Selenium in eggs and parental blood of a Dutch marine wader

On the basis of earlier reports on high selenium levels in organs of marine waders from the Dutch Wadden Sea, adverse effects in wader reproduction were anticipated. A local breeding population of the wader Haematopus ostralegus, oystercatcher, was examined for embryotoxicity and selenium levels in eggs and parental blood. Egg and/or blood samples from breeding oystercatchers were obtained also from two reference sites, a Dutch meadow nature reserve and a Norwegian Atlantic island. The blood selenium levels were high in the Dutch marine birds (red blood cells contained 21 mg/kg vs 0.1–1.2 mg/kg dry weight in man), but the highest red blood cell levels were recorded in the red cells of birds sampled at the Norwegian reference site (maximal value 42 mg/kg dry weight). Both the concentrations in eggs from the Wadden Sea and in eggs from inland pastures (about 2 mg/kg dry weight), were at background level and embryotoxicity was not observed. Considering the results, it was concluded that selenium is not a potential threat to the reproduction of waders from the Dutch Wadden Sea, despite the high selenium concentrations in the tissues of the waders foraging in this area. Selenium in egg white was about 1.6 times higher than in yolk. The first egg had a 10% higher egg white and a 19% higher yolk concentration compared to the subsequent eggs in the coastal clutches. Red blood cell levels were about 3.5 times higher in marine feeding birds than in inland feeding birds. Selenium concentrations in the plasma and red blood cells were positively correlated.     

The effects of 2,4,5-trichlorophenoxyacetic acid and 2,3,7,8-tetrachlorodibenzo-P-dioxin on developing chicken embryos

Analytical grade 2,4,5-T and TCDD were dissolved in acetone and injected into the airspace of fertile chicken eggs. Toxicity studies suggest that the LD₅₀ for 2,4,5-T is 133.1 mg of 2,4,5-T per kg of egg weight. The LD₅₀ for TCDD was estimated to be 2.4 × 10^–4 mg of TCDD per kg of egg weight. A partitioned chi-square analysis of the embryo viability data and the nonparallel dose response lines obtained from 2,4,5-T and TCDD suggest an independent mode of action for the two chemicals.As a result of the injection of these two chemicals, increased liver weight to egg weight percentages occurred. Liver weight enlargement as a result of elevated nucleic acid content was ruled out based on the following observations: (1) both RNA and DNA levels per gram of liver tissue were depressed and (2) treatment group RNA to DNA ratios remained the same as controls.     

Transfer of DDT and Metabolites from Fruit Orchard Soils to American Robins (Turdus migratorius) Twenty Years After Agricultural Use of DDT in Canada

Wildlife contamination studies found high levels of DDT and associated metabolites in bird eggs from Canadian orchard sites during the early 1990s. The present study investigated local dietary uptake of DDT and geographic variability in tissue concentrations in the same orchards. A soil–earthworm–robin food chain was chosen for study, as early surveys showed that robins contained the highest levels of DDT of several avian species and because published research indicated that earthworms were a probable dietary exposure route. Organochlorine pesticides and PCBs were measured in soil, earthworm, robin egg, and robin nestling samples collected from fruit orchards and reference sites. High average DDE (soil: 5.2 mg/kg; earthworm: 52 mg/kg; robin egg: 484 mg/kg dry weight) and DDT (soil: 9.2 mg/kg; earthworm: 21 mg/kg; robin egg: 73 mg/kg dry weight) concentrations in Okanagan (British Columbia) samples confirmed that previously recorded contamination was common in the region. Concentrations detected in Simcoe, Ontario, orchards were not as high but were still significantly elevated relative to levels in soils and robins from reference areas. Significant positive linear regressions between soil and earthworm concentrations and consistent trends in food chain accumulation suggested that robins were acquiring DDT and metabolite (DDTr) burdens locally. Low concentrations of DDT and DDTr in robin eggs collected from nests in nearby nonorchard and post-DDT orchard habitats suggested that the local sources were in orchards. Persistence of DDT in orchard food chains is likely due to a combination of retarded degradation rates for DDT in soil and its extensive use historically. DDT concentrations in some robin eggs and earthworms were at levels comparable to those observed in field studies where mortality or reproductive effects occurred. Received: 18 October 1999/Accepted: 13 March 2000     

