Polychlorinated naphthalenes in foods: estimated dietary intake by the population of Catalonia,Spain

Concentrations of polychlorinated naphthalenes (PCNs) were measured in foodstuffs randomly acquired in seven cities of Catalonia, Spain. A total of 108 samples, belonging to 11 food groups (vegetables, tubers, fruits, cereals, pulses, fish and shellfish, meat and meat products, eggs, milk, dairy products, and oils and fats), were analyzed by high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS). The levels of tetra-, penta-, hexa-, and hepta-CNs, those of octachloronaphthalene, and the mean sum concentration of tetra-octa-CN were determined. The highest concentration of total PCNs was found in oils and fats (447 pg/g), followed by cereals (71 pg/g), fish and shellfish (39 pg/g), and dairy products (36 pg/g). In general, tetra-CN was the predominant homologue in all food groups except for fruits and pulses, which had greater proportions of hexa-CNs. The dietary intake of total PCNs was subsequently determined. For calculations, recent data on consumption of the selected food items were used. Intake of PCNs was estimated for five population groups of Catalonia: children, adolescents, male and female adults, and seniors. When the dietary intake of total PCNs was expressed in nanogram per kilogram of body weight per day, it was age-dependent, with the highest and lowest values corresponding to children (1.65) and seniors (0.54), respectively. The largest contribution to the daily PCNs intake came from oils and fats and from cereals. The result of the current study is the first published report concerning human exposure to PCNs through the diet.     

Comparison of PCDD/F and dl-PCB levels in Turkish foodstuffs: industrial versus rural,local versus supermarket products,and assessment of dietary intake

Polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs) and dioxin-like and non-dioxin-like (indicator) polychlorinated biphenyls (PCBs) were monitored in various foodstuffs of animal origin and edible oil samples obtained from two different cities in Turkey both rural and industrial. Total dioxin+dioxin-like PCBs and indicator PCB concentrations of pooled samples ranged 0.20–4.19 pg World Health Organization-Toxic Equivalency (WHO-TEQ)₍₁₉₉₈₎/g fat and 57.2–1710 pg/g fat, respectively. The dominant congeners were 2,3,4,7,8-PeCDF, 1,2,3,7,8-PeCDD, 2,3,7,8-TCDD and PCB126. Dietary intake of dioxin+dioxin-like PCBs and indicator PCBs from fish, dairy products, edible oil, egg and meat was 0.509 pg WHO-TEQ₁₉₉₈/kg bw (body weight)/day and 839 pg/kg bw/day in Afyon and 0.588 pg WHO-TEQ₁₉₉₈/ kg bw/day and 1070 pg/kg bw/day in Kocaeli, respectively. The major contributors to total exposure were dairy products and fish. Despite the unexplained high contamination level in an individual egg sample from Kocaeli, average concentration levels in Turkey, even in industrialized regions, were low compared to reported concentrations in Western Europe. Exposure levels were well below the tolerable daily intake (TDI) of 2 pg WHO-TEQ₁₉₉₈/kg body weight.     

Polychlorinated biphenyls, hexachlorobenzene, hexachlorocyclohexane isomers, and pesticide organochlorine residues in cod-liver oil dietary supplements

Levels of polychlorinated biphenyls (PCBs), hexachlorobenzene, hexachlorocyclohexane isomers (alpha, beta, gamma), and chlorinated pesticides (DDTs) in cod-liver oil used as a dietary supplement were determined. Total PCB and DDT concentrations varied from 25 to 201 ng g(-1) lipid weight basis and from 25 to 133 ng g(-1) lipid weight basis, respectively. Hexachlorobenzene contributed very little to the overall contaminant burden of dietary supplement oils, whereas hexachlorocyclohexane isomers were below the instrumental detection limits in all samples. The daily intake of PCBs and DDTs derived by the consumption of cod-liver oil at manufacturer-recommended doses varied from 0.004 to 2.01 microg/day and from 0.004 to 1.24 microg/day, respectively. Relative to some dioxin-like PCB congeners (mono-ortho PCB 105, 118, and 156; non-ortho PCB 77, 126, and 169), the intakes calculated varied from less than 0.001 to 0.74 pg of toxic equivalency values (TEQ) per kg of body weight per day. These values, although below the range of 1 to 4 pg of TEQ per kg of body weight per day set by the World Health Organization, emphasize the need for strict and continuous monitoring of fish oil contamination to reduce, as much as possible, the risks to human health.     

