Dioxin- and POP-contaminated sites--contemporary and future relevance and challenges: overview on background, aims and scope of the series.

Background, Aim And Scope: Once they have been generated, polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and other persistent organic pollutants (POPs) can persist in soils and sediments and in waste repositories for periods extending from decades to centuries. In 1994, the US EPA concluded that contaminated sites and other reservoirs are likely to become the major source of contemporary pollution problems with these substances. With this in mind, this article is the first in a new series in ESPR under the title 'Case Studies on Dioxin and POP Contaminated Sites--Contemporary and Future Relevance and Challenges', which will address this important issue.

[Distribution pattern of chemicals in surface waters as a reflexion of entry pattern--heavy metals].

The concentrations of the heavy metals lead, cadmium and mercury were measured in surface water samples of an industrialized city and its surroundings. All but one value of Cd (particular) were less than 0.5 microgram l-1, 30% of the lead (particular) values were less than 0.

[Distribution pattern of chemicals in surface waters as a reflexion of entry pattern--volatile halogenated hydrocarbons].

The part gives some data about various light volatile halogenated hydrocarbons in surface waters of the industrialized city and its surroundings--the halogenated forms, chloroform and bromoform and the most used solvents trichloroethylene, tetrachloroethylene, tetrachloromethane and 1,1,2,2-tetrachloroethane. 80% of the concentrations of chloroform, tri- and tetrachloroethylene were in the range of less than 1 microgram l-1, 90% of bromoform, tetrachloromethane and 1,1,2,2-tetrachloroethane were found to amount less than 0.1 microgram l-1.

[Distribution pattern of chemicals in surface waters as a reflexion of entry pattern--description of the problems].

The distribution pattern of persistent substances made transparent chemically-analytically, in surface waters reflects--considering spatial-temporal limitations--an image of the input pattern. This permits in special cases repercussions on attributable (industrial enterprises, trade, plant production, pest control) or partly or completely anonymous (landfills, ancient deposits, contamination centres, traffic, atmospheric depositions) causative agents The classification of these information requires the knowledge of substance and substrate specifics, especially detailed information about production and/or application of the substances and so represents an interdisciplinary task. Assessing single substance analyses permits a comparison with limit values or literature data.

[Distribution pattern of chemical in surface waters as a reflexion of entry pattern--nonvolatile halogenated hydrocarbons].

The concentrations of some nonvolatile halogenated hydrocarbons in surface waters of an industrialized city and its surroundings are given. About 80% of the ballast isomers of hexachlorocyclohexane (alpha, beta and delta BHC) and of DDT and its metabolites are in the range of less than 5 micrograms l-1, whereas ca. 50% of lindane (gamma BHC) were found to be between 5 and 100 micrograms l-1.