Abstract Twenty‐five blood and biopsy fat samples were collected from donors with and without a Down's Syndrome child, and analyzed for 29 selected polychlorinated biphenyl isomers. Differences in polychlorinated biphenyl isomer levels in blood and adipose tissue of donors with or without a Down's Syndrome child were not statistically significant. Most polychlorinated biphenyl Isomers observed in blood were also detected in adipose tissue, except for the 3,4,4'‐trichlorobiphenyl, which was sometimes observed in blood, but not in adipose tissue. The blood/adipose tissue ratios of the polychlorinated biophenyl isomers indicated lower and more constant ratios for the higher chlorinated congeners. No significant differences were observed for the polychlorinated biphenyl isomer levels in blood of males and females, while in adipose tissue only the 2,4,4'‐trichloro‐,2,3,4,3’,4'‐pentachloro‐ and 2,3,4,5,6,2’,3’,4’,5'‐ nona‐chlorobiphenyl congeners were significantly (p<0.05) different between the sexes. Donors, who gained weight in the year prior to sample collection, showed significant (p<0.05) lower levels of several isomers in blood lipids. Key words: PCBisomerslevelbloodadiposeDown's Syndrome
Polychlorinated biphenyls (PCBs) are synthetic chemicals, manufactured in volume from about 1929 to the 1970s. Environmental contamination by PCBs has been documented in various substances, including human tissue. PCBs have been measured in human tissue by a variety of analytical methods. PCB levels have been reported as an approximation of total PCB content expressed in terms of a commercial mixture, by identification and quantification of chromatographic peaks, or by qualitative and quantitative characterization of specific congeners. Until recently, the coplanar mono-ortho- and di-ortho substituted PCBs, which are especially toxic and present in significant concentration in humans from industrial countries, had not been measured in human tissues. Examples of various types of commonly used analyses are presented in general population subjects and in persons who experienced special exposure. In this paper, the usefulness of PCB blood determinations following potential exposure is demonstrated, and their application in health studies is illustrated from a number of case studies. Coplanar PCB, mono-ortho-substituted and di-ortho-substituted PCB levels in human blood are presented and compared with polychlorinated dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) levels in the U.S. population. Dioxin toxic equivalents for the two groups of chemicals are calculated and compared. It is found that mono-ortho-substituted and, to a lesser extent, coplanar PCBs, contribute substantially to dioxin toxic equivalents (TEq) in blood from U.S. adults. Because of substantial PCB contribution to dioxin toxic equivalents, total dioxinlike toxicity can only be determined if dioxins, dibenzofurans, and dioxinlike PCBs are measured.(ABSTRACT TRUNCATED AT 400 WORDS)
Abstract A minimum acceptable volume of blood for the simultaneous determination of the lipid and chlorinated hydrocarbon content was established at 50 ml. At that volume the coefficients of variation for lipid and chlorinated hydrocarbon residue determinations were > 10 and 20% respectively. Comparing chlorinated hydrocarbon levels in whole blood with serum and plasma from the same blood pool, indicated that approximately 25% of the tri-to penta chlorobiphenyls were found in the serum and 40% in the plasma. In contrast, 55–83% of the hexa-to octachlorobiphenyls were found in the serum and plasma. From among the organochlorine pesticides, between 80–110% of the trans-nonachlor and DDTs appeared in the serum and plasma, but for others this range was considerably lower (40–71%). In general no appreciable differences were observed in the recoveries of some chlorinated hydrocarbons from fortified blood and serum.
Abstract Changes in the fatty acids composition of the oil in flax and safflower seed that occur during the seed‐ripening period have been measured. Concentrations of lipid or of specific fatty acid, expressed on a weight‐per‐seed basis, have been plotted as functions of days after fertilization and of percentage of oil development. Relations between these two independent variables have been established, and limitations to the unsefulness of the latter variable have been pointed out. Days after fertilization proved to be the more useful abscissa. Nonpolar solvents were used to remove free lipid from the tissue, and the total extractable matter was separated into true lipid and nonlipid components. With both flax and safflower, weight of true free lipid per seed and total unsaturation increased during the same period of growth. Nonlipid extractable matter was an inverse function of the extent of development. In developing flax seed, oleic, linoleic, and linolenic acids all increased continuously; oil in immature seed however was more saturated than oil in more mature seed. Nevertheless the ratio of linolenic acid to linoleic acid that characterizes linseed oil was established by the 20th day after fertilization during a normal growing season. In developing safflower seed, oleic acid concentration increased slowly during the first 30 days after fertilization and then appeared to level off in some cases as maturity was approached. Initially linoleic acid was present in almost the same amount as oleic acid, but by the 20th day after fertilization its concentration was three times that of oleic acid. This ratio of linoleic to oleic acid tended to increase steadily during the latter part of seed development.
Abstract The feasibility of using specific PCB congeners was studied in two parts: a questionnaire to obtain information on the methodology used in various countries for quantification of PCBs and an international check sample program to evaluate the accuracy of the specific PCB congener approach. Information from the questionnaires indicated the use of a wide variety of PCB quantification procedures and considerable interest in using specific PCB congeners. In the check sample program, participants were requested to analyze two mixtures of Aroclor 1242 and 1254 in different proportions, and a human milk extract. The results indicated that when individual congeners were present at less than approximately 5 pg/μl per injection, the coefficients of variation for reproducibility were unsatisfactory for many congeners, some of which could not be detected by the participants. Interlaboratory coefficients of variation were generally acceptable (<20%) for many congeners at concentrations >5 pg/μl with the exception of congener No. 28, which is known to co-elute with PCB congener No. 31 and thus affect its estimation.
