Anticipating the future health of the global environment has now become a necessity. Due to its incidence on Human health, air pollution is a major source of concern, and is now a critical societal issue for most countries. The need to evaluate, monitor and understand the parameters controlling the quality of our atmosphere is quickly arising. Today, the management strategies for air quality are almost exclusively based on monitoring pollutants concentration levels in a selection of sites and samples through time. However, there are now ample evidences that this concentration approach does not allow to establish unambiguously the different pollutant sources and their respective contributions to the degradation of air quality. It is also observed that increasing the density of data points by increasing the number of environmental monitoring stations and/or the number of samples does not help much and generates extremely high additional costs. As a direct consequence of this it is often difficult to design and verify the effect of environmental management measures and plans implemented to control air pollution in a given area. The results of recent research show that the limitations of the concentration monitoring approach could be overcome by using an isotope approach. Although the application of a (multi)-isotope tracing approach to air pollution issues is fairly recent, it has already proven to be very effective at precisely discriminating the different vectors of pollution in different atmospheric settings (i.e. urban, agricultural or natural sources), identifying these sources and quantifying their respective contributions to a contaminated atmosphere.
The monitoring of air quality is traditionally conducted through direct measurements of physical parameters and chemical assays. The latter often face analytical challenges due to the typically low concentrations of pollutants in environmentally relevant conditions. Bioindicators are used to assess the cumulative impacts of chemical pollutants over time, and consequently represent an alternative fundamentally different from classic assessments of environmental quality, that offer numerous advantages.