Dioxins, PCBs, chlorinated pesticides and brominated flame retardants in free-range chicken eggs from peri-urban areas in Arusha, Tanzania: Levels and implications for human health.

The environment in the northern part of Tanzania is influenced by rapid population growth, and increased urbanization. Urban agriculture is common and of economic value for low income families. In Arusha, many households sell eggs from free-ranging backyard chicken. In 2011, 159 eggs from different households in five different locations in Arusha were collected, homogenized, pooled into 28 composite samples and analyzed for a wide selection of POPs. Levels of POPs varied widely within and between the locations. The levels of dieldrin and ΣDDT ranged between 2 and 98,791 and 2 and 324ng/g lipid weight (lw), respectively. EU MRLs of 0.02mg/kg dieldrin for eggs were exceeded in 4/28 samples. PCBs, HCHs, chlordanes, toxaphenes and endosulfanes were found at lower frequency and levels. Brominated flame retardants (BFRs), e.g polybrominated diphenylethers (PBDEs), hexabromocyclododecane (HBCD) and 1,2-bis(2,4,6-tribromphenoxy)ethane (BTBPE) were present in 100%, 60% and 46% of the composite samples, respectively. Octa-and deca-BDEs were the dominating PBDEs and BDE 209 levels ranged between

Levels and patterns of persistent organic pollutants (POPs) in tilapia (Oreochromis sp.) from four different lakes in Tanzania: geographical differences and implications for human health.

In Tanzania fish is one of the most important protein sources for the rapidly increasing population. Wild fish is threatened by overfishing and pollution from agriculture, industries, mining, household effluents and vector control. To monitor possible implications for public health, the geographical differences of the occurrence and levels of persistent organic pollutants (POPs) in tilapia fish (Oreochromis sp.) from four different Tanzanian lakes were investigated in 2011. Concentrations of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyls (PBDEs) and hexabromocyclododecane (HBCDD) were determined in pooled samples of tilapia muscle from Lake (L) Victoria, L. Tanganyika, L. Nyasa (also called L. Malawi) and L. Babati in Tanzania in 2011. Levels of Σ-DDTs (274 ng/g lipid weight (lw)) and sum of 7 indicator PCBs (Σ-7PCBs) (17 ng/g lw) were significantly higher in tilapia from L. Tanganyika compared to the other lakes. The highest levels of Σ-endosulfan (94 ng/g lw) were detected in tilapia from L. Victoria. Toxaphenes were detected in low levels in fish from L. Tanganyika and L. Babati. Results revealed a geographic difference in the use of DDT and endosulfan between L. Victoria and L. Tanganyika. Low ratios of DDE/DDT in tilapia from L. Tanganyika indicated an on-going use of DDT in the area. Median levels of ΣBDEs, including BDE-209, were highest in L. Victoria (19.4 ng/g lw) and BDE-209 was present in 68% of the samples from this lake. The presence of BDE-209 indicates increasing influence of imported products from heavy industrialized countries. The measured POP levels in the studied tilapia were all below MRLs of EU or were lower than recommended levels, and thus the fish is considered as safe for human consumption. They may, however, pose a risk to the fish species and threaten biodiversity.

Summer variation in the concentration of steroidal sapogenins in and the degree of fungal infection on Narthecium ossifragum plants from Møre og Romsdal County, Norway.

