Production and frozen storage of minced Baltic herring (Clupea harengus membras)

The production and storage of minced Baltic herring was investigated to develop a convenient semi-finished product which could be manufactured industrially and stored frozen as such or in the form of pre-manufactured convenience foods. Baltic herring has several disadvantages as a raw material for such use, namely small size, dark colour, strong odour, and soft texture. Dark colouring of the mince can be reduced considerably by skinning. The dark pigments of the belly lining are eliminated on filleting. The strong odour which evolves when Baltic herring is heated can be moderated by adding a small amount of suitable protein such as milk protein. This addition also has a positive influence on the water binding capacity and taste of the mince. The texture is improved by adding barley or wheat starch or possibly by pre-texturing part of the mince by heating to give a heterogeneous structure. Fish are skinned prior to mincing and 0.1–0.2% ascorbic acid or sodium erythorbate is added as antioxidant. The mince is vacuum packed in a gas-tight material such as polyethylene/polyamide laminate. In this way it is possible to store frozen minced Baltic herring at ?25 °C for at least one year. Even after such a period the mince is still quite acceptable and no rancidity or peroxides can be detected. Although it appears that certain adverse protein changes cannot be avoided during frozen storage, their effects can be masked in part by adding milk protein, starch and triphosphate to increase the water-binding capacity and generally improve the functional properties of the mince and mince-based products.     

Modeling relationships between Baltic Sea herring (Clupea harengus) biology and contaminant concentrations using multivariate data analysis

Baltic Sea herring (Clupea harengus) is a pelagic, zoo-planktivorous fish and young (2-5 years old) individuals of this species are sampled annually in the Swedish marine monitoring program. This study determined concentrations of organochlorines (OCs) and brominated flame retardants (BFRs) in dorsal muscle from herring (n = 60) of varying age (2-13 years), weight (25-200 g), and body length (16-29 cm) caught at three locations in the Swedish part of the Baltic Proper. In order to ensure that the fish biology was as varied as possible, though still similar from all sampling sites, the fish to be chemically analyzed were selected from a large number of fish with determined biology using Multivariate Design. In statistical evaluation of the data, univariate and multivariate data analysis techniques, e.g. principal components analysis (PCA), partial least-squares regression (PLS), and orthogonal PLS (OPLS), were used. The results showed that the fish are exposed to a cocktail of contaminants and levels are presented. Significant OPLS models were found for all biological variables versus concentrations of OCs and BFRs, showing that fish biology covaries with fish contaminant concentrations. Correlation coefficients were as high as 0.98 for e.g. βHCH concentration (wet weight) versus the lipid content. Lastly, the OC concentrations in herring muscle were modeled against the BFR concentrations to determine whether concentrations of either could be used to predict the other. It was found that OPLS models allowed BFR concentrations to be predicted from OC concentrations with high, but varying, accuracy (R(2)Ys between 0.93 to 0.75). Thus, fish biology and contaminant concentrations are interwoven, and fish biological parameters can be used to calculate (predict) contaminant concentrations. It is also possible to predict the BFR concentrations in an individual fish from its concentrations of OCs with very high accuracy.     

Influence of salt concentration on properties of marinated meat from fresh and frozen herring (Clupea harengus L.)

Salt concentrations of brine above 10% are still commonly used in fish marinating process. The study has showed an increasing salt concentrations affect to adversely all the properties of marinated herring meat. Increase in salt concentration from 5% to 15% resulted in significantly (P < 0.05) decrease content of water, non‐protein nitrogen and products of protein hydrolysis. Consequently, weight yield of marinated fresh herring decreased from 83% to 74%. The most palatable marinades contained 2–3% NaCl in meat only. The higher salt concentrations applied significantly (P < 0.05) worsened the taste, texture and colour of marinated herring. Texture profile analyses (TPA), free hydroxyproline content and colour analyses (L*a*b) confirmed the negative influence of high salt concentration on the marinades quality. Frozen and thawed herring tissue showed greater sensitivity to salt. Namely, marinades from frozen fish contained by 0.3 more salt (P < 0.05), and the weight yield was by 2.3–10.3 percent point lower than from the fresh herring. Meat from frozen herring when matured has significantly (P < 0.05) lower sensory value, lower content of protein hydrolysis products, free hydroxyproline and higher parameter b* value of than the fresh one.     

