Ecotoxicology: Current Research Articles

 
Current Articles in the field of ecotoxicology, environmental toxicology published online in scientific journals.

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On this page considered biochemistry journals:

Ecotoxicology - published by Springer -
... is an international journal devoted to the publication of fundamental research on the effects of toxic chemicals on populations, communities and terrestrial, freshwater and marine ecosystems.

Environmental Toxicology - published by Wiley-Interscience -
The journal publishes in the areas of toxicity and toxicology of environmental pollutants in air, dust, sediment, soil and water, and natural toxins in the environment.

Current research articles of the mentioned journals:

Low levels of lead exposure induce oxidative damage and DNA damage in the testes of the frog Rana nigromaculata Abstract  We have investigated the chronic effects of low concentrations of lead (Pb) on oxidative damage and DNA damage in testes of the frog Rana nigromaculata. Sixty adult male frogs were randomly divided into six groups of ten. Based on the levels of the Integrated Wastewater Discharge Standard (GB 8978-1996) of China, five groups (II–VI) were treated by epidermal absorption with a PbNO3 solution at concentrations of 0.1, 0.2, 0.4, 0.8, 1.6 mg/l, respectively. The first group (I), which served as a control, was treated with distilled water only. Thirty days after treatment, all frogs were sacrificed and the testis tissues removed for the measurement of malondialdehyde (MDA) and glutathione (GSH) levels. DNA damage, including indicators of damage rate, DNA tail length (TL), and DNA tail moment (TM), was also analyzed by comet assays. Our data suggest that MDA levels in all treatment groups and GSH levels in the 0.2–1.6 mg/l Pb groups increased significantly relative to the controls (P < 0.01). Treatment with Pb at concentrations >0.4 mg/l also increased DNA damage rate and TM, while TL increased when the Pb level was >0.2 mg/l (P < 0.01 for DNA damage rate and TM, P < 0.05 for TL). Positive correlations were also found between DNA damage levels in the testes and MDA levels (r = 0.796 for DNA damage rate, r = 0.811 for TL, r = 0.796 for TM; P < 0.01 for all) as well between MDA and GSH levels (r = 0.455, P < 0.05) in the testes. Results from MDA measurements indicated that Pb-induced DNA damage in the testes of R. nigromaculata was possibly due to oxidative damage. Taken together, we conclude that Pb can induce male reproductive toxicity in R. nigromaculata. Content Type Journal Article DOI 10.1007/s10646-008-0262-5 Authors Mei-Zhen Wang, Hangzhou Normal University College of Life and Environment Sciences Hangzhou Zhejiang 310036 People’s Republic of China Xiu-Ying Jia, Hangzhou Normal University College of Life and Environment Sciences Hangzhou Zhejiang 310036 People’s Republic of China Journal Ecotoxicology Online ISSN 1573-3017 Print ISSN 0963-9292 Source: Ecotoxicology | 3 Sep 2008 | 10:45 am CEST

Bioaccumulation and physiological effects of mercury in Pteris vittata and Nephrolepis exaltata Abstract  Anatomical, histochemical and biochemical approaches were used to study mercury uptake and phytotoxicity as well as anti-oxidative responses in two species of ferns [Chinese brake fern (Pteris vittata) and Boston fern (Nephrolepis exaltata)], grown in a hydroponic system. The roots of both cultivars accumulated large amounts of mercury, but exhibited limited mercury translocation to shoots. Mercury exposure led to more pronounced phytotoxicity accompanied by stronger oxidative stress in the shoots of P. vittata than in N. exaltata. N. exaltata established a more effective anti-oxidative system against mercury-induced oxidative stress than did P. vittata. The activity of anti-oxidative enzymes (superoxide dismutase, catalase and glutathione reductase) increased. The reduced ascorbate (ASA) and oxidized ascorbate (DHA) are regulated. Mercury exposure led to an increase in the concentration of glutathione (GSH) in both fern species. The present study suggests that N. exaltata is more tolerant to mercury exposure than P. vittata, which has been also reported to be more tolerant to arsenic exposure. N. exaltata may thus have potential for phytostabilization of soils or phytofiltration of waste water contaminated with mercury. Content Type Journal Article DOI 10.1007/s10646-008-0264-3 Authors Jian Chen, Nanjing Agricultural University Department of Biochemistry & Molecular Biology, College of Life Science Nanjing 210095 People’s Republic of China Safwan Shiyab, Mississippi State University Institute for Clean Energy Technology (ICET) Starkville MS 39759 USA Fengxiang X. Han, Mississippi State University Institute for Clean Energy Technology (ICET) Starkville MS 39759 USA David L. Monts, Mississippi State University Institute for Clean Energy Technology (ICET) Starkville MS 39759 USA Charles A. Waggoner, Mississippi State University Institute for Clean Energy Technology (ICET) Starkville MS 39759 USA Zhimin Yang, Nanjing Agricultural University Department of Biochemistry & Molecular Biology, College of Life Science Nanjing 210095 People’s Republic of China Yi Su, Mississippi State University Institute for Clean Energy Technology (ICET) Starkville MS 39759 USA Journal Ecotoxicology Online ISSN 1573-3017 Print ISSN 0963-9292 Source: Ecotoxicology | 3 Sep 2008 | 10:45 am CEST

Assessing the toxicity of TBBPA and HBCD by zebrafish embryo toxicity assay and biomarker analysis Tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCD) are two of the most widely used brominated flame retardants (BFRs). The biological toxicity effect of TBBPA and HBCD was studied by means of zebrafish embryo toxicity assays in combination with three biomarkers, including superoxide dismutase (SOD), lipid peroxidation, (LPO), and heat shock protein (Hsp70). The standard zebrafish embryo assay showed that high concentrations of TBBPA ([ge]0.75 mg/L) can cause lethality or malformation. For HBCD within the concentration range (0.002-10 mg/L), no endpoint was observed. Furthermore, SOD activities of zebrafish embryos exposed to TBBPA were increased with the increasing concentrations. SOD activities in the group treated by HBCD showed an increase followed by a decline. Regardless of TBBPA or HBCD, LPO were increased along with the increase of the concentration. The change pattern of Hsp70 levels was the same with LPO. All these results showed that TBBPA and HBCD could cause oxidative stress and Hsp70 overexpression, inducing acute toxicity to zebrafish embryo in a short-term exposure. The study also indicates that the zebrafish embryo assay in combination with the biomarkers is effective in aquatic environmental toxicology and risk assessment. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 2 Sep 2008 | 5:33 pm CEST

Effect of 1-butyl-3-methylimidazolium tetrafluoroborate on the wheat (Triticum aestivum L.) seedlings Although many studies describe ionic liquids (ILs) as potentially greener solvents, few studies address their relationship with the environment. Recent researches suggest that some ILs have toxicity. 1-Butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]) was reported to have the lowest toxicity among ILs. In this work, we studied the toxicity of this IL on wheat seedlings. It was shown that wheat germination was reduced to 38.0% in the presence of 4.4 mmol/L [C4mim][BF4] compared with 100% germination for the control. Similarly, the root and shoot length of wheat seedlings decreased with increasing concentrations of [C4mim][BF4]. The activity of amylase increased in shoots and roots, but it decreased significantly in germinating seeds when the [C4mim][BF4] concentration exceeded 1.8 mmol/L. Peroxidase (POD) activity and soluble protein content in shoots treated with [C4mim][BF4] changed similarly, but chlorophyll content tended to decrease with increasing concentration of [C4mim][BF4], except for at 1.8 mmol/L. Thus, [C4mim][BF4] at the concentration of 0.9 mmol/L or more was toxic to wheat seedlings. Some remedial measures are suggested to deal with IL pollution in the environment. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 2 Sep 2008 | 5:27 pm CEST

