Biological air quality monitoring: A review

Air quality monitoring is currently ensured by captors measuring few physicochemical parameters, then they cannot evaluate unforeseen compounds and the interaction effects of pollutants. On the contrary, the use of bioindicators can answer these problems. Among them, plants are used in two ways: 1) Passive bioindicators: trees, lichens and mosses are used to determine the distribution and even the contaminants long-term effects on vast zones and, possibly, the concentrations of pollutants to which they were exposed. 2) Active bioindicators: tobacco and mosses make available the defective zones in plants and enable determination of deposition fluxes. Moreover, techniques based on biomarkers identification should increase the answer's sensitivity. However, the plants present the disadvantage of being unable to provide a response in a time lapse comparable with that of the on-line analysers. Lastly, the development of tools using animal cells should allow, in the near future, to measure the total polluting load under conditions close to those of the routine techniques. Then, the real impact of the contaminant on public health could be approached.