Congener-specific tissue distribution and hepatic sequestration of PCDD/Fs in wild herring gulls from Bohai Bay, North China: comparison to coplanar PCBs

Tissue distribution is an important property of pharmacokinetic behaviors of dioxins to provide information for risk assessment to wild avian species. In this study, concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and coplanar polychlorinated biphenyls (coplanar PCBs) were determined in muscle, liver, spleen, kidney, brain, and adipose of wild herring gulls collected from Bohai Bay, North China. Tissue distribution results showed preferential accumulation of PCDD/Fs in liver and of co-PCBs in adipose. The congener patterns of coplanar PCBs were constant in different tissues, but the congener patterns for PCDD/F were tissue-specific. The liver/adipose concentration ratios for PCDD/ Fs were found to increase statistically significantly with log K(ow), providing the quantitative relationship of structure-activity for hepatic sequestration of PCDD/Fs for the first time. Furthermore, this relationship was compared with those developed on the basis of previous results reported in the literature showing that the wild herring gulls in Bohai Bay are still in the exposure period.     

Destruction of the World Trade Center and PCBs, PBDEs, PCDD/Fs, PBDD/Fs, and chlorinated biphenylenes in water, sediment, and sewage sludge

Ash-laden runoff samples collected near Ground Zero soon after the September 11, 2001 attack on the World Trade Center (WTC) and subsequent fire demonstrate the release of polychlorinated biphenyls (PCBs), polybrominated dipheyl ethers (PBDEs), polybrominated dibenzo-p-dioxins and polybrominated dibenzofurans (PBDD/Fs), polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), and tetra- and pentachlorinated biphenylenes (PCBPs) from the incident. Relative abundances of PCDD/F congeners in the runoff water and post-disaster lower Manhattan dust samples were different from those seen in pre-disaster NYC combined sewer outfall (CSO) samples. The WTC-related samples showed a greater relative abundance of 2,3,4,7,8-PeCDF than usually seen in CSOs, sludges, and treated wastewaters. This congener may be associated with certain types of incineration. Comparison of sediment and water samples collected in the lower Hudson River before and shortly after September 11, 2001 (9/11) showed no changes in PCB or PCDD/F concentrations or homologue profiles determined down to the parts per quadrillion range. Comparisons of ambient water samples collected post-9/11 with archived samples suggest that the WTC disaster did not significantly impact ambient concentrations of the target chemicals. Ambient concentrations of PBDD/Fs in New York Harbor are similar to those of PCDD/Fs, suggesting that these contaminants deserve increased scrutiny with respect to toxicity, sources, and fate in the environment.     

Occurrence and destruction of PAHs,PCBs, CIPhs,CIBzs, and PCDD/Fs in ash from gasification of straw

Two experiments were performed with an atmospheric circulating fluidized bed gasifier (ACFBG), the first with pelletized straw and the second with loose straw, to investigate the occurrence of polycyclic aromatic hydrocarbons (PAHs), chlorophenols (CIPhs), polychlorinated biphenyls (PCBs), polychlorinated benzenes (ClBzs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) in the bottom ash and fly ash formed during gasification. Only PAHs were present in large amounts, and only in the fly ash, ranging from 300 to 555 mg/kg ash in the tests with pelletized straw and from 73 to 118 mg/kg ash in those with loose straw. These amounts are so high that environmentally safe disposal or reuse of the ash would be difficult, so the development of a technique to handle the problem was included in the project. The method investigated was to burn the fly ash in a circulating fluidized bed (CFB) boiler in order to destroy the PAHs. This worked surprisingly well, eliminating 99% of the PAHs, without any further formation of the other harmful organic compounds analyzed. Thus, this method could actually be useful in practice. Especially the fact that the formation of PCDD/Fs was minimal during gasification and further treatment of the ash in the CFB boiler makes the gasification technique highly competitive relative to conventional combustion methods.     

