Polychlorinated dibenzo-p-dioxin, polychlorinated dibenzofurans and polychlorinated biphenyls in farmed fish, water, sediment, and feed

Halogenated aromatic pollutants in routine animal-derived food of south China: Occurrence, sources, and dietary intake risks

Halogenated aromatic pollutants (HAPs) including polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), polychlorinated biphenyls (PCBs), polybrominated dibenzo-p-dioxins/furans (PBDD/Fs), and polybrominated diphenyl ethers (PBDEs) exhibit diverse toxicities and bio-accumulation in animals, thereby imposing risks on human via animal-derived food (ADF) consumption. Here we examined these HAPs in routine ADFs from South China and observed that PBDEs and PCBs showed statistically higher concentrations than PCDD/Fs and PBDD/Fs. PCDD/Fs and PCBs in these ADFs were mainly from the polluted feed and habitat of animals, except PCDD/Fs in egg, which additionally underwent selective biotransformation/progeny transfer after the maternal intake of PCDD/F-polluted stuff. PBDEs and PBDD/Fs were mostly derived from the extensive use of deca-BDE and their polluted environments. Significant interspecific differences were mainly observed for DL-PCBs and partly for PBDD/Fs and PBDEs, which might be caused by their distinct transferability/biodegradability in animals and the different living habit and habitat of animals. The dietary intake doses (DIDs) of these HAPs via ADF consumption were all highest for toddlers, then teenagers and adults. Milk, egg, and fish contributed most to the DIDs and risks for toddlers and teenagers, which results of several cities exceeded the recommended thresholds and illustrated noteworthy risks. Pork, fish, and egg were the top three risk contributors for adults, which carcinogenic and non-carcinogenic risks were both acceptable. Notably, PBDD/Fs showed the lowest concentrations but highest contributions to the total risks of these HAPs, thereby meriting continuous attention.

Exposure of farmed fish to petroleum hydrocarbon pollution and the recovery process: A simulation experiment with tiger puffer Takifugu rubripes

Petroleum hydrocarbon (PH) pollution threatens both wild and farmed marine fish. How this pollution affects the nutrient metabolism in fish and whether this effect can be recovered have not been well-known. The present study aimed to evaluate these effects with a feeding trial on tiger puffer, an important farmed species in Asia. In a 6-week feeding trial conducted in indoor flow-through water, fish were fed a control diet (C) or diets supplemented with diesel oil (0.02 % and 0.2 % of dry matter, named LD and HD, respectively). Following this feeding trial was a 4-week recovery period, during which all fish were fed a same normal commercial feed. At the end of the 6-week feeding trial, dietary PH significantly decreased the fish growth and lipid content. The PH significantly accumulated in fish tissues, in particular the liver, and caused damages in all tissues examined in terms of histology, anti-oxidation status, and serum biochemical changes. Dietary PH also changed the volatile flavor compound profile in the muscle. The hepatic transcriptome assay showed that the HD diet tended to inhibit the DNA replication, cell cycle and lipid synthesis, but to stimulate the transcription of genes related to liver protection/repair and lipid catabolism. The 4-week recovery period to some extent mitigated the damage caused by PH. After the recovery period, the inter-group differences in some parameters disappeared. However, the differences in lipid content, anti-oxidase activity, liver PH concentration, and histological structure still existed. In addition, differences in cellular chemical homeostasis and cytokine-cytokine receptor interaction at the transcriptional level can still be observed, indicated by the hepatic transcriptome assay. In conclusion, 6 weeks of dietary PH exposure significantly impaired the growth performance and health status of farmed tiger puffer, and a short-term recovery period (4 weeks) was not sufficient to completely mitigate this impairment.

PCDDs, PCDFs and PCBs in farmed fish produced in Greece: Levels and human population exposure assessment

Fish is among the essential components of Mediterranean diet and has beneficial effects on human health. Farmed fish is an affordable alternative to wild fish and a significant food export product for Greece. Published studies worldwide have reported significant levels of environmental pollutants in fish tissues. Especially for PCDDs/Fs and PCBs, the studies suggest that the most important contribution to human dietary intake is from fish and seafood. In the present study, we investigate the levels of PCDDs/Fs, dioxin-like and non dioxin-like PCBs in the most common farmed fish species produced in Greece i.e. sea bass, sea bream and rainbow trout. These species are widely consumed in Greece and are also exported to many countries worldwide. The mean levels found were WHO-PCDD/F-TEQ: 0.22 pg g(-1) wet weight (w.w.), WHO-PCDD/F-PCB-TEQ: 0.88 pg g(-1) w.w. for sea bream, WHO-PCDD/F-TEQ: 0.13 pg g(-1) w.w., WHO-PCDD/F-PCB-TEQ: 0.68 pg g(-1) w.w. for sea bass and WHO-PCDD/F-TEQ: 0.10 pg g(-1) w.w., WHO-PCDD/F-PCB-TEQ: 0.43 pg g(-1) w.w. for rainbow trout. For non dioxin-like PCBs, mean sum values found were 8.02 ng g(-1) w.w. for sea bream, 5.24 ng g(-1) w.w. for sea bass and 2.90 ng g(-1) w.w. for rainbow trout. All concentrations found were far below maximum levels set by the European Union and in the same range as wild-caught fish also presented for comparison. Daily intake from the consumption of farmed fish species examined is calculated at 1.3 pg WHO-TEQ kg(-1) b.w., which is at the lowest end of TDI values proposed by the WHO.

