The effect of low ventilation rates on the cognitive function of a primary school class

Several studies have suggested that recommended ventilation rates are not being met within schools. However these studies have not included an evaluation of whether or not this failure might have an impact on pupil performance and learning outcome. The work reported here was designed as an initial investigation into this question. Using the Cognitive Drug Research computerised assessment battery to measure cognitive function, this study demonstrates that the attentional processes of school children are significantly slower when the level of CO₂ in classrooms is high. The effects are best characterised by the Power of Attention factor which represents the intensity of concentration at a particular moment, with faster responses reflecting higher levels of focussed attention. Increased levels of CO₂ (from a mean of 690 ppm to a mean of 2909 ppm) led to a decrement in Power of Attention of approximately 5%. Thus, in a classroom where CO₂ levels are high, students are likely to be less attentive and to concentrate less well on what the teacher is saying, which over time may possibly lead to detrimental effects on learning and educational attainment. The size of this decrement is of a similar magnitude to that observed over the course of a morning when students skip breakfast.