Polychlorinated biphenyls (PCBs), dioxins and furans (PCDD/Fs): Occurrence in fishery products and dietary intake

Concentrations and congener specific profiles of PCBs, PCDDs and PCDFs were determined in various edible fish from the Adriatic Sea. PCBs were the dominant chemicals (116–1980 ng g⁻¹ lipid wt), followed by PCDFs (ND-58.3 pg g⁻¹ lipid wt) and PCDDs (ND-20 pg g⁻¹ lipid wt). The levels of these contaminants varied among species. Benthic organisms possessed the highest concentrations, followed by demersal and pelagic fish species. PCB and PCDD/F accumulation pattern in the samples analysed showed a distribution typically reported for marine samples. The mean weekly intake of toxic equivalency (TEQ) was estimated to be 0.84 pg TEQs/kg bw/week. The dioxin-like PCBs accounted for more than 77% of this intake, followed by PCDDs (15.5%) and PCDFs (13.1%). In general, the samples analysed in this survey can be considered safe with regard to the levels obtained and the in-force legislation, nevertheless the consumption of some species may be of significance importance for consumer health.     

Influence of skinning on lipid oxidation in different horizontal layers of herring (Clupea harengus) during frozen storage

This study was conducted to evaluate the effect of skinning and of compositional differences on the oxidative stability of various horizontal layers from herring (Clupea harengus) during frozen storage. Herring fillets, with and without skin, were stored at -18°C for 0, 3, 9, 16 and 28 weeks. After each storage period, the fillets were divided horizontally into three layers: ‘under skin’, ‘middle part’ and ‘inner part’. Each layer was then extracted for total lipids, in which peroxide value (PV), absorbance at 234 nm (A₂₃₄) and 268 nm (A₂₆₈) as well as lipid-soluble fluorescent oxidation products (FP) were measured. Prior to storage, the fat content, fatty acid pattern and α-tocopherol were also analysed. During storage of skinless fillets, the under skin layer increased most in PV, A₂₃₄, A₂₆₈ and FP (P<0·05), followed by the inner and middle parts. In fillets stored with skin, the high oxidation rate of the under skin layer lipids was suppressed, but this layer still gave rise to the highest responses. Firstly, these results point to the protective properties of the skin and, secondly, to the unfavourable composition of the under skin layer: a lot of dark muscle; the silver surface; the highest fat content and the lowest level of α-tocopherol. Concerning the fatty acid pattern in the three layers, the amount of C20: 5, C18:1 and C20:1 in the fat gradually decreased from the under skin layer towards the inner part of the fillet, whereas the opposite was true for C22: 6. © 1998 Society of Chemical Industry.     

Levels of PCDD/Fs, PCBs, and PCNs in soils and vegetation in an area with chemical and petrochemical industries

The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDFs), polychlorinated biphenyls (PCBs), and polychlorinated naphthalenes (PCNs) have been determined in soil and wild chard samples collected in an area of Tarragona County (Catalonia, Spain) with an important number of chemical and petrochemical industries. Samples were also collected in urban/residential zones, as well as in presumably unpolluted sites. In soils, the levels of PCDD/Fs ranged from 0.16 ng I-TEQ/kg (unpolluted sampling points) to 2.65 ng I-TEQ/kg (industrial zone), and those of sigmaPCBs ranged from 657 to 12038 ng/ kg in these same zones. In turn, sigmaPCNs ranged from 32 (unpolluted sites) to 180 ng/kg (residential/urban sites). In contrast to soil concentrations, there were not significant differences among collection zones in the levels of PCDD/Fs, PCBs, and PCNs found in chard. However, PCB and PCN concentrations in chard samples collected at the unpolluted sampling points were higher than the respective concentrations in soils. In general terms, the current concentrations of the organic pollutants analyzed in this study are similar or lower than data from previous reports in other countries.     