Bioaccumulation of mercury and polychlorinated dibenzo-p-dioxins and dibenzofurans in salty water organisms

Mercury and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) accumulate in organisms through food webs and exert potentially toxic effects on aquatic organisms and humans. This study examined the levels of mercury and PCDD/Fs in organisms and sediment samples collected from a saltwater pond at the An-Shun site, a chloralkali factory that shut down in Tainan City, Taiwan. It was also a pentachlorophenol production plant. After the factories were shut down in the 1980s, mercury and PCDD/Fs contamination remained, posing severe health hazards. The correlation between PCDD/Fs congener accumulation patterns in distinct fish organs and the sediment was evaluated. Mercury and PCDD/Fs levels in all the fish samples exceeded food safety limits, and the concentrations of mercury and PCDD/Fs in each species were closely correlated (n = 12, Spearman's rank correlation [R] = 0.811, p < 0.01). The mercury concentrations were positively but non-significantly correlated with the weight (n = 11, R = 0.741, p < 0.01) and length (n = 11, R = 0.618, p < 0.05) of the species. The fish likely accumulated the contaminants through ingestion of other organisms or the sediment. However, after the pollutants entered a fish, they exhibited distinct accumulation patterns because of their differing chemical properties. Specifically, the mercury concentration was correlated with organism weight and length, whereas the PCDD/Fs concentration was associated with organ lipid content. The study results are valuable for assessing the health risks associated with ingesting mercury- and PCFF/F-contaminated seafood from the study site.

Unexpected interaction with dispersed crude oil droplets drives severe toxicity in Atlantic haddock embryos

The toxicity resulting from exposure to oil droplets in marine fish embryos and larvae is still subject for debate. The most detailed studies have investigated the effects of water-dissolved components of crude oil in water accommodated fractions (WAFs) that lack bulk oil droplets. Although exposure to dissolved petroleum compounds alone is sufficient to cause the characteristic developmental toxicity of crude oil, few studies have addressed whether physical interaction with oil micro-droplets are a relevant exposure pathway for open water marine speices. Here we used controlled delivery of mechanically dispersed crude oil to expose pelagic embryos and larvae of a marine teleost, the Atlantic haddock (Melanogrammus aeglefinus). Haddock embryos were exposed continuously to two different concentrations of dispersed crude oil, high and low, or in pulses. By 24 hours of exposure, micro-droplets of oil were observed adhering and accumulating on the chorion, accompanied by highly elevated levels of cyp1a, a biomarker for exposure to aromatic hydrocarbons. Embryos from all treatment groups showed abnormalities representative of crude oil cardiotoxicity at hatch (5 days of exposure), such as pericardial and yolk sac edema. Compared to other species, the frequency and severity of toxic effects was higher than expected for the waterborne PAH concentrations (e.g., 100% of larvae had edema at the low treatment). These findings suggest an enhanced tissue uptake of PAHs and/or other petroleum compounds from attached oil droplets. These studies highlight a novel property of haddock embryos that leads to greater than expected impact from dispersed crude oil. Given the very limited number of marine species tested in similar exposures, the likelihood of other species with similar properties could be high. This unanticipated result therefore has implications for assessing the ecological impacts of oil spills and the use of methods for dispersing oil in the open sea.

Impacts of cooking technique on polychlorinated biphenyl and polychlorinated dioxins/furan concentrations in fish and fish products with intake estimates

Polychlorinated biphenyl (PCB) and polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) concentrations were determined in composites of 18 different fish products and were prepared as raw, baked, boiled, and fried. ∑PCB concentrations were found to range from 0.12 ng·g(-1) whole weight (ww) in raw octopus to 33 ng·g(-1) ww in baked mackerel. Boiled monkfish was found to have the lowest ∑PCDD/F concentrations (0.41 pg·g(-1) ww), while maximum concentrations were observed in fried catfish (59 pg·g(-1) ww). PCB and PCDD/F concentrations in fish were generally reduced during cooking, although differences were small. The average PCB reduction in finfish was 7.9%, while an increase in PCB mass was observed in non-finfish (2.9%). PCDD/F losses, on average, were observed in both the finfish (3.6%) and non-finfish products (25%). Maximum ∑PCB, ∑PCDD/F, and TEQ(PCDD/F+DL-PCB) (toxic equivalency) intakes, based on 150 g serving size, were determined to be 3300 ng (mackerel), 6600 pg (catfish), and 270 pg (catfish), respectively. PCB and PCDD/F changes associated with cooking generally were small (<15%), although larger mean differences (∼40%) were observed in some fish products (e.g., catfish).

