Ioannis Athanassiadis

Children show highest levels of polybrominated diphenyl ethers in a California family of four: a case study.

Polybrominated diphenyl ethers (PBDEs), a major class of flame retardants, are ubiquitous environmental contaminants with particularly high concentrations in humans from the United States. This study is a first attempt to report and compare PBDE concentrations in blood drawn from a family. Serum samples from family members collected at two sampling occasions 90 days apart were analyzed for PBDE congeners. Concentrations of the lower-brominated PBDEs were similar at the two sampling times for each family member, with children’s levels 2- to 5-fold higher than those of their parents. Concentrations of, for example, 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) varied from 32 ng/g lipid weight (lw) in the father to 60, 137, and 245 ng/g lw in the mother, child, and toddler, respectively. Decabromodiphenyl ether (BDE-209) concentrations differed significantly between the two samplings. September concentrations in the father, mother, child, and toddler were 23, 14, 143, and 233 ng/g lw, respectively. December concentrations (duplicate results from the laboratory) were 2 and 3, 4 and 4, 9 and 12, and 19 and 26 ng/g lw, respectively. Parents’ ∑PBDE concentrations approached U.S. median concentrations, with children’s concentrations near the maximum (top 5%) found in U.S. adults. The youngest child had the highest concentrations of all PBDE congeners, suggesting that younger children are more exposed to PBDEs than are adults. Our estimates indicate that house dust contributes to children’s higher PBDE levels. BDE-209 levels for all family members were 10-fold lower at the second sampling. The short half-life of BDE-209 (15 days) indicates that BDE-209 levels can decrease rapidly in response to decreased exposures. This case study suggests that children are at higher risk for PBDE exposures and, accordingly, face higher risks of PBDE-related health effects than adults.

Temporal trends of polybrominated diphenyl ethers and hexabromocyclododecane in milk from Stockholm mothers, 1980-2004.

Environmental and human exposures to brominated flame retardants (BFR) have been of emerging concern since some BFR are persistent and bioaccumulative compounds. Among those, polybrominated diphenyl ethers (PBDE) have frequently been reported in low to high ng/g concentrations in human blood around the world while hexabromocyclododecane (HBCDD) only occasionally has been reported and then in the low ppb concentrations in human blood. The present study concerns PBDE congener and HBCDD concentrations in human milk from Stockholm from 1980 to 2004. HBCDD concentrations has increased four to five times since 1980 until 2002 but seems to have stabilized at this concentration in the last years (2003/04). Similarly, BDE-153 has continued to increase at least to 2001, after which it has stabilized in the mothers milk. Other PBDE congeners with four to five bromine substituents peaked 5 years earlier (1995) and are all decreasing. DecaBDE (BDE-209) is not a suitable biomarker for time trend studies according to the present results, showing no changes over time. This is likely due to its short apparent half-life in humans and poor transfer from blood to milk.

Significantly Higher Polybrominated Diphenyl Ether Levels in Young U.S. Children than in Their Mothers

While young children are rarely included in biomonitoring studies, they are presumed to be at greater risk of ingesting environmental contaminants-particularly those that accumulate in foods or shed from consumer products. The widely used fire retardants polybrominated diphenyl ethers (PBDEs) are ubiquitous contaminants in the indoor environment and are widely detected at higher levels in Americans than in individuals from other countries. However, there are only three studies of PBDEs in U.S. children. We hypothesized that PBDEs are present in higher concentrations in young children than their mothers. PBDEs were assessed in blood samples collected concurrently from 20 mothers and their children, ages 1.5 to 4 years. The chemical analyses were performed by GC/MS applying selected ion monitoring. The samples were analyzed for 20 PBDE congeners; 11 were detected. SigmaPBDEs for children were typically 2.8 times higher than for mothers, with median child:mother ratios varying from 2 to 4 for individual congeners. In 19 of 20 families studied, children had higher SigmaPBDE concentrations than their mothers with significant (p < 0.01) concentration differences for five of the PBDE congeners. Decabromodiphenyl ether (BDE-209) was quantitated in 13 children and 9 mothers. Other studies indicate PBDEs are not elevated at birth, suggesting that early life is an intense period of PBDE intake. Childrens increased hand-to-mouth activity, dietary preferences, and exposures from breast milk may result in greater ingestion of PBDEs than adults. These findings suggest that measurements from adults likely do not reflect exposures to young children despite sharing homes and similar diets.