Activation of JNK and PAK2 is essential for citrinin-induced apoptosis in a human osteoblast cell line The mycotoxin citrinin (CTN), a natural contaminant in foodstuffs and animal feeds, exerts cytotoxic and genotoxic effects on various mammalian cells. CTN causes cell injury, including apoptosis. Previous studies by our group showed that CTN triggers apoptosis in mouse embryonic stem cells, as well as embryonic developmental injury. Here, we investigated the precise mechanisms governing this apoptotic effect in osteoblasts. CTN induced apoptotic biochemical changes in a human osteoblast cell line, including activation of c-Jun N-terminal kinase (JNK), loss of mitochondrial membrane potential, and caspase-3 and p21-activated protein kinase 2 (PAK2) activation. Experiments using a JNK-specific inhibitor, SP600125, and antisense oligonucleotides against JNK reduced CTN-induced activation of both JNK and caspase-3 in osteoblasts, indicating that JNK is required for caspase activation in this apoptotic pathway. Experiments using caspase-3 inhibitors and antisense oligonucleotides against PAK2 revealed that active caspase-3 is essential for PAK2 activation. Moreover, both caspase-3 and PAK2 require activation for CTN-induced apoptosis of osteoblasts. Interestingly, CTN stimulates two-stage activation of JNK in human osteoblasts. Early-stage JNK activation is solely ROS-dependent, whereas late-stage activation is dependent on ROS-mediated caspase activity, and regulated by caspase-induced activation of PAK2. On the basis of these results, we propose a signaling cascade model for CTN-induced apoptosis in human osteoblasts involving ROS, JNK, caspases, and PAK2. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 2 Sep 2008 | 5:26 pm CEST

Combined repeated dose and reproductive/developmental toxicities of copper monochloride in rats This study investigated the combined repeated dose and reproductive/developmental toxicity of copper monochloride in rats. The test substance was administered once daily by gavage at 0, 1.3, 5, 20, or 80 mg/kg/day. Male rats were dosed for a total of 30 days beginning 14 days before mating. Female rats were dosed from 2 weeks before mating to day 3 of lactation throughout the mating and gestation period. At 80 mg/kg/day, deaths were observed in 3 out of 12 females. There was a dose-dependent increase in the incidence of clinical signs and a reduction in the food consumption. Hematological and serum biochemical investigations revealed a decrease in the red blood cell, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin (MCH), and serum total protein levels and an increase in the white blood cell and platelets in males, and a decrease in the MCH and an increase in the platelets in females. Histopathological examination showed an increased incidence of squamous cell hyperplasia of the stomach in both genders as well as increased hematopoiesis of the femur in males. There was an increase in the number of icteric and runt pups at birth. At 20 mg/kg/day, there was an increase in the incidence of clinical signs and squamous cell hyperplasia of the stomach in both genders. At 5 mg/kg/day, an increase in the incidence of squamous cell hyperplasia of the stomach was observed in females. There were no adverse effects in the lowest group in both genders. Based on these findings, the no-observed-adverse-effect levels of copper monochloride were concluded to be 5 mg/kg/day in male rats and 1.3 mg/kg/day in female rats for general toxicity and 20 mg/kg/day for reproductive/developmental toxicity. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 2 Sep 2008 | 5:25 pm CEST

The value of stress protein 70 as an environmental biomarker of fish health under field conditions Hsp70 protein in three tissue types (gill, liver, and muscle) from black bream (Acanthopagrus butcheri) collected in a highly variable estuarine environment was investigated to determine which tissue provides better intersite discrimination. The usefulness of hsp70 expression to identify anthropogenic stress under field conditions was evaluated. Intersite differences were detected in hsp70 levels in gill and white muscle of black bream while liver showed no spatial difference. There was high interfish variability in hsp70 levels in each tissue group. A post hoc power analysis of the datasets for each tissue found that in black bream, white muscle provided the best discriminatory power to elucidate spatial variability. Only 11 fish per site are required to identify significant intersite differences in white muscle whereas for gill and liver tissues 14 and 21 fish per site, respectively, would be required. Because of high intertissue and interindividual variability, field measurement of hsp70 should be complemented by evidence of changes in other biomarkers of fish health. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 2 Sep 2008 | 5:22 pm CEST

Effect of short-time exposures to nickel and lead on brain monoamine oxidase from Danio rerio and Poecilia reticulata The aim of this work was to verify, in two small size freshwater teleosts Danio rerio and Poecilia reticulata, the effects of short-time exposures (24 and 72 h) to a sublethal dose (500 [mu]g/L) of nickel and lead, on brain monoamine oxidase (MAO), an important neural enzyme. The 24-h treatment using both metals caused a strong reduction of MAO activity in D. rerio brain, whereas causing a slight MAO activity stimulation in P. reticulata brain. The same treatment in both species did not affect the brain MAO mRNA production as showed by RT-PCR. Extending the duration of treatment as far as 72 h, partly (D. rerio) or completely (P. reticulata) reversed the metal effects on brain MAO activity suggesting that mechanisms to neutralize the metals had been activated. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 2 Sep 2008 | 5:21 pm CEST

Influence of aroclor 1254 on benzo(a)pyrene-induced DNA breakage, oxidative DNA damage, and cytochrome P4501A activity in human hepatoma cell line Both polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) are important environmental pollutants. They coexist widely in the environment at very low levels. Numerous studies indicated that aroclor1254 (one of PCBs mixture) is the inducer of cytochrome P450 1A enzyme acitivity. Benzo(a)pyrene (BaP) can cause a variety of toxicities in vitro, such as oxidative DNA damage and genotoxicity. In the present study, HepG2 cells were treated with either BaP (50 [mu]M) or aroclor1254 at concentrations of 11.5 (low), 23.0 (medium), and 46.0 [mu]M (high) alone, or pretreated the cells with aroclor1254 (11.5, 23.0, and 46.0 [mu]M), followed by BaP (50 [mu]M). It was found that 7-ethoxyresorufin-O-deetylase (EROD) activities of HepG2 cells exposed to either BaP or aroclor 1254 increased. DNA damage measured by DNA migration and the formation of 8-hydroxy-2[prime]-deoxyguanosine (8-OHdG) also increased in cells exposed to BaP, but not in cells exposed to aroclor1254. Under the Aroclor 1254 pretreatment condition, BaP-induced EROD activities was enhanced in cells exposed to the medium and high concentrations of aroclor1254 (P < 0.01 for both), whereas in all pretreatment groups aroclor1254 significantly increased BaP-induced DNA migration (P < 0.01 for all) and the 8-OHdG formation (P < 0.05 for all). In addition, there was positive correlation between the EROD induction activity and Olive tail moment (r2 = 0.958, P < 0.01) or the levels of 8-OHdG (r2 = 0.992, P < 0.01). The findings suggest that under the experimental conditions aroclor1254 may enhance BaP-induced DNA migration and oxidative DNA damage in HepG2, due to inducing CYP1A enzyme activity. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 2 Sep 2008 | 5:20 pm CEST

