Uptake of gaseous toluene in plant leaves: A two compartment model

Sorption experiments of gaseous toluene in plant leaves were carried out, using a dynamic exposure system. Living as well as cut needles of Pseudotsuga menziesii (Mirb.) Franco (douglas fir) were exposed to a humidified air stream containing a constant concentration of 349 μg m−3 toluene and 350 or 0 ppm CO2. The concentration of toluene in the needles was followed as a function of exposure time. The results show that a two compartment model should be applied to describe sorption kinetics of lipophilic air pollutants in plant leaves. The first leaf compartment can be attributed to the non-living plant cuticle, whereas for the second compartment plant components within the leaf interior which are available to metabolism can be proposed.