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Archives of Environmental Contamination and Toxicology (v.41, #2)
Toluene Mineralization and Growth Potential of Pseudomonas putida PaW164 Under Toluene-Limiting Conditions by T. G. H. Lim; K.-D. Gan; T. A. Hughes; S. S. Hayasaka (pp. 117-122).
Toluene-induced cells of Pseudomonas putida PaW164 (pWWO-164) were monitored for growth potential, maintaining the TOL plasmid, and potential toluene mineralization activity in toluene-amended and nonamended soil. A follow-up study was done in a carbon-free mineral salts solution to obtain further information on physiological changes that occur during starvation. These studies showed that there was a larger decline in colony forming units (CFUs) recovered on a toluate- or benzoate-defined mineral salts medium than on a complex agar medium, a greater percent decrease of CFU than of potential mineralization activity, no decrease in direct counts, and no loss of the TOL plasmid during starvation. Toluene-induced cells also showed an increasing lag time and a decreasing potential for mineralization of 14C-toluene with starvation. In contrast, the lag time for mineralization of glucose was longest at the onset of starvation and reached a minimum by 3 days; thereafter, the potential for glucose mineralization remained high.
Influence of Organic Solvents on the Growth of Marine Microalgae by Y. Okumura; J. Koyama; H. Takaku; H. Satoh (pp. 123-128).
Ninety-six-hour toxicity tests of five organic solvents (methanol, ethanol, acetone, N,N-dimethylformamide [DMF], and dimethyl sulfoxide [DMSO]) on nine species of marine microalgae (Bacillariophyceae; Skeletonema costatum, and Chaetoceros calcitrans, Prasinophyceae; Tetraselmis tetrathele, Haptophyceae; Isochrysis galbana and Pavlova lutheri, Dinophyceae; Prorocentrum minimum, Raphidophyceae; Heterosigma akashiwo, Euglenophyceae; Eutreptiella sp., Chlorophyceae; Dunaliella tertiolecta) were conducted. For D. tertiolecta, T. tetrathele, I. galbana, and P. lutheri, methanol was the least toxic solvent. For S. costatum, C. calcitrans and Eutreptiella sp., DMSO was the least toxic solvent. For Heterosigma akashiwo, DMF was the least toxic solvent. In general, solvent toxicity was ethanol > methanol or acetone > DMF > DMSO. In relation to sensitivity of the microalgae to solvents, D. tertiolecta and T. tetrathele were lower in sensitivity, and Eutreptiella sp. and H. akashiwo were higher in sensitivity than the other species. The no observed effect concentration (NOEC) of acetone, DMF, and DMSO were higher than for ethanol and methanol. Acetone, DMF, and DMSO were suitable for carrier solvents used in toxicity test of water-insoluble chemicals. Excellent regression between logEC50 and logNOEC was obtained (logNOEC = 1.09 × logEC50− 0.84, R2= 0.91). This equation indicated that higher toxicity was higher application factor (EC50/NOEC) than lower toxicity. All application factors were higher than 0.1.
Toxic Effects of Wastewaters Collected at Upstream and Downstream Sites of a Purification Station in Cultures of Rainbow Trout Hepatocytes by C. Risso-de Faverney; A. Devaux; M. Lafaurie; J. P. Girard; R. Rahmani (pp. 129-141).
