The Significance of Mould in Buildings

A Comprehensive Perspective

Mould within buildings is a topic of considerable discussion and concern, involving a spectrum of professionals from health experts to architects. As specialists in building performance, our focus extends beyond the medical realm, targeting the interplay between mould presence and human comfort. The essence of our argument is underscored by the understanding that unhealthy buildings can detrimentally affect occupant well-being.

Recent studies, such as the Finnish research discussed in the Skeptics Guide Podcast, or in Unbiased Science Podcasthave explored the relationship between mould exposure in homes and health outcomes like asthma in children. While the findings of such studies often present a complex picture, suggesting that while the direct impact of mould on health issues like asthma might not be conclusive.

The Unbiased Science Podcast - a Recap

The podcast explored the evidence surrounding the health risks associated with mould exposure. It was highlighted that while mould can cause allergic reactions and respiratory problems in sensitive individuals, the scientific community remains divided on the extent of its impact, particularly concerning more severe health outcomes. An important part of the discussion was the prevalence of mould in indoor environments and the challenges it presents for building maintenance and occupant health. Mould growth is often a sign of moisture problems within a building, necessitating proper ventilation and humidity control as preventive measures. The episode also touched on the concept of mould sensitivity or allergy, emphasizing that individuals can have varied reactions to mould spores. For some, mould exposure can exacerbate asthma symptoms or lead to allergic reactions, while others may not be noticeably affected. Dr. Love and Dr. Steier addressed the issue of misinformation surrounding mould, noting that exaggerated claims about "toxic mould" often lead to unnecessary fear and anxiety. They stressed the importance of relying on scientific evidence to understand the real risks and how to manage mould exposure effectively. The podcast offered advice on preventing mould growth through proper building maintenance, including controlling humidity levels, fixing leaks promptly, and ensuring good ventilation. In cases where mould contamination is found, professional remediation was recommended, especially when dealing with large areas of growth. The hosts acknowledged that while there is a consensus on the need to address indoor mould growth for general health and well-being, research is ongoing to better understand the full spectrum of health effects associated with mould exposure.

The "Skeptics' Guide to the Universe" podcast - a Recap

The study was a part of a larger birth cohort study, examining children from infancy to early childhood. It aimed to determine whether the types and amounts of fungi present in home dust samples could be linked to the later development of asthma. Researchers collected house dust samples and analysed them for various types of fungi, using DNA sequencing to identify the specific species present. They monitored the children's health over several years to see if there was any correlation between early exposure to different types of fungi and the onset of asthma. The study found no significant correlation between the presence of moulds in house dust and the development of asthma. This was a surprising result to some, as moulds are often considered a potential trigger for asthma. The findings suggest that the relationship between indoor mould exposure and asthma development may be more complex than previously thought and possibly influenced by a multitude of environmental and genetic factors. The discussion highlighted the importance of considering a wide range of environmental factors when assessing asthma risks. While moulds may not directly correlate with asthma development, they are indicative of dampness and poor air quality, which are known to have various health implications. This underscores the need for holistic approaches to indoor air quality and health, beyond focusing solely on mould presence.

Comment

In our view mould, its origins, and its implications for both building health and occupant wellness is informed by comprehensive understanding and evidence-based practice. (I have yet to read a negative review on living in a Passive House...)

Mould in buildings typically originates from conditions conducive to its growth, which include persistent moisture, inadequate ventilation, and insufficient heating, among other factors. These conditions not only support mould proliferation but are also indicative of broader issues in building design, maintenance, and operation.

Our views align with the scientific consensus that mould presence is a symptom of constructional and environmental inefficiencies within a building. It signals moisture problems, which could stem from various sources such as leaks, condensation, or high humidity levels. This is crucial because these underlying issues, if left unaddressed, can lead to material decay, compromised structural integrity, and a decline in indoor air quality.

While the presence of mould is undesirable and a marker of poor building health, the Finnish study discussed in the Sceptic’s Guide podcast suggests that the correlation between mould exposure and the development of specific health conditions, such as asthma, might not be as straightforward as previously thought.

This highlights the complexity of assessing health risks associated with mould, which can vary significantly based on individual susceptibility, the types of mould present, and the levels of exposure.

However these mould-related issues stem from and coexist with other factors that impact health, such as poor insulation, heating, and ventilation in a building over prolonged periods of time. One could also speculate that inhabitants of these buildings might also grapple with additional challenges, like inadequate nutrition and healthcare access. Mould may therefore be part of a cluster of interrelated factors contributing to health issues.

This does not diminish the importance of addressing mould in buildings?

Not for us. We stand by a holistic approach that encompasses building improvements and occupant well-being. By doing so, we strive towards healthier living environments, while acknowledging that while mould’s role in certain health conditions like asthma may be part of a bigger picture, its eradication from our buildings remains a priority for both structural integrity and at the very least occupant comfort and potentially health.

Mould serves as a clear indicator that a building is not performing as it should, in terms of both protecting its structure and ensuring the well-being of its occupants. Effective mould management, therefore, involves not just treating mould outbreaks but also rectifying the underlying building science issues that allow mould to thrive in the first place. Strategies might include improving building envelope performance to prevent moisture ingress, enhancing ventilation to control indoor humidity levels, and ensuring that heating systems are adequate to maintain comfortable and healthy indoor temperatures.

This aligns with our broader mission to promote sustainable building

Comprehensive solutions in building design, maintenance, and operation to mitigate risks for mould also mitigate the underlying conditions. Poor insulation, poor indoor air quality and high humidity and directly improve energy efficiency and subsequently our operational carbon.

We should continue striving to eliminate mould from our buildings, not merely because of its potential health risks, which may vary, but because its presence signals a failure to provide a safe, healthy, and sustainable indoor environment. This approach aligns with our commitment to enhancing knowledge around building science, improving occupant health, and achieving sustainability goals in the built environment.