Thirty-nine leaf samples of Narthecium ossifragum collected from eight sites in Møre og Romsdal County, Norway, during June-September 1997 and 41 leaf samples collected at five sites in the same county during June-August 1998 were analysed for the concentrations of steroidal sapogenins using GC-MS. The 1998 samples were also examined for fungal elements (conidia and hyphae) after incubation in a moist chamber for 10-14 days. The highest 1997 and 1998 leaf sapogenin concentrations (4881 and 7115 mg/kg dry matter, respectively) were 13-14 times greater than the lowest sapogenin concentrations found (344 and 531 mg/kg dry matter, respectively). The results did not reveal systematic differences in sapogenin concentrations between the two seasons, or between samples harvested early or late in the same seasons, or between sapogenin concentrations in plants harvested at different sites. Cladosporium magnusianum was the predominant fungus found in the samples. The degree of fungal infection on the samples was in generally low, but the number of C. magnusianum colonies in the moist chamber preparations and fungal elements (conidia and hyphae) in leaf washings and on leaves tended to increase with time. Factor analysis and multiple regression analysis performed on the chemical and fungal results suggest that sporulation may have occurred in the fungi in response to increase in sapogenin concentrations.

Ruminal metabolism in sheep of saponins from Yucca schidigera.

Fifty-five mg per kg live weight of crystallized Yucca schidigera saponins, corresponding to 26 mg/kg live weight of sapogenins, was given daily intraruminally to two lambs for 11 consecutive days. Neither of the lambs showed any sign of toxicity throughout the experimental period. One lamb was killed 5 h after the last dose and GC-MS analysis of the free and conjugated sapogenin content samples of liver, and of the contents of the rumen, omasum, abomasum, duodenum, jejunum, ileum, colon and rectum, of faecal samples collected before dosing started, and of parts of the administered Yucca saponin were performed. The Yucca material contained mainly sarsasapogenin and smilagenin saponins. Ingested saponins were quickly hydrolysed in the rumen to free sapogenins and, in part, epimerized at C-3 to afford episapogenins. The absorption of free sapogenins appeared to occur in the jejunum. The metabolism of Yucca saponins was identical to that of Narthecium ossifragum saponins, and it is suggested that Yucca saponins could replace N. ossifragum saponins for toxicity studies on the latter plant.

Male and female mate choice affects offspring quality in a sex-role-reversed pipefish.

Where both sexes invest substantially in offspring, both females and males should discriminate between potential partners when choosing mates. The degree of choosiness should relate to the costs of choice and to the potential benefits to be gained. We measured offspring quality from experimentally staged matings with preferred and non-preferred partners in a sex-role-reversed pipefish, Syngnathus typhle L. Here, a substantial male investment in offspring results in a lower potential reproductive rate in males than in females, and access to males limits female reproductive success rather than vice versa. Thus, males are choosier than females and females compete more intensely over mates than do males. Broods from preferred matings were superior at escaping predation, when either males or females were allowed to choose a partner. However, only 'choosing' females benefited in terms of faster-growing offspring. Our results have important implications for mate-choice research: here we show that even the more competitive and less choosy sex may contribute significantly to sexual selection through mate choice.

Some effects of the fungicide propiconazole on cytochrome P450 and glutathione S-transferase in brown trout (Salmo trutta).

The fungicide propiconazole (1-(2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-ylmethyl) -1H-1,2,4-triazole) induced the hepatic cytochrome P4501A (CYP1A) activity towards ethoxyresorufin-O-deethylase (EROD), the content of CYP1A protein as quantified by enzyme-linked immunosorbent assay (ELISA) and the glutathione S-transferase (GST) activity towards the three commonly used substrates CDNB(1-chloro-2,4-dinitrobenzene), cumene hydroperoxide (CU) and ethachrynic acid (EA) in brown trout (Salmo trutta) depending on dose and body weight. An exponential dose response relationship existed between propiconazole exposure and CYP1A activity. A 2. order polynomial regression of the propiconazole concentration (square root transformed) on the data for CDNB, EU and CU revealed a bell-shaped pattern of the GST induction. Reverse-phase HPLC of the GSH-affinity chromatography purified GST isozymes in trout exposed to respectively 8.3, 23, 93, 313 and 606 microg l(-1) propiconazole in the water indicated that the propiconazole treatment may lead to changes in the composition of the subunits compared to the controls. Thus, propiconazole exposure through the water changed the properties of the brown trout hepatic CYP1A and GST, and these changes may be used as a bioindicator on the molecular level of exposure and effect of propiconazole in controlled experiments. The use in monitoring of propiconazole exposure under natural field conditions is possible, however needs further investigation.

