Isomer-specific analysis and toxic evaluation of polychlorinated biphenyls in striped dolphins affected by an epizootic in the western Mediterranean sea

Isomer-specific concentrations of polychlorinated biphenyls (PCBs) including planar, mono- and di-ortho congeners and concentrations of DDT were determined in striped dolphins affected by a morbillivirus epizootic in the western Mediterranean in 1990. Extremely high concentrations of PCBs ranging from 94 to 670 g/g (wet wt) were detected in the blubber. Similarly, DDT concentrations were high, between 22 and 230 g/g (wet wt). The concentrations of three non-ortho coplanar PCBs were 43 (3,3,4,4-T₄CB), 6.8 (3,3,4,4,5-P₅CB), and 7.8 (3,3,4,4,5,5-H₆CB) ng/g (wet wt), respectively, the highest residue levels reported to date. The estimated 2,3,7,8-TCDD toxic equivalents of non-, mono- and di-ortho PCB congeners in striped dolphins were several times higher than those observed for other marine mammals and humans. Mono-ortho congeners contributed greater 2,3,7,8-TCDD toxic equivalents than non-ortho members. The higher ratio of 3,3,4,4,5,5-H₆CB/3,3,4,4,5-P₅CB (IUPAC 169/126) suggested a strong induction of mixed function oxidase enzymes and highlighted the possibility of using this ratio as an index for risk assessment of PCB contamination in marine mammals. Elevated concentrations of PCBs may have played a role in the immune depression in striped dolphins, ultimately leading to the development of morbillivirus disease.     

Critical evaluation of polychlorinated biphenyl toxicity in terrestrial and marine mammals: Increasing impact of non-ortho and mono-ortho coplanar polychlorinated biphenyls from land to ocean

Residues of potentially toxic non-ortho chlorine substituted coplanar 3,3,4,4-tetra-,3,3,4,4,5-penta-, 3,3,4,4,5,5-hexachlorobiphenyl and their mono- and di-ortho analogs (2,3,4,4,5-penta-, 2,3,3,4,4-penta-, 2,3,3,4,4,5-hexa-and 2,2,3,3,4,4-hexa-, 2,2,3,4,4,5-hexa-chlorobiphenyl) were determined in humans, dogs, cats (terrestrial), a finless porpoise (Neophocoena phocoenoides-coastal), Dall's porpoises (Phocoenoides dalli,dalli), Baird's beaked whales (Berardius bairdii) and killer whales (Orcinus orca-open ocean). Among the coplanar polychlorinated biphenyl (PCB) congeners, the concentration of the di-ortho congeners was the highest and the non-ortho congeners was the lowest. However, all three coplanar PCBs occurred at significantly higher levels than toxic polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The relative bioconcentration and metabolic capacity of terrestrial and marine mammals to these chemicals, suggest that the toxic threat of coplanar PCBs increases from land to ocean, but the reverse is true for PCDDs and PCDFs. The toxic threat of coplanar PCBs to higher aquatic predators such as cetaceans was principally assessed by 2,3,7,8-T₄CDD Toxic Equivalent Analysis which is based on the induction of arylhydrocarbon hydroxylase (AHH) and ethoxyresorufinO-deethylase (EROD). Analysis indicates, in particular, that the bioaccumulation of toxic 3,3,4,4,5-penta- and 2,3,3,4,4-pentachlorobiphenyls in carnivorous marine mammals is a cause for considerable concern.     

Effects of thyroidectomy on the storage of organochlorine insectisides

Summary Rats submitted to p,p-DDT at 200 ppm in drinking water showed increased p, p-DDT storage which was not statistically different from that of thyroidectomized rats receiving p, p-DDT. Rats receiving p, p-DDT also showed increased fat storage of total o, p-DDT and Dieldrin and decreased total BHC storage.Thyroidectomy decreased the amount of p, p-DDT naturally occurring in the animal body and raised the metabolization of this compound.In thyroidectomized rats submitted to the same dosage of p, p-DDT, increased storage of p, p-DDT, o, p-DDT and Dieldrin was found. A statistically significant increase in BHC was also observed.It is concluded that p, p-DDT in the diet may affect the storage level of other organochlorine insecticides depending on its concentration, and that the physiopathological state of the body, e. g. thyroidectomy has a definite influence on the storage of organochlorine insecticides in the animal body and on their biological effect.     