The toxic effects of wastewater samples, collected in December 1998, from upstream (U) and downstream (D) sites of the purification station of the town of Nice (South-East France on the coast of the Mediterranean Sea) were assessed undiluted and at various dilutions (75%, 50%, and 25% of collected water sample), on trout hepatocyte cultures treated for 48 or 72 h. Chemical contamination (PCBs, PAHs, Cd, Cu, Pb, and Zn) was also evaluated by chemical analysis. The water samples from the upstream site were more cytotoxic than those from the downstream site. The induction of CYP1A enzyme and metallothioneins (MTs) were selected as specific indicators of exposure to organic contaminants and metals, respectively. CYP1A-related EROD activity as well as protein expression were found to be greatly induced after 72 h exposure of the hepatocytes to the undiluted water samples (U100% and D100%), but CYP1A1 mRNA was significantly overexpressed only by samples from the upstream site. Maximal MT levels were reached after 48 h of treatment with the least concentrated water samples (U25% and D25%). Glutathione S-transferase (GST) activities were similarly increased under the same conditions. On the other hand, there was no significant glutathione peroxidase (GPx) activity response. Induction of apoptosis was analyzed by using as markers both the fragmentation of the nuclear DNA into oligonucleosomal-length fragments recognized as a “DNA ladder” and the activation of DEVD (Asp-Glu-Val-Asp)-dependent protease considered as the central mediator of programmed cell death. Significant DNA cleavage was only detectable after 72-h exposure to the most concentrated water samples from upstream sites (U75% and U100%). DEVD-dependent protease activities were significantly increased, mainly in cells exposed to U75% and D25% for 72 h. In addition, pollution-related DNA damage assessed by using the Comet assay was approximatively 1.5 times greater than that of the control level with the undiluted water samples U100% and D100%, after 72-h and 48-h exposure, respectively. The present study shows that such a multibiomarker-based approach could provide complementary information, for aquatic pollution monitoring, about the early biochemical effects in cells exposed to complex chemical pollution and could be considered as early warning systems to aquatic pollution.
DDT Toxicity and Critical Body Residue in the Amphipod Leptocheirus plumulosus in Exposures to Spiked Sediment by G. R. Lotufo; J. D. Farrar; B. M. Duke; T. S. Bridges (pp. 142-150).
The lethal and sublethal toxicity of dichlorodiphenyltrichloroethane (DDT) to the estuarine amphipod Leptocheirus plumulosus was determined using sediment spiked with 14C-labeled compound. Juvenile amphipods were exposed to concentrations up to 9.9 nmol/g dry weight (3.5 μg/g). Acute effects on survival were determined in a 10-day experiment. Chronic effects on survival, growth, and reproduction were assessed in a 28-day experiment. The DDT in the sediments transformed to dichlorodiphenyldichloroethane (DDD), dichlorodiphenyldichloroethylene (DDE), and polar metabolites during the 14-day sediment storage prior to exposing the amphipods. The mixture of DDT and its breakdown products (tDDT) was comprised mostly of DDT at the beginning of the exposures. DDD was the prevalent compound at termination of the 28-day exposure. Complete mortality occurred at sediment concentrations of tDDT as low as 7 nmol/g (2.3 μg/g) in both acute and chronic experiments. Most of the mortality appeared to have occurred within the first 4 days of exposure. No sublethal reductions in growth or reproduction were observed in the 28-day experiment. In the 10-day experiment, where amphipods did not receive supplemental food, growth was significantly increased in DDT treatments where survival was not affected. The concentration of tDDT in amphipod tissues was determined at exposure termination. In the 10-day experiment, a mean body residue of 14 nmol/g wet weight was associated with significant mortality (30%). Lower critical body residues were observed in the 28-day experiment, where the median lethal tissue residue (LR50) was 7.6 (6.8–8.4, 95% confidence interval) nmol/g wet weight. Based on previous studies, the lethal critical body residue for L. plumulosus is similar to those determined for freshwater amphipods and substantially lower than those determined for cladocerans and polychaetes.
Trophic Barriers to Fertilizer Cd Bioaccumulation Through the Food Chain: A Case Study Using a Plant–Insect Predator Pathway by G. Merrington; D. Miller; M. J. McLaughlin; M. A. Keller (pp. 151-156).
