Human tissues, analytical problems

The identification of PCB residues in fish, wildlife, and human tissues has been reported since the 1970s (9—13,20—26). The results of these analytical studies led to the ultimate ban on further use and production of these compounds. The precise composition of PCB extracts from biota samples is highly variable and depends, in part, on the specific analyte and the commercial PCB preparations associated with a contaminated area (14). PCBs found in a composite human milk sample from Michigan (26) were highly complex, and the congener composition and their relative concentrations did not resemble any of the commercial PCB preparations. This fact raises obvious problems with regard to the ha2ard assessment of PCB mixtures (27). 

To appraise the extent of environmental contamination is a problem in organic pesticide analysis. Analytical methods for such diverse samples as air and human tissue have been developed and are yielding important information. The fate and persistence of pesticides constitutes another complex problem. It includes consideration of environmental and biological effects upon pesticides, how they move in rivers, and how they are translocated from one environmental medium to another. Finally, there is the question of damage control. Can we reduce the introduction of pesticides into air and water If not, can we effectively remove these poisons from the parts we consume ... 

Quantitative data on PCT concentrations in human milk,blood, and adipose tissue are only known for Japan and Netherlands [38, 39,44], All data are from the 1970s. Due to the analytical problems it is difficult to make any assessment. PCT concentrations in Dutch human milk varied between 0.5 and 0.8 mg/kg on a lipid weight basis. PCT concentrations in Japan varied between 0 mg/kg and 0.22 mg/kg on a lipid weight basis, while PCT concentrations in other tissues (blood, liver, adipose tissue, kidney, brain) varied between 0.04 mg/kg and 9.2 mg/kg on a lipid weight basis. PCTs were qualitatively determined in human adipose tissue from the USA [45]. 

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