Polychlorobiphenyls, ΣDDT,and hexachlorocyclohexane isomers in the western North Pacific ecosystem

Polychlorobiphenyls (PCBs), DDT (p,p-DDT,p,p-DDD, andp,p-DDE and HCH isomers (hexachlorocyclohexanes including , , and isomers) were determined in a marine food chain, including seawater, zooplankton, myctophid, squid and striped dolphin collected from the western North Pacific waters. The concentrations of these pollutants increased in higher trophic levels, where the highest bioconcentration factors (concentration ratio in organisms to water), as much as 10⁷, were obtained from both PCBs and DDT in striped dolphin. The proportions of highly chlorinated biphenyls,p,p-DDE and -HCH increased in higher-ranking predators. These observations suggest that the bioaccumulation mechanisms in lower trophic levels depend primarily on the physicochemical properties of pollutants, whereas those in higher trophic levels are affected by the biodegradability of the pollutants and the metabolic capacity and life-span of the organisms.     

DDT,DDD, and DDE contamination of sediment in the Newark Bay estuary,New Jersey

Two hundred and forty-six surface and buried sediment samples from Newark Bay, New Jersey, and its major tributaries (Passaic River, Hackensack River, Newark Bay, Arthur Kill, Elizabeth River, and Kill Van Kull) were assayed for p,p-dichlorodiphenyltrichloroethane (p,p-DDT), p,p-dichlorodiphenyldichloroethane (p,p-DDD), and p,p-dichlorodiphenylchloroethylene (p,p-DDE) between February 1990 and March 1993. Chronological profiles in sediments from pre-1940 to the present were determined by radioisotope activities of ²¹⁰Pb and ¹³⁷Cs. The concentrations of these chemicals were compared to National Oceanic and Atmospheric Administration (NOAA) benchmark sediment values (Long and Morgan 1991). The objectives were to (a) determine the spatial and temporal distributions of DDT compounds in sediments, (b) identify possible sources, and (c) assess the potential for sediment toxicity within the estuary. Mean concentrations in surface sediments in individual waterways ranged from 5 to 473 g/kg for p,p-DDT, 18 to 429 g/kg for p,p-DDD, and 5 to 111 g/kg for p,p-DDE. A regional background mean concentration of approximately 100–300 g/kg p,p-DDT (sum of p,p-DDT, p,p-DDD, and p,p-DDE) was measured in surface sediments throughout the estuary, with the exception of the Arthur Kill, where mean concentrations exceeded 700 g/kg. The elevated concentrations found in recently deposited surface sediments in the Arthur Kill may be due to the presence of ongoing sources. The highest concentrations in buried sediments occurred in the lower Passaic River at depths corresponding to historical deposits from 1940 to 1970, the peak time period for production and usage of DDT in the United States. Comparisons to NOAA benchmark sediment toxicity values indicate that p,p-DDT, p,p-DDD, and p,p-DDE concentrations in surface sediments may pose a potential hazard to fish, shellfish, and other benthic and demersal organisms in some portions of the estuary, particularly in the upper and lower Arthur Kill.     

Polychlorinated biphenyl congeners (PCBs),p,p′-DDE and hexachlorobenzene in human milk in three areas of upstate New York

Forty human milk samples from women in an urban and a rural vicinity on Lake Ontario (Rochester and Oswego) and a mixed urban and rural location on the Hudson River (Albany), New York, were analyzed for 74 PCB congeners,p,p-DDE, hexachlorobenzene, and mirex in order to determine the intake of breast-fed infants. All of the compounds were detected in the samples, but only eight PCB congeners andp,p-DDE accounted for 88% of the chlorinated hydrocarbons detected.p,p-DDE was the predominant pollutant (mean 78 ng/g wet weight), but the levels detected were low compared with the results from other parts of North America. Eight individual PCB congeners comprise 52% of the total PCB residue (mean 26.5 ng/g of whole milk); they ranged in mean concentration from 3.2 ng/g (2,4,5,2,4,5-hexachlorobiphenyl) to 1 ng/g (2,3,4,3,4-pentachlorobiphenyl). Statistical correlation analysis among PCB congeners indicates a possible higher exposure to less chlorinated congeners at Oswego than at Albany.     