The objective of this study was to assess the uptake and subsequent transfer of Cd and Zn from a soil amended with a single application (150 kg P ha−1) of triple super phosphate fertilizer to wheat plants, aphids, and a predator and biocontrol agent of aphids, lacewings.The fertilizer amended soil and wheat plants grown on this soil had elevated concentrations of Cd compared to the controls, but similar concentrations of Zn. Aphids feeding on wheat plants on the fertilized soil had between three and seven times the concentrations of Cd and Zn observed in aphids feeding on the control plants. However, the lacewings showed no significant accumulation of Cd or Zn, and no differences in larval performance were recorded.Changes in the availability of Cd and Zn in the soils and the transfer through the plant–insect pathway were monitored using isotope dilution, by labeling the soils with carrier-free 109Cd and 65Zn. Decreases in the specific activities for Cd in the plants and aphids were observed for the fertilized soils compared to the controls, suggesting an increase in bioavailable Cd.On the fertilized soils the Cd:Zn ratio of the phloem-feeding aphids (0.008) was significantly less than the host plants (0.025), indicating a reduced relative uptake of Cd and a possible barrier for Cd along the soil–plant–herbivorous insect pathway—reducing uptake by phloem feeders and subsequently their predators.
Content of Metals in Compartments of Ecosystem of a Siberian Pond by M. I. Gladyshev; I. V. Gribovskaya; A. V. Moskvicheva; E. Y. Muchkina; S. M. Chuprov; E. A. Ivanova (pp. 157-162).
During three field seasons (June–September) of 1997–99 contents of Na, K, Ca, Mg, Fe, Mn, Zn, Cu, Al, Cr, Ni, Cd, and Pb were determined in compartments of ecosystem (surrounding soils, bottom sediments, water, zoobenthos, macrophytes, and fish) of a fish and recreation pond situated at the edge of Krasnoyarsk City (Siberia, Russia). Contents of most parts of metals in soils, water, and macrophytes significantly correlated with each other. As concluded, their contents were determined by natural, general, geochemical peculiarities of the region. Heavy metals, contents of which were higher than federal upper limits of concentration, were revealed. In muscles of fish with different feeding spectra—crucian and perch—concentrations of some metals differed significantly; correlation graphs for metals also had different structures. Comparison of our data with those on diverse aquatic ecosystems of Siberia, Europe, North America, and China published in the last decade was carried out. It was concluded that a distribution of heavy metals in the compartments of an aquatic ecosystem presently have to be determined for each particular water body until general regularities are discovered.
Effects of Copper and Cadmium Exposure on Functional Responses of Hemocytes in the Clam, Tapes philippinarum by V. Matozzo; L. Ballarin; D. M. Pampanin; M. G. Marin (pp. 163-170).
The effects of Cu and Cd on functional responses of hemocytes in Tapes philippinarum, a Veneridae clam widespread in the lagoon of Venice, were evaluated. Bivalves were exposed for 7 days to various concentrations of CuCl2· 2H2O (0, 10, 60, and 110 μg/L) and CdCl2· H2O (0, 150, 300, and 450 μg/L). Hemocytes were collected from exposed clams, and the effects of Cu and Cd on phagocytosis, Neutral Red retention capacity, superoxide dismutase, and cytochrome oxidase activities were investigated. Hemocytes from animals exposed to Cu showed a significant decrease in phagocytic activity, whereas no inhibition was observed in cells from Cd-exposed animals. Diffusion of Neutral Red into the cytosol, an index of lysosomal membrane alteration, was enhanced by high concentrations of both metals. Different results in biochemical parameters were observed. Exposure to 60 and 110 μg Cu/L caused a significant reduction in hemocyte superoxide dismutase activity, whereas no changes resulted after Cd exposure. Increased cytochrome oxidase activity was observed in hemocytes from mollusks exposed to 60 μg Cu/L and 300 μg Cd/L; no significant differences were found in cells from bivalves exposed to 110 μg Cu/L and 450 μg Cd/L. These results suggest a relationship between heavy metal exposure and alterations in functional responses of hemocytes in T. philippinarum and indicate that the type of observed effects vary with the nature and concentration of heavy metals. Moreover, the data obtained in the analyzed clam support the possibility of using it as sentinel organism in biomonitoring studies, even if used biomarkers will be further evaluated in field conditions.
