Biomonitoring of Polybrominated Dioxins & Furans, Polychlorinated Dioxins & Furans, and Dioxin Like Polychlorinated Biphenyls in Vietnamese Female Electronic Waste Recyclers.

OBJECTIVE: E-waste is rising globally. This is a follow up to our study reporting metals/polybrominated diphenyl ethers (PBDE's)/polychlorinated biphenyls (PCBs) in female e-waste recyclers. Here we report polybrominated, polychlorinated dioxins/furans, and dioxin-like polychlorinated biphenyls in these same workers. METHODS: Female Vietnamese recyclers and non-recyclers recruited; blood samples collected. Polybrominated, polychlorinated dioxins/furans, and dioxin-like polychlorinated biphenyls levels compared in recyclers, non-recyclers, and National Health and Nutrition Examination Surveys (NHANES). RESULTS: Recyclers >non-recyclers: 12378-PBDD, 2378-TBDF, 12378-PCDF, 123478-HxCDF, 123678-HxCDF, 1234678-HpCDF, PCB-126. Non-recyclers >NHANES: 123478-HxCDF, 123678-HxCDF, 234678- HxCDF, PCB-126, PCB-169. NHANES >non-recyclers: 12378-PCDD, 123478-HxCDD, 123678-HxCDD, 123789-HxCDD, 1234678-HpCDD, 123789-HxCDF, 1234678-HpCDF, 1234789-HpCDF, OCDF, PCB-81, PCB-114, PCB-156, PCB-157, PCB-167, PCB-189. Recyclers >NHANES: S: 2378-TeCDF, 12378-PCDF, 23478-PCDF, 123478-HxCDF, 123678- HxCDF, 234678-HxCDF, PCB-126. NHANES >recyclers: 12378-PCDD, 123478-HxCDD, 123678-HxCDD, 123789-HxCDD, 1234678-HpCDD, OCDD, 123789-HxCDF, 1234678-HpCDF, 1234789-HpCDF, OCDF, PCB- 81, PCB-114, PCB-156, PCB-157, PCB-189. CONCLUSION: 12378 PCDD, 2378-TCDD, PCB 126 makeup most total dioxin equivalences (TEQs) in AQ5 these workers, indicating increased exposure; remediation indicated.

Retention of polybrominated diphenyl ethers and hydroxylated metabolites in paired human serum and milk in relation to CYP2B6 genotype.

Polybrominated diphenyl ethers (PBDEs) and their hydroxylated metabolites (OH-BDEs) are endocrine disrupting compounds prevalent in human serum and breast milk. Retention of PBDEs and OH-BDEs in humans may be affected by differences in PBDE metabolism due to variants in cytochrome P450 2B6 (CYP2B6). The objectives of this study are to assess the partitioning profiles of PBDEs and OH-BDEs in forty-eight paired human serum and milk samples, and to evaluate the relationship between variants in CYP2B6 genotype and PBDE and OH-BDE accumulation in humans. Results show that the geometric mean (GM) concentrations of PBDEs are similar in serum (GM = 43.4 ng/g lipid) and milk samples (GM = 52.9 ng/g lipid), while OH-BDEs are retained primarily in serum (GM = 2.31 ng/g lipid), compared to milk (GM = 0.045 ng/g lipid). Participants with CYP2B6*6 genotype had a greater relative retention of PBDEs in serum and milk, and significant relationships (p <  0.05) were also observed for PBDE-47, 5-OH-BDE-47 and 6-OH-BDE-47 concentrations relative to CYP2B6*5 and CYP2B6*6 genotypes. These results are the first to show that CYP2B6 genotype is significantly related to the relative retention of PBDEs in humans, which may have direct implications for variability in the susceptibility of individuals to the potential adverse effects of these contaminants.

Biomonitoring of Metals, Polybrominated Diphenyl Ethers, Polychlorinated Biphenyls, and Persistent Pesticides in Vietnamese Female Electronic Waste Recyclers.

