Gunilla Lindström

Exposure of Perfluorinated Chemicals through Lactation: Levels of Matched Human Milk and Serum and a Temporal Trend, 1996–2004, in Sweden

Background Only limited data exist on lactation as an exposure source of persistent perfluorinated chemicals (PFCs) for children. Objectives We studied occurrence and levels of PFCs in human milk in relation to maternal serum together with the temporal trend in milk levels between 1996 and 2004 in Sweden. Matched, individual human milk and serum samples from 12 primiparous women in Sweden were analyzed together with composite milk samples (25–90 women/year) from 1996 to 2004. Results Eight PFCs were detected in the serum samples, and five of them were also above the detection limits in the milk samples. Perfluorooctanesulfonate (PFOS) and perfluorohexanesulfonate (PFHxS) were detected in all milk samples at mean concentrations of 0.201 ng/mL and 0.085 ng/mL, respectively. Perfluorooctanesulfonamide (PFOSA), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) were detected less frequently. Discussion The total PFC concentration in maternal serum was 32 ng/mL, and the corresponding milk concentration was 0.34 ng/mL. The PFOS milk level was on average 1% of the corresponding serum level. There was a strong association between increasing serum concentration and increasing milk concentration for PFOS (r2 = 0.7) and PFHxS (r2 = 0.8). PFOS and PFHxS levels in composite milk samples were relatively unchanged between 1996 and 2004, with a total variation of 20 and 32% coefficient of variation, respectively. Conclusion The calculated total amount of PFCs transferred by lactation to a breast-fed infant in this study was approximately 200 ng/day. Lactation is a considerable source of exposure for infants, and reference concentrations for hazard assessments are needed.

Overview on environmental fate of chlorinated dioxins and dibenzofurans. Sources, levels and isomeric pattern in various matrices

Abstract Polychlorinated dioxins and dibenzofurans have been identified in technical products and pesticides, most of which are not very widely used today. Other sources are incinerators of various types like MSW incinerators, but also hazardous waste incinerators and industrial incinerators. PCDDs and PCDFs have also been identified in exhausts from cars running on leaded gasoline with halogenated additives. Background levels of PCDDs and PCDFs have been identified in fish and other aquatic organisms from the Great Lakes and the Baltic Sea, and also in human adipose tissue samples from USA, Canada, Sweden, Japan and Viet Nam as well as in samples of breast milk from Sweden, Denmark, West Germany, the Netherlands, Yugoslavia and Viet Nam. The isomeric pattern in all these biological samples is very similar.

Human exposure to perfluorinated chemicals through the diet: intake of perfluorinated compounds in foods from the Catalan (Spain) market.

The aim of this study was to determine the dietary intake of perfluorinated chemicals (PFCs) by the population of Tarragona County (Catalonia, Spain). PFC levels were determined in 36 composite samples of foodstuffs randomly purchased in various locations. Exposure to PFCs through the diet was estimated for various age/gender groups. Perfluorooctane sulfonate (PFOS), perfluorocarboxylate perfluorooctanoate (PFOA), and perfluoroheptanoic acid (PFHpA) were the only detected PFCs in foodstuffs. On average, for a standard adult man (70 kg of body weight), the dietary intake of PFOS was estimated to be 62.5 or 74.2 ng/day (assuming ND=0 or ND=1/2 LOD, respectively). Fish, followed by dairy products and meats, were the main contributors to PFOS intake. For an adult man, the intake of PFOS (1.07 ng/kg/day) and those of PFOA and PFHpA were lower than that recently reported for Canada (4.0 ng/kg/day), and considerably lower than that previously found in the United Kingdom, the only two countries where, to date, results concerning this issue have been reported. A correlation between dietary intake and blood levels of PFOS is suggested. However, the current results do not justify dietary intake as the main route of exposure governing blood concentrations of other PFCs.