Changes in Selenium, Copper, Cadmium, and Zinc Concentrations in Mullet (Mugil cephalus) from the Southern Basin of Lake Macquarie, Australia, in Response to Alteration of Coal-Fired Power Station Fly Ash Handling Procedures by J. Kirby; W. Maher; D. Harasti (pp. 171-181).
Selenium, copper, cadmium, and zinc concentrations were measured in mullet (Mugil cephalus) from the southern basin of Lake Macquarie, Australia, in 1997 to determine if improved ash-handling practices at an adjacent coal fired power station, implemented in 1995, had significantly lowered trace metal concentrations in mullet tissues. Mean muscle tissue concentrations of selenium (5.9 ± 0.7 μg/g dry mass), copper (3.6 ± 0.1 μg/g dry mass), and zinc (14 ± 1 μg/g dry mass) are lower than previously reported for mullet analyzed in 1993 (10 ± 2, 21 ± 3, 27 ± 3 μg/g dry mass, respectively). Cadmium concentrations in liver tissues increased from 2.3 ± 0.3 to 6 ± 2 μg/g dry mass. Significant intra-tissue correlations between metal concentrations were found for all tissues except muscle. Strong correlations of selenium, copper, and zinc concentrations were found in liver tissues, indicating a common primary source may exist for these metals, such as fly ash. All trace metals were found to have significant inter-tissue correlations, with strong correlations occurring for selenium between all tissues and for cadmium between all tissues except muscle. Regulation of copper, cadmium, and zinc appears to be occurring in muscle tissue. Selenium concentrations in mullet are still above levels considered to be of concern to human consumers. Trace metal concentrations are below that known to effect the health of fish. Mullet are directly exposed to trace metal concentrations as a result of feeding and the ingestion of contaminated sediment and detritus. Lower metal concentrations found in mullet tissues are attributed to the burial of highly contaminated sediment with material containing lower trace metal concentrations. Little of the variations in trace metal concentrations between mullet was explained by mass, gender, or age.
Plasma Androgen Correlation, EROD Induction, Reduced Condition Factor, and the Occurrence of Organochlorine Pollutants in Reproductively Immature White Sturgeon (Acipenser transmontanus) from the Columbia River, USA by E. P. Foster; M. S. Fitzpatrick; G. W. Feist; C. B. Schreck; J. Yates; J. M. Spitsbergen; J. R. Heidel (pp. 182-191).
White sturgeon (Acipenser transmontanus) support an active fishery in the Columbia River, but there is poor reproductive success within the impounded sections. The poor reproductive success has been attributed to hydroelectric development; however, water pollution could be a significant factor. White sturgeon plasma, liver, and gonad samples were collected from four Columbia River locations and a California aquaculture facility. Total length and weight of the fish were measured, and plasma samples were analyzed for testosterone (T), 11-ketotestosterone (KT), 17β-estradiol (E2), and vitellogenin. Liver samples were analyzed for chlorinated pesticides and polychlorinated biphenyls, ethoxyresorufin-O-deethylase (EROD) activity and histopathology. Gonads were examined histologically to assess sexual maturity and characterize any lesions. Significant differences by location existed for p,p′-DDE, EROD activity, and condition factor. Plasma T was negatively correlated with p,p′-DDE in males and females, and plasma KT was negatively correlated in males. These data indicate that pollutants could be adversely affecting white sturgeon in the Columbia River basin.
Behavioral and Olfactory Responses to Prochloraz, Bentazone, and Nicosulfuron-Contaminated Flows in Goldfish by P. Saglio; K. H. Olsén; S. Bretaud (pp. 192-200).
