Spatial-temporal distribution of polycyclic aromatic hydrocarbons in seawater at West Nanao Bay, Noto Peninsula

Abstract

The mean total 14 PAHs (particulate plus dissolved) concentrations were highest in summer and lowest in winter. Correspondingly, 8.50 ng L⁻¹, 14.44 ng L⁻¹, 10.31 ng L⁻¹, and 7.01 ng L⁻¹, respectively for the 4 sampling surveys. Particulate-dissolved phase distribution had discrepancies among seasons, tightly related with rainfall amounts, days before sampling. Highest particulate PAHs in the west area, decreasing towards the east area was the general trend. Riverine runoffs were a major transportation pathway of particulate-PAHs towards the bay. The risk quoefficient for ∑14 PAHs varied from 0 to 82.49 in 60 surface seawater samples, representing a very low to low risks to marine life.