Heavy metal concentrations in three shorebird species from Okgu Mudflat, Gunsan, Korea Abstract  Iron, zinc, copper, lead, and cadmium were measured in livers of three shorebird species from Okgu Mudflat, Korea in the East Asian-Australian migration flyways. Iron concentrations in red-necked stints (Calidris ruficollis) (geomean = 1,322 μg/g dw) were higher than in terek sandpipers (Xenus cinereus) (467 μg/g dw), and great knots (Calidris tenuirostris) (158 μg/g dw). Copper concentrations in great knots (85.8 μg/g dw) were significantly higher than in red-necked stints (15.9 μg/g dw) and terek sandpipers (10.4 μg/g dw). However, significant differences in zinc concentrations were not found in livers among shorebird species. Iron, zinc, and copper concentrations from this study were within the range of other shorebird studies. We suggest that essential elements such as iron, zinc, and copper are within normal range and are maintained there by normal homeostatic mechanism. Lead and cadmium concentrations differed among shorebird species; red-necked stints (geomeans 27.8 μg/g dw and 4.69 μg/g dw, respectively) were higher than in terek sandpipers (12.9 and 0.44 μg/g dw, respectively), and great knots (5.43 and 0.29 μg/g dw, respectively). Some red-necked stints exceeded toxic levels of lead and cadmium for wild birds. In livers of red-necked stints from Okgu Mudflat, lead and cadmium concentrations were higher than previously reported in other shorebirds. Content Type Journal Article DOI 10.1007/s10646-008-0257-2 Authors Jungsoo Kim, Kyung Hee University Department of Environmental Science and Engineering Yongin, Gyeonggi-do 446-701 Republic of Korea Hwa-Su Lee, Kyung Hee University Department of Environmental Science and Engineering Yongin, Gyeonggi-do 446-701 Republic of Korea Tae-Hoe Koo, Kyung Hee University Department of Environmental Science and Engineering Yongin, Gyeonggi-do 446-701 Republic of Korea Journal Ecotoxicology Online ISSN 1573-3017 Print ISSN 0963-9292 Source: Ecotoxicology | 2 Sep 2008 | 9:46 am CEST

Geostatistical analysis of biomarkers of genotoxicity in cattle, Bos taurus and Bos taurus  ×  Bos indicus , sentinels near industrial facilities Abstract  This study, performed at the behest of ranchers living and working down-prevailing wind from industrial facilities located in Calhoun County, Texas investigated locational risks to ecosystem health associated with proximity to specific industrial complexes. Concerns expressed were for potential genotoxicity in cattle resulting from the release of complex chemical mixtures. The Comet Assay and flow cytometric evaluation of variations in DNA content were utilized to evaluate DNA damage. Bayesian geo-statistical analysis revealed the presence of important spatial processes. The Comet assay’s optical density provided a strong indication of increased damage down-prevailing wind from the industrial complexes. Results indicated that proximity to and location down-prevailing winds from industrial facilities increased the locational risk of genotoxicity in this sentinel species. Content Type Journal Article DOI 10.1007/s10646-008-0261-6 Authors Wesley Bissett, Texas A&M University Department of Large Animal Clinical Sciences 4475 TAMU, Mail Stop 4476 College Station TX 77843-4475 USA Roger Smith, Texas A&M University Department of Veterinary Pathobiology 4467 TAMU College Station TX 77843-4467 USA L. Garry Adams, Texas A&M University Department of Veterinary Pathobiology 4467 TAMU College Station TX 77843-4467 USA Robert Field, Texas A&M University Department of Large Animal Clinical Sciences 4475 TAMU, Mail Stop 4476 College Station TX 77843-4475 USA William Moyer, Texas A&M University Department of Large Animal Clinical Sciences 4475 TAMU, Mail Stop 4476 College Station TX 77843-4475 USA Tim Phillips, Texas A&M University Department of Veterinary Integrative Biosciences 4458 TAMU College Station TX 77843-4458 USA H. Morgan Scott, Texas A&M University Department of Veterinary Integrative Biosciences 4458 TAMU College Station TX 77843-4458 USA James A. Thompson, Texas A&M University Department of Large Animal Clinical Sciences 4475 TAMU, Mail Stop 4476 College Station TX 77843-4475 USA Journal Ecotoxicology Online ISSN 1573-3017 Print ISSN 0963-9292 Source: Ecotoxicology | 2 Sep 2008 | 9:46 am CEST

Genotoxic effects of produced waters in mosquito fish ( Gambusia affinis ) Abstract  The aim of this study was to assess the potential genotoxic effects of produced water (PW) from an Italian on-shore oil plant. Produced water is a complex mixture containing residual hydrocarbons, trace elements, naturally occurring radioactive material and potentially toxic treatment chemicals such as biocides, dispersants, detergents and scale inhibitors used in oil production. The test organism, mosquito fish (Gambusia affinis), was divided into male and female groups and exposed for 8 days in the laboratory to 50% concentrations of different produced waters: PW before treatment and after settling treatment. The fish were also exposed to lower concentrations (10%) of the same PW for 30 days. DNA damage was evaluated in erythrocytes by single cell gel electrophoresis (Comet assay) and micronucleus test, while an oxidative stress biomarker, was assessed. Polycyclic aromatic hydrocarbons (PAH) metabolites in bile were also evaluated. A higher sensitivity in biomarker responses was found in females in comparison to males. An increase in DNA strand breaks was observed in both genders after 30 days exposure and a statistically significant increase of micronucleated cells was found in females after 8 days exposure. A positive correlation between presence of micronucleated cells and PAH metabolites in bile was also observed. Content Type Journal Article DOI 10.1007/s10646-008-0259-0 Authors Ilaria Caliani, University of Siena Department of Environmental Sciences Via Mattioli, 4 53100 Siena Italy Serena Porcelloni, University of Siena Department of Environmental Sciences Via Mattioli, 4 53100 Siena Italy Gabriele Mori, University of Siena Department of Environmental Sciences Via Mattioli, 4 53100 Siena Italy Giada Frenzilli, University of Pisa Department of Human Morphology and Applied Biology Via Volta 4 Pisa Italy Maria Ferraro, University of Siena Department of Environmental Sciences Via Mattioli, 4 53100 Siena Italy Letizia Marsili, University of Siena Department of Environmental Sciences Via Mattioli, 4 53100 Siena Italy Silvia Casini, University of Siena Department of Environmental Sciences Via Mattioli, 4 53100 Siena Italy Maria Cristina Fossi, University of Siena Department of Environmental Sciences Via Mattioli, 4 53100 Siena Italy Journal Ecotoxicology Online ISSN 1573-3017 Print ISSN 0963-9292 Source: Ecotoxicology | 2 Sep 2008 | 9:46 am CEST