The immediate behavioral responses of goldfish (Carassius auratus) to pesticide-contaminated flows were recorded in a countercurrent olfactometer. In addition, electro-olfactograms were recorded from the epithelial surface of the olfactory rosette as a preliminary check for the olfactory sensitivity of the fish to the pesticides tested. All tests were run on prochloraz (imidazole fungicide), bentazone (diazine herbicide), and nicosulfuron (sulfonylurea herbicide). Behavioral effects were assessed, at four concentrations (10 μg/L, 100 μg/L, 1 mg/L, 10 mg/L), on endpoints related to swimming pattern (preference-avoidance responses, burst swimming reactions), comfort activities (buccal movements, feeding attempts), and social relations (antagonistic acts, grouping). The behavior of the fish appeared particularly sensitive to prochloraz exposure. As a whole, prochloraz-contaminated flows showed significant effects on the six behaviors studied; bentazone and nicosulfuron affected three and five, respectively. At the lowest concentration, prochloraz also showed more effects than the two other pesticides. Some of the behavioral endpoints were found particularly sensitive to a given chemical. Pesticide-contaminated flows also induced significant changes in swimming orientation of the fish. Attraction was observed in response to flowing solutions of prochloraz (1 mg/L, 10 mg/L), bentazone (10 μg/L, 10 mg/L), and nicosulfuron (1 mg/L, 10 mg/L). At a concentration of 1 mg/L, none of the pesticides induced a noticeable depolarization of the olfactory epithelium, suggesting that these chemicals are not detected by the olfactory sense of the fish. These results are discussed in the light of the data concerning effects of pesticides on behavior and chemical communication in fish.
Metabolic Alterations Without Metal Accumulation in the Ovary of Adult Bufo arenarum Females, Observed After Long-Term Exposure to Zn2+, Followed by Toxicity to Embryos by F. Naab; M. Volcomirsky; A. Burlón; M. E. Caraballo; M. Debray; J. M. Kesque; A. J. Kreiner; M. J. Ozafrán; J. A. Schuff; P. Stoliar; M. E. Vázquez; J. Davidson; M. Davidson; T. M. Fonovich de Schroeder (pp. 201-207).
Long-term exposure of aquatic organisms to metals, even those considered micronutrients, may affect their metabolism and produce sublethal effects. We evaluated the effects of long-term exposure of adult amphibian (Bufo arenarum) females to 4 μg/L of Zn2+ (ZnSO4· H2O) in Ringer solution on the concentration of Zn and Fe, the activity of the key enzyme of the pentose phosphate pathway glucose 6-phosphate dehydrogenase, and glutathione content, both in the liver and ovary of these animals. We also performed early embryonic development studies by in vitro insemination from control and treated females. Zn exposure rendered lower Zn concentrations in the ovaries than did exposure of animals to Ringer solution without metal addition (97 ± 50 versus 149 ± 46 Zn μg/wet tissue g). Zn and Fe concentration correlation was positive and linear in the ovary, but was negative and nonlinear in the liver of the studied females. The activity of the enzyme glucose 6-phosphate dehydrogenase decreased (0.0599 ± 0.0109 versus 0.0776 ± 0.0263 μmol of NADPH/min · mg of proteins) and the endogenous glutathione content increased (0.027 ± 0.005 versus 0.018 ± 0.007 mg/10 mg of proteins) in the ovary but remained unaltered in the liver as a consequence of Zn treatment. Our results suggest the existence of different mechanisms of regulation of Zn and Fe concentrations in the ovary and in the liver of adult B. arenarum females. Binding of Zn to low-molecular-weight proteins, as metallothioneins, may occur in the liver, thus protecting this organ from toxic effects. In the ovary high-molecular-weight proteins, like glucose-6-phosphate dehydrogenase, should be able to bind Zn, leading to oxidative stress responsible for the observed increase in endogenous glutathione content. Inhibition of the pentose phosphate pathway in the ovary by Zn can be responsible for the reproductive failure that we detected through embryos survival studies during early life stages: 81.3 ± 6.3% of embryos from control females survived versus 63.1 ± 13.8% of embryos from Zn-treated females at the branchial circulation stage of development.
Lead Toxicosis and Trace Element Levels in Wild Birds and Mammals at a Firearms Training Facility by L. A. Lewis; R. J. Poppenga; W. R. Davidson; J. R. Fischer; K. A. Morgan (pp. 208-214).