The storage of herring (Clupea harengus) in ice,refrigerated sea water and at ambient temperature. Chemical and sensory assessment

Herring caught during the winter and summer were stored in ice, refrigerated sea water (RSW) and at ambient temperature. Chemical tests and a sensory assessment of the fish were made on samples stored for up to 13 days. Results indicate that herring can be chilled simply and rapidly using an RSW plant and that spoilage changes in the fish stored in ice and RSW are similar during the first 4 or 5 days of storage. The chemical tests investigated serve more as indicators of spoilage rather than quantitative guides.     

UK dietary exposure to PCDD/Fs,PCBs, PBDD/Fs,PBBs and PBDEs: comparison of results from 24-h duplicate diets and total diet studies

ABSTRACT

Chemicals in food are monitored to check for compliance with regulatory limits and to evaluate trends in dietary exposures, among other reasons. This study compared two different methods for estimating human dietary exposure to lipophilic persistent organic pollutants (POPs) during 2011/12: (1) the 2012 Total Diet Study (TDS) conducted by the UK Food Standards Agency (FSA) and (2) a 24-h duplicate diet (DD) study of 20 adults from the North East of England. The equivalence of the two approaches was assessed; anything less than an order of magnitude could be considered reasonable and within three-fold (equivalent to 0.5 log) as good. Adult dietary exposure estimates derived from the DD study for both average and high-level (97.5th percentile) consumers compared well with those from the TDS. Estimates from the DD study when compared with those from the TDS were within 10% for P97.5 for total PCDD/F/PCB with divergence increasing to a factor of 3.4 for average BDE-209. Most estimates derived from the TDS were slightly higher than those derived from the DD. Comparison with earlier UK TDS data over the last 30 years or so confirmed a gradual decline in levels of PCDD/F/PCBs in food. Such comparisons also indicated peaks in dietary exposure to ∑PBDE (excluding BDE-209) between 2000 and 2005. Exposure estimates for all measured compounds using both TDS and DD data were found to be within recommended tolerable daily intakes where available or within acceptable margins of exposure.     

Intake estimation of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in salmon: the inclusion of uncertainty

Dioxins and dioxin-like PCBs are given toxic equivalency factors (TEFs) in order to calculate the combined toxic equivalence (TEQ) of these contaminants in a sample of food. This study calculates the probability of an average consumer exceeding the recommended tolerable daily intake of 1-4 pg WHO-TEQ kg^-1 bw day^-1 as the amount of salmon in the diet is increased. Probabilistic risk analysis is used to account for the known uncertainties in this calculation. When the TEF uncertainty was excluded with no salmon consumption, the background dietary intake ranged from 1.36 to 1.78 pg TEQ kg^-1 bw day^-1. A weekly consumption of three standard salmon portions resulted in a 36% chance of exceeding the upper limit of the TDI. Inclusion of the TEF uncertainty increased the background dietary intake range from 2.1 to 4.4 pg TEQ kg^-1 bw day^-1, and the weekly consumption of one salmon portion resulted in a 79% chance of the average consumer exceeding the upper TDI. The most important factors contributing to the uncertainty in these results were, in order of magnitude, the TEF for PCB 126 and the sampling uncertainty (sample size) followed by the measurement uncertainty of PCB 126. We recommend that it is more important to increase sample size and produce more precise estimates in the TEF than to improve analytical accuracy.     

Emissions of PCDD/Fs, PCBs, and PAHs from a modern diesel engine equipped with catalyzed emission control systems

