Effects of a ventilation intervention in classrooms upon cognitive performance and respiratory health of primary school pupils.

In schools children have a high exposure to CO2, odour and other bio-effluents
emanating from classmates, and to particulate matter dispersed from classmates
and their clothes, and resuspended from floors. This exposure may influence the
cognitive function and respiratory health of children. However, the available
evidence is not sufficient to infer a dose response relationship between
ventilation levels and parameters of cognitive functioning and health. This
hampers the introduction of health-based guidelines.

Main objective of this study is to investigate whether a high air exchange rate
improves cognitive and/or respiratory functions in elementary school pupils in
classrooms. Furthermore: to identify environment determinants of effects of
ventilation to performance of pupils, to elucidate an optimal level of outdoor
air supply and to adjust or strengthen evidence based ventilation guidelines
and uses, and school building policies.

The study is an intervention study with a cross-over design, control condition
and baseline measurements, data collection is longitudinal with the
participants acting as their own control.

In the twelve schools where the intervention will take place, a system for
mechanical ventilation will be installed. During the study (in the heating
season of 2010-2011 and 2011-2012), the concentrations of CO2 will be
maintained at preset levels, established with the mechanical ventilation. In
all cases, the set limits of CO2 will not exceed 1400 ppm which is below the
levels that usually occur in Dutch classrooms. In the 6 classrooms that will
act as controls, no mechanical ventilation is installed and therefore no
intervention takes place. At the end of each week, cognitive and respiratory
functioning test will be performed.

As this study is specifically aimed at the primary school population, children
are involved in this study. As a benefit of this study, parents, teachers and
school will gain more insight in the effects of ventilation upon health and
cognitive functioning.
Although this study contains exposure to different levels of ventilation, it is
not considered to be an invasive exposure. Furthermore, the set limits of CO2
will not exceed 1400 ppm which is below the levels that usually occur in Dutch
classrooms.
The health risks of lung function testing and measuring exhaled NO are
negligible, there are no health risk for measuring cognitive functioning.