In May 1999, lead poisoning was diagnosed in a yellow-rumped warbler (Dendroica coronata) and a gray squirrel (Sciurus carolinensis) found at the Federal Law Enforcement Training Center (FLETC), Glynn County, GA, based on detection of 6.2 and 90.0 ppm wet weight (WW) lead in the liver of the warbler and squirrel, respectively. From October 21–26, 1999, 72 wild animals (37 mammals and 35 birds), comprised of 22 different species, were collected from a 24-ha area surrounding the FLETC outdoor firearms shooting range complex to evaluate exposure to lead and other trace elements. Ten animals were used as controls (five mammals and five birds) and were collected from areas 1.5–3 km outside the shooting range area. Kidney and liver tissues were analyzed for lead, zinc, and other trace elements. Bird gizzards and white-tailed deer abomasums were examined grossly and radiographically to detect metallic objects. Twenty-four (33.3%) animals (11 species) had kidney or liver tissue lead levels > 1.00 ppm, and 12 of these (6 species) had levels > 2.00 ppm. Carcasses of one brown-thrasher (Toxostoma rufum) and two white-tailed deer (Odocoileus virginianus) contained lead fragments. Elevated liver tissue levels of zinc (111.0 ppm) were detected in one brown thrasher that also had elevated kidney and liver tissue lead levels. In February 2000, seven yellow-rumped warblers and one solitary vireo (Vireo solitarius) found dead near the FLETC firearms shooting range also were diagnosed with lead poisoning, with liver and kidney tissue lead levels from 1.77–11.6 and 4.55–17.8 ppm WW, respectively. This frequency of elevated tissue lead levels among the animals examined, in combination with confirmed lead toxicosis in both avian and mammalian species at FLETC, indicates significant lead exposure of local wild bird and mammal communities via bullets and fragments in and on the soil surface of the four outdoor ranges. Most FLETC firearms training is being shifted to new baffled ranges (four walls with semiopen top) with bullet recovery capabilities to preclude future deposition of lead in the environment; existing outdoor ranges will be remediated to remove existing lead.
Courtship Behavior of Captive American Kestrels (Falco sparverius) Exposed to Polychlorinated Biphenyls by S. A. Fisher; G. R. Bortolotti; K. J. Fernie; J. E. Smits; T. A. Marchant; K. G. Drouillard; D. M. Bird (pp. 215-220).
Polychlorinated biphenyls (PCBs) adversely affect reproduction in birds. Captive adult male and female American kestrels (Falco sparverius) were studied to investigate the potential behavioral and hormonal alterations during the courtship period resulting from clinical exposure to PCBs. American kestrels ingested 7 mg/kg/body weight/bird/day of a 1:1:1 mixture of Aroclors 1248, 1254, and 1260 through their diet of day-old cockerels. The dietary dosage of Aroclors resulted in environmentally relevant total PCB residues in the eggs, averaging 34.1 μg/g wet weight (geometric mean). There was no difference between treatment and control birds in the circulating levels of total androgens (p = 0.44) or in 17β-estradiol (p = 0.29), one week following pairing. Male kestrels exposed to dietary PCBs exhibited significantly more sexual behaviors (p = 0.034) and flight behaviors (p = 0.026) than the control males. Sexual behaviors of male kestrels included; nest-box inspections, solicitation of copulation, the offer of food to the female, and giving the female food. The flight behaviors of the male included; flying from one perch to another and aerial display. In addition, the frequency of male sexual behaviors were correlated (r = 0.605, p = 0.001) with total PCB residues in the eggs of their mates. A concurrent study found that these same PCB-exposed kestrels experienced a delay in clutch initiation as well as a greater number of completely infertile clutches.
Anthropogenic and Natural Organohalogen Compounds in Blubber of Dolphins and Dugongs (Dugong dugon) from Northeastern Australia by W. Vetter; E. Scholz; C. Gaus; J. F. Müller; D. Haynes (pp. 221-231).