Human exposure to polychlorinated naphthalenes and polychlorinated diphenyl ethers from foods in Catalonia, Spain: temporal trend

Although polychlorinated naphthalenes (PCNs) and polychlorinated diphenyl ethers (PCDEs) are pollutants that have been detected in a number of environmental samples, information concerning human exposure to these compounds through the diet is very scarce. In this study, the concentrations of PCNs and PCDEs were determined in samples of foodstuffs widely consumed by the population of Catalonia, Spain. The dietary intake of PCNs and PCDEs also was estimated for the population of this Spanish region, and the results were compared to those of a previous survey performed during 2000. The highest sigmaPCNs corresponded to fish and seafood (47.1 ng/kg wet wt), followed by oils and fats (21.5 ng/kg wet wt), bakery products (15.3 ng/kg wet wt), and dairy products (11.7 ng/ kg wet wt). The highest sigmaPCDEs corresponded also to fish and seafood (1094.7 ng/kg wet wt), a value that was notably higher than those concerning the remaining food groups. For a standard male adult of 70 kg body weight, the dietary intakes of PCNs and PCDEs were 7.25 and 51.68 ng/day, respectively (or 0.10 and 0.74 ng/kg body wt/day). These results mean a reduction of 84% for PCNs with respect to the daily intake of these pollutants in the 2000 survey, mainly due to the decreases in the contribution of cereals and oils and fats. By contrast, the intake of PCDEs increased to 26%, fish and seafood being the main contributors to this increase.     

Dioxin-like polychlorinated biphenyls in marine fish from Shandong,China, and human dietary exposure

The occurrence and human dietary exposure of 12 dioxin-like polychlorinated biphenyls (DL-PCBs) in 41 marine fish samples from Shandong Province of China were investigated. The DL-PCB congeners were extracted using automated Soxhlet extraction, purified via a composite column clean-up procedure and analysed by gas chromatography-triple quadrupole mass spectrometry. DL-PCB congeners were found in all analysed samples, with a mean concentration of 0.887 ng/g ww (wet weight). The TEQ concentrations of DL-PCBs in individual fish samples ranged from 0.011 to 9.214 pg WHO TEQ/g ww. The mean dietary intake for all fish species was 36.5 pg TEQ/kg bw/month, which was lower than the provisional tolerable monthly intake of 70 pg TEQ/kg bw/month set by the Joint FAO/WHO Expert Committee on Food Additives. To monitor the trend of DL-PCBs in fish for food safety control, it is necessary to maintain a surveillance programme.     

Exposure of Taiwan residents to polychlorinated biphenyl congeners from farmed, ocean-caught, and imported fish

This study is to assess PCB levels in five frequently consumed fish species in Taiwan, tilapia, milkfish, white pomfret, hairtail, and cod. Seventeen congeners were measured in fillet samples purchased from major markets in northern, central, and southern Taiwan. All 136 samples had traces of PCBs. The median concentrations were 0.18, 0.46, 0.62, 0.69, and 7.34 ng/g wet wt and 1.01, 0.28, 1.14, 5.06, and 19.3 pg-WHO-TEQ/g lipid in tilapia, milkfish, white pomfret, hairtail, and cod samples, respectively. Cod (the imported fish) had the highest wet weight PCB concentrations. The fish caught off-shore (white pomfret and hairtail) had higher levels than the farmed fish (tilapia and milkfish). The congener profiles varied among species. PCB 105/153 and 126 accounted for more than 28% and 53% of the 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (WHO-TEQs) in hairtail and cod, respectively; while PCB 156 was the major TEQ contributor in the other species. The estimated median PCB intake of the general public from consumption of the five species ranged from 0.000023 to 0.048 pg-WHO-TEQ/kg/day. It was also found that samples farmed or caught along the southern coast had higher PCB levels than those from other parts of Taiwan, indicating possible elevated PCB contamination around that area.     

Levels of specific polychlorinated biphenyl congeners in fatty foods from five Canadian cities between 1986 and 1988.