The occurrence and dynamics of polychlorinated hydrocarbons in brown hare (Lepus europaeus) in south-western Slovakia

This study aimed at obtaining the data on the occurrence, levels and correlations of organic pollutants present in game animals (n = 75, Brown hare, Lepus europaeus Pall.) in the region of south-western Slovakia. The analyses performed included dichlorodiphenyltrichloroethane (DDT), hexachlorobenzen (HCB), alpha- and beta hexachlorocyclohexane (α+β-HCH), gamma-hexachlorocyclohexane (γ-HCH), and polychlorinated biphenyls (PCB-delor, commercial mixture of PCB congeners). A gas chromatograph with an electron capture detector was used for the analysis. PCB-delor and DDT were accumulated significantly in the highest level (0.105 ± 0.059 mg/kg; 0.070 mg/kg) in depot fat in brown hares; however maximum permissible limits for the observed pollutants were not exceeded. Significantly higher concentrations of DDT, HCB, γ-HCH, and PCB-delor were found in adult animals when compared with juvenile hares. Gender and season had no effect on the accumulation of observed pollutants. Moderately positive correlation was found between PCB-delor and DDT (r = 0.59). Monitoring of environmental pollution with polychlorinated hydrocarbons is important with regard to public health, as game animals constitute an important part of food chain also for humans.

Estimation of the physicochemical properties of PCDD/Fs using three-dimensional holographic vector of atomic interaction field

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are a group of important persistent organic pollutants. In the present study, the three-dimensional holographic vector of atomic interaction field (3D-HoVAIF) method is used to describe the chemical structures of PCDD/Fs. After variable screening using a stepwise multiple regression (SMR) technique, the linear relationships among six physicochemical properties of PCDD/Fs and 3D-HoVAIF descriptors are built using a partial least-squares (PLS) regression model. The results show that the 3D-HoVAIF descriptors can be used to express the quantitative structure-property relationships of PCDD/Fs. The predictive capabilities of the models have also been confirmed by leave-one-out cross-validation. The optimum model has been used to estimate values for PCDD/Fs for which no experimental data on physicochemical properties are available. Supplemental materials are available for this article. Go to the publisher's online edition of Journal of Environmental Science and Health: Part A to view the free supplemental file.

Contributions of dry and wet depositions of polychlorinated dibenzo-p-dioxins and dibenzofurans to a contaminated site resulting from a penetachlorophenol manufacturing process

The soils at a factory for manufacturing pentachlorophenol were heavily contaminated by polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). In order to verify the contributions of dry and wet deposition of PCDD/Fs from the ambient air, the concentration of PCDD/Fs in ambient air and soil were measured, the partition of particle- and gas-phases of atmospheric PCDD/Fs was calculated, and the annual fluxes of total dry and wet PCDD/F depositions were modeled. Average atmospheric PCDD/F concentration was 1.24 ng Nm(-3) (or 0.0397 ng I-TEQ Nm(-3)). Moreover, over 92.8% of total PCDD/Fs were in the particle phase, and the dominant species were high chlorinated congeners. The total PCDD/F fluxes of dry and wet deposition were 119.5 ng m(-2) year(-1) (1.34 ng I-TEQ m(-2) year(-1)) and 82.0 ng m(-2) year(-1) (1.07 ng I-TEQ m(-2) year(-1)), respectively. By scenario simulation, the total fluxes of dry and wet PCDD/F depositions were 87.1 and 68.6 ng I-TEQ, respectively. However, the estimated PCDD/F contents in the contaminated soil were 839.9 μ g I-TEQ. Hence, the contributions of total depositions of atmospheric PCDD/F were only 0.02%. The results indicated that the major sources of PCDD/F for the contaminated soil could be attributed to the pentachlorophenol manufacturing process.

Polychlorinated dibenzo-p-dioxins and dibenzofuran contents in fish and sediment near a pentachlorophenol contaminated site

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in sediment and fish of aqua farms close to a contaminated site of a pentachlorophenol production plant (CPDC-ASS) were investigated. The total PCDD/F I-TEQ level in sediment and fish ranged from 0.725 to 87.9 ng I-TEQ kg(-1)d.w.(-1) and 0.044 to 3.10 pg I-TEQ g(-1)w.w.(-1), respectively, meaning that the CPDC-ASS was a long-term exposure PCDD/F contaminated area. The four dominant congeners in sediment and fish were OCDD, OCDF, 1,2,3,4,6,7,8-HpCDF and 1,2,3,4,6,7,8-HpCDD. The correlated coefficient of total I-TEQ PCDD/F contents between fish and sediment was 0.82 (R(2)), indicating a positive correlation between exposure to PCDD/Fs in sediment and biota. In addition, the biota-to-sediment accumulation factors (BSAFs) values of low chlorinated PCDD/F congeners such as those of 2,3,7,8-TeCDD for Milkfish and Tilapia were 0.00739 and 0.00593, respectively, which were much higher than those of highly chlorinated congeners. For example, the BSAFs of OCDD for Milkfish and Tilapia were 0.000207 and 0.000277, respectively. A negative relationship of log K(ow) and log BSAF for PCDD/F congeners was found, and the highest value was observed at approximately K(ow)= 7.0-7.5. The results of this study provide valuable information for establishing the PCDD/F regulated standard for the sediment of fish ponds.