In temperate climates, we spend on average 85% of our time in indoor environments – houses, workplaces, public buildings and transportation vehicles – with the majority of this time spent in the home. In all these places we may be exposed to numerous pollutants, including:
- chemical pollutants: volatile organic compounds (VOCs), nitrogen oxide (NOx), carbon monoxide (CO), polycyclic aromatic hydrocarbons (PAHs), phthalates, etc. ;
- organic contaminants: mould, household allergens from dust mites, pets and cockroaches, pollens, etc. ;
- physical pollutants: particles and fibres (asbestos, artificial mineral fibres), etc.
These pollutant emissions can have various sources: building components, furniture, combustion appliances (boilers, stoves, water heaters, etc.) and the transfer of outdoor air pollution, in addition to certain lifestyle factors (smoking or having pets, for example).
The quality of the air we breathe can affect our well-being and our health, from simple discomfort (nasal congestion, drowsiness, irritation of the eyes and skin) to the onset or aggravation of serious conditions: respiratory allergies, asthma, cancer, disabling or fatal poisoning, etc.
In recent years, this subject has received increasing attention, including the French government’s creation of the French Indoor Air Quality Observatory (OQAI) in 2001.
As of 2004, the Agency has been involved in the topic of indoor air quality, primarily through its work providing expert assessment. Since then, we have worked in close collaboration with the OQAI and the Agency participates in the OQAI’s Supervisory Board and Scientific Council.
Collaboration to expand scientific knowledge of indoor air quality
The OQAI conducts national measurement campaigns that focus on a number of specific types of environments:
- French housing: an initial report on indoor air quality was provided in 2006 with the publication of the results of the national campaign conducted between 2003 and 2005 to measure over 30 different pollution factors inside housing ;
- kindergartens and primary schools ;
- office buildings.
These campaigns provide the Agency with essential information for its health risk assessment work.
Indoor air quality guideline values (IAGVs)
To deal with the health issue surrounding indoor air quality and provide the public authorities with useful information to manage this risk, ANSES has been conducting expert assessments for ten years on the development of indoor air quality guidelines (IAQGs), based exclusively on health criteria. The IAQGs proposed by ANSES aim to protect the general public from any harmful effects of airborne exposure to substances. These guidelines are used by the authorities to set regulatory levels for the monitoring of indoor air quality.
Up to now, 11 indoor air pollutants of interest have been assessed by ANSES's experts: formaldehyde, carbon monoxide, benzene, naphthalene, trichloroethylene, tetrachloroethylene, particulate matter, cyanhydric acid, nitrogen dioxide, acroleine and acetaldehyde.
The reduction of pollutant emissions at their source
Building materials, interior decoration products and furniture are regularly mentioned as potential sources of pollution of indoor environments, due to their emissions of volatile or semi-volatile substances. Initial work has been conducted by ANSES on building materials and interior decoration products.
A procedure for promoting "low VOC" materials, based on standardised tests of volatile organic compound emissions, has been proposed. This work has led to mandatory labelling since 2013 of products sold in France. In keeping with this work, and for the development of regulations applicable to furniture, ANSES has identified and selected a number of top priority chemicals emitted by furniture products.
The cost of indoor air pollution
The Agency, in collaboration with a professor of the Université Sorbonne Panthéon I and the OQAI, has also conducted a scoping study of the socio-economic cost of indoor air pollution. While several studies of this type on air pollution already exist (less than twelve worldwide), this is the first one on indoor air pollutants in France. This study estimated that the cost of indoor air pollution totalled approximately 19 billion euros per year and it illustrated the consequences of this pollution for the community, corresponding to the costs of the health impact generated by the six selected pollutants (estimated costs of: premature deaths, healthcare, production losses, etc.).
Risks for workers in underground railway transportation areas
Underground railway transportation areas are a unique type of environment whose air pollution has been the subject of a number of measurement campaigns which revealed high levels of suspended particles (often much higher than those measured in ambient air).
These particles can penetrate the respiratory apparatus, and the smallest ones can settle in the pulmonary alveoli. For workers, inflammation of the respiratory tract and the subsequent effects of this inflammation are probably due to chronic exposure to particles from underground railway areas.
Furthermore, exposure levels appear to be higher for infrastructure maintenance workers due to the emissions generated by maintenance work itself and to the use of Diesel engines.
Mould exposure in buildings
When ANSES was asked by the ministries of health and the environment to conduct an expert assessment on the issue of mould growth and the correlated production of mycotoxins in buildings, the Agency produced a report on current knowledge of the health effects of mould and methods for measuring it in indoor air, floor dust and materials.
The expert assessment conducted by the Agency confirms the existence of established respiratory health effects linked to mould exposure. These effects include the development or exacerbation of asthma in children and in adults exposed in the workplace, in addition to allergic rhinitis.
The assessment also showed that certain population groups are more susceptible to developing pathologies when exposed to mould. These include infants (starting at birth), asthmatic children and adults, individuals with a predisposition for developing allergies (atopical subjects) or who suffer from hypersensitivity, and patients who are immunodepressed or have chronic respiratory conditions. Groups who may experience overexposure to mould due to socio-economic disadvantages, such as fuel poverty or overcrowded housing conditions, are also affected.
According to the assessment, exposure to mould in indoor environments affects a high percentage of housing units, with visible mould present in 14 to 20% of French dwellings. In addition, geographical differences in fungal species also exist, mainly due to variable weather and climate conditions that can have an influence locally.
In its conclusions, the Agency recommends preventing mould in buildings first by reinforcing coordination between the sectors involved (construction, energy, etc.) and between the authorities and public entities, and second, through improved communication with housing occupants.
The Agency also recommends preventing health problems, especially for the most vulnerable population groups, through changes in the regulations in order to better integrate the risks of mould exposure in housing.