OBJECTIVE: Electronic waste is increasing. It is frequently recycled in developing countries. This is the first study to report metals, polybrominated diphenyl-ethers (PBDEs), polychlorinated biphenyls (PCBs), 2,2-bis(4-chlorophenyl)-1,1,1-trichloroethane (p,p'-DDT), and p,p'-DDE concentrations in female e-waste workers. METHODS: Female Vietnamese recyclers and non-recyclers were studied. Metals and halogenated organics were measured in blood and urine, and compared with levels in women in the US National Health and Nutrition Examination Survey (NHANES). RESULTS: Recyclers had higher serum PBDE than nonrecyclers. PCB-138/158 and PCB-153 were higher in 18 to less than 38-year-old nonrecyclers. Median urinary arsenic in both cohorts was six to seven-fold higher than NHANES. Median lead in blood and urine was 40% to 60% higher in recyclers than nonrecyclers. Lead in nonrecyclers was four to six-fold higher than NHANES. Both cohorts had higher arsenic and mercury than NHANES. CONCLUSION: Occupational exposure to PBDEs and lead occurred in recyclers. Environmental exposure to arsenic, lead, and mercury occurred in both cohorts. Occupational and environmental remediation are recommended.

"One-shot" analysis of polybrominated diphenyl ethers and their hydroxylated and methoxylated analogs in human breast milk and serum using gas chromatography-tandem mass spectrometry.

The presence of polybrominated diphenyl ethers (PBDEs) and their hydroxylated (OH-BDE) and methoxylated (MeO-BDE) analogs in humans is an area of high interest to scientists and the public due to their neurotoxic and endocrine disrupting effects. Consequently, there is a rise in the investigation of the occurrence of these three classes of compounds together in environmental matrices and in humans in order to understand their bioaccumulation patterns. Analysis of PBDEs, OH-BDEs, and MeO-BDEs using liquid chromatography-mass spectrometry (LC-MS) can be accomplished simultaneously, but detection limits for PBDEs and MeO-BDEs in LC-MS is insufficient for trace level quantification. Therefore, fractionation steps of the phenolic (OH-BDEs) and neutral (PBDEs and MeO-BDEs) compounds during sample preparation are typically performed so that different analytical techniques can be used to achieve the needed sensitivities. However, this approach involves multiple injections, ultimately increasing analysis time. In this study, an analytical method was developed for a "one-shot" analysis of 12 PBDEs, 12 OH-BDEs, and 13 MeO-BDEs using gas chromatography with tandem mass spectrometry (GC-MS/MS). This overall method includes simultaneous extraction of all analytes via pressurized liquid extraction followed by lipid removal steps to reduce matrix interferences. The OH-BDEs were derivatized using N-(t-butyldimethylsilyl)-N-methyltrifluoroacetamide (TBDMS-MTFA), producing OH-TBDMS derivatives that can be analyzed together with PBDEs and MeO-BDEs by GC-MS/MS in "one shot" within a 25-min run time. The overall recoveries were generally higher than 65%, and the limits of detection ranged from 2 to 14 pg in both breast milk and serum matrices. The applicability of the method was successfully validated on four paired human breast milk and serum samples. The mean concentrations of total PBDEs, OH-BDEs, and MeO-BDEs in breast milk were 59, 2.2, and 0.57 ng g(-1) lipid, respectively. In serum, the mean total concentrations were 79, 38, and 0.96 ng g(-1) lipid, respectively, exhibiting different distribution profiles from the levels detected in breast milk. This "one-shot" GC-MS/MS method will prove useful and cost-effective in large-scale studies needed to further understand the partitioning behavior, and ultimately the adverse health effects, of these important classes of brominated flame retardants in humans.

Exposure assessment of adult intake of bisphenol A (BPA) with emphasis on canned food dietary exposures.