DDT Residues in samples of human milk,and in mothers' and cord blood serum,in a continental town in Croatia (Yugoslavia)*

Summary Concentrations of p,p'-DDE, p,p-DDD, and p,p-DDT were determined in 34 samples of human milk obtained 3–5 days after delivery and in 37 samples obtained at later times of lactation (up to 55 weeks). All samples contained p,p-DDE, but only several contained p,p-DDD and p,p-DDT. The concentrations of p,p-DDE were 31 g/l in the beginning of lactation and 53 g/l at later time intervals. The concentration ranges in both groups overlap almost completely and the difference in the mean values is not significant.Serum samples from 35 mothers and cord blood were also analyzed. All samples contained p,p-DDE, the concentrations being 18 g/l and 6.8 g/l in the mothers' and cord blood serum, respectively. Serum samples of 24 nonpregnant women contained the same amount of p,p-DDE (20 pg/1) as mothers' sera.All samples were collected in a continental town of Croatia (Yugoslavia) between 1977 and 1979. The concentrations of DDT residues were determined by gas chromatography, and two methods for extraction from milk were used and compared.This work was supported in part by the Environmental Protection Agency (USA) and the World Health Organization (Geneva)     

Presence of PCB,DDE and DDT in human milk in the provinces of New Brunswick and Nova Scotia,Canada

Summary PCB, p,p-DDE and p,p-DDT residue levels were measured in human milk from New Brunswick and Nova Scotia. Preliminary results indicate that the levels of p,p-DDT and p,p-DDE are higher in the former area, possibly because of the wider use of insecticide sprays in the past. It should be emphasized that because of the limited number of samples analyzed, further work must be done before a significant difference in these areas can be established.     

Levels of β-HCH,HCB, p,p′-DDE,p,p′-DDT and PCBs in human milk from a continental town in Croatia,Yugoslavia

Summary Concentrations of -HCH, HCB, p,p-DDE, p,p-DDT and PCBs were determined by gas chromatography in 50 human milk samples collected from the general population during 1981/1982 in a continental town in Croatia (Yugoslavia). The samples were collected between one and 22 weeks after delivery from mothers breast-feeding one child only. The mothers' age was 18 to 31 years, and they were nursing their first or second child. All 50 samples contained -HCH, HCB, p,p-DDE and PCBs, whereas p,p-DDT was present in 37 samples. The concentrations of -HCH, HCB, p,p-DDE, p,p-DDT and PCBs expressed on a whole milk basis were (median in g/kg): 11, 7.1, 67, 7.3 and 22 respectively, and expressed on a fat basis (median in mg/kg): 0.28, 0.21, 1.9, 0.18 and 0.62 respectively. The fat content was 3.7% (median). PCBs were present in a mixture containing penta-, hexa- and heptachlorobiphenyls.     

Chromatographic determination of dicofol and metabolites in egg yolks

Egg yolk was spiked withp,p-dicofol (p,p-DCF) (0.1–2.0 g/gm),p,p-dichlorobenzophenone (p,p-DCBP) (0.1–2.0 (g/gm), and 1,1-bis(4-chlorophenyl)-2,2-dichloroethylene (p,p- DDE) (0.05–1.0 g/gm). The fortified egg yolk (2–5 g) was mixed with acetonitrile to extract non-fat organic materials. After removal of acetonitrile, the spiked chemicals were separated with a column chromatograph packed with acid alumina. Recovery efficiencies forp,p-DCBP andp,p-DDE were determined by gas chromatography, and forp,p-dicofol by high performance liquid chromatography. The recovery efficiencies forp,p-dicofol,p,p-DCBP andp,p-DDE were 77.2–93.8%, 84.1–101.1%, and 88.5–96.0%, respectively.     