Polybrominated diphenyl ethers in aircraft cabins – a source of human exposure

Commercial aircrafts need a high degree of fire protection for passenger safety. Brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs), may be used for this purpose. Because PBDEs readily absorb to dust particles, aircraft crew and passengers may receive significant PBDEs exposure via inhalation. The aims of this work were to assess whether PBDEs could be found in aircraft cabin dust and whether serum levels of PBDEs increased in passengers after long-distance flights. Hence nine subjects on intercontinental flights collected cabin dust samples, as well as donated blood samples before departure and after return to Sweden. Two subjects who were domestic frequent flyers were also investigated. The levels of PBDEs in dust and serum were determined by GC/MS in electron capture negative ionization (ECNI) mode. Authentic reference substances were used for identification and quantitation. PBDEs were found in all aircraft dust samples at high concentrations, higher than in common household dust. Congener patterns indicated that the technical products PentaBDE, OctaBDE and DecaBDE were used in the aircrafts. Serum concentrations in the travellers were similar to those observed in Swedish residents in general. Post-travel serum levels of BDE-28, BDE-99, BDE-100, BDE-153, and BDE-154 were significantly higher (p<0.05) than concentrations prior to travel. The findings from this pilot study call for investigations of occupational exposures to PBDEs in cabin and cockpit crews.

In Vivo Doses of Acrylamide and Glycidamide in Humans after Intake of Acrylamide-Rich Food

For assessment of cancer risk from acrylamide (AA) exposure through food, the relation between intake from food in humans and the in vivo doses (area under the concentration-time curve, AUC) of AA (AUC-AA) and of its genotoxic metabolite glycidamide (GA) (AUC-GA) is used as a basis for extrapolation between exposure levels and between species. In this study, AA-rich foods were given to nonsmokers: a high intake of 11 μg AA/kg body weight (bw) and day for 4 days or an extra (medium) intake of 2.5 μg AA/kg bw and day for a month. Hemoglobin (Hb)-adduct levels from AA and GA, measured in blood samples donated before and after exposures, were used for calculation of AUC-AA and AUC-GA using reaction rate constants for the adduct formation measured in vitro. Both AA- and GA-adduct levels increased about twofold after the periods with enhanced intake. AUC for the high and medium groups, respectively, in nanomolar hours per microgram AA per kilogram bw, was for AA 212 and 120 and for GA 49 and 21. The AA intake in the high group was better controlled and used for comparisons with other data. The AUCs per exposure dose obtained in the present human study (high group) are in agreement with those previously obtained at 10(2) times higher exposure levels in humans. Furthermore, the values of AUC-AA and AUC-GA are five and two times higher, respectively, than the corresponding values for F344 rats exposed to AA at levels as in published cancer bioassays.

Extensive organohalogen contamination in wildlife from a site in the Yangtze River Delta.

The environmental and human health concerns for organohalogen contaminants (OHCs) extend beyond the 23 persistent organic pollutants (POPs) regulated by the Stockholm Convention. The current, intense industrial production and use of chemicals in China and their bioaccumulation makes Chinese wildlife highly suitable for the assessment of legacy, novel and emerging environmental pollutants. In the present study, six species of amphibians, fish and birds were sampled from paddy fields in the Yangtze River Delta (YRD) were screened for OHCs. Some extensive contamination was found, both regarding number and concentrations of the analytes, among the species assessed. High concentrations of chlorinated paraffins were found in the snake, Short-tailed mamushi (range of 200-340 μg g(-)(1)lw), Peregrine falcon (8-59 μg g(-1)lw) and Asiatic toad (97 μg g(-)(1)lw). Novel contaminants and patterns were observed; octaCBs to decaCB made up 20% of the total polychlorinated biphenyls (PCBs) content in the samples and new OHCs, substituted with 5-8 chlorines, were found but are not yet structurally confirmed. In addition, Dechlorane 602 (DDC-DBF) and numerous other OHCs (DDTs, hexachlorocyclohexanes (HCHs), polybrominated diphenyl ethers (PBDEs), hexbromocyclododecane (HBCDD), chlordane, heptachlor, endosulfan and Mirex) were found in all species analyzed. These data show extensive chemical contamination of wildlife in the YRD with a suite of OHCs with both known and unknown toxicities, calling for further in-depth studies.

Chlorinated and brominated organic contaminants in fish from Shanghai markets: a case study of human exposure.