Bisphenol A (BPA) is a high-volume, synthetic compound found in epoxy resins and plastics used in food packaging. Food is believed to be a major source of BPA intake. In this study, we measured the concentration of BPA in convenience samplings of foodstuffs purchased in Dallas, Texas. Sampling entailed collection of 204 samples of fresh, frozen, and canned foods in two rounds in 2010. BPA was positive in 73% of the canned food samples, while it was found in only 7% of non-canned foods at low concentrations. The results of this food sampling program were used to calculate adult dietary intakes of BPA. A pathway approach combined food intakes, a "canned fraction" parameter which described what portion of total intake of that food came from canned products, and measured food concentrations. Dietary intakes were calculated as 12.6 ng/kg-day, of which 12.4 ng/kg-day was from canned foods. Canned vegetable intakes alone were 11.9 ng/kg-day. This dietary intake was compared to total intakes of BPA estimated from urine measurements of the National Health and Nutrition Examination Survey (NHANES). Total adult central tendency intakes ranged from 30 to 70 ng/kg-day for NHANES cycles between 2005 and 2010. Three possibilities were explored to explain the difference between these two approaches for intake estimation. Not all foods which may have been canned, particularly canned beverages such as soft drinks, were sampled in our food sampling program. Second, non-food pathways of exposure may be important for adults, including thermal paper exposures, and dust and air exposures. Finally, our canned food concentrations may not be adequately representative of canned foods in the United States; they were found to be generally lower compared to canned food concentrations measured in six other worldwide food surveys including three in North America. Our finding that canned food concentrations greatly exceeded non-canned concentrations was consistent with other studies, and underscores the importance of canned foods in the overall exposure of adults of BPA.

Polybrominated diphenyl ethers, 2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153), and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) concentrations in sera collected in 2009 from Texas children.

Polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) have been measured in surplus serum collected in 2009 from a convenience sample of 300 Texas children (boys and girls) in the birth to 13 years of age range. Serum concentrations of traditional persistent organic pollutants such as 2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153) and p,p'-DDE did not change consistently with age. By contrast, serum concentrations of tetra-, penta-, and hexa-BDEs were lowest in the youngest children (birth to two year old) and increased 3.0 to 7.9 times, depending on the analyte, for children in the >4 to 6 years of age group. From the apex concentration to the 10 to 13 years of age group, concentrations decreased significantly except for 2,2',4,4',5,5'-hexabromodiphenyl ether (PBDE-153), which also had a longer apex concentration of >4 to 8 years of age. This concentration trend for PBDE-153 is most likely due to a longer half-life of PBDE-153 than of other PBDE congeners. The observed PBDEs concentration patterns by age may be related, at least in part, to ingestion of residential dust containing PBDEs through hand-to-mouth behavior among toddlers, preschoolers, and kindergarteners. Further studies to characterize young children's exposure to PBDEs are warranted and, in particular, to determine the lifestyle factors that may contribute to such exposures.

Phthalate concentrations and dietary exposure from food purchased in New York State.

BACKGROUND: Phthalates have been found in many personal care and industrial products, but have not previously been reported in food purchased in the United States. Phthalates are ubiquitous synthetic compounds and therefore difficult to measure in foods containing trace levels. Phthalates have been associated with endocrine disruption and developmental alteration. OBJECTIVES: Our goals were to report concentrations of phthalates in U.S. food for the first time, specifically, nine phthalates in 72 individual food samples purchased in Albany, New York, and to compare these findings with other countries and estimate dietary phthalate intake. METHODS: A convenience sample of commonly consumed foods was purchased from New York supermarkets. Methods were developed to analyze these foods using gas chromatography-mass spectroscopy. Dietary intakes of phthalates were estimated as the product of the food consumption rate and concentration of phthalates in that food. RESULTS: The range of detection frequency of individual phthalates varied from 6% for dicyclohexyl phthalate (DCHP) to 74% for di-2-ethylhexyl phthalate (DEHP). DEHP concentrations were the highest of the phthalates measured in all foods except beef [where di-n-octyl phthalate (DnOP) was the highest phthalate found], with pork having the highest estimated mean concentration of any food group (mean 300 ng/g; maximum, 1,158 ng/g). Estimated mean adult intakes ranged from 0.004 µg/kg/day for dimethyl phthalate (DMP) to 0.673 µg/kg/day for DEHP. CONCLUSIONS: Phthalates are widely present in U.S. foods. While estimated intakes for individual phthalates in this study were more than an order of magnitude lower than U.S. Environmental Protection Agency reference doses, cumulative exposure to phthalates is of concern and a more representative survey of U.S. foods is indicated.