A total of 155 fatty food composites from five major Canadian cities were analysed for 36 selected polychlorinated biphenyl (PCB) congeners. Total PCB congener levels of more than 1 ng/g (wet weight) were found in fresh water fish, canned fish, butter, marine fish and cheese, with fresh water fish (18.7 ng/g) containing 5 to 10 times more total PCBs than the other four food commodities. Milk (2%), cooking oils/salads and canned meat soup contained less than 0.1 ng/g (wet weight). The observed total PCB residue levels in fatty foods were well within the Canadian guidelines for fish, dairy products, poultry, eggs and beef. The most predominant congeners found in fish, butter, cheese, meat and poultry were the 2,2',4,4',5-, 2,3',4,4', 5-pentachloro-, 2,2',3,4,4',5'-, 2,2',4,4',5,5'-hexachloro- and 2,2',3,4,4',5,5'-heptachlorobiphenyls. The predominant congener pattern was not always evident in other dairy products (e.g. ice cream) and processed foods (e.g. canned meat soup). An attempt was made to relate the intake of PCB congeners from fatty foods with congener levels found in adipose tissue of Canadians. The estimated daily intake of some specific PCB congeners from fatty foods, in most cases accounted for more than half the total deposit of these congeners in adipose tissue of Canadians.     

Isomer-specific analysis of PCBs including toxic coplanar isomers in canned cod livers commercially processed in Poland.

Concentrations of highly toxic coplanar non-ortho (IUPAC Nos. 77, 126 and 169), mono-ortho (IUPAC Nos. 60, 105, 118 and 157), di-ortho (IUPAC Nos. 128, 139 and 170) members and 73 other isomers and congeners of PCBs were determined in canned cod livers W 9tróbka rybna po Kaukasku produced by a company in Gdańsk, Poland in early 1990. Total PCB concentrations ranged over 1.2-2.6 micrograms/g wet mass. Concentrations of ten toxic coplanar PCBs (IUPAC Nos. 77, 126, 169, 60, 105, 118, 156, 128, 138, and 170) were found to be in the range of 360 to 690 ng/g wet mass and their TCDD TEQs were 370 to 530 pg/g for aryl hydrocarbon hydroxylase and from 290-430 pg/g for ethoxy-resorufin O-deethylase. Among these toxic congeners IUPAC No. 126, which showed 84% of total TEQ values, imparted most significant toxic threat. Considering these observations, canned cod livers are likely to pose concern to human health since they exceed the tolerance limit of total PCBs (2.0 micrograms/g for edible parts of fishery products) and contain significant residue levels of toxic coplanar PCBs.     

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.     

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.     

Polychlorinated biphenyls (PCBs) and their congener-specific accumulation in edible fish from the Gulf of Gdańsk, Baltic Sea.

Concentrations and composition profiles of polychlorinated biphenyls (PCBs) were investigated in composite samples of 10 species of edible fish from the Gulf of Gdańsk, in the southern part of the Baltic Sea, Poland, to understand the status of contamination and possible human exposure risk. Apart from the total PCBs, planar non-ortho (IUPAC nos 77, 126, 169) and mono-ortho (nos 105, 114, 118, 123, 156, 157, 167, 189) chlorobiphenyls were also quantified and their dioxin-like toxicity assessed. The absolute total PCB concentrations in fish ranged from 43 to 490 ng g(-1) wet wt (910-11000 ng g(-1) lipids), while of TCDD TEQs of planar members were from 0.15 to 3.1 pg g(-1) wet wt (8.1-81 pg g(-1) lipids). The penta- and hexa-CBs usually comprised 70-80% of the total PCBs and were followed by hepta-, tetra- and tri-CBs, and for a specific site tri- and tetra-CBs comprised as much as 22%. Among the individual CB congeners, nos 118, 153 (+132) and 138 (+160 +163 +164) were the most abundant, while no. 110 comprised between 6.8 and 9.3% of the total PCBs in some species. Principal component analysis (PCA) was applied to examine the interdependences among CB congeners in the factor space. The PCA model and cluster analyses were further used to examine site- and species-specific differences and similarities of PCB composition, and the results are discussed. An assessed daily intake rate of TCDD TEQ of planar PCBs with the fishmeal of the Gulf of Gdańsk in the 1990s was between 78 and 96 pg per capita or between 1.3 and 1.6 pg kg(-1) body weight.     

