Case Study: Indoor Air Quality Assessment at a Primary School

Sysco Environmental Ltd conducted an indoor air quality assessment at a primary school in Rugeley. This indoor air quality survey was prompted by complaints from staff and some of the children about unusual odours, stuffiness, and headaches. Concerns raised by these symptoms led the school administrators to seek a professional indoor air quality testing to determine if there was a genuine risk to the health and well-being of the staff and students. The goal of the indoor air quality survey was to identify any biological or chemical contaminants and provide recommendations to improve the overall indoor air quality and well-being of the school’s occupants.
 
The assessment was performed in the corridors and classroom areas of the primary school, which include two classrooms joined by a corridor/cloakroom area and adjacent WC facilities. The building is constructed of plaster to brick walls, linoleum/carpet to concrete flooring, and plasterboard ceilings, with no visible water damage or mould contamination. Natural ventilation through windows and doors is the primary means of air exchange. Given the reports of discomfort and potential health symptoms, it was essential to assess the indoor environment comprehensively.

Our Indoor Air Quality Sampling and Analysis Strategy

 
Our team adhered to strict protocols and guidelines from the WHO and the HSE for sampling and analysis. The following methods were employed to ensure a comprehensive evaluation of indoor air quality:
 
- Airborne Moulds: Samples were collected using Vesta Spore Trap Cassettes, which capture airborne spores over a set period. These samples were then analysed for spore counts and identification. Monitoring for airborne moulds helps identify potential sources of allergens and respiratory irritants that could affect the health of the school occupants.
 
- Volatile Organic Compounds (VOCs): Air samples were drawn through charcoal sorbent tubes, which absorb VOCs from the air. These samples were subsequently analysed to determine the concentration of VOCs present. VOCs can originate from various sources such as cleaning products, building materials, and furnishings, and prolonged exposure can lead to symptoms such as headaches, dizziness, and respiratory issues.
 
- Carbon Monoxide: Continuous monitoring was conducted using calibrated data loggers, which recorded carbon monoxide levels over time. Carbon monoxide is a colourless, odourless gas that can be harmful or even fatal at high concentrations, making its monitoring crucial for ensuring a safe indoor environment.
 
- Airborne Particulates: Particle counts were measured using a Trotec PC200 Particle Counter, which detects and quantifies particulate matter in the air across various size fractions. Airborne particulates, such as dust and pollen, can cause respiratory problems and exacerbate conditions like asthma.
 
- Temperature and Humidity: These parameters were monitored using portable data loggers to record the environmental conditions within the school. Maintaining appropriate temperature and humidity levels is essential for comfort and can also help prevent the growth of mould and the release of VOCs.
 
Each of these methods was carefully selected to address specific risks associated with indoor air quality, providing a thorough assessment of potential health hazards in the school environment.

Indoor Air Quality Guidelines

 
The assessment utilised strict protocols and guidelines from the World Health Organization (WHO) and the Health and Safety Executive (HSE) to ensure comprehensive and accurate results. These guidelines provide benchmark values for various contaminants and environmental conditions to assess and improve indoor air quality.
 
World Health Organization (WHO): The WHO Guidelines for Indoor Air Quality cover a range of pollutants, including biological contaminants and volatile organic compounds (VOCs). These guidelines are essential for assessing indoor air quality in various environments, aiming to protect human health and provide safe indoor conditions.
 
Health and Safety Executive (HSE): The HSE’s Control of Substances Hazardous to Health (COSHH) regulations and EH40/2005 Workplace Exposure Limits provide critical guidance on permissible exposure levels for various contaminants in occupational settings. These regulations ensure that workplaces maintain air quality standards that prevent health risks to employees.
 
Beyond the WHO and HSE, several other organisations around the globe set indoor air quality standards and provide further guidance:
 
American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE): ASHRAE sets standards for ventilation and indoor air quality, including ASHRAE Standard 62.1, which provides guidelines for acceptable indoor air quality in commercial buildings, and ASHRAE Standard 55, which focuses on thermal environmental conditions for human occupancy.
 
International Organization for Standardization (ISO): ISO develops and publishes international standards, including those related to indoor air quality. ISO 16000 series, for example, provides comprehensive guidelines for air quality measurement and assessment.
 
United States Environmental Protection Agency (EPA): The EPA provides guidelines and resources on indoor air quality, including the IAQ Tools for Schools, which helps schools maintain a healthy indoor environment.
 