Geostatistical analysis of DNA damage in oysters, Crassostrea virginica, in Lavaca Bay, Texas Abstract  This study evaluated the health of the marine ecosystem in Lavaca Bay, Texas using the Eastern oyster (Crassostrea virginica) as the sentinel species. Lavaca Bay has a history of having gradients of concentrations of pollutants present with some areas containing concentrations high enough to pose a threat to marine ecosystem health. The Comet assay was used to evaluate for the presence of genotoxic response in oyster hematocytes. Bayesian geostatistical analysis was then used to determine if the DNA damage in oyster hematocytes was spatially oriented and to develop continuous surface maps of the risk of DNA damage in this sentinel species. Results indicated that proximity to industrial facilities increased the locational risk of genotoxicity in this species. Content Type Journal Article DOI 10.1007/s10646-008-0258-1 Authors Wesley Bissett, Texas A&M University Department of Large Animal Clinical Sciences, 4475 TAMU Mail Stop 4476 College Station TX 77843-4475 USA Lauren Smith, Texas A&M University College of Veterinary Medicine, 4467 TAMU College Station TX 77843-4467 USA James A. Thompson, Texas A&M University Department of Large Animal Clinical Sciences, 4475 TAMU Mail Stop 4476 College Station TX 77843-4475 USA Journal Ecotoxicology Online ISSN 1573-3017 Print ISSN 0963-9292 Source: Ecotoxicology | 2 Sep 2008 | 9:46 am CEST

Effect of 2,4-D herbicide (2,4-dichlorophenoxyacetic acid) on oxygen consumption and ammonium excretion of juveniles of Geophagus brasiliensis (Quoy & Gaimard, 1824) (Osteichthyes, Cichlidae) Abstract  Fish form important fisheries and aquaculture resources worldwide. In Brazil, pearl eartheater (Geophagus brasiliensis) is an important commercially exploited species and is an ideal animal for studying the impairment caused by the effects of herbicides that are often detected in the aquatic environment. The main purpose of the present study was to detect the acute toxicity of 2,4-dichlorophenoxyacetic acid (2,4-D) to G. brasiliensis and investigate its effects on oxygen consumption, ammonium excretion, and the neutral red retention time assay to estimate effects at the cellular level. Such investigations have not been carried out before with this species. First, the acute toxicity of 2,4-D to G. brasiliensis in terms of the 24-, 48-, 72-, and 96-h medium lethal concentration (LC50) was calculated to be 45.95, 32.49, 28.28, and 15.16 mg/l, respectively. Furthermore, it was found that exposure of fish to 40 mg/l 2,4-D caused reduction in oxygen consumption and ammonium excretion of 59% and 85%, respectively, in relation to the controls. Mean neutral red retention time assay was significantly lower in comparison with control for organisms exposed to 1, 5, 10, and 40 mg/l 2,4-D. However, the effects at the cellular level were progressive, suggesting that the fish are not able to recover from such increasing effects. Content Type Journal Article DOI 10.1007/s10646-008-0256-3 Authors Edison Barbieri, Instituto de Pesca-APTA-SAA/SP Caixa Postal 61 Cananeia 11990-000 São Paulo Brazil Journal Ecotoxicology Online ISSN 1573-3017 Print ISSN 0963-9292 Source: Ecotoxicology | 30 Aug 2008 | 1:03 pm CEST

Interactive effects of simultaneous ozone and fluoranthene fumigation on the eco-physiological status of the evergreen conifer, Japanese red pine ( Pinus densiflora Sieb et. Zucc.) Abstract  Forest decline has long been attributed to air pollution and acid rain/fog, with ozone having a record for damaging trees. This study investigated eco-physiological changes on Japanese red pine caused by simultaneous fumigation of O3 (O) and fluoranthene (F) over a 90 day period. Seedlings were exposed individually or in combinations to 10 μM fluoranthene and O3 (3 ppm and 6 ppm in 60 days and 90 days, respectively) inside growth chambers. Eco-physiological parameters monitored included gas exchange, chlorophyll fluorescence, needle chlorophyll content, and visual appearance. After 90 days, O + F treatment showed deleterious effects on visual needle appearance and the net photosynthesis rate near saturated irradiance. In addition, decreased levels in stomatal conductance, photochemical efficiency of PS II in the dark, and total chlorophyll and Chl a: Chl b were observed. F only treatment showed similar results but in lesser magnitude compared with F + O treatment. O treatment alone showed no significant negative effect, probably due to its low concentration in the 60 day treatment. The addition of mannitol (OH radical scavenger) mitigated O + F and F negative effects. Fluoranthene deposited on Japanese red pine presents great eco-physiological damage risk, even at low O3 concentration. Furthermore, the effects of O3 assisted phyto-toxicity of fluoranthene on red pine may have relevance to other plant species. Content Type Journal Article DOI 10.1007/s10646-008-0263-4 Authors Ilemobayo Oguntimehin, Hiroshima University Department of Environmental Dynamics and Management, Graduate School of Biosphere Science 1-7-1 Kagamiyama Higashi-Hiroshima 739-8521 Japan Hiroshi Sakugawa, Hiroshima University Department of Environmental Dynamics and Management, Graduate School of Biosphere Science 1-7-1 Kagamiyama Higashi-Hiroshima 739-8521 Japan Journal Ecotoxicology Online ISSN 1573-3017 Print ISSN 0963-9292 Source: Ecotoxicology | 30 Aug 2008 | 1:03 pm CEST

Harmful algal toxins of the Florida red tide ( Karenia brevis ): natural chemical stressors in South Florida coastal ecosystems Abstract  The Florida red tide is a descriptive name for high concentrations of the harmful marine alga, Karenia brevis. Although most prevalent along the south-west Florida coast, periodic blooms have occurred throughout the entire US and Mexico Gulf coasts and the Atlantic coast to North Carolina. This dinoflagellate produces a suite of polyether neurotoxins, called brevetoxins, that cause severe impacts to natural resources, as well as public health. These naturally produced biotoxins may represent one of the most common chemical stressors impacting South Florida coastal and marine ecosystems. Impacts include massive fish kills, marine mammal, sea turtle and sea bird mortalities, benthic community die-off and public health effects from shellfish contamination and inhalation of air-borne toxins. The primary mode of action is binding to voltage-gated sodium channels causing depolarization of nerve cells, thus interfering with nerve transmission. Other effects include immune depression, bronchial constriction and haemolysis. Parent algal toxins are synthesized within the unicellular organism, others are produced as metabolic products. Recent studies into the composition of brevetoxins in cells, water, air and organisms have shown PbTx-2 to be the primary intracellular brevetoxin that is converted over time to PbTx-3 when the cells are ruptured, releasing extracellular brevetoxins into the environment. Brevetoxins become aerosolized by bubble-mediated transport of extracellular toxins, the composition of which varies depending on the composition in the source water. Bivalved molluscs rapidly accumulate brevetoxins as they filter feed on K. brevis cells. However, the parent algal toxins are rapidly metabolized to other compounds, some of which are responsible for neurotoxic shellfish poisoning (NSP). These results provide new insight into the distribution, persistence and impacts of red tide toxins to south-west Florida ecosystems. Content Type Journal Article DOI 10.1007/s10646-008-0241-x Authors R. H. Pierce, Mote Marine Laboratory 1600 Ken Thompson Parkway Sarasota FL 34236 USA M. S. Henry, Mote Marine Laboratory 1600 Ken Thompson Parkway Sarasota FL 34236 USA Journal Ecotoxicology Online ISSN 1573-3017 Print ISSN 0963-9292 Source: Ecotoxicology | 30 Aug 2008 | 1:03 pm CEST