Dioxins,furans and non-ortho-PCBs in Canadian total diet foods 1992–1999 and 1985–1988

In the period from 1985 to 1999, about 600 samples of total diet foods from Canadian cites were analysed for dioxins, furans and non-ortho-PCBs. Toxic equivalent (TEQ) concentrations on a lipid basis were found to be the highest in dairy and beef products followed by poultry and pork. These levels decreased over the 15-year period of sampling, particularly those for fluid milk, less so for poultry and pork and little or no change for beef. Calculation of the human daily intake for the years 1985–1988 showed values a little less than 1?pg of TEQ₂₀₀₅ polychlorinated dibenzo-p-dioxin/polychlorinated dibenzofuran per kg body weight, falling progressively to less than 0.5?pg of TEQ in 1999. These estimates are lower than the 2.3?pg of TEQ currently recommended by the WHO. The main categories of foods contributing to the TEQ were animal meats and dairy products, with lesser amounts from fish and other foods.     

Survey of polybrominated diphenyl ether levels in Spanish commercial foodstuffs

Concentrations of 15 BDEs flame retardants have been determined in a large variety of food samples purchased in different markets across Spain. This is the first time that BDEs 184, 191, 196, and 197; impurities from BDEs formulations; and/or degradation products of BDE 209, have been detected in foodstuffs. Values ranged from <0.01 to 2482 pg/g fresh weight. The highest total BDE concentrations were found in fish samples (median of 189, range of 24-880 pg/g f.w.), followed by oils (median of 119, range of 14.8-2958 pg/g f.w.), meats (median of 75.9, range of 6.82-2518 pg/g f.w.), shellfish (median of 75.7, range of 3.29-677 pg/g f.w.), eggs (median of 73.5, range of 12.8-557 pg/g f.w.), and dairy products (median of 66.1, range of 3.24-1588 pg/g f.w.). The total BDE values found in this study are consistent with research reported elsewhere. They are in the same range as those recently reported by other European and Asian studies and lower than those conducted in the U.S. BDE 47 was the predominant congener in fish, shellfish, dairy products (except butter), and meats, while BDE 209 was the predominant in oil and egg samples. The most remarkable findings in this study were the large contribution of the highest brominated BDEs (hepta- to deca-BDE), and principally BDE 209, to the total BDE concentration found in Spanish foods, except fish and shellfish, and the presence of BDE 184, 191, 196, and 197 in many of the samples. The calculated intake of 38.5 ng/day of BDEs was comparable to intake assessment from other UE countries.     

Exposure assessment of dioxins/furans consumed in dairy foods and fish

Dioxins/furans are ubiquitous environmental contaminants whose primary route of human exposure occurs via the consumption of fatty foods of animal origin. The US FDA conducted a market basket survey of dairy products and commercial fish and shellfish to obtain data on levels of 17 dioxin/furan congeners (2, 3, 7, 8- congeners) in the US. The dairy products sampled included various cheeses (American, cheddar, Swiss, cottage), ice cream, yogurt, butter, and milk. The finfish and shellfish (molluscs and crustacea) sampled are those marine species consumed in the greatest amounts and include canned tuna, shrimp, cod, blue crab, and oysters. Catfish was sampled because it is the dominant aquaculture species. Samples were collected in 1995/96 and analysis for 17 dioxin/furan congeners was performed by high-resolution gas chromatography following extraction and clean-up. Limits of detection (LOD) and quantitation (LOQ) for each congener in each food were reported. Point estimates of exposure were calculated using a 3-day (1-day diary plus 2-day recall) food consumption survey for eaters-only and for the general population (USDA/CSFII, 1989-92). Toxicity equivalency factors (TEFs) developed by the World Health Organization (1997) were used to derive overall dioxin/furan toxicity equivalents (TEQ) for each sample food. Mean estimates of TEQ exposure for each food were derived using five values for nondetects (ND 0; ND 1/2 LOD or LOQ; ND = = = LOD or LOQ) on both a total sample and eaters-only basis. Using zero and the LOD provide lower and upper bounds on the range of estimated exposure, respectively. The bounds on mean dioxin intakes (pg/person/ day) calculated for consumers of specific foods were estimated as follows (using zero or LOD for nondetects): butter (0.5-11), cheese (1.6-3.2), ice cream (4-19), yogurt (0.8-28), catfish (148-150), fish (other than catfish) (0.03-9), crustacea (32-35), mollusks (16.1-16.6), and shrimp (0.09-4.5). Exposure estimates derived by the five ND-methods are strongly dependent on the LOD and LOQ and represent upper bound estimates of exposure. Uncertainty in the exposure estimates is reduced with refinements in the analytical method.     

