Detection of Indicator Contaminant (s) for Evaluating the Micro-Organic Pollution of Lake

Sediments: Application to the Sediment Samples of Akanoi Bay, Lake Biwa

Abstract

The pollution of lake sediments by organic micropollutants has been of growing environmental concern due to their suspected long term effects on both human health and the surrounding ecosystem. In this research, in order to search the indicator organic micro-contaminant (s) which can be usable for representing the micro-organic pollution, an analytical methodology consisting of freeze-drying, soxhlet extraction with di chloromethane, concentration by rotary-evaporator, purification by Sep-pak florigil cartridge, and quantification by GC/MS was formulated and applied to the lake sediments of Akanoi Bay, Lake Biwa. With the detection of two polycyclic aromatic hydrocarbons (PAHs)(i. e., fluoranthene and pyrene) in the sediment samples, it was concluded that these two PAHs can be the candidate of the indicator contaminants. Based on the horizontal distribution of these PAHs and the particle size distribution of the sediment samples, it was furthermore considered that the river inflows into the Bay are the main pollution sources.