In the present study were two favorite edible fish species for local residents, i.e., mandarin fish and crawfish, collected from the Shanghai market and analyzed for selected organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), hexabromocyclododecane (HBCDD), polybrominated diphenyl ethers (PBDEs) and methoxylated PBDEs (MeO-PBDEs). Efforts were also made to identify the potential sources of these contaminants. Comparable concentrations of hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs) and HBCDD were found in muscle tissue of mandarin fish from Guangdong (GDF), the Pearl River Delta and from Taihu Lake (TLF), the Yangtze River Delta. Levels of chlordanes, PCBs and PBDEs were about one magnitude lower in TLF compared to GDF. The concentrations of OCPs in the butter-like gland of the crawfish (CFB) were 2-5 times of those in the crawfish muscle (CFM) while concentrations of PCBs, PBDEs and MeO-PBDEs were comparable. The different patterns and levels of chlorinated and brominated organohalogen contaminants seen in mandarin fish from GDF and TLF indicates that different types of chemicals might be used in the two delta regions. The present study also shows a good correlation between the concentrations of hexachlorobenzene (HCB) and pentachloroanisol (PCA) in fish for the first time. Fish consumption limits based on chemical contaminants with non-carcinogenic effects were calculated. The estimated maximum daily consumption limit for GDF, TLF, CFM and CFB were 1.5, 2.6, 3.7 and 0.08 kg, respectively, indicating no significant risk regarding the persistent organic pollutants measured in the present study.

Higher PBDE Serum Concentrations May Be Associated with Feline Hyperthyroidism in Swedish Cats

Serum from 82 individual cats was analyzed for decabromobiphenyl (BB-209), polybrominated diphenyl ethers (PBDEs), hydroxylated PBDEs (OH-PBDEs), and 2,4,6-TBP in order to study differences in body burden between healthy and sick cats diagnosed with Feline Hyperthyroidism (FH). Within the study group, 60 of these cats had a euthyroid (n = 23) or hyperthyroid (n = 37) status, all of which were used in the comparison. This study shows that hyperthyroid compared to euthyroid cats have higher serum concentrations for some of the investigated PBDEs (BDE-99, BDE-153, and BDE-183) and CB-153 on a fat weight basis. Further, it is intriguing, and beyond explanation, why the flame retardant BB-209 (discontinued in 2000) is present in all of the cat serum samples in concentrations similar to BDE-209. Median BDE-47/-99 ratios are 0.47 and 0.32 for healthy and euthyroid cats, respectively, which differs significantly from Swedes, where the ratio is 3.5. Another important finding is the occurrence of very low levels or the absence of hydroxylated PBDE metabolites in the cats. In addition, the major OH-PBDE, 6-OH-BDE47, is likely of natural origin, probably ingested via cat food. The statistics indicate an association between elevated PBDE concentrations in the cats and FH.

Alcohol influence on acrylamide to glycidamide metabolism assessed with hemoglobin-adducts and questionnaire data

Our purpose was to investigate whether alcohol (ethanol) consumption could have an influence on the metabolism of acrylamide to glycidamide in humans exposed to acrylamide through food. We studied a subsample from a population-based case-control study of prostate cancer in Sweden (CAPS). Questionnaire data for alcohol intake estimates was compared to the ratio of hemoglobin-adduct levels for acrylamide and glycidamide, used as a measure of individual differences in metabolism. Data from 161 non-smoking men were processed with regard to the influence of alcohol on the metabolism of acrylamide to glycidamide. A negative, linear trend of glycidamide-adduct to acrylamide-adduct-level ratios with increasing alcohol intake was observed and the strongest association (p-value for trend=0.02) was obtained in the group of men with the lowest adduct levels (47 pmol/g globin) when alcohol intake was stratified by acrylamide-adduct levels. The observed trend is likely due to a competitive effect between ethanol and acrylamide as both are substrates for cytochrome P450 2E1. Our results, strongly indicating that ethanol influence metabolism of acrylamide to glycidamide, partly explain earlier observations of only low to moderate associations between questionnaire data on dietary acrylamide intake and hemoglobin-adduct levels.

Hydroxylated PCB metabolites in nonhatched fulmar eggs from the Faroe Islands.

Abstract Thirty-six polychlorinated biphenylols (OH-PCBs) congeners were characterized in Fulmar (Fulmarus glacialis) eggs collected from the Faroe Islands. The seven most abundant congeners were quantified in 19 samples, and the ΣOH-PCB concentrations ranged between 0.92 and 4.0 ng g−1 fresh weight (f.w.). These eggs constitute a part of the traditional diet for at least a part of the population on the Faroe Islands and may contribute to the high levels of these contaminants found in the blood of pregnant Faroese women. Because the metabolites are present in the nonhatched fulmar egg, it is concluded that the OH-PCBs are transferred to the egg before laying. High levels, 3300–18 000 ng g–1 l.w., of Σpolychlorinated biphenyls (PCB) were determined in the fulmar eggs, which are a considerable source for human exposure. The high PCB levels are a source for metabolic formation of hydroxylated PCBs.