Hexabromocyclododecane (HBCD) stereoisomers in U.S. food from Dallas, Texas.

BACKGROUND: Hexabromocyclododecane (HBCD) is a brominated flame retardant used in polystyrene foams in thermal insulation and electrical equipment. The HBCD commercial mixture consists mainly of α, ß, and γ stereoisomers. Health concerns of HBCD exposure include alterations in immune and reproductive systems, neurotoxic effects, and endocrine disruption. Stereoisomer-specific levels of HBCD have not been measured previously in U.S. food. OBJECTIVES: We measured HBCD stereoisomer levels in U.S. foods from Dallas, Texas, supermarkets. METHODS: Convenience samples of commonly consumed foods were purchased from supermarkets in Dallas in 2009-2010. Food samples included a wide variety of lipid-rich foods: fish, peanut butter, poultry, pork, and beef. Thirty-six individual food samples were collected in 2010 and analyzed for α-, ß-, and γ-HBCD stereoisomers using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Ten pooled food samples previously collected in 2009 for a study of total HBCD levels using gas chromatography-mass spectrometry (GC-MS), were reanalyzed for α-, ß-, and γ-HBCD stereoisomers using LC-MS/MS. RESULTS: Of the 36 measured individual foods, 15 (42%) had detectable levels of HBCD. Median (ranges) of α- and γ-HBCD concentrations were 0.003 (< 0.005-1.307) and 0.005 (< 0.010-0.143) ng/g wet weight (ww), respectively; ß-HBCD was present in three samples with a median (range) of 0.003 (< 0.005-0.019) ng/g ww. Median levels (range) for α-, ß-, and γ-HBCD, in pooled samples were 0.077 (0.010-0.310), 0.008 (< 0.002-0.070), and 0.024 (0.012-0.170) ng/g ww, respectively. CONCLUSIONS: α-HBCD was detected most frequently and at highest concentrations, followed by γ-, and then ß-HBCD, in food samples from Dallas, Texas. Food may be a substantial contributor to the elevated α-HBCD levels observed in humans. These data suggest that larger and more representative sampling should be conducted.

Polyfluoroalkyl compounds in Texas children from birth through 12 years of age.

BACKGROUND: For > 50 years, polyfluoroalkyl compounds (PFCs) have been used worldwide, mainly as surfactants and emulsifiers, and human exposure to some PFCs is widespread. OBJECTIVES: Our goal was to report PFC serum concentrations from a convenience sample of Dallas, Texas, children from birth to < 13 years of age, and to examine age and sex differences in PFC concentrations. METHODS: We analyzed 300 serum samples collected in 2009 for eight PFCs by online solid phase extraction-high performance liquid chromatography-isotope dilution-tandem mass spectrometry. RESULTS: Perfluorohexane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) were detected in > 92% of participants; the other PFCs measured were detected less frequently. Overall median concentrations of PFOS (4.1 ng/mL) were higher than those for PFOA (2.85 ng/mL), PFNA (1.2 ng/mL), and PFHxS (1.2 ng/mL). For PFOS, PFOA, PFNA, and PFHxS, we found no significant differences (p < 0.05) by sex, significantly increasing concentrations for all four chemicals by age, and significantly positive correlations between all four compounds. CONCLUSIONS: We found no significant differences in the serum concentrations of PFOS, PFOA, PFNA, and PFHxS by sex, but increasing concentrations with age. Our results suggest that these 300 Texas children from birth through 12 years of age continued to be exposed to several PFCs in late 2009, years after changes in production of some PFCs in the United States.

Contamination of U.S. butter with polybrominated diphenyl ethers from wrapping paper.

