Abstract:
Polycyclic aromatic hydrocarbons (PAHs) are a group
of emerging chemical pollutants that pose severe health
challenges and toxicity to people and aquatic organisms
exposed to these pollutants. This study sought to assess the
types and levels of PAHs and their eco-toxicity indices in
surface waters of Narok and Bomet counties of Kenya, which
have witnessed an increase in charcoal-burning activities and
vehicular emissions near water bodies. Sampling was done in
eight regions of the two counties based on their proximity
to PAH sources. Extraction of the water samples was
done via a solid-phase mmethod. Seven US Environmental
Protection Agency (US EPA) priority PAHs were detected. The
concentrations of these PAHs varied from below the limits of
detection up to 31.42 µg l−1 for dibenzo[a,h]anthracene. The
majority of the PAHs from Narok County were pyrogenic,
while those from Bomet were petrogenic based on PAH
diagnostic ratios. The surface waters were significantly
polluted with dibenzo[a,h]anthracene, with risk quotients
above 1.0 in the surface waters, and were found to be
hazardous, with hazard quotients above 10.0, thus indicating
potential environmental risks. The findings indicate the need
for stringent measures to be put in place to mitigate the risks
posed by these PAHs.
