Table 4.

Results of total PAHs (μg/g), PAHs > 4 ring (μg/g) and PAHs 3–4 ring (μg/g and %) with their standard errors, for all black crust samples analyzed

Sample	PAHs total (μg/g)	PAHs > 4 ring (μg/g)	PAHs 3–4 ring (μg/g)	PAHs 3–4 ring (%)
GS	3.81 ± 0.05	0.85 ± 0.02	2.74 ± 0.03	71.8 ± 0.1
AF	2.86 ± 0.05	0.71 ± 0.02	1.93 ± 0.03	67.5 ± 0.1
GRP	1.85 ± 0.04	0.40 ± 0.02	1.28 ± 0.02	69.2 ± 0.2
RP	1.22 ± 0.04	0.20 ± 0.02	0.94 ± 0.02	77.3 ± 0.3
GC	0.72 ± 0.02	0.04 ± 0.01	0.49 ± 0.02	68.7 ± 0.4
EP	0.76 ± 0.03	-	0.57 ± 0.01	74.5 ± 0.3
Mean (Range)	1.87 (0.72–3.81)	0.44 (0.04–0.85)	1.32 (0.49–2.74)	71.5 (67.5–77.3)