Exhaust emissions of 17 2,3,7,8-substituted chlorinated dibenzo-p-dioxin/furan (CDD/F) congeners, tetra-octa CDD/F homologues, 12 2005 WHO chlorinated biphenyls (CB) congeners, mono-nona CB homologues, and 19 polycyclic aromatic hydrocarbons (PAHs) from a model year 2008 Cummins ISB engine were investigated. Testing included configurations composed of different combinations of aftertreatment including a diesel oxidation catalyst (DOC), catalyzed diesel particulate filter (CDPF), copper zeolite urea selective catalytic reduction (SCR), iron zeolite SCR, and ammonia slip catalyst. Results were compared to a baseline engine out configuration. Testing included the use of fuel that contained the maximum expected chlorine (Cl) concentration of U.S. highway diesel fuel and a Cl level 1.5 orders of magnitude above. Results indicate there is no risk for an increase in polychlorinated dibenzo-p-dioxin/furan and polychlorinated biphenyl emissions from modern diesel engines with catalyzed aftertreatment when compared to engine out emissions for configurations tested in this program. These results, along with PAH results, compare well with similar results from modern diesel engines in the literature. The results further indicate that polychlorinated dibenzo-p-dioxin/furan emissions from modern diesel engines both with and without aftertreatment are below historical values reported in the literature as well as the current inventory value.     

Effect of heating fatty fish: Baltic herring (Clupea harengus membras), European sprat (Sprattus sprattus) and rainbow trout (Oncorhynchus mykiss) on lipid oxidation and contents of eicosapentaenoic and docosahexaenoic acids

In this study, analyses were carried out to establish the impact of heating three species of fatty fish: trouts, herrings and sprats, on the lipids oxidation and on contents of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. The comminuted fish tissue was heated at restricted access of oxygen at temperature of 60, 100 and 160 °C for 15–120 min. Lipids, extracted with the Bligh‐Dyer method, were determined for peroxide value (PV) and anisidine value (AV). The Fatty acid methyl esters were prepared directly from the tissue, whereas contents of EPA and DHA were determined with the GC/MS method. Depending on the temperature applied, 15‐min heating of fish meat tissue caused 30–80% decrease of PN and 20–40% decrease of AV, on average. Generally, the continued heat treatment caused successive decreases in both PV and AV and the rate of this process was observed to increase along with an increasing temperature. The heating of trout and sprats at temperature of 60, 100 and 160 °C even for 1–2 h did not evoke losses either in EPA or in DHA content. In turn, in the case of herring caught during the pre‐spawning season, ca. 90–120 min of heat treatment contributed to ca. 20–25% decrease in contents of these fatty acids.     

PCBs, PCDD/Fs, and organochlorine pesticides in farmed Atlantic salmon from Maine, eastern Canada, and Norway, and wild salmon from Alaska

Farmed Atlantic salmon (Salmo salar) from Maine and eastern Canada, wild Alaskan Chinook salmon (Oncorhynchus tshawytscha), and organically farmed Norwegian salmon samples were analyzed for the presence of polychlorinated biphenyls (PCBs), dioxin-like PCBs, polychlorinated dibenzo-p-dioxins (PCDDs), dibenzo-p-furans (PCDFs), and chlorinated pesticides. PCDD and PCDF congeners were not detected in > 80% of the samples analyzed. Total PCB concentrations (7.2-29.5 ng/g, wet weight, ww) in the farmed salmon were significantly higher than those in the wild Alaskan Chinook samples (3.9-8.1 ng/g, ww). Concentrations of PCBs, WHO PCB TEQs, and chlorinated pesticides varied significantly by region. PCB and WHO PCB TEQ concentrations in farmed salmon from eastern Canada were lower than those reported in samples collected two years earlier, possibly reflecting recent industry efforts to lower contaminant concentrations in feed. Organically farmed Norwegian salmon had the highest concentrations of PCBs (mean: 27 ng/g, ww) and WHO PCB TEQs (2.85 pg/g,ww); their TEQ values are in the higher range of those reported in farmed salmon from around the world. Removal of skin from salmon fillets resulted in highly variable reductions of lipids and contaminants, and in some skin-off samples, contaminant levels were higher, suggesting that skin removal does not protect the consumer from health risks associated with consumption of farmed salmon.     