Toxicity and persistence of PCB homologs and isomers in the avian system

This study reports the biotransformation and persistence of PCBs in the hen, her eggs, and chicks hatched from these eggs. Twelve White Leghorn hens and one rooster were given 50 µg/ml of the PCB mixture Aroclor 1254 in their drinking water (6.3 mg/kg body weight) for six weeks. The resultant concentration in the yolk of eggs laid during the following 20 weeks and in the tissues of surviving embryos and chicks was determined by thin-layer chromatography and gas chromatography. Mortality of embryos and deformity of chicks were found to be correlated with PCB content of the eggs. Moreover, after storage of the PCB mixture in the hen's body, the toxic potency of the PCB mixture deposited in the eggs more than doubled. It was shown that 3,4,2,3,6-pentachlorobiphenyl (peak 9) was cleared faster from the hen than 3,4,2,4,5-pentachlorobiphenyl (peak 12) and 2,3,4,2,4,5-hexachlorobiphenyl (peak 14) and that 4,4-chlorination is more important than degree of chlorination in determining persistence of chlorinated biphenyls in the hen, embryo, and chick.     

Organochlorine pesticide contaminations in human milk samples from women living in Amman,Jordan

Concentrations of 15 organochlorine pesticides were determined by capillary gas chromatography in 59 human milk samples collected from the general population during 1989/1990 in the Jordanian capital of Amman. In addition to hexachlorbenzene (HCB), three groups of organochlorine compounds namely, DDT and its metabolites, hexachlorcyclohexane (HCH-isomers) and the cyclopentadiene group (aldrin, dieldrin, endrin, heptachlor, and heptachlor epoxide) were analyzed.The results show that almost all samples contained HCB, -HCH, p,p-DDE and p,p-DDT, whereas p,p-DDD, heptachlor, -HCH, -HCH and o,pDDT were found in 42, 40, 33, 22 and 20 analyzed samples, respectively. The concentration of HCB, -HCH, p,p-DDE, p,p-DDT and heptachlor expressed on a milk-fat basis (median in mg/kg milk fat): 0.29, 0.4, 2.04, and 0.7 respectively.For the comparative purposes and in order to try to find the possible sources of mother-milk contaminations, different types of locally produced and imported cow milk samples were also analyzed for the same organochlorine compounds. Almost all types of tested milk were contaminated with p,p-DDE.     

Congener-specific data on polychlorinated biphenyls in tissues of common porpoise from Puck Bay,Baltic Sea

Individual congeners of polychlorinated biphenyls (PCBs), including the highly toxic non-ortho coplanar 3,3,4,4-tetrachlorobiphenyl (IUPAC No. 77), 3,3,4,4,5-pentachlorobiphenyl (IUPAC No. 126), and 3,3,4,4,5,5-hexachlorobiphenyl (IUPAC No. 169), and their mono- and di-ortho analogs, have been identified and quantified in the blubber, liver, and muscles of three female common porpoise Phocoena phocoena collected from the Puck Bay (inner Gulf of Gdask, Poland) in 1989–1990, to elucidate actual concentrations and toxic potential. The total 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalent for 13 coplanar PCBs in blubber was 1,500±470 pg/g wet wt. 2,3,4,4,5-Pentachlorobiphenyl (IUPAC No. 118) was the most contributing individual and occupied between 57 and 67% in total toxic equivalent of coplanar PCBs in blubber, while 2,2,4,4,5,5-hexachlorobiphenyl (IUPAC No. 153), 2,3,3,4,4-pentachlorobiphenyl (IUPAC No. 105) and 2,2,3,4,4,5-hexachlorobiphenyl (IUPAC No. 138) comprised between 9.5–14, 7.6–11.5, and 7.2–11.0%, respectively (totally 82–95%), and 2,3,3,4,4,5-hexachlorobiphenyl (IUPAC No. 156) was absent. A potentially most toxic non-ortho PCB members such as 3,3,4,4,5-pentachlorobiphenyl, 3,3,4,4,5,5-hexachlorobiphenyl and 3,3,4,4-tetrachlorobiphenyl were only minor contributors, altogether occupying between 1.0 and 14.5% in total TEQ of coplanar PCBs. Concentrations of total PCBs in lipids of the blubber ranged from 26 to 47 g/g and were comparable or lower than reported earlier for common porpoises from the Baltic Sea, North Sea, and North Atlantic by other authors.     

