Polycyclic Aromatic Hydrocarbons in Kenyan Coral Reef Sediments: Distribution, Sources, and Equivalent Ecological Risks
Abstract
This study evaluated the spatial distribution, source apportionment, and equivalent ecological risk of polycyclic aromatic hydrocarbons (PAHs) in 18 surface sediments across four Kenyan coral reef ecosystems (Malindi, Watamu, Kilifi, and Mombasa-Nyali). Total PAH concentrations (∑PAHs) averaged 1.24 ng•g -1 (0.19-7.63 ng•g -1 ), with Kilifi recording the highest levels (mean: 3.45 ng•g -1 ) and Malindi showing baseline levels an order of magnitude lower (mean: 0.32 ng•g -1 ). Diagnostic ratios and principal component analysis (PCA) revealed a clear pollution gradient dominated by pyrolytic sources Phe/(Phe + Ant) > 0.6; Flu/(Flu + Pyr) = 0.52). Heavy PAH ratios indicated mixed gasoline vehicular exhausts and biomass burning BaA/(BaA + Chr): 0.37-0.42 and IP/(IP + BghiP) mean: 0.44), with PCA confirming a strong vehicular signature (F1, 73.61), notably in Kilifi stations and secondary biomass burning inputs (F2, 10.83%). In contrast, baseline sites of Malindi and Watamu Marine Park were influenced by localized petrogenic inputs from leisure boats and Sabaki riverine discharges. Sediment quality guidelines indicated below 0.1, corresponding to a <10% probability of adverse biological effects. Overall, these sedimentary environments present a negligible immediate threat to benthic communities, though potential long-term bioaccumulation highlights the need for monitoring.
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BibTeX
@article{mwadzombo2026polycyclic,
title = {{Polycyclic Aromatic Hydrocarbons in Kenyan Coral Reef Sediments: Distribution, Sources, and Equivalent Ecological Risks}},
author = {Nyinge Mwadzombo and Maurine Kerubo Arori and Marie-Alexandrine Sicre and Bernerd Mulwa Fulanda and Vincent Klein and Nicolas Chevalier},
journal = {Oceans},
year = {2026},
month = oct,
doi = {10.3390/oceans7050088},
url = {https://hal.science/hal-05803584v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Polycyclic Aromatic Hydrocarbons in Kenyan Coral Reef Sediments: Distribution, Sources, and Equivalent Ecological Risks
AU - Nyinge Mwadzombo
AU - Maurine Kerubo Arori
AU - Marie-Alexandrine Sicre
AU - Bernerd Mulwa Fulanda
AU - Vincent Klein
AU - Nicolas Chevalier
PY - 2026
DA - 2026/10/16
JO - Oceans
DO - 10.3390/oceans7050088
UR - https://hal.science/hal-05803584v1
AB - This study evaluated the spatial distribution, source apportionment, and equivalent ecological risk of polycyclic aromatic hydrocarbons (PAHs) in 18 surface sediments across four Kenyan coral reef ecosystems (Malindi, Watamu, Kilifi, and Mombasa-Nyali). Total PAH concentrations (∑PAHs) averaged 1.24 ng•g -1 (0.19-7.63 ng•g -1 ), with Kilifi recording the highest levels (mean: 3.45 ng•g -1 ) and Malindi showing baseline levels an order of magnitude lower (mean: 0.32 ng•g -1 ). Diagnostic ratios and principal component analysis (PCA) revealed a clear pollution gradient dominated by pyrolytic sources Phe/(Phe + Ant) > 0.6; Flu/(Flu + Pyr) = 0.52). Heavy PAH ratios indicated mixed gasoline vehicular exhausts and biomass burning BaA/(BaA + Chr): 0.37-0.42 and IP/(IP + BghiP) mean: 0.44), with PCA confirming a strong vehicular signature (F1, 73.61), notably in Kilifi stations and secondary biomass burning inputs (F2, 10.83%). In contrast, baseline sites of Malindi and Watamu Marine Park were influenced by localized petrogenic inputs from leisure boats and Sabaki riverine discharges. Sediment quality guidelines indicated below 0.1, corresponding to a <10% probability of adverse biological effects. Overall, these sedimentary environments present a negligible immediate threat to benthic communities, though potential long-term bioaccumulation highlights the need for monitoring.
SN - 2673-1924
ER -