Effect of Various Copper Supplements to Feed of Laying Hens on Cu Content in Eggs, Liver, Excreta, Soil, and Herbage

Copper is often added to poultry diets as an antimicrobial agent at doses greatly exceeding the nutritional requirement. In this study, the basal diet of laying hens containing 9.2 mg Cu/kg was supplemented with CuSO₄ċ5H₂O at 0, 25, 65, 115, and 240 mg Cu/kg dry matter (DM). At Cu dietary concentration just below the level permitted by the European Union (35 mg/kg), the Cu content in the egg yolk was significantly (p < 0.05) increased by 26%, and nonsignificantly by 4.1, 9.1, and 7.9% in the egg white, eggshell, and liver, respectively. When Cu concentration in the diet was doubled, the effect of Cu on Cu content in eggshell and liver was statistically significant as well. In no liver sample was the hygienic limit of Cu content (80 mg/kg) exceeded. Supplementation of diets with Cu increased Cu concentration in excreta linearly from 25.3 to 396.8 mg/kg DM. Dried excreta were used for fertilization of grassland at 21 g N/m². Three months later, soil and herbage were sampled and analyzed. The Cu concentration in soil increased from 25.3 to only 46.4 mg/kg DM when dietary Cu concentration rose from 9.2 to 243.7 mg Cu/kg DM. Corresponding Cu concentrations in herbage were 6.8 and 19.2 mg/kg DM. It can be concluded that the deposition of Cu in eggs and liver of hens fed Cu-supplemented diets does not represent a hygienic risk. The accumulation of Cu in soil fertilized with excreta of Cu-fed hens and in herbage was limited.     

Minerals and trace elements in a collection of wheat landraces from the Canary Islands

Phosphorous, Na, K, Ca, Mg, Fe, Cu, Zn, Mn and Se were determined in eighteen wheat landraces from Canary Islands and a commercial cultivar. The mean values obtained were: P (2370 ± 333 mg/kg); Na (102 ± 52 mg/kg); K (4363 ± 386 mg/kg); Ca (351 ± 62 mg/kg); Mg (1163 ± 155 mg/kg); Fe (40.0 ± 5.5 mg/kg); Cu (2.68 ± 0.93 mg/kg); Zn (32.1 ± 2.9 mg/kg); Mn (22.1 ± 3.5 mg/kg); Se (67.7 ± 40.4 μg/kg). There were differences (P < 0.05) in the mineral and trace element between the analyzed cultivars, and between the species and subspecies of wheats. Therefore, the Triticum aestivum species had higher mean P, Mg, Fe, Cu, Zn and Mn concentrations, and a lower mean Se concentration, than Triticum turgidum species. The environment and agronomic practices could affect the genetic information of the seeds determining changes in the mineral and trace element composition. The wheat represents an excellent source of Mn (over 100% of recommended dietary intake, RDI), as well as P, Mg, Fe, Cu, Zn and Se (20–50% of RDI). Many correlations were found between the parameters analyzed emphasizing the Cu–Mg (r = 0.691) and Cu–Mn (r = 0.619) correlations. Linear discriminant analysis allowed a good differentiation of the wheat samples according to the cultivar (89.7% of wheat samples classified correctly).     

Ecotoxicological Effects of Buprofezin on Fecundity,Growth, Development,and Predation of the Wolf Spider <Emphasis Type="Italic">Pirata piratoides</Emphasis> (Schenkel)

The toxicological effects of buprofezin, an insect growth regulator, on the fecundity, development, and pest control potential of the wolf spider Pirata piratoides (Schenkel) (Araneae: Lycosidae) were investigated in the laboratory. It was shown that buprofezin had low toxicity to P. piratoides and that the median lethal dosage (LD₅₀) 48 h and 10% lethal dosage (LD₁₀) after topical application for female spiders were 653 and 316 mg buprofezin/mg fresh weight of spider, respectively. Buprofezin significantly reduced the percent hatching of spiders’ eggs but had only a slight effect on egg production. No negative effects on the development and growth were observed. However, spider predation rates were strongly affected: Insecticide-treated females predated on fewer prey than the controls, and their predation rate did not recover even 5 days after insecticide application. This indicated that their pest control potential might be influenced by buprofezin, and the use of buprofezin in biological control of insects is discussed.     