Modification of the acute toxic response of Daphnia magna Straus 1820 to Cr(VI) by the effect of varying saline concentrations (NaCl) Abstract   Daphnia magna Straus is a freshwater organism that can strive in environments with a salinity of up to 12 psu, although its life cycle and survival are significantly affected by increasing salinities. Saline environments are not devoid of chemical contaminant influences, such as toxic metals; for freshwater species this could be another stress factor aside from that caused by salinity. In this study, we assessed the acute (48 h) toxicity produced by hexavalent chromium [Cr(VI)] in neonates of a D. magna strain previously acclimated to different salinities induced by adding NaCl to reconstituted hard water. The Mean Lethal Concentration (CL50) values determined for Cr(VI) were 0.14 ± 0.12, 1.35 ± 0.34, 1.79 ± 0.41, 2.0 ± 0.21, 2.02 ± 0.075, and 2.6 ± 0.23 mg l−1 for salinities of 0.3, 1, 2, 3, 4, and 5 psu, respectively, evidencing that D. magna’s sensitivity to Cr(VI) decreased with increasing salinity. The increase in tolerance could be due to a possible antagonic effect of NaCl on Cr(VI) rather than due to a reduction in Cr(VI) bioavailability due to the NaCl concentration. Although it was not demonstrated that the stress produced by salinity increased the sensitivity to the exposed toxicant, care must be exerted in inferring that the impact of contaminants, such as toxic metals, could be lower on freshwater species that sporadically or permanently strive in brackish water environments. Content Type Journal Article DOI 10.1007/s10646-008-0260-7 Authors María de la Paz Gómez-Díaz, Escuela Nacional de Ciencias Biológicas, I.P.N. Laboratory of Experimental Hydrobiology Prol. Carpio Esq. Plan de Ayala s/n, Col. Sto. Tomás Mexico DF 11340 Mexico Fernando Martínez-Jerónimo, Escuela Nacional de Ciencias Biológicas, I.P.N. Laboratory of Experimental Hydrobiology Prol. Carpio Esq. Plan de Ayala s/n, Col. Sto. Tomás Mexico DF 11340 Mexico Journal Ecotoxicology Online ISSN 1573-3017 Print ISSN 0963-9292 Source: Ecotoxicology | 30 Aug 2008 | 1:03 pm CEST

Acute and chronic cadmium toxicity to a saltwater cladoceran Moina monogolica Daday and its relative importance Abstract  Acute and chronic toxicity tests of a saltwater cladoceran Moina monogolica Daday exposed to cadmium were conducted according to the American Society for Testing and Materials (ASTM) guidelines. The 24- and 48-h LC50s and their 95% confidence intervals (CIs) were calculated as 9.59 (8.91–10.26) and 1.87 (1.46–2.32) mg Cd/l, respectively, based on measured cadmium concentrations. When compared with different phyla or classes of saltwater animals, M. monogolica had moderate sensitivity and was suitable to be used as an indicator organism. Eight end points used to evaluate chronic effects were affected at chronic cadmium concentrations. Test organisms ceased to reproduce when exposed to equal to or greater than 308.10 μg Cd/l. Comparisons of chronic effects showed that mechanisms of metal accumulation patterns M. monogolica exposed to cadmium are different from those of dissolved copper exposure. The point estimates using linear regression equations of net reproductive rate generated the maximum-acceptable-toxicant concentration of 1.78 μg Cd/l, the lowest-observed-effect concentration of 3.01 μg Cd/l and the no-observed-effect concentration of 1.11 μg Cd/l. Comparisons among thresholds, cadmium concentrations in natural aquatic systems and water quality criteria showed that aquatic organisms were possibly negatively affected at some sites of higher cadmium concentrations. Further research is needed to focus on risk assessment of cadmium on saltwater aquatic organisms and water quality criteria development of China. Content Type Journal Article DOI 10.1007/s10646-008-0255-4 Authors Zaosheng Wang, Chinese Academy of Sciences Research Center of Urban Ecological Health and Environmental Safety, Institute of Urban Environment 2 Huyuan Road Xiamen 361003 China Changzhou Yan, Chinese Academy of Sciences Research Center of Urban Ecological Health and Environmental Safety, Institute of Urban Environment 2 Huyuan Road Xiamen 361003 China Xian Zhang, Chinese Academy of Sciences Research Center of Urban Ecological Health and Environmental Safety, Institute of Urban Environment 2 Huyuan Road Xiamen 361003 China Journal Ecotoxicology Online ISSN 1573-3017 Print ISSN 0963-9292 Source: Ecotoxicology | 22 Aug 2008 | 2:36 pm CEST

Effects of salinity, heavy metals and pesticides on health and physiology of oysters in the Caloosahatchee Estuary, Florida Abstract  The Caloosahatchee Estuary has been exhibiting signs of impaired ecological health due to the extensive hydrological alteration, agricultural land use, and increasing watershed development. This project investigated the responses of the American oyster, Crassostrea virginica at five locations in the Caloosahatchee River in relation to salinity changes, levels of heavy metals, pesticides, and PCBs in the water as well as in the oyster tissue. Individual heavy metal and organochlorine pesticide concentrations in oysters varied significantly between sampling locations and sampling months. PCB concentrations in oyster tissues were below detection limits as were the metal, pesticide and PCB concentrations in water at all the sampling locations. Both heavy metal and pesticide concentrations decreased with increasing distance downstream indicating upstream source of contaminants. The highly pathogenic oyster parasite Perkinsus marinus infection intensity (level) and prevalence (% infected oysters), condition index, spat recruitment, and gonadal index showed a seasonal trend varying with spawning activity and increased downstream. However, juvenile oyster growth was higher at upstream estuarine locations. Oyster responses varied more with seasonal programming (salinity), rather than due to contaminant levels. While significant correlations were noted between some oyster responses and metal concentrations in oyster tissues, overall metal concentrations were low compared to national averages. It appears that oyster health in the Caloosahatchee River is influenced more by freshwater inflow and resulting salinity fluctuations, rather than due to the measured contaminants. Content Type Journal Article DOI 10.1007/s10646-008-0242-9 Authors Aswani K. Volety, Florida Gulf Coast University 10501 FGCU Blvd South Fort Myers FL 33965 USA Journal Ecotoxicology Online ISSN 1573-3017 Print ISSN 0963-9292 Source: Ecotoxicology | 7 Aug 2008 | 12:12 pm CEST

Humic acid induces G1 phase arrest and apoptosis in cultured vascular smooth muscle cells Humic acid (HA) in well water used by the inhabitants for drinking is one of the possible etiological factors for Blackfoot disease (BFD). In this study, the ability of HA to inhibit cell cycle progression and induce apoptosis in cultured smooth muscle cells (SMCs; A7r5) was investigated. Treatment of the SMCs at various HA concentrations (25-200 [mu]g/mL) resulted in sequences of events marked by apoptosis, as shown by loss of cell viability, morphology change, and internucleosomal DNA fragmentation. HA-induced apoptotic cell death that is associated with loss of mitochondrial membrane potential ([Delta][Psi]m), cytochrome c translocation, caspase-3, -8, and -9 activation, poly ADP-ribose polymerase (PARP) degradation, dysregulation of Bcl-2 and Bax, and upregulation of p53 and phospholyrated p53 (p-p53) in SMCs. Flow cytometry analysis demonstrated that HA blocked cell cycle progress in the G1 phase in SMCs. This blockade of cell cycle was associated with reduced amounts of cyclin D1, CDK4, cyclin E, CDK2, and hyperphosphorylated retinoblastoma protein (pRb) in a time-dependent manner. Apparent DNA strand breaks (DNA damage) were also detected in a dose-dependent manner using Single-cell gel electrophoresis assay (comet assay). Furthermore, HA induced dose-dependent elevation of reactive oxygen species (ROS) level in SMCs, and antioxidant vitamin C and Trolox effectively suppressed HA-induced DNA damage and dysregulation of Bcl-2/Bax. Our findings suggest that HA-induced DNA damage, cell cycle arrest, and apoptosis in SMCs may be an underlying mechanisms for the atherosclerosis and thrombosis observed in the BFD endemic region. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 5 Aug 2008 | 12:05 pm CEST