Comparison of dietary and waterborne exposure to benzo a pyrene: bioavailability,tissue disposition and CYP1A1 induction in rainbow trout Oncorhynchus mykiss.

Absorption and tissue distribution of benzo\ [a] pyrene (BaP)-derived radioactivity were studied in juvenile rainbow trout following dietary or waterborne exposure. In order to compare the bioavailability of BaP, the fish were exposed to 1.5 mCi 3H-BaP kg-1 fish, either in the diet or in the water as a 2 days static exposure. Furthermore, tissue levels of BaP-derived radioactivity bound to macromolecules in different tissues were studied in non-induced fish, and in fish induced by additional treatment with unlabelled BaP (corresponding to 5 mg kg-1 fish) in the water. Absorption and tissue distribution of 3H BaP were studied by liquid scintillation counting and whole-body autoradiography. BaPderived radioactivity bound to macromolecules in different tissues was studied by autoradiography of solvent-extracted whole-body sections. The hepatic CYP1A induction was measured as EROD activity. Exposure to unlabelled BaP resulted in a marked induction of hepatic EROD activity in rainbow trout 2 days after the start of the exposure. Significant higher concentrations of radiolabelled compound were observed in waterborne-exposed fish, in contrast to dietary-exposed fish. High concentrations of radiolabelling were observed in the gills, liver, bile, intestines, olfactory organ, kidney and the skin of the waterborne-exposed fish. In the dietary-exposed fish, high levels of radioactivity were observed in the intestines and the bile, whereas lower concentrations were present in the liver. Only traces of radioactive compound were observed in the gills. In contrast to waterborne-exposed fish, no radioactivity was detected in the olfactory organ or skin. In autoradiograms of sections extracted with a series of polar and non-polar solvents, a large fraction of radioactivity was still present in the gills, olfactory organ, liver, kidney, skin and intestinal mucosa of the waterborne-exposed fish, indicating that reactive BaP intermediates formed by CYP1A-mediated metabolism were bound to macromolecules in these tissues.

Time- and dose-dependent biom arker responses in flounder (Platichthys flesus L.) exposed to benzo[a]pyrene, 2,3,3',4,4', 5-hexachlorobiphenyl (PCB-156) and cadmium.

Responses in flounder (Platichthys flesus) towards benzo [a]pyrene (BaP), 2,3,3',4,4',5-hexachlorobiphenyl (PCB-156), and cadmium (Cd) were investigated in time-course and dose-response studies of selected biomarkers. Measurements of biliary fluorescent BaP metabolites and hepatic concentrations of PCB-156 and cadmium showed that the injected toxicants were rapidly m obilized from the muscle to the liver, but a depot effect was indicated in the highest dose groups of BaP and PCB-156 (12 mg kg(-1) bodyweight). Clearest biomarker responses were found in the induction of hepatic cytochrome P450 1A (CYP1A) enzymes as a response towards BaP and PCB-156 exposure. Maximum induction of CYP1A dependent 7-ethoxyresorufin O-deethylase (EROD) activity was observed after 2 and 8 days in BaP and PCB-156-treated flounder, respectively. Positive dose-effect relationships were observed towards both compounds, but the CYP1A induction was more persistent with PCB exposure than with BaP exposure. In Cd-exposed fish, the hepatic level of metallothionein responded more slowly with highest levels observed after 16 days in the time-study. In the combined BaP + Cd treatment, the CYP1A induction was only slightly suppressed. Aspartate aminotransferase in serum appeared to be responsive towards BaP, but also towards the acetone vehicle in controls in the first part of the exposure period. Hematocrit as well as hepatic activities of aldrin epoxidase, glutathione S-transferase, and UDP-glucuronyl transferase were not responsive to any treatm ent in the present study. In general, the results demonstrate that selected biom arkers in flounder are responsive to PAH, PCB, and heavy metal pollutant exposure, indicating the applicability of this species in future environmental pollution monitoring programmes.

