To extend the study on the association between micro-organic pollutants and lipid classes from PCBs to other micropollutants: organochlorine pesticides and polyaromatic hydrocarbons. The study will allow verification of the importance of physicochemical partitioning, considering a broader range of micro-organic pollutants (with a broader range of physicochemical characteristics). As the polyaromatic hydrocarbons are subjected to degradation and metabolization, these processes will also be considered in the interpretation of the data. To study the relation between the amount of particulate (and if possible dissolved) organic matter and bioconcentration of PCBs, organochlorine pesticides and polyaromatic hydrocarbons in natural conditions.