Everglades restoration and water quality challenges in south Florida Abstract  This paper provides background information and a brief overview of water quality issues for the rest of the papers in this volume that are concerned with Everglades restoration. The Everglades of Florida have been diminished over 50% of their former extent. The Everglades are no longer a free-flowing wetland ecosystem, but are now subject to a complicated system of water management that is regulated primarily for flood control and consumptive use. Attempts to restore a more natural hydropattern to the remaining undeveloped Everglades are made more difficult by the natural extremes in rainfall, flat landscape, highly porous geology, and inaccessibility of the remaining natural areas. The Comprehensive Everglades Restoration Plan (CERP) seeks ecosystem restoration by adding water storage capacity, reducing groundwater seepage, improving regulatory delivery and timing of water to avoid environmental damage, and where feasible, improving the quality of water to be used for Everglades restoration. Water quality issues that currently exist for south Florida include eutrophication (especially phosphorus), mercury, and contaminants from agricultural production and the urban environment. Lands once in agricultural production that will be converted back to wetlands or will become reservoirs may contribute to the water quality concerns. Stormwater runoff from managed lands that will be used for restoration purposes will also present water quality challenges. The state continues to seek water quality improvement with a number of pollution reduction programs, and CERP attempts to improve water quality without sacrificing even more natural areas; however providing water quality sufficient for use in recovery of remaining Everglades wetlands and estuaries will remain a daunting challenge. Content Type Journal Article DOI 10.1007/s10646-008-0240-y Authors William B. Perry, Everglades National Park 950 N Krome Avenue Floor 3 Homestead 33030 FL USA Journal Ecotoxicology Online ISSN 1573-3017 Print ISSN 0963-9292 Source: Ecotoxicology | 5 Aug 2008 | 9:08 am CEST

Sediment copper bioavailability to freshwater snails in south Florida: risk implications for the Everglade snail kite ( Rostrhamus sociabilis plumbeus ) Abstract  Many properties being acquired as part of the Comprehensive Everglades Restoration Plan (CERP) are heavily contaminated with copper. Estimated copper bioaccumulation in the Florida apple snail (Pomacea paludosa) has led to the prediction of risk to the Everglade snail kite (Rostrhamus sociabilis plumbeus) at some CERP projects. Field study results presented in this paper examine the relationship between copper levels in sediments, snails, and other biota. Copper concentrations in all biota (snails, aquatic vascular plants, and periphyton) were strongly correlated with those in sediments. No correlation with water copper concentrations was evident. Mean copper concentrations in snails ranged from 23.9 mg/kg at the reference site to 732 mg/kg at a high copper site. Calculated biota-sediment accumulation factors (BSAFs) ranged from 36.7 to 7.0 over the range of copper levels in sediments. BSAFs were highest at low copper levels in sediments and declined sharply as copper levels in sediment increased. Risk for the snail kite is discussed in light of the results of this study. Content Type Journal Article DOI 10.1007/s10646-008-0233-x Authors Robert A. Frakes, U.S. Fish and Wildlife Service Environmental Contaminants Program 1339 20th Street Vero Beach FL 32960 USA Timothy A. Bargar, U.S. Fish and Wildlife Service Environmental Contaminants Program 1339 20th Street Vero Beach FL 32960 USA Emily A. Bauer, U.S. Fish and Wildlife Service Environmental Contaminants Program 1339 20th Street Vero Beach FL 32960 USA Journal Ecotoxicology Online ISSN 1573-3017 Print ISSN 0963-9292 Source: Ecotoxicology | 5 Aug 2008 | 9:08 am CEST

Ecological risk of methylmercury in Everglades National Park, Florida, USA Abstract  Dramatic declines in mercury levels have been reported in Everglades biota in recent years. Yet, methylmercury (MeHg) hot spots remain. This paper summarizes a risk assessment of MeHg exposure to three piscivorous wildlife species (bald eagle, Haliaeetus leucocephalus; wood stork, Mycteria americana; and great egret, Ardea albus) foraging at a MeHg hot spot in northern Everglades National Park (ENP). Available data consisted of literature-derived life history parameters and tissue concentrations measured in 60 largemouth bass (Micropterus salmoides), 60 sunfish (Lepomis spp.), and three composite samples of mosquitofish (Gambusia holbrooki) collected from 2003 to 2005. To assess risk, daily MeHg intake was estimated using Monte Carlo methods and compared to literature-derived effects thresholds. The results indicated the likelihood was very high, ranging from 98–100% probability, that these birds would experience exposures above the acceptable dose when foraging in northern ENP. Moreover, the likelihood that these birds would experience exposures above the lowest-observed-adverse-effect level (LOAEL) ranged from a 14% probability for the wood stork to 56% probability for the eagle. Data from this study, along with the results from several other surveys suggest that biota in ENP currently contain the highest MeHg levels in South Florida and that these levels are similar to or greater than other known MeHg hot spots in the United States. Given these findings, this paper also outlines a strategic plan to obtain additional measured and modeled information to support risk-based management decisions in ENP. Content Type Journal Article DOI 10.1007/s10646-008-0234-9 Authors D. G. Rumbold, South Florida Water Management District West Palm Beach FL USA T. R. Lange, Fish and Wildlife Research Institute Eustis FL USA D. M. Axelrad, Florida Department of Environmental Protection Tallahassee USA T. D. Atkeson, Florida Department of Environmental Protection Tallahassee USA Journal Ecotoxicology Online ISSN 1573-3017 Print ISSN 0963-9292 Source: Ecotoxicology | 5 Aug 2008 | 9:08 am CEST

Corticosterone in relation to tissue cadmium, mercury and selenium concentrations and social status of male lesser scaup ( Aythya affinis ) Abstract  Combined lesser scaup (Aythya affinis) and greater scaup (A. marila) populations have declined steadily from the 1970s. Accompanying the population decline have been two shifts in lesser scaup demographics: a decrease in the proportion of young birds and an increase in male to female ratio. In addition, there are concerns about potential effects of contaminants and trace elements. These metals may influence the stress response and corticosterone secretion. We examined impacts of cadmium, selenium and mercury on the stress response in relation to social status in male lesser scaup near Yellowknife, NWT May to June 2004 and 2005. Kidney cadmium and liver selenium and mercury ranged 0.78–93.6, 2.12–9.64, and 0.56–3.71 μg/g, dry weight, respectively. Results suggest that corticosterone release may be influenced by complex contaminant interactions in relation to body condition and body size. When cadmium was high and birds were in good body condition, there was a negative relationship between liver selenium and corticosterone (R 2 = 0.60, n = 10, P = 0.008) but not in birds with poor body condition (R 2 = 0.07, n = 9, P = 0.50). Unfortunately we were unable to draw any conclusions about metals and social status in relation to corticosterone or glucose and T4. This study emphasizes the complex nature of biological systems and the importance of considering interactions to characterize effects of metals. Content Type Journal Article DOI 10.1007/s10646-008-0250-9 Authors Brady Pollock, University of Saskatchewan Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine 52 Campus Drive Saskatoon SK Canada S7N 5B4 Karen L. Machin, University of Saskatchewan Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine 52 Campus Drive Saskatoon SK Canada S7N 5B4 Journal Ecotoxicology Online ISSN 1573-3017 Print ISSN 0963-9292 Source: Ecotoxicology | 2 Aug 2008 | 8:59 am CEST