A range of organohalogen compounds (10 polychlorinated biphenyl [PCB] congeners, DDT and metabolites, chlordane-related compounds, the potential natural organochlorine compound Q1, toxaphene, hexachlorobenzene, hexachlorocyclohexanes, dieldrin, and several yet unidentified brominated compounds) were detected in the blubber of four bottlenose dolphins (Tursiops truncatus), one common dolphin (Delphinus delphis), and seven dugongs (Dugong dugon), as well as in adipose tissue of a green turtle (Chelonia mydas) and a python (Morelia spilota) from northeast Queensland (Australia). The green turtle and dugongs accumulated lower organohalogen levels than the dolphins. Lower levels in dugongs were expected because this species is exclusively herbivorous. Highest PCB and DDT levels recorded in dugongs were 209 and 173 μg/kg lipids, respectively. Levels of the nonanthropogenic heptachlorinated compound Q1 (highest level in dugongs was 160 μg/kg lipids) were estimated using the ECD response factor of trans-nonachlor.Highest organohalogen levels were found in blubber of dolphins for sumDDT (575–52,500 μg/kg) and PCBs (600–25,500 μg/kg lipids). Furthermore, Q1 was a major organohalogen detected in all samples analyzed, ranging from 450–9,100 μg/kg lipids. The highest concentration of Q1 determined in this study represents the highest concentration reported to date in an environmental sample. Levels of chlordane-related compounds were also high (280–7,700 μg/kg, mainly derived from trans-nonachlor), but concentrations of hexachlorobenzene, hexachlorocyclohexanes, dieldrin, and toxaphene were relatively low and contributed little to the overall organohalogen contamination. Furthermore, a series of three major (BC-1, BC-2, and BC-3) and six minor (BC-4 through BC-9) unknown brominated compounds were observable by extracting m/z 79 and m/z 81 from the GC/ECNI-MS full scan run. Structural proposals were made for the two major recalcitrant compounds (referred to as BC-1 and BC-2). BC-2 appears to be a tetrabromo-methoxy-diphenylether (512 u) and BC-1 has 14 u (corresponding with an additional CH2 group) more relative to BC-1. In general, the organohalogen pattern observed in blubber of dolphins was different compared to similar samples from other locations in the world, which is apparent from the fact that the four major abundant signals in the GC/ECD chromatogram of D. delphis originated from the four unknown compounds Q1, BC-1, BC-2, and BC-3.
Transgene Expression of Thioredoxin (TRX/ADF) Protects Against 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD)-Induced Hematotoxicity by B.-I. Yoon; Y. Hirabayashi; T. Kaneko; Y. Kodama; J. Kanno; J. Yodoi; D. Y. Kim; T. Inoue (pp. 232-236).
TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) has a variety of toxic effects on a number of organs, including the hematopoietic system. The importance of TCDD-induced oxidative stress has been evaluated in several target organs. However, its role in hematotoxicity remains poorly understood, although bone marrow is known to produce reactive oxygen species. The aim of this study is to evaluate not only the contribution of oxidative stress to TCDD-induced hematotoxicity but also the protective function of TRX/ADF, a known anti-oxidative stress agent, on the hematotoxicity of TCDD in ADF wild-type (WT) and transgenic (Tg) mice. WT and Tg mice received a single intraperitoneal injection of 20 μg TCDD/kg. One day after the treatment, blood and bone marrow cellularity was measured and bone marrow levels of granulotyce/macrophage colony-forming units were determined in the in vitro colony assay. The expression of human TRX transgene by their bone marrow cells was analyzed by Western blot electrophoresis. Our results showed that overexpression of TRX/ADF protects against TCDD-induced hematotoxicity, indicating that induction of oxidative stress that results in disruption of redox regulation may be an important mechanism in TCDD-induced bone marrow toxicity. Moreover, we detected a significant decrease of AhR mRNA levels in bone marrow cells of Tg mice following TCDD treatment, suggesting a biological role of TRX/ADF in the AhR-mediated pathway through which TCDD induces oxidative stress.
