Evaluation of chlorinated benz[a]anthracene on hepatic toxicity in rats and mutagenic activity in Salmonella typhimurium.

Chlorinated benz[a]anthracenes (Cl-BaA) are halogenated aromatic compounds (typified by dioxins) found in the environment at relatively high concentrations. Fischer 344 rats were intragastrically administered 0, 1, or 10 mg of Cl-BaA or its parent compound benz[a]anthracene (BaA) per kg of body weight for 14 consecutive days. Both chemicals at 10 mg/kg/day inhibited the gain in body weight, and consequent increase in relative liver weight. Hepatic gene expression of cytochrome P450 (CYP) 1A1, 1A2, and 1B1 was significantly stimulated by administration of BaA (10 mg/kg/day) compared with the control. After administration of Cl-BaA, only the CYP1A2 gene was significantly induced, even at the lower dosage; CYP1A1 and 1B1 mRNA levels remained unchanged in Cl-BaA-treated rats compared with controls. To elucidate the role of such Cl-BaA exposure and induced CYPs at toxicity onset, we investigated the mutagenicity of BaA and Cl-BaA using Salmonella typhimurium TA98 and TA100. BaA and Cl-BaA at 10 µg/plate produced positive results in both strains in the presence of rat S-9. Incubation of Cl-BaA with recombinant rat CYP1A2 produced a significantly higher number of revertant colonies in TA98 and TA100 than in controls, but no such change was observed for BaA. In conclusion, BaA changes its own physiological and toxicological actions by its chlorination; (1) daily exposure to Cl-BaA selectively induces hepatic CYP1A2 in rats and (2) Cl-BaA induces frameshift mutations in the presence of CYP1A2, although BaA does not exert mutagenicity. This indicates that CYP1A2 may metabolize Cl-BaA to active forms.

Perfluorooctanesulfonate and related fluorochemicals in human blood samples from China.

Perfluorooctanesulfonylfluoride (POSF)-based compounds have been manufactured and used in a variety of industrial applications. These compounds degrade to perfluorooctanesulfonate (PFOS) which is regarded as a persistent end-stage metabolite and is found to accumulate in tissues of humans and wildlife. PFOS, perfluorohexanesulfonate (PFHxS), perfluorooctanoate (PFOA), and perfluorooctanesulfonamide (PFOSA) have been found in human sera from the United States. In this study, concentrations of PFHxS, perfluorobutanesulfonate (PFBS), PFOS, perfluorohexanoic acid (PFHxA), PFOA, perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorododecanoic acid (PFDoDA), and PFOSA were measured in 85 samples of whole human blood collected from nine cities (eight provinces) in China, including Shenyang (Liaoning), Beijing (Hebei), Zhengzhou (Henan), Jintan (Jiangsu), Wuhan (Hubei), Zhoushan (Zhejiang), Guiyang (Guizhou), Xiamen (Fujian), and Fuzhou (Fujian). Among the 10 perfluorinated compounds (PFCs) measured, PFOS was the predominant compound. The mean concentration of PFOS was greatest in samples collected from Shenyang (79.2 ng/mL) and least in samples from Jintan (3.72 ng/mL). PFHxS was the next most abundant perfluorochemical in the samples. No age-related differences in the concentrations of PFOA, PFOS, PFOSA, and PFHxS were observed. Gender-related differences were found,with males higher for PFOS and PFHxS, and females higher in PFUnDA. Concentrations of PFHxS were positively correlated with those of PFOS, while concentrations of PFNA, PFDA, and PFUnDA were positively correlated with those of PFOA. There were differences in the concentration profiles (percentage composition) of various PFCs in the samples among the nine cities.

Polychlorinated dibenzo-p-dioxins, -dibenzofurans, and biphenyls in domestic animal food stuff and their fat.

Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzo-p-dioxins (PCDFs) and dioxin-like coplanar PCBs and 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs) were measured in domestic animal related samples such as feed ingredient, mixed feed and animal fat from Japan. The mean concentration of total PCDDs, PCDFs and coplanar PCBs in fish oil was 17000pg g-1 lipid wt, which 9- to 30-fold greater than that from other animal originated ingredients. Mixed feed for chicken and chicken fat contained greater total PCDDs, PCDFs, coplanar PCBs concentrations (190 and 2100pg g-1 lipid wt) compared to those for pig (120 and 320pg g-1 lipid wt). WHO-TEQs were ranged 0.39-13, 0.15-0.22 and 0.73-2.8pg g-1 lipid wt for ingredients, mixed feeds and animal fats, respectively. Greater biomagnification factor was noticed for congeners 1,2,3,7,8-PeCDD, 1,2,3,6,7,8-HxCDD, 2,3,7,8-TCDF and 1,2,3,4,7,8-HxCDF in chicken and pig fat. Biomagnification factors for both mono- and non-ortho coplanar PCBs were greater in chicken fat compared to those in pig fat.