Polychloronaphthalenes and other dioxin-like compounds in Arctic and Antarctic marine food webs

Here we report accumulation patterns of polychlorinated naphthalenes (PCNs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and pesticides (HCB, p,p'DDE) in polar organisms (polar bear from Alaskan Arctic and krill, sharp-spined notothen, crocodile icefish, Antarctic silverfish, Adélie penguin, South polar skua, and Weddell seal from the Ross Sea, Antarctica). PCNs, found in most of the samples, ranged from 1.5 pg/g in krill to 2550 pg/g in South polar skua on a wet weight basis. Lower chlorinated PCNs were the predominant congeners in organisms except skua and polar bear that showed similar PCN homologue patterns. PCDD/F concentrations were <90 pg/g wet wt in polar organisms; PCDD congeners showed peculiar accumulation patterns in different organisms. Correlation existed between PCN and PCB concentrations. PCB, HCF, and p,p'DDE levels were the highest in skua liver (11,150 ng/g wet wt, 345 ng/g wet wt, and 300 ng/g wet wt, respectively). Contribution of PCNs to 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQ) was negligible (<0.1%) because of the lack of most toxic congeners. The highest TEQ was found in South polar skua liver (45 pg/g, wet weight). This is the first study to document the occurrence of PCNs in Antarctic organisms. High levels of dioxin-like chemicals in skua suggest the importance of intake via diet and migration habits, thus POP detection can be useful to trace migration behavior. Moreover, POP concentrations in penguin and skua eggs prove their transfer from the mother to eggs.     

Brominated flame retardants in US food

We and others recently began studying brominated flame retardant levels in various matrices in the US including human milk and other food. This paper reviews the food studies. In our studies, ten to thirteen polybrominated diphenyl ether (PBDE) congeners were measured, usually including BDE 209. All US women's milk samples were contaminated with PBDEs from 6 to 419 ng/g, lipid, orders of magnitude higher than levels reported in European studies, and are the highest reported worldwide. We compared our market basket studies of meat, fish and dairy products with other US food studies of meat and fish. US studies showed somewhat higher levels of PBDEs than reported elsewhere. Fish were most highly contaminated (median 616 pg/g), then meat (median190 pg/g) and dairy products (median 32.2 pg/g). However, unlike some European countries where fish predominates, dietary intake of PBDEs in the US is mostly from meat, then fish and then dairy products. Broiling can decrease the amount of PBDEs per serving. We also measured levels of hexabromocyclododecane (HBCD), another brominated flame retardant, in human milk. The levels are lower than PBDEs, 0.16-1.2 ng/g, similar to European levels, unlike PBDEs where US levels are much higher than European levels.     

Human dietary exposure to hexachlorobenzene in Catalonia, Spain

The concentrations of hexachlorobenzene (HCB) were measured in samples of foodstuffs widely consumed by the population of Catalonia, Spain. Food samples were randomly acquired in 12 cities of Catalonia between March and June of 2006. HCB levels were determined by high-resolution gas chromatography-high-resolution mass spectrometry. The dietary intake of HCB was subsequently estimated for the population of Catalonia, and the results were compared with those of a survey performed in 2000. The highest HCB concentrations were found in oils and fats, fish and seafood, and dairy products, with mean levels of 0.481, 0.330, and 0.284 ng/g of fresh weight, respectively. HCB intake was estimated for four population groups: children, adolescents, adults, and seniors (aged >65 years). The highest and lowest HCB intake corresponded to children and seniors, respectively. Similar results were found in our 2000 survey. For a standard male adult of 70-kg body weight, in the 2000 study, total dietary intake of HCB was 166.2 ng/day (2.4 ng/kg of body weight per day), whereas in the current survey the intake was 71.6 ng/day (1.0 ng/kg of body weight per day). On a body-weight basis, it means a decrease of 57%, which was mainly due to the important reductions in the contribution of dairy products (mainly cheese), as well as those of meat and meat products and fish and seafood. All the intakes are considerably lower than the World Health Organization tolerable daily intake, which is 0.17 microg/kg/day for noncancer effects and 0.16 microg/kg/day for neoplastic effects in humans.     

