Indoor Air Quality
9. What kind of research on indoor air quality is needed?
- 9.1 How much information on indoor air quality is available today?
- 9.2 What questions about human exposure need to be answered?
- 9.3 What research is needed regarding health effects of indoor air pollutants?
- 9.4 Are existing measurement standards for indoor air quality adequate?
9.1 How much information on indoor air quality is available today?
It is necessary to investigate how people are exposed to
pollutants in indoor air
The chemicals and particles present in indoor air and their
concentrations vary greatly across different indoor spaces and
in different EU countries. The data for
risk assessment are scarce
and often insufficient to account for all the variability and
complexity in the indoor environment.
Information is available on the levels in indoor air of some
well-known pollutants (such as
nitrogen oxides, VOCs,
etc.) in Europe. These data help identify the
compounds with highest
concentrations and of greatest concern. Effects and risks for
most of these “usual” pollutants are known so it is possible to
create strategies to mitigate their impact. However, new sources
of pollutants have emerged (such as VOCs from air fresheners)
and some of them may react to produce
secondary pollutants whose
effects are unclear.
At present, outdoor air quality is monitored for some
ozone) but the data cannot
be extrapolated to predict the concentrations that reach the
inside of buildings, because several local factors contribute to
the access of pollutants indoors (e.g. tightness of the
building). Instead, the levels of pollutants in indoor air also
have to be measured, though this may be difficult to do in a
systematic way in private spaces. To help
risk assessment it is also
necessary to monitor other factors such as the ventilation rate,
the level of
carbon dioxide, general
cleanliness and signs of dampness.
Guideline values should be provided for key pollutants as well
as guidance on how to deal with them.
9.2 What questions about human exposure need to be answered?
The existing data on indoor air pollutants should be reviewed
and the major air pollutants and their levels in each Member
State of EU should be identified. It is a priority to compile a
European-wide database that identifies data gaps and serves as
background for future research.
Existing experiences and methods of doing
risk assessments should be
collected and organised.
The main research priorities are to:
- Investigate the variation of exposure to indoor air
pollutants; identify which factors that can easily be
measured could serve as indicators of the exposure of an
- Identify the main sources of pollutants in indoor
environment and quantify how much each source contributes to
total concentrations in indoor air.
- Measure the emission levels of chemicals from consumer
products in realistic use situations.
- Obtain information on harmful emissions in
water-damaged buildings, such as toxic
compounds released when
building materials decompose.
Moreover it is recommended to:
- Identify, evaluate, verify and harmonize models that
are currently used to predict the sources and the fate of
indoor air pollutants.
- Evaluate potentially harmful emissions from indoor
9.3 What research is needed regarding health effects of indoor air pollutants?
As far as health effects of indoor air pollutants are
concerned, it is a high priority to increase research on:
- Effects due to exposure to mixtures of indoor air
pollutants and methods for their evaluation.
- Adverse health effects of microbes and biological
those affecting other organs than the
- The contribution of indoor air pollutants to childhood
Moreover, research is needed on:
- Effects and risks of products which emit indoor air
pollutants that can react in indoor air.
- Possible effects and risks of man-made
nanoparticles in indoor
- The contribution of
fine and ultrafine
particles from indoor sources to adverse health effects.
- Persons suffering symptoms in buildings damaged by
9.4 Are existing measurement standards for indoor air quality adequate?
The development of new measurement standards for indoor air
quality are not a high priority, but existing ones should be
validated and harmonized, in particular those concerned with
indoor emissions from building materials and with biological
Some of the measurement methods developed for outdoor air
quality can also be applied to many indoor environments. In
workplaces however, methods are often developed for higher
concentrations of pollutants.