Distributions and sources of persistent organic pollutants (aliphatic hydrocarbons, PAHs, PCBs and pesticides) in surface sediments of an industrialized urban river (Huveaune), France

Abstract

Surface sediments from the Huveaune River were analyzed for n-alkanes, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine and organophosphorous pesticides (OCs and OPs) by using gas chromatography–mass spectrometry (GC–MS). Concentrations of total alkanes ranged from 184 to 26,780μg·kg−1 sediment dry weight (dw) with a mean concentration of 6126±8006μg·kg−1dw, concentrations of total PAHs ranged from 572 to 4235μg·kg−1dw with a mean concentration of 1966±1104μg·kg−1 dw, concentrations of total PCB ranged from 2.8 to 435μg·kg−1dw with a mean concentration of 148±164μg·kg−1dw and concentrations of total pesticides ranged from 0.07 to 1.25μg·kg−1dw with a mean concentration of 1.23±1.29μg·kg−1dw. The spatial distribution of POPs reveals that pollutant concentration is relatively higher at the mouth of the river. The molecular indices of specific n-alkanes (CPI, NAR and TAR) and molecular indices of PAHs (Ant/(Ant+Phe), Fl/(Fl+Pyr), BaA/(BaA+Chry), IPyr/(Ipyr+BghiP)) were calculated to evaluate the possible sources of hydrocarbons. These molecular indices suggest mainly pyrolytic inputs which are markedly biogenic. All contaminant levels were also compared with Sediments Quality Guidelines (SQG) showing that the contamination levels in all stations were most of the time lower than their respective SQG. While, for PCBs, five stations (H5, H6, H7, H8 and H9) were higher than their effect range median (ERM) values which may indicate high potential toxicity of the sediment with probable adverse effects to the living biota.