Levels in food and beverages and daily intake of perfluorinated compounds in Norway

Perfluorinated compounds (PFCs) have been determined in 21 samples of selected food and beverages such as meat, fish, bread, vegetables, milk, drinking water and tea from the Norwegian marked. Up to 12 different PFCs were detected in the samples. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) were found in concentrations similar to or lower than what has been observed in other studies world-wide. Differences in the relative proportion of PFOA and PFOS between samples of animal origin and samples of non-animal origin were observed and support findings that PFOS has a higher bioaccumulation potential in animals than PFOA. Based on these 21 measurements and consumption data for the general Norwegian population, a rough estimate of the total dietary intake of PFCs was found to be around 100 ng d(-1). PFOA and PFOS contributed to about 50% of the total intake. When dividing the population in gender and age groups, estimated intakes were decreasing with increasing age and were higher in males than females. The estimated intakes of PFOS and PFOA in the present study are lower than what has been reported in studies from Spain, Germany, United Kingdom, Canada and Japan. This study illustrates that by improving the analytical methods for determination of PFC in food samples, a broad range of compounds can be detected, which is important when assessing dietary exposure.

Levels and temporal trends of chlorinated pesticides, polychlorinated biphenyls and brominated flame retardants in individual human breast milk samples from Northern and Southern Norway.

Human breast milk samples from primipara women from Northern (Tromsø) (N=10) and Southern Norway (Oslo) (N=19) collected in 2000-2001 were analysed with respect to hexachlorobenzene (HCB), hexachlorocyclohexane (HCHs), chlordanes (CHLs), DDTs, mirex, toxaphenes (CHBs), polychlorinated biphenyls (PCBs), polybrominated diphenylethers (PBDEs) and hexabromocyclododecane (HBCD). CHBs, PBDEs and HBCD were only analysed in the Tromsø samples. Sum-PCBs and sum-DDTs were the major organochlorines (OCs) (170 and 110 ng g(-1) lipid weight (lw), respectively). Other OCs were found in levels of approximately 10- to 300-fold lower than sum-PCBs. Overall, the concentrations of OCs followed the decreasing order of PCBs>DDTs>HCB>HCHs approximately CHLs>CHBs>mirex. Concentrations of sum-HCHs were significantly higher in breast milk from Oslo compared to Tromsø (p<0.05). The PCB profile was dominated by PCB-153, -138 and -180. The PBDE pattern was dominated by PBDE-47 and PBDE-153. The median level of sum-PBDEs was 4.1 ng g(-1) lw. PBDE-209 was detected in all analysed samples (median 0.13 ng g(-1) lw). The estimated daily intake (EDI) for the median (range) of sum mono-ortho (mo) PCBs(8) was 3.7 (1-9) pg TEQ kg(-1) body weight per day for breast fed infants in Norway. This exceeded the TDI by a factor of 1.8 (1-4) based only on intake of mono-ortho PCBs. The present study shows that concentrations of OCs in primipara breast milk have decreased 50-60% since 1991, and that this trend is continuing.

Case-Control Study on Concentrations of Organohalogen Compounds and Titers of Antibodies to Epstein-Barr Virus Antigens in the Etiology of Non-Hodgkin Lymphoma

A rapid increase in incidence of non-Hodgkin lymphoma (NHL) has been reported from many countries. Exposure to certain pesticides and organochlorines has been shown to be risk factors. Epstein-Barr virus (EBV) is a human herpesvirus that has been associated with some subgroups of NHL, such as Burkitt lymphoma and lymphomas related to severe immunosuppression. In this study, we measured lipid adjusted blood concentrations of 36 congeners of polychlorinated biphenyls (PCBs), p,p′-dichlorodiphenyl-dichloroethylene (p,p′-DDE), hexachlorobenzene (HCB), four different subgroups of chlordanes (trans-nonachlordane, cis-nonachlordane, MC6 and oxychlordane) and 2,2′,4,4′-tetrabrominated diphenyl ether (TBDE) in incident cases of NHL and controls from the general population. Titers of antibodies to the Epstein-Barr early antigen (EA) were correlated to concentrations of organochlorines. We found a significant difference in lipid adjusted blood concentrations of total PCBs and TBDE between cases and controls. Titers of antibodies to EA IgG > 80 were correlated to an increased risk for NHL with odds ratio (OR) = 1.9, 95% confidence interval (CI) =0.94–3.8. This risk was further increased in those with a level above the median value of “sum of PCBs” (OR=4.0, CI=1.2–14), HCB (OR=5.3, CI=1.6–19), sum of chlordanes (OR=4.0, CI=1.2–14) and TBDE (OR=21, CI=4.6–124), suggesting an interaction between EBV and a higher concentration of these chemicals. Also for the “sum of immunotoxic PCBs” increased risk was found in that group (OR=6.4, CI=1.9–24). Subdivision of NHL in histological types yielded highest risks for low-grade B-cell NHL.