Detection of corn intrinsic and recombinant DNA fragments and Cry1Ab protein in the gastrointestinal contents of pigs fed genetically modified corn Bt11.

Genetically modified corn has been approved as an animal feed in several countries, but information about the fate of genetically modified DNA and protein in vivo is insufficient. Genetically modified corn Bt11 is developed by inserting a recombinant DNA sequence encoding insecticidal Cry1Ab protein from Bacillus thuringiensis subsp. kurstaki. We examined the presence of corn intrinsic and recombinant cry1Ab gene by PCR, and the Cry1Ab protein by immunological tests in the gastrointestinal contents of five genetically modified corn Bt11-fed and five nongenetically modified corn-fed pigs. Fragments of corn zein (242 bp), invertase (226 bp) and of ribulose-1,5-bisphosphate carboxylase/ oxygenase genes (1,028 bp) were detected in the gastrointestinal contents of both Bt11 and nongenetically modified corn-fed pigs. Fragments of recombinant cry1Ab gene (110 bp and 437 bp) were detected in the gastrointestinal contents of the Bt11-fed pigs but not in the control pigs. Neither corn intrinsic nor cry1Ab gene fragments were detected in the peripheral blood by PCR. The gastrointestinal contents were positive for Cry1Ab protein by ELISA, immunochromatography, and immunoblot; however, these methods did not work for blood and precluded conclusions about any potential absorption of the protein. These results suggest that ingested corn DNA and Cry1Ab protein were not totally degraded in the gastrointestinal tract, as shown by their presence in a form detectable by PCR or immunological tests.

Accumulation status of persistent organochlorines in albatrosses from the North Pacific and the Southern Ocean.

Current status of contamination by persistent organochlorines (OCs) such as polychlorinated biphenyles (PCBs), dichlorodiphenyl trichloroethane and its metabolites (DDTs), isomers of hexachlorocyclohexane (HCHs), hexachlorobenzene (HCB) and chlordane compounds (CHLs) were examined in 61 individuals belonging to eight albatross species collected from the North Pacific and the Southern Ocean. Generally high OC concentrations were found in albatrosses from the North Pacific than those from the Southern Oceans. Black-footed albatrosses had noticeably high PCBs and DDTs concentrations with mean values of 92 and 33 micrograms/g wet weight in subcutaneous fat, respectively. Among the other OCs, concentration of CHLs was higher than that of HCB in North Pacific albatrosses. HCHs accumulation was the lowest among all the OCs analyzed. Species-specific differences were observed for HCB, CHLs and DDTs in some species in the Southern Ocean. No significant difference of gender and age-related accumulation was observed in total OCs. However, PCB concentrations were higher in mature birds than those from immature ones in the Southern Ocean. Species-specific accumulation patterns of OCs in albatrosses were closely related with their feeding, migration, age and geographical ranges.

Concentration and toxic potential of polychlorinated biphenyl congeners in migratory oceanic birds from the North Pacific and the Southern Ocean.

Concentrations of PCBs and their toxic potential were examined in subcutaneous fat of eight albatross and one petrel species collected from the North Pacific and the Southern Oceans. Among all the species analyzed, high PCB levels were found in adult male blackfooted albatross from the North Pacific with the mean value of 92 microg/g wet weight. No significant gender difference in PCB accumulation was observed (P>0.1). The mean PCB levels in Southern Oceanic birds were 1 or 2 orders of magnitude lower than those from the North Pacific albatrosses. A regional-specific accumulation of non-ortho coplanar congeners were observed, most birds from the Southern Ocean had higher IUPAC 169 levels while IUPAC 126 concentrations were higher in those from the North Pacific. The estimated toxic equivalents for black-footed and Laysan albatrosses from the North Pacific were in the same range of some fish-eating birds, which were highly contaminated by PCBs. The correlation between ratio of IUPAC 169/126 concentration and total PCBs concentration indicated the possibility of induction in cytochrome P450 activities in North Pacific albatrosses (P<0.01). The calculated hazard indices indicated that black-footed and Laysan albatrosses inhabiting in the North Pacific had similar threshold levels which were known to cause toxic effects in some populations of fish-eating birds.

Contamination by persistent organochlorines and butyltin compounds in the west coast of Sri Lanka.