OBJECTIVES: Our aim was to report the first known incidence of U.S. butter contamination with extremely high levels of polybrominated diphenyl ethers (PBDEs). METHODS: Ten butter samples were individually analyzed for PBDEs. One of the samples and its paper wrapper contained very high levels of higher-brominated PBDEs. Dietary estimates were calculated using the 2007 U.S. Department of Agriculture Loss-Adjusted Food Availability data, excluding the elevated sample. RESULTS: The highly contaminated butter sample had a total upper bound PBDE level of 42,252 pg/g wet weight (ww). Levels of brominated diphenyl ether (BDE)-206, -207, and -209 were 2,000, 2,290, and 37,600 pg/g ww, respectively. Its wrapping paper contained a total upper-bound PBDE concentration of 804,751 pg/g ww, with levels of BDE-206, -207, and -209 of 51,000, 11,700, and 614,000 pg/g, respectively. Total PBDE levels in the remaining nine butter samples ranged from 180 to 1,212 pg/g, with geometric mean of 483 and median of 284 pg/g. Excluding the outlier, total PBDE daily intake from all food was 22,764 pg/day, lower than some previous U.S. dietary intake estimates. CONCLUSION: Higher-brominated PBDE congeners were likely transferred from contaminated wrapping paper to butter. A larger representative survey may help determine how frequently PBDE contamination occurs. Sampling at various stages in food production may identify contamination sources and reduce risk.

Does flying present a threat of polybrominated diphenyl ether exposure?

OBJECTIVE: To investigate possible exposure to polybrominated diphenyl ethers (PBDEs) in US professional airline workers. METHODS: We recruited 30 healthy US professional airline workers who lived in the Dallas, Texas, area to test their blood PBDE levels. We examined the relationship between hours worked in an airplane and total PBDE blood levels. RESULTS: Total PBDE blood levels from the 30 volunteers were unremarkable despite minor elevations of certain congeners in a few volunteers. No statistically significant correlations were noted between hours in airplanes in the past 1 or 5 years and levels of individual brominated diphenyl ethers congeners or total PBDEs. CONCLUSIONS: We hypothesized that elevated PBDE levels in commercial aviation workers could be found associated with time spent in airliners. Our findings do not support such an association.

Bisphenol A (BPA) in U.S. food.

Bisphenol A (BPA) is a chemical used for lining metal cans and in polycarbonate plastics, such as baby bottles. In rodents, BPA is associated with early sexual maturation, altered behavior, and effects on prostate and mammary glands. In humans, BPA is associated with cardiovascular disease, diabetes, and male sexual dysfunction in exposed workers. Food is a major exposure source. We know of no studies reporting BPA in U.S. fresh food, canned food, and food in plastic packaging in peer reviewed journals. We measured BPA levels in 105 fresh and canned foods, foods sold in plastic packaging, and in cat and dog foods in cans and plastic packaging. We detected BPA in 63 of 105 samples, including fresh turkey, canned green beans, and canned infant formula. Ninety-three of these samples were triplicates which had similar detected levels. Detected levels ranged from 0.23 to 65.0 ng/g ww and were not associated with type of food or packaging but did vary with pH. BPA levels were higher for foods of pH 5 compared to more acidic and alkaline foods. Detected levels were comparable to those found by others. Further research is indicated to determine BPA levels in U.S. food in larger, representative sampling.

Dietary intake is associated with phthalate body burden in a nationally representative sample.

BACKGROUND: Phthalates are compounds that are used in a wide range of consumer products. However, the contribution of dietary intake to phthalate exposure has not been well defined. OBJECTIVE: The objective of this study was to assess the contribution of different food types to phthalate exposure. Phthalates are chemicals of concern because of the high levels measured in people and the environment, as well as the demonstrated toxicity in animal studies and limited epidemiological studies. Previous research, although limited, has suggested that phthalates contaminate food in various countries. METHODS: We conducted an exploratory analysis of data collected as part of the 2003-2004 National Health and Nutrition Examination Survey (NHANES). Associations between dietary intake (assessed by a 24-hr dietary recall) for a range of food types (meat, poultry, fish, fruit, vegetable, and dairy) and phthalate metabolites measured in urine were analyzed using multiple linear regression modeling. RESULTS: We found that metabolites of di-(2-ethylhexyl) phthalate (DEHP) and high-molecular-weight phthalate metabolites were associated with the consumption of poultry. Monoethyl phthalate, the metabolite of diethyl phthalate (DEP), was associated with vegetable consumption, specifically tomato and potato consumption. DISCUSSION: These results, combined with results from previous studies, suggest that diet is an important route of intake for phthalates. Further research is needed to determine the sources of food contamination with these toxic chemicals and to describe the levels of contamination of U.S. food in a large, representative U.S. sample.