Embryo Toxicity of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin to the Wood Duck (Aix sponsa)

We examined the sensitivity of the wood duck (Aix sponsa) embryo to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) by injecting the toxicant into their eggs. Six groups of wood duck eggs (n = 35 to 211 per trial) were injected with 0 to 4600 pg TCDD/g egg between 2003 and 2005. Injections were made into yolk prior to incubation, and eggs were subsequently incubated and assessed weekly for mortality. Significant TCDD-induced mortality was not observed through day 25 (90% of incubation). Liver, heart, eye, and brain histology were generally unremarkable. Hepatic ethoxyresorufin-O-deethylase activity, a biomarker of dioxin-like compound exposure, was induced by 12-fold in the 4600 pg/g treatment relative to controls. The median lethal dose for chicken (Gallus domesticus) eggs we dosed identically to wood duck eggs was about 100 pg/g, similar to other assessments of chickens. Among dioxin-like compound embryo lethality data for 15 avian genera, the wood duck 4600 pg/g no-observed-effect level ranks near the middle. Because no higher doses were tested, wood ducks may be like other waterfowl (order Anseriformes), which are comparatively tolerant to embryo mortality from polychlorinated dibenzo-p-dioxins and dibenzofurans when exposed by egg injection.     

The Accumulation of Lead and Mercury from Seawater and Their Depuration by Eggs of the Spotted Dogfish Scyliorhinus canicula (Chondrichthys)

Radiotracer experiments using ²¹⁰Pb and ²⁰³Hg demonstrated that eggs of the spotted dogfish Scyliorhinus canicula absorbed lead and inorganic mercury directly from seawater over 21 days of experimental exposure, attaining total egg concentration factors (CFs) relative to water of approximately 400 for Pb and 180 for Hg, predominantly (≥98%) due to their accumulation by the collagenous egg case. The rates of accumulation of both Pb and Hg by the total egg were significantly (P < 0.0001) reduced by its increasing age since parturition, whereas only the rate of depuration of Pb was reduced (P < 0.0001) with increasing age; these effects indicate a declining chemical reactivity of the egg case that may be due to the continued tanning of the case following parturition. The egg case per se, attained average CFs of about 1,500 and 850 for Pb and Hg, respectively. Both Pb and Hg showed declining concentration gradients from the exterior to the interior membranes of the wall of the egg case; CFs for Pb declined from 3,500 to 2,000 and for Hg from 5,000 to 500. Comparison of concentrations in separate membranes also demonstrated significant (P ≤ 0.01) depurations of Hg from the external and internal membranes during the loss experiments. The presence of radiotracers of Pb and Hg in the internal components of the egg at the end of uptake phase, and prior to the opening of the apertures, confirmed the permeability of the egg case wall to them, consistent with their observed gradients in it. The average CFs for all embryos at the end of the uptake experiment were 34 and 44 for Pb and Hg, respectively, but were significantly (P < 0.001) enhanced for Hg by a factor of 6 in the older eggs. The accumulatory and kinetic characteristics of the egg-case may operate to optimize the exposure of embryos to Pb and Hg following episodic contaminant events in coastal habitats.     

Accumulation and Resistance to Copper of Two Biotypes of <Emphasis Type="Italic">Cynodon dactylon</Emphasis>

The effects of copper accumulation and resistance in two biotypes of Cynodon dactylon were studied. Results showed that at a low concentration of copper (<100 mg/kg), the growth of Cynodon dactylon was generally unaffected. As copper concentration increased, negative effects on the growth of Cynodon dactylon became apparent. The critical concentration at which the plant exhibited poisoning symptoms was different for the two biotypes of Cynodon dactylon. At 500 mg/kg copper concentration in soil, the biotype from the polluted area showed significantly higher tolerance of copper than the biotype from the unpolluted area.     