Acute toxicity and cytotoxicity of Bacillus thuringiensis and Bacillus sphaericus strains on fish and mouse bone marrow Abstract  The insecticidal properties of delta-endotoxins from Bacillus thuringiensis (Bt) serotypes kurstaki and israelensis and crystal proteins of Bacillus sphaericus (Bs) serotype H5 have been used in insect control for decades. The availability of microbial toxins in biopesticides as well as in plants with incorporated protection has been increasing the concerns about biosafety. Acute toxicity to Danio rerio and cytotoxicity on mouse bone marrow cells and peripheral erythrocytes of Oreochromis niloticus were tested with Bt israelensis, Bt kurstaki and Bs H5 strains. The concentration and dose tested were 106 and 108 spores/ml, respectively. Neither lethality nor effects on mouse bone marrow were promoted by any strain. In necrosis–apoptosis study on peripheral erythrocytes of O. niloticus an increased frequency of necrotic cells caused by exposure to strains of B. thuringiensis was found. Exposure to B. sphaericus did not show cytotoxic effects in either tested system. None of the strains studied induced apoptosis in contrast with the chemical controls. Content Type Journal Article DOI 10.1007/s10646-008-0252-7 Authors Cesar Koppe Grisolia, Universidade de Brasília Departamento de Genética e Morfologia, IB Brasilia DF 70910-900 Brazil Eduardo Cyrino Oliveira-Filho, Embrapa Cerrados Laboratório de Ecotoxicologia Planaltina DF 73310-970 Brazil Felipe Rosa Ramos, Embrapa Recursos Genéticos e Biotecnologia Brasilia DF 70770-900 Brazil Madaí Cruz Lopes, Centro Universitário de Brasília, UniCEUB Brasilia DF 70790-075 Brazil Daphne Heloisa Freitas Muniz, Embrapa Cerrados Laboratório de Ecotoxicologia Planaltina DF 73310-970 Brazil Rose Gomes Monnerat, Embrapa Recursos Genéticos e Biotecnologia Brasilia DF 70770-900 Brazil Journal Ecotoxicology Online ISSN 1573-3017 Print ISSN 0963-9292 Source: Ecotoxicology | 1 Aug 2008 | 8:19 am CEST

Potential effects of environmental contaminants on P450 aromatase activity and DNA damage in swallows from the Rio Grande and Somerville, Texas Abstract  Cliff swallows (Petrochelidon pyrrhonota) and cave swallows (P. fulva) were sampled during the breeding season at several locations in the Rio Grande, Texas, to evaluate the potential effects of environmental contaminants on P450 aromatase activity in brain and gonads and DNA damage in blood cells. The tritiated water-release aromatase assay was used to measure aromatase activity and flow cytometry was used to measure DNA damage in nucleated blood cells. There were no significant differences in brain and gonadal aromatase activities or in estimates of DNA damage (HPCV values) among cave swallow colonies from the Lower Rio Grande Valley (LRGV) and Somerville. However, both brain and gonadal aromatase activities were significantly higher (P < 0.05) in male cliff swallows from Laredo than in those from Somerville. Also, DNA damage estimates were significantly higher (P < 0.05) in cliff swallows (males and females combined) from Laredo than in those from Somerville. Contaminants of current high use in the LRGV, such as atrazine, and some of the highly persistent organochlorines, such as toxaphene and DDE, could be potentially associated with modulation of aromatase activity in avian tissues. Previous studies have indicated possible DNA damage in cliff swallows. We did not observe any differences in aromatase activity or DNA damage in cave swallows that could be associated with contaminant exposure. Also, the differences in aromatase activity and DNA damage between male cliff swallows from Laredo and Somerville could not be explained by contaminants measured at each site in previous studies. Our study provides baseline information on brain and gonadal aromatase activity in swallows that could be useful in future studies. Content Type Journal Article DOI 10.1007/s10646-008-0251-8 Authors M. A. Sitzlar, Texas A&M University Department of Wildlife and Fisheries Sciences 2258 TAMU College Station TX 77843-2258 USA M. A. Mora, Texas A&M University Department of Wildlife and Fisheries Sciences 2258 TAMU College Station TX 77843-2258 USA J. G. W. Fleming, Texas A&M University Department of Animal Science and Center for Animal Biotechnology and Genomics 442 Kleberg Center, 2471 TAMU College Station TX 77843-2471 USA F. W. Bazer, Texas A&M University Department of Animal Science and Center for Animal Biotechnology and Genomics 442 Kleberg Center, 2471 TAMU College Station TX 77843-2471 USA J. W. Bickham, Texas A&M University Department of Wildlife and Fisheries Sciences 2258 TAMU College Station TX 77843-2258 USA C. W. Matson, Texas A&M University Department of Wildlife and Fisheries Sciences 2258 TAMU College Station TX 77843-2258 USA Journal Ecotoxicology Online ISSN 1573-3017 Print ISSN 0963-9292 Source: Ecotoxicology | 1 Aug 2008 | 8:19 am CEST

Sensitivity of different biological responses to accumulation and depuration of butyltins in the neogastropod Thais clavigera : implications for biomonitoring Abstract  We conducted a 3-month reciprocal transplant of the neogastropod Thais clavigera in cages between a site heavily contaminated with tributyltin and a relatively clean site to compare the sensitivity of its reproductive and physiological responses to accumulation and depuration of butyltins. Transplanting T. clavigera from the relatively clean site to the contaminated site resulted in a higher butyltin tissue concentration, higher relative penis size index (RPSI), as well as lower scope for growth (SFG) and lower Oxygen : Nitrogen (O:N) ratio. Nevertheless, growth and vas deferens sequence index (VDSI) were unaffected. Transplanting T. clavigera from the contaminated site to the relatively clean site resulted in a significant decline in tissue burden of butyltins and an elevation of scope for growth (SFG) and O:N ratio; however, there were no marked changes in growth, RPSI or VDSI. Our results thus indicated that growth is not sensitive enough for use in short-term transplant study, SFG and O:N ratio can be used as sensitive biomarkers of both accumulation and depuration of butyltins, whereas RPSI can be used only as a biomarker of accumulation of butyltins. Content Type Journal Article DOI 10.1007/s10646-008-0249-2 Authors Ka Ming Chan, Hong Kong Baptist University Department of Biology Hong Kong People’s Republic of China Siu-Gin Cheung, City University of Hong Kong Department of Biology and Chemistry Hong Kong People’s Republic of China Zongwei Cai, Hong Kong Baptist University Department of Chemistry Hong Kong People’s Republic of China Jian-Wen Qiu, Hong Kong Baptist University Department of Biology Hong Kong People’s Republic of China Journal Ecotoxicology Online ISSN 1573-3017 Print ISSN 0963-9292 Source: Ecotoxicology | 25 Jul 2008 | 8:57 am CEST