Perfluorinated compounds, polychlorinated biphenyls, and organochlorine pesticide contamination in composite food samples from Dallas, Texas, USA.

OBJECTIVES: The objective of this article is to extend our previous studies of persistent organic pollutant (POP) contamination of U.S. food by measuring perfluorinated compounds (PFCs), organochlorine pesticides, and polychlorinated biphenyls (PCBs) in composite food samples. This study is part of a larger study reported in two articles, the other of which reports levels of polybrominated diphenyl ethers and hexabromocyclododecane brominated flame retardants in these composite foods [Schecter et al. 2010. Polybrominated diphenyl ethers (PBDEs) and hexabromocyclodecane (HBCD) in composite U.S. food samples, Environ Health Perspect 118:357-362]. METHODS: In this study we measured concentrations of 32 organochlorine pesticides, 7 PCBs, and 11 PFCs in composite samples of 31 different types of food (310 individual food samples) purchased from supermarkets in Dallas, Texas (USA), in 2009. Dietary intake of these chemicals was calculated for an average American. RESULTS: Contamination varied greatly among chemical and food types. The highest level of pesticide contamination was from the dichlorodiphenyltrichloroethane (DDT) metabolite p,p -dichlorodiphenyldichloroethylene, which ranged from 0.028 ng/g wet weight (ww) in whole milk yogurt to 2.3 ng/g ww in catfish fillets. We found PCB congeners (28, 52, 101, 118, 138, 153, and 180) primarily in fish, with highest levels in salmon (PCB-153, 1.2 ng/g ww; PCB-138, 0.93 ng/g ww). For PFCs, we detected perfluorooctanoic acid (PFOA) in 17 of 31 samples, ranging from 0.07 ng/g in potatoes to 1.80 ng/g in olive oil. In terms of dietary intake, DDT and DDT metabolites, endosulfans, aldrin, PCBs, and PFOA were consumed at the highest levels. CONCLUSION: Despite product bans, we found POPs in U.S. food, and mixtures of these chemicals are consumed by the American public at varying levels. This suggests the need to expand testing of food for chemical contaminants.

Polybrominated diphenyl ethers (PBDEs) and hexabromocyclodecane (HBCD) in composite U.S. food samples.

OBJECTIVES: This study was designed to update previous U.S. market basket surveys of levels and polybrominated diphenyl ether (PBDE) dietary intake calculations. This study also quantifies hexabromocyclododecane (HBCD) levels in U.S.-purchased foods for the first time and estimates U.S. dietary intake of HBCD. This is part of a larger market basket study reported in two companion articles, of current levels of certain persistent organic pollutants (POPs) PBDEs, HBCD, perfluorinated compounds, polychlorinated biphenyls, and pesticides in composite food samples collected in 2008-2009. METHODS: In this study, we measured concentrations of 24 PBDE congeners and total HBCD in composite samples of 31 food types (310 samples). U.S. dietary intake of PBDEs and HBCD was estimated referencing the most current U.S. Department of Agriculture loss-adjusted food availability report. RESULTS: Total PBDE concentrations in food varied by food type, ranging from 12 pg/g wet weight (ww) in whole milk to 1,545 pg/g ww in canned sardines and 6,211 pg/g ww in butter. Total HBCD concentrations also varied substantially within and among food groups, ranging from 23 pg/g in canned beef chili to 593 pg/g in canned sardines. HBCD was not detected in any dairy samples. Dietary intake of all PBDE congeners measured was estimated to be 50 ng/day, mostly from dairy consumption but also from meat and fish. HBCD intake was estimated at 16 ng/day, primarily from meat consumption. CONCLUSION: PBDEs and HBCDs currently contaminate some food purchased in the United States, although PBDE intake estimated in this study is lower than reported in our previous market basket surveys. HBCD is in food at higher levels than expected based on previously reported levels in milk and blood compared with PBDE levels and is comparable to European levels.

