David J. Davies

Polychlorinated biphenyls and organochlorine pesticides in milk and blood of Canadian women during lactation.

Blood and breast milk samples of 16 women were analyzed for PCBs (polychlorinated biphenyls) and some organochlorine pesticides during eight intervals of a 98 day lactation period. Although a general downward trend in residue levels of blood and breast milk was evident, this trend was interrupted by sporadic increases. Most residues in breast milk showed an apparent increase during the first 30 days of lactation, which was not statistically significant. However, during lactation a statistically significant decrease was observed for the following residues, expressed on a milkfat basis: HCB (hexachlorobenzene), oxychlordane, transnonachlor (1-exo, 2-endo, 3-exo-4,5,6,7,8,8-nonachloro-3a,4,7,7a-tetrahydro-4,7-methanoindene), βHCH (hexachlorocyclohexane),p,p′-DDE andp,p′-DDT. Average milk/blood ratios for PCBs, HCB, oxychlordane(1-exo,2-endo-4,5,6,7,8,8-oc-tachloro-2,3-exo-epoxy 2,3,3a,4,7,7a-hexa-hydro-4,7-methanoindene),p,p′-DDE (2,2-bis-(p-chlorophenyl)- 1, 1-dichloroethylene), dieldrin (1,2,3,4, 10,10-hexachloro-exo-6,7-epoxy-1,4,4a,5,6,7,8,8a-octahydro- 1,4-endo- exo- 5,8-dimethanonaphthalene) and p,p′-DDT (1,l-bis-(p-chlorophenyl)-2,2,2-trichloroethane) levels were 23, 20, 9, 19, 5 and 30 respectively. Milk/blood ratios for PCB andp,p′-DDE levels remained relatively constant during lactation (coefficient of variation ∼20). Accumulation of residues in infant body fat were theoretically estimated

Polychlorinated biphenyl and other chlorinated hydrocarbon residues in adipose tissue of Canadians.

The data reported in this paper are part of a continuing monitoring program of chlorinated hydrocarbons in adipose tissue of Canadians in order to determine a possible trend in both the disappearance of restricted OC pesticides, such as p,p,-DDT, as well as the appearance of new environmental contaminants, such as hexachloro-1,3-butadiene (HCBD).

The effect of long-term feeding of Aroclor 1254 to female rhesus monkeys on their polychlorinated biphenyl tissue levels.

The result of feeding Aroclor 1254 ® to female Rhesus monkeys at doses of 0, 5, 20, 40 and 80 μg/kg body weight/day for a period of 37 months was measured in terms of polychlorinated biphenyl (PCB) levels in blood, adipose tissue, and feces. PCB concentrations in whole blood increased more rapidly during the first 10 months of the study than in the remaining 27 months for all dose groups. On a blood-lipid basis, however, another rapid increase in PCB levels was observed after 27 months of dosing, which could not be explained on the basis of an overall decrease in blood-lipid levels. Concentrations in adipose tissue and adipose fat increased continuously during the 37 months of dosing. These observations were reflected in the ratio profiles of PCB levels in blood/PCB levels in adipose tissue, which remained relatively static between the 2nd and 27th month of continuous feeding.Expressing the data in terms of relative concentrations (concentration/dose) suggests that bio-accumulation or retention of PCBs may be dose-dependent, particularly for adipose tissue, with the higher relative concentrations of the lowest dose group significantly (p < 0.001) different from all other dose groups. Similarly, the limited feces data available suggests a dose-dependent PCB absorption. The distribution of PCB peaks in the gas Chromatographie elution pattern of all analyzed substrates showed considerable deviation from that of administered Aroclor 1254. Only minor changes in the percent distribution pattern were observed between dose groups.