Profile of Organochlorine Pesticides in Soil Cores from Some Hotspot Areas of Beijing,China

Mercury content of egg and eggshell from Whiskered Terns of Anzali wetlands of the Caspian Sea were determined. Mercury levels in egg content of both abandoned (433 ± 4) and non-abandoned (459 ± 15) eggs were 150 times greater than eggshells. Eggshell thickness differed between non-abandoned (0.5 ± 0.03) and abandoned eggs (0.6 ± 0.5) (p < 0.001). No significant association was found between shell Hg and shell thickness in this study. There was significantly more Hg in egg content than in shell (p < 0.001). Mercury levels in eggs did not exceed the levels associated with adverse reproductive effects.     

Transfer of Copper,Lead and Zinc in Soil–Grass Ecosystem in Aspect of Soils Properties,in Poland

The total metal concentrations in soil samples from polluted area (roadside soils) ranged from 13.87 to 195.76 mg/kg for Cu; 13.56–310.17 mg/kg for Pb and 18.43–894.11 mg/kg for Zn and they were, respectively about 5, 2 and 13 times above the corresponding values in soil samples from country area. The mean values of EDTA-extractable concentrations in soil samples at unpolluted sites were: 2.47 mg/kg for Cu, 6.33 mg/kg for Pb and 4.94 mg/kg for Zn. The highest concentrations of Cu, Pb and Zn in grass were measured in soils from polluted area. Higher values of proportions of EDTA-extractable metals (24% for Cu, 40% for Pb and 38% for Zn) indicate that anthropogenic metals were more mobile and bioavailable than the same metals in soils from unpolluted area (20, 16 and 20% for Cu, Pb and Zn, respectively). The availability of Cu, Pb and Zn are affected by soil properties such as pH, organic matter content and cation exchange capacity. Correlation between the EDTA-extractable forms concentrations of metals and the total concentration in the various soils was observed. The coefficients of determination (R²) varied between 0.809 for Cu; 0,709 for Pb and 0.930 for Zn in polluted soils and they are higher than corresponding values in unpolluted soils.     

Toxicological Responses of Red-Backed Salamander (Plethodon cinereus) Exposed to Aged and Amended Soils Containing Lead

The use of lead in military and civilian small arms projectiles is widely acknowledged to have resulted in high soil lead concentrations at many small arms ranges. These ranges are often adjacent to wildlife habitat or have become habitat when no longer used. To assess the potential toxicity of lead to terrestrial amphibians in contaminated areas, we exposed 100 red-backed salamanders (Plethodon cinereus) to either a control soil or one of four soil treatments amended with lead acetate for 28 days. Analytical mean soil concentrations were 14 (control), 553, 1700, 4700, and 9167 mg Pb/kg soil dry weight. An additional 60 salamanders were also exposed for 28 days to one of six field-collected soil samples from a small arms range and a skeet range. The field soil concentrations ranged from 11 (background) to 16,967 mg Pb/kg soil dry weight. Food consisted of uncontaminated flightless Drosophila melanogaster. Salamander survival was reduced in amended soil treatments of 4700 and 9167 mg/kg by 15% and 80%, respectively. Inappetence was observed at 4700 and 9167 mg/kg and growth decreased in the 9167 mg/kg treatment. Total white blood cells decreased 32% at 4700 mg/kg compared to controls and were 22% lower in the 9167 mg/kg treatment. In contrast, survival was 100% for all field-collected soils with no hematological effects. At 16,967 mg/kg there was evidence of soil avoidance and decreased growth. These data suggest marked differences in toxicity and bioavailability of the lead-amended soil in contrast to the field-collected soil containing lead.     