Concentrations and chromatographic profile of DDT metabolites and polychlorobiphenyl (PCB) residues in stranded beluga whales (Delphinapterus leucas) from the St. Lawrence Estuary,Canada

The concentrations and high resolution gas Chromatographic profiles of DDT metabolites and polychlorobiphenyl (PCB) congeners were determined in blubber, liver, kidney and lung tissue and milk samples of stranded beluga whales (Delphinapterus leucas) collected at localities along the coasts of the Saint Lawrence Estuary, Canada from November 1983 through December 1984. The analyses indicate that the major PCB components of the tissues were 2,2,5,5-tétra-, 2,2,4,4,5-penta-, 2,2,3,4,4,5-hexa-, 2,2,4,4,5,5-hexa-, 2, 2,3,3,4,5-hexa-, 2,3,3,5,5,6-hexa-, 2,2,3,4, 5,5,6-hepta- and 2,2,3,4,4,5,5-heptachlorobiphenyls. Although the highest organochlorine chemical concentrations were found primarily in the blubber, concentrations of 1.72 g/g for PCB and 2.04 g/g for DDT were determined in one milk sample. No correlation was established between PCB,p,p-DDE and DDT concentrations and the fat content of the kidney liver and lung tissues. The Chromatographie patterns of the PCB congeners were similar from one tissue to another with the exception of the kidney; the profile indicates the retention of PCB congeners which are minor components in the other tissues. Relations of residue concentrations between tissue are described and the significance of congener-specific PCB analysis is discussed in terms of the structureactivity effects on PCB persistence and toxicity.Portions of this work were presented at the Sixth Biennial Conference on the Biology of Marine Mammals, Vancouver, British Columbia, November 22–26, 1985.     

A comparison of organochlorine pesticide residues in maternal adipose tissue,maternal blood,cord blood,and human milk from mother/infant pairs

A total of 41 samples of maternal blood, milk, subcutaneous fat and umbilical cord blood were collected from mothers giving birth by Caesarean operation at Kenyatta National Hospital in Nairobi in 1986. The samples were analyzed for organochlorine contaminants. The main contaminants found in all the samples were p,p-DDT (100%), p,p-DDE (100%), o,p-DDT (59%), dieldrin (27%), transnonachlor (15%), -HCH (12%) and lindane (2%) of all the samples analyzed. Polychlorobiphenyl (PCB) residues were not detected in any of the samples.The mean levels (mg/kg fat) of sum of DDT were 5.9 in subcutaneous fat, 4.8 in mothers milk, 2.7 in maternal serum and 1.9 in umbilical cord serum. There was a significant correlation between the levels of sum DDT in subcutaneous fat and milk fat (r=0.963), subcutaneous fat and maternal serum fat (r=0.843), and maternal serum fat and maternal milk fat (r=0.868), indicating the coherence of DDT in the body.Hexachlorocyclohexane (-HCH) was found in subcutaneous fat and milk fat with the mean levels of 0.03 and 0.26 mg/kg fat, respectively. Dieldrin detected in mothers milk and subcutaneous fat could not be quantified.     

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), HCH (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     

Chronic toxicity and bioaccumulation of 2,5,2′,5′- and 3,4,3′,4′-tetrachlorobiphenyl and Aroclor® 1242 in the amphipodHyalella azteca

The addition of 100 (g/L of Aroclor^® 1242 (A1242) or 2,5,2,5-tetrachlorobiphenyl (TeCB) during 10 week chronic toxicity tests withHyalella azteca resulted in complete mortality. There were no effects on survival, growth, or reproduction after addition of 30 g/L. Toxic effects were observed at tissue levels of between 30 and 180 g/g on a wet weight basis, and tissue levels appear to be a better indicator of toxicity than levels in water. No toxic effects were observed after additions of up to 2,700 g/L of the coplanar congener 3,4,3,4-TeCB.H. azteca has the ability to avoid accumulating in excess of 140 g/g 3,4,3,4-TeCB. The amount taken up was proportional to the amount added in water up to 100 g/L, but was constant at higher additions, possibly accounting for its relatively low toxicity. The low toxicity of the coplanar congener, as compared to the non-coplanar 2,5,2,5-TeCB, is in direct contrast to the high toxicity of coplanar PCB congeners to mammals and may be associated with slower rates of aromatic hydrocarbon metabolism in amphipods. Polychlorinated biphenyl levels measured in amphipods from Lake Ontario are approximately 100-fold below levels associated with toxicity inH. azteca, but are above levels which, through biomagnification up the food chain, lead to salmonid residues in excess of 2 g/g, a tolerance limit for human consumption.     

