## 3 Results and Discussion
Currently, SPME-based methods are used for sampling and quantitative analysis of PAHs in water [93], soil [94, 95, 96, 97], and air [98]. The SPME-based method involves different PAH capturing methods followed by thermal extraction of analytes using a thermogravimetric analyzer to Tedlar bags and determination of concentration by SPME in a conventional exposed fiber coating mode [99], which is comparable to the methodology used in the present study (Figure 1). Exposed SPME fibers have been used for determining PAHs directly in tailpipes [98, 100]. The absence of PAHs in the sample could indicate that the preparation method avoids production of these compounds. Figure 2: Abundance of chemical compounds present in fumes from warm mix asphalt. Values indicate mean + standard error (SE). %: Calculated considering compounds detected. VOCs and SVOCs listed in Table 2 were classified on the basis of their chemical structure into seven groups of chemical compounds. The major groups of VOCs and SVOCs emitted by the prepared asphalt mixtures are compared in Figure 3.  
In general, asphalt mixtures prepared at lower temperatures emitted fewer saturated and unsaturated aliphatic hydrocarbons and aromatic compounds than asphalt mixtures produced at higher temperatures. The addition of zeolite allows lower manufacturing temperatures to be used [18; 19; 101], and asphalt mixtures containing 0.6% natural zeolite produced fewer saturated and unsaturated aliphatic hydrocarbons and aromatic compounds than mixtures containing 0-0.3% zeolite--although Z0.6-R10-125 emitted significantly more unsaturated aliphatic hydrocarbons than the standard mixture (zeolite-free PR10-155). Additionally, among the asphalt mixtures prepared with RAP, all mixtures containing 0.6% natural zeolite produced fewer saturated and unsaturated aliphatic hydrocarbons and aromatic compounds than hot mixtures, excepting the unsaturated aliphatic hydrocarbons emitted by Z0.6-R10-125. Compared to standard mixtures (P-155, PR10-155, PR20-155, and PR30-155), saturated aliphatic hydrocarbons and aromatic compounds emissions increased slightly when RAP was added at concentrations of 10% and 30% but significantly decreased when 20% RAP was added. However, the incorporation of 0.6% natural zeolite into the mixture with 10-30% RAP produced a substantial decrease in emissions. These results are consistent with the incorporation of synthetic zeolites into asphalt mixtures to decrease the production temperatures and thus produce fewer fumes; this agrees with Report FHWA/OH-2009/08 of the Ohio Research Institute for Transportation and the Environment [102], in which the production of VOCs from three WMAs were measured. The WMAs were prepared with the following different materials: Aspha-min (contains zeolite with 20-21%  
Figure 3: Comparison of groups of VOCs and SVOCs emitted by warm mix asphalt. (**A**) Saturated aliphatic compounds; (**B**) Aromatic compounds; (**C**) Unsaturated aliphatic compounds; (**D**) Chlorinated compounds. Values indicate mean + SE. Different letters indicate significant differences based on the Tukey HSD test (\(p\leq 0.05\)). of water), Sasobit (a sasol wax, commercially known as FT hard wax), and Evotherm (a chemical material not described by the authors). Aspha-min WMA, containing zeolite at 0.3% by mass of the mix, and Sasobit WMA both show substantial reductions in VOCs of 62.8% and 51.3%, respectively, compared to conventional HMA. On the other hand, Evotherm WMA shows a substantial increase in VOCs, over two and a half times compared to conventional HMA [102]. Similarly, [PERSON] and [PERSON] [16] demonstrated that the VOCs identified in atmospheric samples taken from HMA and WMA decreased with the use of synthetic zeolites as additives, compared to VOC emissions from mixes without additives at 180, 140, and 120 \({}^{\circ}\)C. The reduction in VOC emissions increased continuously as the zeolite dosage was increased from 2% to 6%.