growing on most substances as long as moisture is present, mould spores can become airborne and cause irritation to the nose, eyes and skin, respiratory infections, and a range of other issues, especially when inhaled. It is also more harmful to those with an allergy to mould or existing health condition such as asthma or lung disease. As a result, it is important to control moisture and limit the growth of mould, particularly in indoor environments where there is less air circulation and therefore a greater health concern.
This article will explore the impact of moisture on mould growth, methods of identifying mould, and the importance of proper mould assessment.
The Impact of Moisture and Temperature on Mould Growth
The two key factors that influence the growth of mould are moisture and temperature. To eliminate mould, moisture is the most important factor as mould can only grow in areas where there is sufficient moisture on a surface or humidity in the air. Leaks in roofs and walls, areas that are commonly wet, and condensation can all lead to the development of mould. Conversely, reducing moisture is a key step to limiting the growth of mould. Given that there is no method to completely eliminate the presence of mould indoors, it is vital that moisture is controlled to reduce opportunities for mould to grow. Ensuring areas prone to moisture are well ventilated and dried quickly can help keep humidity from accumulating, therefore reducing the ability of mould to thrive.
Aside from moisture, temperature also plays a pivotal role in the growth of mould. Mould typically thrives in warm temperatures, and while extreme heat and cold can stagnate the growth of mould, it will not eliminate it completely. Instead, it is more important to have adequate air circulation which can help regulate both air and surface temperatures.
Managing Mould in the Workplace
The management of mould is essential to workplace health and safety as employers are mandated by the Work Health and Safety Act 2011 to take reasonable measures to protect the health and safety of their workers. This in particular is vital in sectors where mould is a common threat, such as in the hospitality sector where there is frequent usage of water and in waste management, where the decomposition of organic waste, combined with ambient temperatures and moisture, creates a conducive environment for mould proliferation.
Identification and Assessment of Mould Growth
Identifying mould early is crucial to prevent its further spread and mitigate potential health and structural risks. Some signs of mould include a musty odour, allergic reactions and discoloured patches on walls, ceilings and other surfaces that may be green, black, white or otherwise and fuzzy or slimy in texture. While mould can sometimes be identified through these more obvious cues, it can also grow unnoticed and become airborne, where it can easily spread and be inhaled posing significant health issues.
Proper mould assessments are necessary when mould growth is unclear and there is a potential health risk. Even when the presence of mould is confirmed, it is important to sample to determine the type of mould so that the health effects and extent of remediation required is made clear. Air sampling and surface sampling should be conducted by an experienced professional donning the appropriate personal protective equipment (PPE). Disturbing a mouldy area can also cause the mould to spread, so it is important that caution is taken during an investigation.
Mould Sampling Equipment and Testing
There are two main methods for sampling mould; air sampling and surface sampling. Air sampling for bioaerosols such as mould spores involves using an air sampling pump with a high flow-rate such as the QuickTake 30 Sampling Pump to draw air through a cassette like the VersaTrap Spore Trap Cassette. Samples are typically taken from an indoor test area and compared to a separate baseline sample taken outdoors. This method can help determine both the mould genera and the concentration of spores.
Surface sampling is a simple method conducted using swabs or tape such as Stick-to-it Lift Tape to test for mould on surfaces. This method can also be helpful for assessing surfaces after remediation efforts to ensure that the mould has been successfully removed.
Mould samples collected through both air sampling and surface sampling are taken to a laboratory for analysis, where they are stained on slides and analysed microscopically to determine the presence of mould and its species. Once this has been established, a remediation plan can then be structured and actioned. The ANSI/IICRC S520 Standard is a helpful resource that provides guidance for professional mould remediation, including both important procedures and precautions to follow.
Personal Protective Equipment for Mould Sampling and Remediation
When sampling for mould or carrying out remediation work, it is important to wear PPE to protect the health of assessors and any other individuals at risk of exposure. In low-risk situations, disposable gloves can be worn to help protect skin contact with hazardous substances as well as any solutions used to clean them, and a properly fitted P2 or higher particulate respirator is necessary. Safety goggles are important for blocking spores and dust particles from reaching the wearer’s eyes in higher risk environments. Additionally, protective clothing including shoe covers and long rubber gloves are also vital to properly protect the wearer. When working with mould in high-risk situations, fit tested respiratory protective equipment (RPE) is especially important for preventing the inhalation of airborne mould spores.
RPE is required under section 44 of the WHS Regulations to be suitable in regards to the nature of the work and hazard it is used for, as well as a suitable size and fit. Fit testing is required for all tight fitting RPE to ensure a proper fit is achieved and that the respirator is providing a sufficient level of protection against hazardous substances and particulate matter. This can be conducted using a respirator fit tester such as the QuantiFit2, which requires a specific protocol to be followed to ensure that workers are properly protected. The AS/NZS 1715 Standard sets out the requirements for the use and maintenance of RPE, including mask fit testing.
Given the complicated and hazardous nature of mould, thorough identification and assessment is vital to ensure the safe health of workers, occupants and any others potentially exposed to a mould infestation. Promptly taking remedial action is key to preventing mould from spreading further and ensuring long term safety, especially in moisture and mould prone areas. For more information on the essential equipment needed for the identification and assessment of mould, contact your local Air-Met Scientific and a friendly representative will help you understand the solutions that best fit your needs.
