Sources Of Dioxins In The Environment - 2nd Stage Study Of Pcdd/Fs In Ancient Human Tissue And Environmental-Samples

This is one second report on the origin of PCDD/F contamination in the environment. In our previous paper 1 , we reported that most PCDD/Fs from tetra- to octa-congener groups were not detected in ancient Eskimo human tissue samples that were frozen for more than one hundred years. It could not be concluded, however, whether H 7 CDD and OCDD were present in the tissue samples because of trace amounts of contamination in the blank. In this study, the reanalysis of those ancient tissues shows a presence of low ppt levels of H 7 CDD and OCDD in the samples after the contamination was carefully eliminated. The levels of PCDD/F are well below those reported for modern persons. In addition, no PCDD/Fs were found in a charcoal sample from a redwood forest damaged by a natural fire prior to 1850. The data support the hypothesis that the main source of PCDD/Fs is anthropogenic.