Polychlorinated biphenyl (PCB), DDT, DDE and hexachlorobenzene (HCB) and PCDD/F isomer levels in various organs in autopsy tissue from North American patients

Abstract Autopsies were performed on three patients from the North American Continent, with no known chemical exposure history, and multiple tissues analyzed for PCB isomers as well as for DDT, DDE and HCB. Previous analysis of tissues from two of the patients is also presented for PCDD/Fs. Differences were observed in PCB isomer distribution within a given tissue and between the various tissues of the donors, both on a wet tissue and lipid basis. This was also reflected in total PCB levels (sum of all isomers) which ranged from 2 ppb in spleen to 107 ppb (mg/g) in subcutaneous fat for patient 1, 3 ppb in testis to 223 ppb in adipose for patient 2 and 9 ppb in spleen to 455 ppb in subcutaneous fat for patient 3. Levels of p,p′-DDT and p,p′-DDC were much lower in patient 1 (6 and 8 ppb. respectively) than in patients 2 and 3, where they ranged from 60 to 4406; ppb respectively. HCB residue levels were considerably more uniform.

Traces of Mirex in Some Canadian Human Milk Samples

Mirex (l,2,3,4,5,5,6,7,8,9,10,10-dodeeachlorooctahydro1,3,4-metheno-2H-cyclobuta (c,d) pentalene) has mainly been associated with the control of the Fire ant in the Southeastern U.S.A. (ALLEY 1973), where it was subsequently found in non-target organisms (COLLINS et al. 1973, WOJCIK et al. 1975) including man (ANONYMOUS 1976). Recently Mirex has been found in Canada in fish from Lake Ontario (KAISER 1974) and in eggs of double crested cormorants (ZITKO 1976). This paper reports on a limited study of Mirex in human milk samples from across Canada, using U.V. irradiation to limit interference from polychlorinated biphenyls (PCBs).

The Determination of Polychlorinated Biphenyl in Small Samples of Monkey Milk and Tissues. I

The feasibility of analysing less than or equal to 5 ml blood and 1 ml monkey milk samples for polychlorinated biphenyls (PCBs) was tested by fortification of similar size human blood and milk samples with Aroclor 1260 at the 1, 5, 10 and 10 ng/g level, respectively. Recoveries were 71, 82 and 89% for blood and 95% for milk. Recoveries of > 90% were obtained, when 100 mg samples of monkey liver, kidney and adipose tissue were fortified with Aroclor 1254 at the 0.2, 0.5 and 1 microgram/g level. The methodology was then applied to blood, collected from monkeys receiving Aroclor 1254 at definite intervals of dosing. The initial PCB level rose from 2.2 to 4.5 ng/g after 120 days. Monkey milk analysed at different days of lactation showed little variation in the PCB content on a whole milk basis. The peak height ratios varied among the substrates and with those of standard Aroclor 1254.

The Determination of Polychlorinated Biphenyl in Small Samples of Monkey Milk and Tissues. II. Extraction Efficiency

The extraction efficiency of benzene, toluene, dichloromethane, acetone:hexane and chloroform:methanol with respect to lipids and polychlorinated biphenyls was investigated using small samples of monkey adipose tissue, liver, kidney, brain, skin, feces and milk. The most efficient solvents were: acetone:hexane and chloroform:methanol for brain, feces, kidney, liver and milk; acetone:hexane and dichloromethane for adipose tissue; acetone:hexane and toluene for blood and dichloromethane for skin tissue. Within these solvent pairs acetone:hexane was the most outstanding with respect to an average of 90% PCB recoveries from fortified samples in the range of 0.02-2 ppm. In addition, a comparison was made between the lipid determination before and after Florisil column chromatography. Only adipose and blood lipids were sufficiently recovered from Florisil to make a lipid determination after chromatography feasible.

The effect of extraction technique on the fat content, polychlorinated biphenyl level and tri- to octabiphenyl distribution in human milk

Abstract Six different extraction techniques for PCBs in human milk were studied. Although some variation in the PCB levels and fat content was observed, the greatest differences were found in the isomer composition.