Personal exposure to air pollutants
The air quality limit values which the European Commission has been working on for the last couple of years apply to ambient air. In this sense, ‘ambient air’ is defined as outdoor air in the troposphere, excluding workplaces. The purpose of the air quality limit values is to help attain a high level of protection of human health and the environment in the European Community. The averaging time for the air quality measurements varies with the pollutant, depending on the targeted health effect, and is typically 1 hour, 24 hours or the calendar year. Health effects, however, are caused by pollutants in air that people actually breathe. CONCAWE has long argued that knowledge of personal exposures to airborne pollutants is essential to understand the associations of health effects and ambient air quality. Personal exposures are the result of all polluting sources of breathing air, of which ambient air is only one. Internationally, researchers have started to act on this acknowledged shortcoming in the epidemiological database. Several studies have now been published on this subject, with more likely to follow, especially in the USA but also in Europe. Some of these studies are looking at subgroups of the population, such as young children, or elderly people living at retirement homes, both considered to be particularly sensitive to some of the air pollutants.