Determination of brominated flame retardants and brominated dioxins in fish collected from three regions of Japan

The concentrations of brominated dioxins which are polybrominated dibenzo-p-dioxins/polybrominated dibenzofurans (PBDD/DFs) and mono-bromo polychlorinated dibenzo-p-dioxins/dibenzofurans, polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol A (TBBPA) were investigated in a total of 45 fish samples collected from three regions in Japan. In the brominated dioxins, 1,2,3,4,6,7,8-heptabromodibenzofuran (HpBDF) was the most abundant congener, and it was found in seven fish samples at 0.10-25.6 pg/g wet weight (ww). The highest concentration of 1,2,3,4,6,7,8-HpBDF was found in the pike eel. Regarding other congeners, 2,3,7,8-tetrabromodibenzo-p-dioxin was detected in the sea bream at 0.02 pg/g ww, and 2,3,7,8-tetrabromodibenzofuran was detected in the conger eel at 0.03 pg/g ww. 3-Bromo-2,7,8-trichlorodibenzofuran was detected in the Sardinella zunasi and the conger eel at 0.01 pg/g ww and 0.02 pg/g ww, respectively. Using toxic equivalency factors of chlorinated dioxins, we calculated the PBDD/DFs concentrations of these fish samples at 0.001-0.256 pg TEQ/g ww. PBDEs were detected in all of the fish samples. The concentrations of total PBDEs were 0.01-2.88 ng/g ww. The seerfish and the yellowtail containd PBDEs in high concentrations. The most dominant congener in most of the fish was 2,2',4,4'-tetrabromo diphenyl ether. TBBPA was detected in 29 fish samples at 0.01-0.11 ng/g ww. The mean level of TBBPA was about one-tenth or less of the total level of PBDEs. A good correlation was obtained between total PBDEs and fat content. On the other hand, no correlation was obtained between TBBPA and fat content. The daily intakes from fish were estimated to be 0.58 ng/kg body weight (bw)/day for total PBDEs, 0.03 ng/kg bw/day for TBBPA, and 0.01 pg TEQ/kg bw/day for brominated dioxins in the case assuming that the average bw of a Japanese adult person is 50 kg and that the average fish consumption is 82 g/day. For PBDEs, the provisionally calculated value was much less than the lowest observed adverse effect level value (1 mg/kg bw/day). For brominated dioxins, the daily intake was at a very low level compared with the Japanese daily intake of polychlorinated dioxins from fish. Even if the value of PBDD/DFs is added to the amount of chlorinated dioxin exposure, it was estimated that it is less than the tolerable daily intake (4 pg TEQ/kg bw/day) in Japan.     

Comparison of dioxin and PCB concentrations in human breast milk samples from Hong Kong and the Netherlands

The adverse effects of dioxins and polychlorinated biphenyls (PCBs) on human health are of increasing concern. These lipophilic compounds are concentrated through the food chain and are present in human milk. This study compares PCB levels in human milk samples from Hong Kong and Dutch mothers. Ten breast milk samples from Hong Kong and 10 from the Netherlands were collected during home visits between 2 and 6 weeks postpartum. Total toxic equivalence (TEQ) of dioxin and PCBs were determined using the DR-CALUX® bioassay. The total dioxin and PCB levels in breast milk samples for Hong Kong ranged from 3.1 to 29.9 pg TEQ g^-1 lipid and for the Netherlands from 8.9 to 89.5 pg TEQ g^-1 lipid. Despite Hong Kong's high degree of industrialization, the levels of dioxin and PCBs were fourfold lower in the Hong Kong than in the Dutch samples. This may be due to a lower dietary intake of dioxins and PCBs in Hong Kong because of lower background levels of these contaminants or to different food habits.     

Estimation of dietary intake of PCB and organochlorine pesticides for children and adults

Levels of organochlorine substances, including a number of organochlorine pesticides and PCB, are monitored in food, including meat, fish and dairy products. The substances are slowly degradable and therefore persist for long periods in the environment, where they accumulate in the fatty tissues of animals and humans. They are included, because of the potential health-hazardous effect of these compounds on humans. The highest average contents are found in cod liver and fatty fish. The Danish population’s average daily intake has been estimated at between 0.03 and 0.3 μg/day for organochlorine pesticides and 0.9 μg/day for the indicator PCB-sum. People with a relatively high intake of these substances (the 95th percentile) are estimated to consume approximately twice as much. In general, the highest contributions to the intake of the organochlorine environmental contaminants are from fish, meat and dairy products. However, children have a relatively higher intake from milk and milk products and a lower intake from fish compared to adults.