UK Department for Environment, Food & Rural Affairs (DEFRA): DEFRA offers guidelines and resources for monitoring and improving indoor air quality, particularly focusing on reducing exposure to air pollutants.
 
Chartered Institute of Building Services Engineers (CIBSE): CIBSE provides guidelines for maintaining good indoor air quality and thermal comfort in buildings. The CIBSE Guide A outlines environmental design criteria, including temperature and humidity levels for different types of spaces.
 

 Major Guidance Documents on Indoor Air Quality

 
1. WHO Guidelines for Indoor Air Quality:
   - WHO Guidelines for Indoor Air Quality: Dampness and Mould
   - WHO Guidelines for Indoor Air Quality: Selected Pollutants
 
2. HSE Guidance Documents:
   - EH40/2005 Workplace Exposure Limits
   - COSHH Essentials
 
3. ASHRAE Standards:
   - ASHRAE Standard 62.1: Ventilation for Acceptable Indoor Air Quality
   - ASHRAE Standard 55: Thermal Environmental Conditions for Human Occupancy
 
4. ISO Standards:
   - ISO 16000-1: Indoor Air – Part 1: General Aspects of Sampling Strategy
   - ISO 16000-2: Indoor Air – Part 2: Sampling Strategy for Formaldehyde
   - ISO 16000-3: Indoor Air – Part 3: Determination of Formaldehyde and Other Carbonyl Compounds
 
5. EPA Guidelines:
   - IAQ Tools for Schools Action Kit
   - The Inside Story: A Guide to Indoor Air Quality
 
6. CIBSE Guides:
   - CIBSE Guide A: Environmental Design
   - CIBSE TM40: Health and Wellbeing in Building Services
 
These guidelines and standards form the backbone of our indoor air quality assessment, ensuring that our evaluations are thorough, accurate, and aligned with international best practices.

Our Indoor Air Quality Assessment Findings

 
Airborne Moulds:

The concentration of airborne moulds inside the school was found to be lower than the levels detected in the outdoor environment. This indicates that the indoor air quality, in terms of mould presence, is better than the external conditions. The predominant types of spores identified indoors were ascospores and basidiospores, which are commonly found in the environment and typically pose less of a health risk. Additionally, there was a minimal presence of Penicillium and Aspergillus spores, which are often associated with water-damaged buildings and can be more problematic for individuals with respiratory conditions.
 
Volatile Organic Compounds (VOCs):

The indoor air quality testing detected low levels of several VOCs, including Trichloromonofluoromethane, Toluene, and α-Pinene. Trichloromonofluoromethane is commonly used as a refrigerant and propellant, Toluene is a solvent found in many household products, and α-Pinene is a natural compound found in pine wood and some cleaning products. The concentrations of these VOCs were low enough to pose minimal health risks to the occupants.
 
Carbon Monoxide:

Continuous monitoring for carbon monoxide revealed that the levels remained at 0ppm throughout the assessment period. This result indicates that there was no significant presence of carbon monoxide within the school, eliminating the risk of exposure to this potentially deadly gas.
 
Airborne Particulates:

The counts of airborne particulates inside the school were consistently lower than those measured outdoors, across all particle size fractions. This suggests that the indoor environment is relatively free from particulate pollution, which can be a concern for respiratory health. Consequently, the risk posed by airborne particulates within the school is low.
 
Temperature and Humidity:

The monitoring of temperature and humidity levels indicated that the temperatures within the school often exceeded the recommended maximum levels for significant periods. Additionally, the relative humidity was found to be below the recommended minimum levels for a considerable portion of the time. These conditions can lead to discomfort among the occupants and may contribute to the reported symptoms of stuffiness and headaches. Maintaining appropriate temperature and humidity levels is crucial for ensuring a comfortable and healthy indoor environment.

Recommendations and Conclusion from the IAQ Survey

 
To enhance the indoor air quality at the Primary School, Sysco Environmental Ltd recommends ensuring an adequate supply of fresh air to maintain comfortable temperatures and appropriate humidity levels. Introducing humidifiers or house plants can help achieve optimal humidity, addressing the discomfort caused by low humidity levels. These measures will not only improve the overall well-being of the students and staff but also create a healthier and more conducive learning environment.
 
The assessment concluded that the overall risk to health from the identified contaminants is low. By providing these tailored recommendations, Sysco Environmental Ltd has delivered valuable insights and actionable steps to improve indoor air quality. We remain available for further consultations and follow-up assessments to ensure ongoing compliance with health and safety standards, safeguarding the school environment for all occupants.