Molecular markers in Tokyo Bay sediments: Sources and distribution

The spatial distribution of different classes of molecular markers in Tokyo Bay sediments, a semi-enclosed system surrounded by one of the most urbanized areas in the world, has been investigated. In order to study the environmental stability of different chemical classes of sewage markers, their isomeric composition was determined in river particulate matter, waste-water influent and surficial sediments. Among the molecular markers characterized, linear alkylbenzenes (LAB) and trialkylamines (TAM) were the most useful for tracing the transport of contaminants from point-sources of pollution, because of their stability in sediments, and for assessing biodegradation processes during transport. Detection of LAB as well as TAM in the sediments outside of Tokyo Bay, more than 20 km from riverine inflow and 300 m water depth, clearly indicates long-range lateral transport of land-based pollutants