Indoor air quality
The Institution of Environmental Sciences and the Institute of Air Quality Management held a conference in January 2007 at the Building Research Establishment (BRE), Watford, with the title Personal Choice or National Responsibility for Indoor Air Quality?
Derrick Crump (BRE) opened the proceedings by emphasising the potential health effects of indoor air pollution. Pollutants such as VOCs, allergens, and fibres can be sourced from indoors (e.g. furnishings, cooking, smoking) and outdoors (ambient air); and the concentrations of such pollutants indoors is intimately connected to building heating, cooling and ventilation systems.
Tadj Oreszczyn (Bartlett School of Graduate Studies, UCL) spoke about the use of Building Physics Models to examine the balance of energy use and ventilation in terms of pollutant concentrations indoors – and the vital need for such models to be grounded with field data. He illustrated the importance of occupant behaviour by reference to conservatories – originally a retro-fit energy reduction intervention but now (depending on the way the conservatory is heated, whether it can be isolated and whether it is used in winter) of uncertain benefit.
Ben Croxford (UCL) focused on the risk associated with indoor gas appliances. His project examined 597 households in east London and of these 23% had some kind of problem appliance: 3% had a very high risk of carbon monoxide poisoning (there was also a 5% high risk and 9% medium risk).
In the final presentation of the first session Jo Barnes (Air Quality Unit, Cornwall College) discussed recent measurements of arsenic concentrations in ambient air in Cornwall and their implications for health. In particular, evidence was presented that for residents in historic mining areas in Cornwall indoor arsenic exposure should be monitored. The case was also made for indoor baseline monitoring of other metals/metalloids in all areas where there was an exposure risk.
Dudley Shallcross (Bristol) opened the second session with a talk about the complexities of the relationship between urban outdoor air pollution and its indoor penetration and circulation.
Vian Kukadia (BRE) continued this theme and described how the BRE was attempting to raise awareness of indoor air quality issues and was undertaking extensive monitoring “. . . to provide industry with guidance and solutions”.
Derrick Crump (BRE) opened the proceedings by emphasising the potential health effects of indoor air pollution. Pollutants such as VOCs, allergens, and fibres can be sourced from indoors (e.g. furnishings, cooking, smoking) and outdoors (ambient air); and the concentrations of such pollutants indoors is intimately connected to building heating, cooling and ventilation systems.
Tadj Oreszczyn (Bartlett School of Graduate Studies, UCL) spoke about the use of Building Physics Models to examine the balance of energy use and ventilation in terms of pollutant concentrations indoors – and the vital need for such models to be grounded with field data. He illustrated the importance of occupant behaviour by reference to conservatories – originally a retro-fit energy reduction intervention but now (depending on the way the conservatory is heated, whether it can be isolated and whether it is used in winter) of uncertain benefit.
Ben Croxford (UCL) focused on the risk associated with indoor gas appliances. His project examined 597 households in east London and of these 23% had some kind of problem appliance: 3% had a very high risk of carbon monoxide poisoning (there was also a 5% high risk and 9% medium risk).
In the final presentation of the first session Jo Barnes (Air Quality Unit, Cornwall College) discussed recent measurements of arsenic concentrations in ambient air in Cornwall and their implications for health. In particular, evidence was presented that for residents in historic mining areas in Cornwall indoor arsenic exposure should be monitored. The case was also made for indoor baseline monitoring of other metals/metalloids in all areas where there was an exposure risk.
Dudley Shallcross (Bristol) opened the second session with a talk about the complexities of the relationship between urban outdoor air pollution and its indoor penetration and circulation.
Vian Kukadia (BRE) continued this theme and described how the BRE was attempting to raise awareness of indoor air quality issues and was undertaking extensive monitoring “. . . to provide industry with guidance and solutions”.
Nicola Carslaw (York) described the application of master equations used to model tropospheric chemistry in studying indoor air pollution. Three features of the indoor system stand out. First, although photolysis is minimised indoors, hydroxyl radical concentrations are still significant – 40 times less than outdoor summer concentrations, but similar to outdoor night-time and winter concentrations. Secondly, there are much larger surface areas indoors than outdoors (0.02 cm2/cm3 indoors and 1 x 10-5 cm2/cm3 outdoors). Thirdly, terpenes and liminoids (often from air fresheners and similar) are important indoor sources of hydrocarbons in indoor air chemistry.
The final presentation (Mike Ashmore, York) dealt with the use of (total) personal exposure modelling as a tool for policy assessment. He emphasised that knowledge of the frequency distributions of exposure in a population (Population Exposure Frequency Distribution) based on the way individuals divide time between indoors and outdoors, roadside and elsewhere, work and home etc. and their activity patterns (e.g. groups such as bus drivers, schoolchildren office workers) was essential in evaluating risk and in designing intervention strategies. Exposure to HGVs seemed to be a particular hazard.
In summary, indoor air pollution has great significance for individual health. Its links to building design, occupant behaviour, outdoor pollution and geographical location are complex and under-researched.
Jo BARNES
Cornwall College,
Pool, Redruth, Cornwall
[email protected]
In summary, indoor air pollution has great significance for individual health. Its links to building design, occupant behaviour, outdoor pollution and geographical location are complex and under-researched.
Jo BARNES
Cornwall College,
Pool, Redruth, Cornwall
[email protected]