Lack of Developmental and Reproductive Toxicity of 2,3,3′,4,4′-Pentachlorobiphenyl (PCB 105) in Ring-Necked Pheasants

Mono-ortho PCBs are global contaminants of wildlife with the potential to produce toxicity by an aryl hydrocarbon receptor (AhR)–mediated mechanism. To determine the potency of 2,3,3′,4,4′-pentachlorobiphenyl (PCB 105) for producing reproductive and developmental toxicity, adult ring-necked pheasant hens (Phasianus colchicus) were orally dosed with 0, 0.06, 0.6, or 6 mg PCB 105/kg hen/week for 10 weeks to achieve cumulative doses of 0, 0.6, 6, or 60 mg PCB 105/kg hen after which hens were bred with untreated roosters once per week for 8 weeks. Except at week 6 of the egg-laying period when cumulative egg production in the 6 mg PCB 105/kg hen group was greater than controls, fertilized egg production was not significantly different between treatment groups. Embryo mortality and chick mortality were not significantly different between treatment groups. Total body and heart weights of all chicks 1 day posthatch (dph) were not different between groups, however, liver weights of chicks from the 60 mg/kg treatment group were greater than controls at 1 dph. The first chick to hatch from each hen was reared to 21 dph and among these birds, the total body, liver, and heart weights were not different between groups. There were no dose-related malformations of the beak or limbs, and no signs of subcutaneous edema, ascites, or pericardial edema in chicks at 1 or 21 dph. Hepatic microsomal monooxygenase activities [ethoxyresorufin-O-dealkylase (EROD), benzyloxyresorufin-O-dealkylase (BROD), and methyloxyresorufin-O-dealkylase (MROD)] were significantly elevated in chicks at 1 dph from hens given a cumulative PCB 105 dose of 6 mg/kg and in chicks at 21 dph from hens given a cumulative PCB dose of 60 mg/kg. These results indicate that a cumulative PCB 105 dose up to 60 mg/kg hen does not decrease the production of fertilized eggs or increase embryo or chick mortality in ring-necked pheasants, but does increase chick hepatic monooxygenase activity. Received: 6 January 1998/Accepted: 1 July 1998     

Cadmium Accumulation in Two Populations of Rice Frogs (<Emphasis Type="Italic">Fejervarya limnocharis</Emphasis>) Naturally Exposed to Different Environmental Cadmium Levels

Contaminant accumulation analysis is important in the study of sentinels. This research determined cadmium accumulation and bioconcentration factors of whole organism, liver, kidney, ovary and testis of Fejervarya limnocharis exposed to different environmental cadmium levels. Frogs from contaminated sites had significantly higher hepatic (1.939 mg/kg), renal (7.253 mg/kg) and testicular (1.462 mg/kg) cadmium than those from the reference sites (0.205, 0.783 and 0.379 mg/kg, respectively). Cadmium accumulation was the highest during the late dry and early rainy seasons. If this species is used as a sentinel for cadmium accumulation, the utilization of its whole organism, liver, kidney and testis is appropriate.     

Effects of methylmercury on reproduction in American kestrels

Sixty breeding pairs of captive American kestrels (Falco sparverius) were exposed to a range of sublethal dietary concentrations of mercury (Hg), in the form of methylmercuric chloride, and their subsequent reproduction was measured. Egg production, incubation performance, and the number and percent of eggs hatched decreased markedly between 3.3 and 4.6 mg/kg dry weight of Hg (1.2 and 1.7 mg/kg wet wt), in the diet. The number of fledglings and the percent of nestlings fledged were reduced markedly at 0.7 mg/kg dry weight (0.3 mg/kg wet wt) and declined further between 2 and 3.3 mg/kg dry weight (0.7 and 1.2 mg/kg wet wt). Dietary concentrations of >or=4.6 mg/kg dry weight (1.7 mg/kg wet wt) were associated with total fledging failure. The estimated decline in fledged young per pair (24%, Bayesian regression) for kestrels consuming 0.7 mg/kg dry weight (0.3 mg/ kg wet wt) raises concerns about population maintenance in areas subject to high inputs of anthropogenic Hg. Mercury concentrations in 20 second-laid eggs collected from all groups were related to dietary concentrations of Hg, and the Hg concentrations in 19 of these eggs were related to eggs laid and young fledged. Concentrations of Hg in eggs from the highest diet group (5.9 mg/kg dry wt; 2.2 mg/kg wet wt) were higher than egg concentrations reported for either wild birds or for captive birds (nonraptors) fed dry commercial food containing 5 mg/kg methylmercury. Accumulation ratios of Hg from diets to eggs were higher than those reported for feeding studies with other species.     

