The effect of outdoor pollution and ventilation on Indoor Air Quality

The importance of reducing the ingress of outdoor pollution into the indoor environment is becoming increasingly important as concerns rise regarding the acute and chronic health effects of air pollution. In general, people in developed countries spend typically 90% or more of their time indoors, with the most susceptible individuals, such as the elderly and those with pre-existing medical conditions, spending almost all of their time indoors. It is therefore vital that optimum ventilation with good quality air is provided and that the ingress of urban pollution into buildings, where occupant exposure is likely to be the highest, is minimised. This will result in good indoor air quality (IAQ) for occupant respiration, health, comfort, wellbeing and productivity.
However, while the benefits of healthier buildings are recognised, and some studies have been carried out over the years on the concentrations of outdoor pollutants found indoors, there is still a general lack of understanding of how outdoor pollutant sources ingress into buildings, their interaction with ventilation/infiltration processes and indoor generated pollutants, and the resulting effect on IAQ. BRE has carried out a number of studies over the years investigating these issues in some types of buildings. The present paper gives a summary of some of these studies.