Concentrations of polychlorinated biphenyls (PCBs), dichlorodiphenyl trichloroethane and its metabolites (DDTs), isomers of hexachlorocyclohexane (HCHs), hexachlorobenzene (HCB), chlordane compounds (CHLs) and butyltin compounds (mono-, di- and tributyltin) were determined in biota and sediments collected from locations on the west coast of Sri Lanka. The PCB concentrations found in fish from the Kelani River mouth were higher than those from other Asian developing countries. The pattern of organochlorine accumulation was in the order of PCBs > DDTs > CHLs > HCHs > HCB, and resembled those reported for most developed countries. The accumulation pattern of butyltins in fish was in the order of TBT > DBT > MBT suggesting recent exposure to TBT sources. Total butyltin concentrations found in rabbit fish liver (11-38 micrograms/g wet wt), collected from the Colombo dockyard, could be the highest ever reported for fish in the world.

Toxic assessment of PCBs by the 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalent in common cormorant (Phalacrocorax carbo) from Japan.

Common cormorants collected from three colonies and their fish diet were analyzed for PCB congeners and 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs) were estimated. The highest total PCBs (40 microg/g wet weight) found in adult cormorants from Shinobazu Pond located in Central Tokyo, was sevenfold higher than that from Lake Biwa. IUPAC 153 was the most abundant congener in adults and eggs, whereas IUPAC 28 + 31 was higher in some chicks and exhibited growth-related congeneric enrichment. The estimated metabolic index (MI) for PCB congeners revealed that monoand non-ortho coplanars had higher bioaccumulation in cormorant liver and were expected to cause toxic effects. Among non-ortho coplanars, IUPAC 126 was predominant, and total non-ortho coplanars and TEQs in cormorants were threefold higher in Shinobazu Pond than those from Lake Biwa. The non-ortho IUPAC 126 contributed a higher portion to the total TEQs followed by IUPAC 105 and IUPAC 77. The hepatic IUPAC 169/126 ratio increased significantly with TEQs, implying a potential induction of drug-metabolizing enzymes in Shinobazu Pond cormorants. Based on the available data, PCB contamination in cormorants is enough to pose sublethal effects, especially in Shinobazu Pond and Godaiba Island, Tokyo, Japan. This could be a reason for recently observed high chick and juvenile mortality in those colonies in Tokyo.

Congener specific accumulation and toxic assessment of polychlorinated biphenyls in common cormorants, Phalacrocorax carbo, from Lake Biwa, Japan.

Isomer-specific accumulation of polychlorinated biphenyls (PCBs) including di-, mono- and non-ortho congeners and hepatic P-450 activities were determined in adult common cormorants from Lake Biwa, Japan. The mean total PCB levels in male and female birds were 7.2 +/- 6.1 and 2.1 +/- 0.74 microg g(-1) wet wt, respectively, in the liver. The highly biomagnified congeners were IUPAC 126, 153, 169, 180 and 194, whereas a higher degree of biotransformation could be observed in both meta-para chlorine unsubstituted congeners in the cormorant liver. The estimated metabolic index also showed that common cormorants had higher PB-type enzyme activities than some avian and marine mammals but poor MC-type enzyme activities. The concentrations of non-ortho coplanar congeners were in the order of IUPAC 126 > IUPAC 169 > IUPAC 77 with mean values 6.1 +/- 5.9, 1.3 +/- 1.4 and 0.43 +/- 0.26 ng g(-1) wet wt, respectively. The calculated mean 2,3,7,8-TCDD toxic equivalent (TEQ) concentration in cormorants was 1.8 +/- 1.7 ng g(-1) wet wt and was dominated by IUPAC 118, followed by IUPAC 126. A significant increase of ethoxyresorufin-O-deethylase (EROD) and pentoxyresorufin-O-deethylase (PROD) activities was observed with estimated TEQ of PCBs in the cormorants, suggesting that the current contamination level is sufficient for altering their biochemical responses.

Distribution, biomagnification, and elimination of butyltin compound residues in common cormorants (Phalacrocorax carbo) from Lake Biwa, Japan.

Concentrations of butyltin compounds (BTs) were determined in various body tissues of common cormorants (Phalacrocorax carbo) collected from the Lake Biwa, Japan. Elevated concentrations of butyltins were detected in the feathers of cormorants. Among other organs and tissues, butyltin levels were also higher in the kidney (290+/-150 ng/g) and liver (270+/-260 ng/g), ranging from 115 to 544 ng/g and 142 to 1007 ng/g (wet wt basis), respectively. The accumulation of BTs in cormorant bodies was in the order of MBT>DBT>TBT and their organ specific burdens were in the order of muscle>/=feathers>skin>liver>rest of the tissues and organs. The higher levels of BTs residues in feather suggested the excretion of about one fourth of their body burden during a complete molting cycle, which has been a natural detoxification mechanism in these birds. Based on the whole body concentrations of BTs in cormorants (42-160 ng/g wet wt) and fish (10-55 ng/g wet wt) biomagnification factors were assessed to be in the range of 1.1-4.1. To our knowledge, this is the first fundamental study to substantially indicate the contamination and kinetics of BTs in wild birds.