Case Study: Securing Healthy Learning Environments: Mould Remediation Case Study in a School Setting

In this case study, we recount our experience with a pressing indoor air quality concern faced by a school. Following numerous complaints from staff about persistent dampness, mould contamination, and related odours in classrooms, we were called upon to conduct a thorough investigation.

Considering the significant amount of time that teachers and pupils spend in these classrooms, often in older buildings or mobile structures with limited ventilation, the potential health risks posed by mould and damp conditions became a critical issue. It is particularly important to recognize the vulnerability of children in such situations, as many are potentially susceptible due to other existing health conditions. These classrooms, which are meant to foster learning and development, had instead become a source of concern for the school community, underscoring the need for immediate intervention.

Exposure to high levels of mould can lead to a range of health problems, especially if this exposure is sustained over a long duration or recurs over a long period of time. The effects can be more pronounced in individuals who are allergic to mould or who have respiratory conditions like asthma.
Moulds produce allergens, irritants, and in some cases, potentially toxic substances known as mycotoxins. Inhaling or touching mould spores can cause allergic reactions in sensitive individuals, including sneezing, red eyes, runny nose, skin rash, and even asthma attacks. For those with asthma or other respiratory conditions, exposure to mould can significantly exacerbate their symptoms.

Long-term exposure to mould can lead to serious health issues. Prolonged or high levels of exposure can lead to the development of chronic respiratory diseases, can increase susceptibility to respiratory infections, and may even trigger the development of asthma in children.

It is particularly concerning when mould exposure happens in places like schools where children spend a significant part of their day. Children are still in a phase of rapid physical development, including their lungs and immune system, and therefore, they are more vulnerable to the harmful effects of mould. If the mould problem isn't addressed promptly and adequately, it could potentially have long-term effects on the health and well-being of the students.

Therefore, it is crucial to handle mould issues with the seriousness they warrant and ensure that a safe, healthy environment is maintained in educational institutions.

Our Method

In our efforts to comprehensively assess the extent of mould contamination in the school, we adopted a meticulous 'top-to-bottom' methodology. This commenced with an examination of the entire building structure for any possible defects that could be contributing to mould growth and accumulation.
We then conducted a thorough moisture survey, inspecting ceilings, walls, and floors for signs of elevated moisture levels, a prime contributing factor for mould growth. The suspended ceilings were lifted, and we looked beneath the surface to detect any hidden issues, not immediately visible. This included areas typically inaccessible, such as floor voids which we opened for a thorough inspection.

In one area, a toilet, we had to resort to destructive intervention to identify the root cause of the issue. However, the floor here was already severely damaged due to wood rot, necessitating its removal. Despite the temporary disruption, this was an essential step to resolve the ongoing issues.
To evaluate the ambient mould levels in the classrooms, we performed air sampling in line with ISO 16000-20: Indoor Air - Part 20: Detection and enumeration of mould in indoor air. This method is a globally recognized standard and involves taking samples of the air and analysing them to detect and count the mould spores present. The samples are collected onto a growth medium, incubated, and then the mould colonies that grow are counted and identified. This technique allows us to quantify the airborne mould concentration in the classrooms, providing a concrete measure of the extent of mould contamination, and helping guide our subsequent recommendations and remediation efforts.

Analysis of the collected samples was carried out in our inhouse laboratory who specialises in mould spore trap analysis as a unique service in the United Kingdom.
 

Finding and Recommendations

Our rigorous and thorough site evaluation revealed a considerably heightened concentration of airborne fungal spores within the school's classroom block. We found these levels to range from 15,000 to 300,000 counts, significantly elevated when compared to the environmental background level of merely 1,700 counts per cubic meter. This marked disparity signalled the presence of abnormal conditions within the classrooms.

Moreover, our qualitative assessment unveiled the predominant presence of certain fungal genera, such as Penicillium/Aspergillus, Scopulariopsis, and hyphal fragments, all which bear strong associations with water damage. Importantly, potentially harmful fungi including Chaetomium and Stachybotrys (often referred to as Toxic Black Mould) were identified in significant amounts, indicating indoor sources of contamination.

From these findings, we draw a concerning conclusion. The indoor air quality within the school's classroom block is severely compromised by mould growth, closely tied to water damage within the buildings. The identified fungal species carry potential allergenic or pathogenic effects, posing considerable health risks to sensitive individuals, including students and staff.

Considering key exposure factors such as the magnitude, duration, and frequency of exposure, the disturbance likelihood, the size of contamination, and the vulnerability of the occupants, we perceive a high to very high overall risk to health from prolonged exposure to these fungal spores.
 
In light of these findings, we recommend immediate actions to mitigate health risks and remediate the issue:

1. If the classrooms must be used continuously, install portable HEPA air filtration units to reduce airborne fungal spore levels to background levels.

2. Regularly measure air quality to ensure implemented measures adequately control airborne fungal spores.

3. Regularly sterilize the air using ozone to deactivate any potentially pathogenic moulds.

4. Install a full-size inspection hatch in the building floor for easy access to the void.

5. Inspect the void for water ingress, particularly during moderate to heavy rain.

6. Investigate the floorboards for wood rot, which requires extensive penetration of the aluminium moisture barrier beneath the floor.

7. Conduct an investigation into wall cavities for potential fungal contamination, creating low and high-level inspection points on each wall of the building.

Following these steps, a comprehensive restoration and remediation program should be devised and implemented. We stress the importance of identifying and remedying all water ingress points before initiating the drying of the building structure, to ensure a long-term solution to the mould issue.

Follow up

Given the persistent demand for classroom spaces and the need to keep the school operational, an interim solution was chosen by the school administration to manage the air quality issue. The strategy adopted involved continuously maintaining air quality through the use of High-Efficiency Particulate Air (HEPA) filtration units on an ongoing basis. This was complemented by regular ozone sterilisation and purification to actively combat and neutralise the presence of harmful mould spores in the indoor environment. Moreover, regular air quality testing was implemented to ensure that the children, staff, and other school occupants were not exposed to hazardous mould spores.

This arrangement served as an effective temporary measure to safeguard the health and wellbeing of the school community until a more comprehensive solution could be undertaken. It was agreed that during the summer holidays, when the classrooms were not in use, building contractors would carry out a full remediation of the affected buildings, tackling the root cause of the mould and damp issues. This practical approach ensured minimal disruption to the educational schedule, whilst prioritising the health and safety of everyone within the school.
 

Value delivered

Our intervention delivered significant value to the school community, addressing both immediate concerns and long-term structural issues. By understanding the specific circumstances of the school and the extent of mould contamination, we were able to identify the root cause of the problem. This allowed the school to bring in specialist contractors equipped with the right knowledge to fix the issue effectively and avoid any recurrence in the future.
 
During the interim period before the remediation works were carried out, we ensured the safety and health of the students, staff, and other occupants through the implementation of temporary air quality management measures. This included continuous HEPA filtration, regular ozone sterilisation and purification, and systematic air quality testing. Such measures allowed the school to continue its essential operations while mitigating the risk of mould exposure.

Once the remediation works were completed, we carried out a thorough re-assessment of the air quality in the school, verifying that the measures taken were successful in resolving the issue. We confirmed that the air quality had returned to safe levels, and the problem of mould contamination was effectively tackled.

Overall, our involvement not only rectified a significant health concern but also facilitated a safer and healthier learning environment for the students. It demonstrated the necessity of swift and accurate response when facing environmental issues in educational settings, and showed that with the right expertise and actions, even complex problems can be managed with minimal disruption to important activities like education.