Environmental Residues and Biomonitoring Estimates of Human Insecticide Exposure from Treated Residential Turf by C. E. Bernard; H. Nuygen; D. Truong; R. I. Krieger (pp. 237-240).
Intentional and unavoidable human exposure is a consequence of using pesticides to nurture and protect residential turf. Limited exposure studies have been conducted for assessing potential human exposure of turf residues. Exposure was measured in persons who performed a 20-minute structured activity (Jazzercise®) on chlorpyrifos (CP)-treated Kentucky bluegrass (12 ± 4 μg CP/cm2). CP exposure was measured by determining urine clearance of the 3,5,6-trichloro-2-pyridinol (TCP). Study participants wore either 100% cotton whole body dosimeters (union suit, gloves, and socks) or exercise suits (shorts and a sports top or one-piece suit with similar amounts of exposed skin). An average of 1.6 mg CP/person was extracted from whole body dosimeters worn by study participants. The measured residue transfer was well below the 35 mg CP/person estimated using the US EPA standard operating procedures. Biomonitoring based on urine clearance of TCP indicated that an average of 1.3 μg CP/kg was absorbed. Absorbed dosages (0.5 to 2 μg CP/kg) derived from transferable residue on cotton cloths pressed to the turf with a weighted roller were similar to estimates from biomonitoring. A very limited amount of CP applied to turf is available for transfer and absorption during intensive human contact.
Correlation Between Lead Exposure Indicators and Sister Chromatid Exchange (SCE) Frequencies in Lymphocytes from Inorganic Lead Exposed Workers by Y. Duydu; H. S. Süzen; A. Aydin; O. Cander; H. Uysal; A. Işimer; N. Vural (pp. 241-246).
Inorganic lead exposure was studied in 31 volunteers employed in storage battery plant. The genotoxicity of lead was measured in terms of sister chromatid exchange (SCE). Erythrocyte δ-aminolevulinic acid dehydrogenase (ALAD) activity, urinary δ-aminolevulinic acid (U-ALA), and blood lead levels (PbBs) were also determined to evaluate some possible relations between these lead exposure indicators and the observed SCE frequencies. Blood lead concentration of 36.31 μg/dl was determined as an average level in the workers. Consequently decreased ALAD activity in erythrocytes and increased U-ALA excretion was observed in statistically higher PbBs when compared with the control group. A statistically significant correlation was observed between the PbBs and SCE frequencies (p < 0.05). Moreover, the correlation between U-ALA excretion and SCE frequencies (p < 0.01) was relatively higher than the correlation between PbBs and SCE frequencies. These results might indicate a possible mechanism of ALA mediation in the genotoxic effects of lead.
Environmental and Physiological Factors Affecting Lead and Cadmium Levels in Deciduous Teeth by J. Bayo; S. Moreno-Grau; M. J. Martinez; J. Moreno; J. M. Angosto; J. J. Guillén Pérez; L. Garcia Marcos; J. Moreno-Clavel (pp. 247-254).
Shed deciduous teeth lead and cadmium content of children from Cartagena (Spain) was assessed. Parents were provided with an interview containing different questions concerning family socioeconomic status, child's health history, zone of residence, or home antiquity. Besides, physiological variables were considered, i.e., sex of donor, presence of caries, type of tooth donated, tooth weight, age of shedding, and position within the mouth. Tooth lead and cadmium data showed a positively skewed distribution and were log-normalized for further analyses. No statistically significant differences could be observed for lead and cadmium values according to the sex of donor. Both heavy metals decreased in content from incisors to molars and with age of shedding. The one-way analysis of variance (ANOVA) displayed both environmental and physiological risk factors contributing to high tooth lead and cadmium values. When a multifactor ANOVA was carried out, the associations between home antiquity, nail biting habit, and jaw with tooth lead levels, as well as those between zone of residence and tooth cadmium levels were found to persist. However, the only common factor for both heavy metals in the multiple analyses was the type of tooth.