Spatial variation in hepatic levels and patterns of PCBs and PCDD/Fs among young-of-the-year and adult Atlantic tomcod (Microgadus tomcod) in the Hudson River estuary

Full congener-specific polychorinated biphenyl (PCB) and partial-congener-specific polychorinated dibenzo-p-dioxin/furan (PCDD/F) analyses were performed on livers from young-of-the-year (YOY) and adult Atlantic tomcod from the Hudson River estuary including multiple sites along the main-stem Hudson River and Newark Bay/Hackensack River, NJ, and from a reference river, the Miramichi River, NB. Highest hepatic burdens of PCBs were found in fish collected in the main-stem Hudson River between river miles (RM) 37 and 50 and in Newark Bay/Hackensack River. By far, the highest concentrations of PCDD/Fs were seen in fish from Newark Bay/Hackensack River. The di- to tetrachlorinated biphenyls dominated the PCB composition in YOY tomcod, whereas the penta- to nonachlorinated biphenyls predominated in adults with particular prevalence of the 2,4,5-substituted diortho congeners. Overall, using a direct mixing model an aroclor composition of approximate 1:1:1, A1242:A1254:A1260, was calculated from the hepatic PCB profiles in YOY tomcod. A linear increase in A1242 characteristics with river mile was seen in YOY collected between RM 0 and RM 80, which was likely due to the well-characterized A1242 source from the former capacitor manufacturing plants located upriver. However, tomcod caught upstream of RM 80 exhibited a PCB pattern with decreasing A1242 characteristics, and it was hypothesized that this was due to the increased depuration or decreased uptake of low chlorinated (log K(OW) < 6) congeners upon entry of the fish into freshwater from brackish water. The most abundant tetra-octa PCDD/F chlorohomologue in tomcod collected from the main stem of the Hudson River was TCDF, whereas 2,3,7,8-TCDD was the major congener detected in tomcod from Newark Bay/Hackensack River, which showed elevated total PCDD/F levels compared to tomcod from the main-stem Hudson River.     

Emission factors and importance of PCDD/Fs, PCBs, PCNs, PAHs and PM10 from the domestic burning of coal and wood in the U.K

This paper presents emission factors (EFs) derived for a range of persistent organic pollutants (POPs) when coal and wood were subject to controlled burning experiments, designed to simulate domestic burning for space heating. A wide range of POPs were emitted, with emissions from coal being higher than those from wood. Highest EFs were obtained for particulate matter, PM10, (approximately 10 g/kg fuel) and polycyclic aromatic hydrocarbons (approximately 100 mg/ kg fuel for sigmaPAHs). For chlorinated compounds, EFs were highest for polychlorinated biphenyls (PCBs), with polychlorinated naphthalenes (PCNs), dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) being less abundant. EFs were on the order of 1000 ng/kg fuel for sigmaPCBs, 100s ng/ kg fuel for sigmaPCNs and 100 ng/kg fuel for sigmaPCDD/Fs. The study confirmed that mono- to trichlorinated dibenzofurans, Cl1,2,3DFs, were strong indicators of low temperature combustion processes, such as the domestic burning of coal and wood. It is concluded that numerous PCB and PCN congeners are routinely formed during the combustion of solid fuels. However, their combined emissions from the domestic burning of coal and wood would contribute only a few percent to annual U.K. emission estimates. Emissions of PAHs and PM10 were major contributors to U.K. national emission inventories. Major emissions were found from the domestic burning for Cl1,2,3DFs, while the contribution of PCDD/F-sigmaTEQ to total U.K. emissions was minor.     

Transfer and uptake of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and polychlorinated biphenyls (PCBs) into meat and organs of indoor and outdoor reared pigs

