Polycyclic Aromatic Hydrocarbons in Soil and Vegetation of Niger Delta, Nigeria: Ecological Risk Assessment

Table 4

Molecular ratio of select PAHs for identification of possible sources in soils and plants.

PAH ratios

Values

Possible sources

Uyo

Choba

Khana

Yenagoa

Eleme

Trans-Amadi

SS

PS

SS

PS

SS

PS

SS

PS

SS

PS

SS

PS

Fle/(Fle + Pyr)

<0.5

Petrol emissions

0.49 (0.87–1.78)

0.32 (1.29–3.97)

0.60 (0.59–0.97)

0.46 (0.89–1.91)

0.5 (0.001–0.002)

0.15 (0.38–2.55)

0.58 (0.12–0.21)

0.44 (1.56–3.55)

0.32 (0.17–0.54)

0.60 (2.09–3.44)

0.19 (0.23–1.22)

0.34 (0.93–2.70)

>0.5

Diesel emissions

Ant/(Ant + Phe)

<0.1

Petrogenic

0.88 (0.61–0.70)

0.48 (1.69–3.49)

0.46 (0.56–1.20)

0.64 (2.09–3.23)

0.5 (0.001–0.002)

0.02 (0.09–3.37)

0.01 (0.002–0.23)

0.52 (1.39–2.64)

0.49 (0.52–1.05)

0.44 (0.87–1.96)

0.31 (0.23–0.75)

0.33 (0.68–2.01)

>0.1

Petroleum, biomass comb

Flt/(Flt + Pyr)

<0.4

Petrogenic

0.45 (0.77–1.67)

0.21 (0.74–3.42)

0.63 (0.67–1.05)

0.60 (1.54–2.57)

0.10 (2.82-2.82)

0.37 (1.31–3.48)

0.74 (0.28–0.38)

0.41 (1.40–3.39)

0.69 (0.36–0.52)

0.55 (1.66–3.01)

0.43 (0.77–1.76)

0.53 (2.01–3.79)

0.4–0.5

Fossil fuel combustion

>0.5

Biomass, coal comb

BaA/(BaA + Cry)

<0.2

Petrogenic

0.27 (0.32–1.17)

0.51 (1.63–3.16)

0.36 (0.08–0.23)

0.54 (1.70–3.09)

0.5 (0.001–0.002)

0.83 (5.73–6.89)

0.68 (0.36–0.53)

0.43 (1.52–3.49)

0.20 (0.25–1.17

0.40 (1.07–2.64)

0.89 (0.27–0.30)

0.34 (0.83–2.38)

0.2–0.35

Petroleum comb

>0.35

Biomass, coal comb

BbF/BkF

0.92

Wood comb

0.30 (0.12–0.4)

0.47 (1.32–2.81)

0.5 (0.2–0.42)

0.13 (0.32–2.34)

0.00 (0.001–3.35)

0.8 (0.71–0.89)

0.73 (0.71–0.97)

0.73 (1.68–2.31)

0.33 (0.13–0.39)

0.76 (1.74–2.28)

0.12 (0.11–0.92)

1.16 (1.27 − 1.09)

1.07

Diesel engine

1.3

Vehicular emission

3.7

Coal combustion

BaP/BghiP

0.3–0.78

Vehicular emission

0.01 (0.01–0.66)

0.85 (1.88 − 1.61)

0.44 (0.32–0.72)

0.78 (1.02–1.29)

0.01 (0.001–0.14)

0.00 (0.003–11.13)

0.84 (0.72–0.85)

0.96 (1.28–1.33)

0.12 (0.10–0.83)

0.76 (1.49–1.94)

0.62 (0.46–0.74)

0.92 (1.34–1.45)

0.9–6.6

Coal comb

BaP/(BaP + Cry)

<0.49

Gasoline

0.009 (0.01–0.86)

0.55 (1.89–3.42)

0.69 (0.32–0.47)

0.42 (1.02–2.41)

0.99 (0.14–0.15)

0.92 (11.34–12.30)

0.83 (0.85–1.02)

0.40 (1.33–3.31)

0.47 (0.82–1.75)

0.48 (1.49–3.06)

0.93 (0.46–0.49)

0.46 (1.34–2.89)

>0.50 –0.73

Diesel engine

Ind/(Ind + BghiP)

<0.2

Petrogenic

0.50 (0.68–1.35)

0.45 (1.30–2.91)

0.29 (0.30–1.02)

0.27 (0.49–1.78)

0.5 (0.001–0.002)

0.5 (0.003–0.006)

0.08 (0.07–0.79)

0.47 (1.14–2.41)

0.89 (0.82–0.92)

0.46 (1.65–3.59)

0.12 (0.11–0.85)

0.45 (1.19–2.64)

0.2–0.5

Petroleum comb

>0.5

Biomass, coal comb

SS = soil sample; PS = plant sample.