## 3 Results and Discussion  
Volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) in fumes from warm mix asphalts produced using natural zeolite and RAP were characterized and evaluated. Between 57 and 81 compounds were identified in fumes captured from the asphalt mixtures, corresponding to 70.8%, 76.8%, 70.6%, 79.3%, 77.9%, 74.8%, 76.5%, 74.3%, and 73.3% of the compounds detected in P-155, Z0.3-135, Z0.6-135, PR10-155, Z0.6-R10-125, PR20-155, Z0.6-R20-135, PR30-155, and Z0.6-R30-145, respectively. The compound identification compiled in Table 2 was confirmed by comparing the calculated retention indices with those available in the literature [69]. In general, the chemical compounds identified in sample fumes were saturated and unsaturated aliphatic hydrocarbons, cyclic hydrocarbons, aromatic and chlorinated compounds, alcohols, aldehydes, and ketones. Saturated aliphatic hydrocarbons were the principal class of compound emitted in the fumes, representing over 43.7% of the total compounds detected in all samples, which is consistent with the literature concerning VOC formation from bitumen production [23]; they were followed by aromatic compounds (6.1% up to 10.5%) and alkenes (4.5% up to 8.1%), as shown in Figure 2. Heptane, 2-methylheptane, octane, 2,3-dimethylheptane, 4-methyloctane, nonane, 3-ethyl-2-methylheptane, decane, and undecane were the most abundant compounds among all samples, as also reported by [PERSON] et al. [71]. The predominance of saturated aliphatic hydrocarbons could indicate fewer oxidized bitumens, considering the partial thermal cracking and further transformations when bitumen mass was deposited on heating elements [23]. The saturated and unsaturated aliphatic hydrocarbons were C5-C16 and C5-C11 linear and branched alkanes and alkenes, respectively. Aromatic compounds included methyl- and ethyl-substituted C6 compounds, such as toxic benzene [72], toluene [73], and xylene [74] derivates. Cyclic compounds included methyl- and ethyl-substituted C4-C6 compounds and toxic chlorinated compounds, namely tri-chlorine and tetra-chlorine C1-C2 compounds [75] (Table 2). Chemical compounds in these fume profiles are similar to those described by [PERSON] et al. [23], in which VOCs from bitumens were analyzed by dynamic head-space gas chromatography coupled to mass spectrometry (DH-GC-MS). [PERSON] et al. [23] identified forty-four compounds at most, of which alkanes and aromatic compounds were the most abundant. Fifteen of those 44 compounds identified were VOCs and SVOCs identified in fumes in the present study, including C6-C14 saturated aliphatic hydrocarbons, toluene, and benzene derivates. Based on studies of bitumen effluents, it is evident that very sensitive, selective detectors are required for detailed analysis of the VNCs and VSCs in asphalt fumes at low concentration levels by GC. For a large number of VNCs, detectors such as nitrogen-phosphorus detector (NPD) [76], chemiluminescent nitrogen detector (CLND) [77], or surface ionization detector (SID) [78] must be used; while flame photometric detector (FPD) [79; 80], pulsed flame photometric detector [24; 81], sulfur chemiluminescence detector [82], or atomic emission detector [83] must be used for sulfur compounds [61; 62].