This study was designed to investigate how and to what extent PCDD/Fs and PCBs are transmitted from exposure sources to porcine muscle and other tissues derived from pigs. The experimental approach involved two longitudinal studies in which indoor and outdoor pigs were reared to market readiness using typical animal husbandry practices; closely matched samples of soil, feed, bedding, meat, etc. were collected and analysed for PCDD/Fs and PCBs. The total PCDD/F?+?PCB WHO-TEQs in pig liver were much higher than in meat and kidney samples from the same animals and exceeded the current relevant European Union maximum limits (6?ng PCDD/F-TEQ?kg^?1?fat). Liver samples were also characterised by much lower PCB contributions to the total TEQ than for the corresponding meat and kidney samples, and by a predominance of many of the hepta- and octa-substituted PCDD/Fs. At ages approaching market readiness, TEQ values in meat samples from outdoor pigs tended to be slightly higher than those from comparable ages in the indoor programme, possibly due to additional intake from soil. Biotransfer factors (BTFs) were derived for each of the 39 PCDD/F and PCB congeners measured. Interpretation of the findings focused particularly on trends in four selected congeners, namely: 2,3,7,8-TCDD, 2,3,4,7,8-PeCDF, PCB 153 and PCB 169. Increases in the BTF for PCB 169 in the pig-rearing programmes were noticed when the diet changed from being dominated by sow's milk to feed. Much higher transfer factors for many of the more heavily chlorinated PCDD/Fs (e.g. 2,3,4,7,8-PeCDF) were found in liver compared with meat or kidney samples from the same animals. Soil consistently accounted for at least 30% of input for many hexa- or higher chlorinated PCDD/Fs, while it rarely representing more than 10% of the total intake.     

Transfer and uptake of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and polychlorinated biphenyls (PCBs) into meat and organs of indoor and outdoor reared pigs

This study was designed to investigate how and to what extent PCDD/Fs and PCBs are transmitted from exposure sources to porcine muscle and other tissues derived from pigs. The experimental approach involved two longitudinal studies in which indoor and outdoor pigs were reared to market readiness using typical animal husbandry practices; closely matched samples of soil, feed, bedding, meat, etc. were collected and analysed for PCDD/Fs and PCBs. The total PCDD/F?+?PCB WHO-TEQs in pig liver were much higher than in meat and kidney samples from the same animals and exceeded the current relevant European Union maximum limits (6?ng PCDD/F-TEQ?kg?1?fat). Liver samples were also characterised by much lower PCB contributions to the total TEQ than for the corresponding meat and kidney samples, and by a predominance of many of the hepta- and octa-substituted PCDD/Fs. At ages approaching market readiness, TEQ values in meat samples from outdoor pigs tended to be slightly higher than those from comparable ages in the indoor programme, possibly due to additional intake from soil. Biotransfer factors (BTFs) were derived for each of the 39 PCDD/F and PCB congeners measured. Interpretation of the findings focused particularly on trends in four selected congeners, namely: 2,3,7,8-TCDD, 2,3,4,7,8-PeCDF, PCB 153 and PCB 169. Increases in the BTF for PCB 169 in the pig-rearing programmes were noticed when the diet changed from being dominated by sow's milk to feed. Much higher transfer factors for many of the more heavily chlorinated PCDD/Fs (e.g. 2,3,4,7,8-PeCDF) were found in liver compared with meat or kidney samples from the same animals. Soil consistently accounted for at least 30% of input for many hexa- or higher chlorinated PCDD/Fs, while it rarely representing more than 10% of the total intake.     

Associations of diet with body burden of dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs): observations on pregnant women from central Taiwan.

The aim of this study was to examine the relationship between placental polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/F) and polychlorinated biphenyls (PCBs) toxic equivalent (TEQ) levels and the consumption of various food types in pregnant women from central Taiwan. Placental PCDD/Fs and PCB congener TEQ levels were evaluated in 109 pregnant women and dietary information was obtained by questionnaire. TEQ levels of PCDD/Fs and PCBs were positively associated with age and annual family incomes (p < 0.05). PCDD/F TEQs were significantly associated with freshwater fish and dairy product consumption after adjustment for age and body mass index (BMI) (p < 0.05). For PCB TEQs, significant associations were detected for saltwater fish consumption (p < 0.05). In summary, positive correlations were found between freshwater fish and dairy product intake and PCDD/F levels, and a marginal correlation between saltwater fish intake and the body burden of PCBs in pregnant women from central Taiwan. Risk assessment of PCDD/Fs and PCB in fishery products is warranted in a future study to quantify the benefits of fish consumption during the perinatal period.