Polychlorinated biphenyls: Photolysis of 3,4,3′,4′-tetrachlorobiphenyl and 4,4′-dichlorobiphenyl in solution

Summary The large difference in retention times for the photoproducts of 3,4,34-tetrachlorobiphenyl can be explained on the basis of their chlorine content and the effect of vicinal chlorosubstitution as observed by V. Zitko and coworkers (4).The absence of biphenyl among the photoproducts of 4,4-dichlorobiphenyl was not surprising since 4-chlorobiphenyl (max 203, 253) does not absorb at the wavelength of irradiation (>286), 4,4-dichlorobiphenyl exhibits only marginal absorption at this wavelength (max 201, 259, 286) this explains the low yield of 4-chlorobiphenyl obtained (appx. .1%). The greater reactivity at the meta position may be the result of bond weakening due to steric interactions with the chlorine atom at the para position. Rate studies may provide an answer to this problem.     

Organochlorine pesticides and polychlorinated biphenyls in maternal adipose tissue,blood, milk,and cord blood from mothers and their infants living in Norway

Samples of maternal blood, milk, and umbilical cord blood were collected from mothers and their infants at Ullevål University Hospital in Oslo, Norway. All the mothers had lived in Oslo during the last two years. Of the Norwegian mothers, 16 were delivered by Caesarean operation, and samples of subcutaneous fat tissues were collected. Hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs),p,p-DDE,p,p-DDT, and dieldrin were found in 157, 135, 168, 22, and 12, respectively, of the 168 samples analyzed, while , and -hexachlorocyclohexane (HCH) were found in 93 and 26, respectively, of the 152 samples analyzed for these compounds. In the samples obtained from the Norwegian mothers and infants, PCBs andp,p-DDE were the major contaminants present. In contrast, only traces of PCBs were found in six immigrant samples, which, however, contained 4–6 times higher levels ofp,p-DDE plusp,p-DDT than the corresponding Norwegian samples. Of the HCH isomers, the -HCH was the predominant isomer present. Two to three times significantly higherp,p-DDE and PCBs levels were found in maternal serum than cord serum. No significant differences were found between the organochlorine residue levels in subcutaneous fat and milk fat. A significant positive linear correlation was found between the levels ofp,p-DDE and PCBs in maternal serum and in milk fat, and between the levels ofp,p-DDE in maternal serum and cord serum from Norwegian mothers giving birth normally.Significantly higher PCBs andp,p-DDE residues were found in the maternal and cord serum samples obtained after Caesarean operation than after normal delivery, while no other such differences were found in the milk samples 5 days post partum.The results demonstrate that organochlorines are transferred from mother to fetus and newborn babies through the placenta and milk and that human milk is a good indicator in monitoring human beings and their environment for organochlorine contamination. Possible toxicological implications of the present results are discussed.     

Effect of long-term feeding of DDT to turkeys

Summary Diets containing 264.6 ppm o,p- or p,p-DDT were fed to 6-week-old male and female turkeys for 7 and 15 weeks. Such chronic feeding of DDT did not cause alterations of: Blood pressure; gross structure of body tissues; histology of heart, aorta, liver, testes, oviduct, ovary, thyroid, or kidney; plasma cholesterol or calcium levels; albumin-globulin ratio; or plasma lipoprotein patterns. The residue of DDT in body fat was determined. Trace amounts were found in birds fed the control diet. Minute quantities of o,p-DDT and large amounts of p,p-DDT were found in fat of turkeys fed p,p-DDT, and the converse was true of turkeys fed o,p-DDT.