Partitioning of polybrominated diphenyl ethers (PBDEs) in serum and milk from the same mothers.

We and others have previously described partitioning of chemicals, including polychlorinated-p-dioxins, dibenzofurans, and biphenyls in different types of human tissues and fluids, including blood and milk. Additionally, we previously reported the blood to milk partitioning of polybrominated diphenyl ethers (PBDEs) in a group of 11 women. Partitioning is of importance in understanding the toxicokinetics of these compounds and also in clinical medicine in improving estimates of levels in different matrices including blood and milk. In this study we extend these findings, describing the levels of PBDEs detected in the serum and milk of 29 women from Texas. The median sum of the levels of the four most detected congeners (BDE 47, 99, 100, and 153) in serum was 27.8 ng g(-1) lipid (range 6.7-501.6 ng g(-1) lipid). In milk, the median sum of the levels of the same congeners was 39.7 ng g(-1) lipid (range 12.9-580.3 ng g(-1) lipid). The levels detected in breast milk in this study are similar to those we reported in 2003, where a median total PBDE level of 34 ng g(-1) lipid was reported. When congener specific blood to milk partitioning ratios were calculated for BDEs 47, 99, 100, and 153, the relatively small tetrabrominated congener, BDE 47, was found in higher concentrations in milk compared to blood, while the higher molecular weight hexabrominated congener, BDE 153, was found in approximately equal quantities in blood and milk, on a lipid normalized basis. The reason for the differential partitioning of PBDE congeners in milk and blood could be due to variation in toxicokinetics, specifically distribution based on molecular size or molecular weight.

Discussion of "Polybrominated diphenyl ethers in aircraft cabins--a source of human exposure?" by Anna Christiansson et al. [Chemosphere 73(10) (2008) 1654-1660].

This paper presents new data on the levels of polybrominated diphenyl ethers (PBDEs) in American airline workers. This pilot study did not find elevated total PBDEs in the blood of nine flight attendants and one aircraft pilot who have worked in airplanes for at least the past 5 years. These findings are not consistent with the findings of elevated blood levels of PBDEs from the 2008 Christiansson et al. publication "Polybrominated diphenyl ethers in aircraft cabins - A source of human exposure?" We agree that more research needs to be done on larger, more representative samples of airline workers to better characterize exposure of airline workers and other frequent flyers to PBDEs.

Polybrominated diphenyl ether levels in foodstuffs collected from three locations from the United States.

OBJECTIVES: The objectives of this study were to provide updated measurements of PBDEs in US food, to estimate possible difference in levels from differing geographical regions, and to provide an improved estimate of current dietary intake. METHODS: Thirty matched food samples for a total of 90 samples were collected from each of three cities (Los Angeles, California; Dallas, Texas; and Albany, New York) and were analyzed for 13 polybrominated diphenyl ether congeners (BDE 28, 47, 49, 66, 85, 99, 100, 138, 153, 154, 183, 203, and 209). Dietary intake of PBDEs was estimated by food type, age, and sex. RESULTS: In this pilot study, we did not note a statistically significant difference in total PBDE levels in food collected from the three locations. The median total PBDE levels (estimating non-detected values as half of the detection limit) in meat, dairy, eggs, and fish were 267 pg/g wet weight (ww) (range 102-3156 pg/g ww), 176 pg/g ww (range 41-954 pg/g ww), 637 pg/g ww (range 193-932 pg/g ww), and 243 pg/g ww (range 36-2161 pg/g ww). PBDE intake from food was estimated to range from 2.7 ng/kg/day for children 2 through 5 years of age to 0.8 ng/kg/day for women aged 60 years and older. This compares closely with our previous study where the intake estimate was 2.7 ng/kg/day for children 2 through 5 years of age and 0.9 ng/kg/day for women aged 60 years and older. CONCLUSION: We did not find a decrease of PBDEs in food since our previous studies which we expected to find due to the declining use of PBDEs in the USA. These findings could be consistent with food contamination from depot sources of PBDEs. A larger, more representative sampling of the US food supply is indicated based on our findings.