The effect of mirex on reproduction of Japanese quail and on characteristics of eggs from Japanese quail and chickens

Laying White Leghorn chickens were fed mirex at 0, 5, 10, 20, 40, 80, and 160 ppm for 12 weeks, and laying Japanese quail were fed mirex at 0, 5, 40, and 80 ppm for 12 weeks. The data suggest that dietary mirex at these levels did not affect egg production, egg weight, shell thickness, shell calcium, the proportion of broken eggs, or the proportion of soft-shelled eggs of either chickens or quail. Statistical significance (P < 0.05) associated with dietary mirex was detected in the analysis of eggshell weight for chickens; however, because a dose-response relationship of shell weightvs. level of mirex fed was not evident, this observation was attributed to chance. The data suggest that dietary mirex did not affect eggshell weight, fertility, or hatchability of quail. Mirex accumulation in eggs and carcasses of both species was proportional to dose and was slightly higher in quail than in chickens.     

Hormesis Associated with a Low Dose of Methylmercury Injected into Mallard Eggs

We injected mallard (Anas platyrhynchos) eggs with methylmercury chloride at doses of 0, 0.05, 0.1, 0.2, 0.4, 0.8, 1.6, 3.2, and 6.4 μg mercury/g egg contents on a wet-weight basis. A case of hormesis seemed to occur because hatching success of eggs injected with 0.05 μg/g mercury (the lowest dose) was significantly greater (93.3%) than that of controls (72.6%), whereas hatching success decreased at progressively greater doses of mercury. Our finding of hormesis when a low dose of methylmercury was injected into eggs agrees with a similar observation in a study in which a group of female mallards was fed a low dietary concentration of methylmercury and hatching of their eggs was significantly better than that of controls. If methylmercury has a hormetic effect at low concentrations in avian eggs, these low concentrations may be important in a regulatory sense in that they may represent a no-observed adverse effect level (NOAEL).     

Cistanches herba induces testis cytotoxicity in male mice

We investigated the effects of Cistanches herba (CH) on the male reproductive system in mice, assessing CREM gene expression and spermatogenesis. Our results demonstrate that CH treatment lead to a significant decrease in sperm count dose-dependently, 298.3 ± 48.9 vs. 296.6 ± 102.4 (250 mg/kg), 236.7 ± 75.1 (500 mg/kg), 223.0 ± 48.7 × 10⁶ (1000 mg/kg), respectively. Additionally, serum testosterone levels decreased following CH treatment to as low as ~57% compared with the vehicle-treated group. CREM gene expression was also down-regulated following CH treatment and histological examination of the testicular seminiferous tubules showed severe damage on CH treatment. These results suggest that CH induces cytotoxicity in the male reproductive system, through the inhibition of spermatogenesis, testicular damage, and limited hormonal function.     

Heavy Metal Pollution Associated with an Abandoned Lead–Zinc Mine in the Kirki Region, NE Greece

The “Agios Philippos” mine in the Kirki region (NE Greece) has been abandoned in 1998 after half a century of ore exploration without a reclamation or remediation plan. This article aims at elucidating the potential environmental risks associated with this site by quantifying pollution in tailing basins, stream waters, stream sediments and agricultural fields. Concentrations of heavy metals in the abandoned mine tailings reached 12,567 mg/kg for Pb, 22,292 mg/kg for Zn, 174 mg/kg for Cd and 241 mg/kg for As. The geoaccumulation index and enrichment factor for these metals were indicative of extremely high contamination (I _geo > 5) and extremely high enrichment (EF > 40), respectively. Stream waters in the proximity of the mine had an acidic pH equal to 5.96 and a high sulfate content (SO₄⁻² = 545.5 mg/L), whereas concentrations of Mn, Zn and Cd reached 2,399 μg/L, 7,681 μg/L and 11.2 μg/L. High I _geo and EF values for Cd, Zn and As in stream sediments indicates that surface water pollution has a historic background, which is typically associated with acid mine drainage. Agricultural fields in the proximity of the mine exhibited high I _geo and EF values, which were in decreasing order Cd > Pb > Zn > As. These findings urge for an immediate remediation action of the afflicted area.