Polybrominated diphenyl ethers detected in human adipose tissue from Spain.

Polybrominated diphenyl ethers (PBDEs) were detected in 13 human adipose tissue samples from Spain, 3 women and 10 men. Tetra-, penta- and hexabrominated diphenyl ethers were determined at ng/g lipid (ppb) level in all the samples. The average TeBDE level was 1.36 ng/g, the average PeBDE was 0.93 ng/g and the HxBDE 1.83 ng/g. Human adipose tissue levels of PBDE obtained in the current samples from Spain are comparable with the tissue levels reported in recent Swedish investigations.

Absorption of polychlorinated biphenyls, dibenzo-p-dioxins and dibenzofurans by breast-fed infants

The absorption of polychlorinated biphenyls, dibenzo-p-dioxins and dibenzofurans was studied in four breast-fed infants. The absorption was measured by comparing the estimated total intake and the excretion in faeces, during 48 hours, at three different time points; 1, 2 and 3 months post parta. The levels of the analysed compounds in the human milk are typical for Sweden, i.e approximately 20 ppt toxic equivalents for the dibenzo-p-dioxins and dibenzofurans and for the polychlorinated biphenyls approximately 16 ppt toxic equivalents. For most of the congeners the absorption is found to be over 95%. Higher excretion is noticed for heptachlorinated and octachlorinated dioxins.

Analytical challenges hamper perfluoroalkyl research

The growing concern over these organohalogens, some of which have been found in human blood and appear to be widespread in the environment, led researchers to gather in Hamburg, Germany, in 2003 to evaluate the current state of methods to analyze for the organic contaminants. Jonathan Martin of the University of Toronto and 20 colleagues from industry, government, and academia summarize the main recommendations from the workshop.

Adipose tissue concentrations of persistent organic pollutants and the risk of prostate cancer.

Objective: We sought to study the concentrations of certain persistent organic pollutants with endocrine-disrupting properties in cases with prostate cancer and controls with benign prostate hyperplasia. Methods: Adipose tissue was obtained from 58 cases and 20 controls. Results: The median concentration among controls was used as cut-off in the statistical analysis. In the total material, a greater-than median concentration of PCB congener 153 yielded an odds ratio (OR) of 3.15 and 95% confidence interval (CI) of 1.04–9.54 and one chlordane type, trans-chlordane, yielded OR 3.49 (95% CI = 1.08–11.2). In the group of case subjects with PSA levels greater than the median level of 16.5 ng/mL, PCB 153 was OR 30.3 (95% CI = 3.24–284), hexachlorobenzene OR = 9.84 (95% CI = 1.99–48.5), trans-chlordane OR = 11.0 (95% CI = 1.87–64.9), and the chlordane-type MC6 OR = 7.58 (95% CI = 1.65–34.9). The grouping of PCBs according to structural and biological activity was found to produce significantly increased risks for enzyme and phenobarbital-inducing PCBs and lower chlorinated PCBs in the case group with PSA levels greater than 16.5 ng/mL. Conclusions: These chemicals might be of etiologic significance but need to be further investigated. The biological relevance of the arbitrary cut-off point of PSA is unclear.