A large part of the active population spends significant time in office spaces. In office spaces, specific sources and activities, such as the presence of printers & photocopiers & regular use of cleaning products that may produce volatile organic compounds (VOCs), raise the question of a specific kind of indoor pollution in these buildings. This indoor pollution is calculated into the Indoor Air Quality Observatory (OQAI) as a measurement.
Poor indoor air quality in office spaces is associated with reduced worker performance. Numerous studies have been conducted under controlled conditions. They showed that temperature, air renewal rates, noise and lighting could have an effect on how quickly and/or accurately some tasks were performed. These factors were also associated with the number of incidents of short-term sick leave. A French study examining this relationship in real-world conditions took place as part of the European project OFFICAIR. The aim of this project (Duration: From 2011 To 2014) was to study air quality and comfort in new or recently renovated office buildings in Europe. Coordinated by the Indoor Air Quality Observatory (OQAI) in France, the study showed that while personal characteristics remained the primary factors determining performance at work, indoor concentrations of xylenes and ozone recorded during the summer could have an effect. For this project, occupants of the offices surveyed were asked about their perception of their workspace, with the main causes of discontent among the 1,190 respondents in the 21 French buildings surveyed being: noise made by other occupants (54% of dissatisfied people), dry air (48%) and confined air (46%). Of health symptoms attributed to the building, headaches were most frequent (31% of respondents), followed by dry eyes(27%), watering or itching eyes (21%) and dry or irritated throat (21%). The ability to control the indoor environment(temperature, lighting, etc.) promoted a more favourable perception of it. Similarly, the existence and effectiveness of a complaint management procedure is associated with a more favourable perception of air quality and comfort, and with a reduction in perceived health effects noted inside and attributed to the building.
As buildings are currently among the priorities for energy savings, the Indoor Air Quality Observatory (OQAI) is paying special attention to air quality and comfort in new and refurbished buildings. In short, improvement in the energy performance of buildings, which comes largely from making the building envelope more airtight, should not be to the detriment of indoor air quality. The Indoor Air Quality Observatory(OQAI) research study in dwellings shows concentrations lower than or equivalent to the exception of three chemicals: hexanal, alpha-pinene and limonene. The factors associated with higher indoor concentrations appear to be linked not to the buildings’ energy performance, but to the presence of wood (frames, floors, furnishings and insulation) and cleaning products.
In buildings under construction, the elimination of unwanted air leakages while the mechanical ventilation system is not yet in operation and the windows are kept closed, combined with the reduction in material drying times, may explain high humidity when the building is made weatherproof / airtight and the presence of molds in the acceptance phase. In renovated buildings, the failure to consider ventilation when making the building envelope more airtight limits the egress of moisture generated by the occupants and their activities, and thus encourages the growth of molds.
The increase in radon concentrations in renovated dwellings also demands attention. In France, extensive measurement campaigns in geographical areas with high ground radon emission potential showed that homes in which windows had been replaced for energy-saving purposes contained statistically significantly higher radon concentrations than homes in which windows had not been replaced. Similar observations were made in other countries (Switzerland, Finland, Lithuania and the United States).
Although further research is necessary to improve our understanding of the airborne substances present in buildings and of their health effects, there are already good practices and tools that can be implemented immediately to improve indoor air quality in our living spaces.
Improving indoor air quality firstly involves using low-emission products and materials. In construction and decoration materials (wall, floor and ceiling coverings, paints and varnishes, insulating materials, etc.) marketed in the countries must be labelled with their potential volatile organic compounds (VOCs) emissions. This labelling is based on emissions of 10 different volatile organic compounds (VOCs) and of volatile organic compounds overall (“total VOCs”). Four classes indicate the emissions level, ranging from “A+” (the product emits no or very few VOCs) to “C” (the product emits a large quantity or has not been evaluated).
In the absence of labelling when choosing products, it is important to follow the usage instructions, which often call for increased ventilation of the area when using products. It is also important to avoid storing products that might emit volatile organic compounds (VOCs) in living spaces, ensure proper ventilation of the storage areas if necessary, and lastly, to take care when using harmful, inflammable, corrosive or toxic products (look for hazard symbols on the labels).
Other actions are also necessary to ensure indoor air quality. Regular cleaning of the building’s equipment and combustion appliances for heating and hot water production is necessary to limit the emission of pollutants such as carbon monoxide. Management of water damage, water ingress and rising damp is also essential to limit the presence of moisture and growth of molds.
The second set of actions to improve indoor air quality concerns air circulation and ventilation. As pollutants cannot be avoided completely, the air should be renewed to remove them. Ventilation systems should be properly sized, installed and maintained. Air inlets should never be blocked. The intake valves for mechanical ventilation systems should be away from any external sources of pollution (road traffic or vents from underground parking if on a wall, air cooling tower or chimney if on a roof). Filters should be cleaned and replaced regularly. A gap of 2 cm should be left under doors to allow air to circulate.
Lastly, the use of air purifiers is the final solution to consider. Great care is required when introducing these devices into buildings, whether as part of ventilation systems, integrated into the materials or as standalone appliances. The effectiveness of these systems and their safety (non-emission of by-products) remains to be determined. In a 2017 investigation, the French National Agency for Food, Environmental and Occupational Health & Safety (ANSES) concluded that current scientific knowledge cannot demonstrate the effectiveness and safety of indoor air purifiers that work on the principles of catalysis or photocatalysis, plasma, ozonation or ionization. Traditional mechanical filtration of particulates at the ventilation system’s air intake or using a standalone appliance is effective if the device is correctly and regularly maintained.
The large-scale observation of occupied building stock is a unique tool for developing and adjusting government policies, motivating professionals and raising awareness among the general public. Our knowledge of the pollutants present in indoor air has progressed greatly in recent years, and major advances have been made in reducing exposure to some chemicals. Further research is necessary, all the more so given that building techniques are constantly evolving and new questions are being raised due to new uses and products. More research is also needed in connection with climate change and the reemergence of asbestos issues as buildings are renovated to be more energy efficient. At the same time, private companies are tackling the problem to integrate it into the act of constructing and operating buildings. The increasing development of miniaturized, connected sensors to measure certain pollutants should make it possible to monitor indoor air quality on a massive scale, and thus alert people to take action in the event of pollution. As indoor air quality has become a performance indicator for buildings, it is becoming increasingly central to society’s concerns and expectations around health protection.
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