The separation and identification of glutathione S-transferase subunits from Orthosia gothica.

Four subunits of the cytosolic glutathione S-transferase (GST) in Orthosia gothica fed on willow leaves and a semisynthetic bean diet were purified as separate peaks (subunits 1-4) by a two-step gradient elution from a reverse-phase HPLC column after an initial purification by glutathione-Sepharose 1-chloro-2,4-dinitro-benzene (CDNB). Subunit 1 with a molecular weight of 26.0 kDa reconstituted into a GST homodimer with an isoelectric point of 4.8 and the N-terminal amino acid sequence (27 steps) indicated a relationship to the class theta GST of Musca domestica in the first 10 steps (50% homology), but also to the GST class pi of Caenohrabditis elegans (50% between steps 10 and 20). The three subunits 2-4 all had a molecular weight of 23.5 kDa and the isoelectric points of the reconstituted homodimers were > 9.0. The N-terminal amino acid sequence was determined (24 steps) and was identical for the three subunits. A high identity of sequence to the GST in C. elegans (70% between steps 1 and 17), and a low homology (25%) to the O. gothica subunit 1 was observed. Thus, we suggest the O. gothica subunit 1 belong to a different class (O. gothica GST class 1) of GST than subunits 2-4 (O. gothica GST class 2). When the larvae hatched and fed on a semisynthetic bean diet, subunits 3 and 4 were not present in the HPLC eluate, and the subunit 2/subunit 1 ratio increased compared to the corresponding ratio in the larvae which hatched and fed on willow leaves until the third instar.

A comparative study of effects of atrazine on xenobiotic metabolizing enzymes in fish and insect, and of the in vitro phase II atrazine metabolism in some fish, insects, mammals and one plant species.

1. Atrazine (3 daily i.p. doses of 0.20 mg/kg or 10 ppb in the water for 14 days) did not change the xenobiotic metabolizing enzyme activities (XME) towards the substrates aldrin epoxidase (AE), NADPH-cytochrome c reductase (NCCR), 7-ethoxyresorufin O-deethylase (EROD), 1-chloro-2,4-dinitro-benzene (CDNB) and 1,2-dichloro-4-nitrobenzene (DCNB) in trout liver (Oncorhynchus mykiss) compared to the controls. 2. Various treatment regimens of atrazine in a semisynthetic diet changed the XME activities towards AE, NCCR, CDNB and DCNB in the cabbage moth (Mamestra brassica L.) soft tissues and midgut compared to the controls. 3. A life-long cabbage diet induced the XME activity towards CDNB in the cabbage moth soft tissues and midgut, whereas no differences in the activities towards AE, NCCR and DCNB were observed compared to controls on a semi-synthetic diet. 4. The cabbage moth GSTs bound poorly to a glutathione (GSH)-linked epoxy-activated Sepharose 6-B; however, based on the CDNB activity recovered by a GSH elution, there were no differences in the molecular weights of the partly purified subunits (27, 26 and 25 kDa) or the pIs (5.4, 4.8, and 4.1) of the molecules in the soft tissues or midguts from respectively atrazine treated and control cabbage moth.(ABSTRACT TRUNCATED AT 250 WORDS)

Toxicity testing of medical device materials tested in human tissue cultures.

Rubber and plastic parts of medical devices were applied to human cell monolayers either directly or as aqueous extracts made at different time/temperature conditions. Thirteen rubber and twelve plastic samples were tested. The cultures were observed and photographed by use of a microscope with a camera before and after treatment with the test materials. The toxicity of the specimens was evaluated by comparison of the photographs. Alterations or disappearance of the cells or inhibited growth were interpreted as toxic effects of the materials. Twelve of the rubber and six of the plastic samples were evaluated as toxic in one or more of the systems.