Persistent organic pollutants chlorinated aromatic compounds

Many persistent organic pollutants (POPs) and other environmental contaminants have been associated with immunotoxic effects, but, in most instances, it remains difficult to assign the effects to pure compounds. For example, immunotoxic effects of PCBs in free-ranging harbor seals have been associated with increasing blubber concentrations of PCBsJ34 yet the waters inhabited by these animals are also contaminated with other POPs, including chlorinated pesticides and chlorinated polynuclear aromatic hydrocarbons. Indeed, the PCBs themselves are mixtures of different moieties with varying immunotoxic properties. 

A major proportion of the priority pollutants are covered by the so-called persistent organic pollutants (POPs) comprising e.g. PCBs, DDT-related compounds as well as further chlorinated aromatics. 

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