Adrenomedullin reduces antioxidant defense system and enhances kidney tissue damage in cadmium and lead exposed rats Adrenomedullin (AdM) is synthesized and secreted by a number of cells and tissue. AdM is a potent vasodilator but it is also considered a neuromodulator, an angiogenic factor, and a hormone regulator. AdM possess antiapoptotic, antioxidant, and antimicrobial properties. Heavy metals such as cadmium and lead are found widely in the environment and they have important biological functions. Lead (Pb) and cadmium (Cd) can accumulate in the lungs, liver, bone, and kidneys and cause serious organ damage. In the present study, we investigated the effect of AdM, Pb + AdM, and Cd + AdM treatments on superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities as well as the level of malondialdehyde (MDA) in the kidney. Heavy metal accumulation was determined in kidney with and without AdM infusion and kidney damage was evaluated by light and electron microscopy. Increased heavy metal accumulation was observed in the heavy metal and AdM treated groups. SOD, CAT, GSH-Px activities, and MDA levels were significantly different in the treatment groups when compared with the control group. Tubular degeneration, necrosis, cell swelling, mononuclear cell infiltration, and degenerated organelles were observed in the kidney following treatment. Therefore, AdM infusion has no beneficial and/or compensatory role in cadmium and lead toxicity in the kidney. We conclude that heavy metal accumulation in the kidney in conjunction with AdM infusion is cytotoxic despite the known beneficial effects of adrenomedullin. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 24 Jul 2008 | 5:18 pm CEST

Cadmium toxicity and phytochelatin production in a rooted-submerged macrophyte Vallisneria spiralis exposed to low concentrations of cadmium Phytochelatins (PCs) have been involved in metal detoxification, and used as potential biomarkers for an evaluation of metal toxicity. However, most studies have generally been limited to high concentrations of metals. In this study, low concentrations of cadmium (Cd) (0.01-0.64 [mu]M) usually present in moderately polluted environments were adopted to investigate Cd toxicity, PC production, and their relationship in a rooted-submerged macrophyte Vallisneria spiralis. It was observed that 0.01-0.04 [mu]M Cd had no significant effects on the growth of this plant when compared with the control plant without Cd, whereas 0.08-0.64 [mu]M Cd showed toxicity, as indicated by the gradual decreases of leaf and root fresh weights. Cadmium accumulation was significantly higher in leaves than in the roots. Correspondingly, PCs were induced in leaves and roots at every Cd concentrations studied, in particular 0.16-0.64 [mu]M, which were higher in leaves than in roots. There existed a positively linear relationship between PC concentrations and Cd toxicity in leaf and root. Furthermore, the levels of glutathione (GSH) in leaves and roots increased with increasing Cd concentrations in solutions and exposure time, but the extent of such increase was lower than that of PCs. Cadmium uptake antagonized Zn uptake. Combined effects of Cd and Fe or Cd and Mn were antagonistic in leaves and synergistic in roots. On the basis of the present results, it was further suggested that PCs can be used as potential biomarkers for monitoring the metal toxicity in moderately polluted environments. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 24 Jul 2008 | 5:17 pm CEST

A whole sample toxicity assessment to evaluate the sub-lethal toxicity of water and sediment elutriates from a lake exposed to diffuse pollution The impact of diffuse pollution in aquatic systems is of great concern due to the difficult to measure and regulate it. As part of an ecological risk assessment (ERA), this study aims to use a whole sample toxicity assessment to evaluate the toxicity of water and sediment from Lake Vela, a lake that has been exposed to diffuse pollution. In this way, standard (algae: Pseudokirchneriella subcapitata; cladoceran: Daphnia magna) and local species (algae: Aphanizomenon flos-aquae; cladoceran: Daphnia longispina) were exposed to surface water, and sediment elutriates were collected seasonally from two sites at Lake Vela: one near the east bank (ES), surrounded by agricultural lands; and the other near the west bank (WS), surrounded by a forest. The results confirmed the seasonal contamination of both environmental compartments by pesticides, including organochlorine pesticides, and the presence of high concentrations of nutrients. Although both sites were contaminated, higher levels of pesticides and nutrients were detected in ES, particularly in the sediments. Bioassays showed that water samples (100% concentration) collected in summer and autumn significantly affected the growth rate of P. subcapitata, which could be attributed to the presence of pesticides. Likewise, they revealed an apparent toxicity of elutriates for P. subcapitata and for both daphnids, in summer and autumn. In fact, although pesticides were not detected in elutriates, high levels of un-ionized ammonia were recorded, which is considered highly toxic to aquatic life. By comparing the several species, P. subcapitata was revealed to be the most sensitive one, followed by the daphnids, and then by A. flos-aquae. Results obtained in this study underlined the importance of whole samples toxicity assessment for characterizing the ecological effects of complex mixtures from diffuse inputs, in the ERA processes. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 24 Jul 2008 | 5:17 pm CEST

Molecular cloning of CYP1A gene and its expression by benzo(a)pyrene from goldfish (Carassius auratus) We cloned and sequenced the cytochrome P450 1A (CYP1A) gene from goldfish (Carassius auratus). It has a 1581 bp open reading frame that encodes a 526 amino acid protein with a theoretical molecular weight of 59.02 kDa. The CYP1A amino acid sequence clusters in a monophyletic group with other fish CYP1As, and more closely related to zebrafish CYP1A (91% identity) than to other fish CYP1As. Exposure to benzo(a)pyrene (BaP) by intraperitoneal injection increased biliary BaP metabolites and liver CYP1A gene expression. BaP exposure also increased CYP1A gene expression in extrahepatic organs, including intestine, and gill, which are sensitive to aqueous and dietary exposure to Arylhydrocarbon receptor (AhR) agonists. Therefore, goldfish CYP1A identified in this study offers basic information for further research related to biomarker use of CYP1A of goldfish. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 24 Jul 2008 | 5:16 pm CEST

Malathion-induced oxidative stress in human erythrocytes and the protective effect of vitamins C and E in vitro Malathion is an organophosphate (OP) pesticide that has been shown to induce oxidative stress in erythrocytes through the generation of free radicals and alteration of the cellular antioxidant defense system. We examined the effect of several different doses of malathion (25, 75, 200 [mu]M), or malathion in combination with vitamin C (VC; 10 [mu]M) or vitamin E (VE; 30 [mu]M), on the levels of malondialdehyde (MDA), and superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities in human erythrocytes in vitro. Erythrocytes were incubated under various treatment conditions (malathion alone, vitamins alone, or malathion plus vitamin) at 37°C for 60 min, and the levels of MDA, and SOD, CAT and GPx activities, were determined. Treatment with malathion alone increased the levels of MDA and decreased SOD, CAT, and GPx activities in erythrocytes (P < 0.05). There were no statistical differences among VC-treated, VE-treated, or VC + VE-treated erythrocyes, as compared with nontreated control cells. Treatment of cells with malathion + VC, malathion + VE, or a combination of all three agents prevented malathion-induced changes in antioxidant enzyme activity and lipid peroxidation. However, this effect was seen only at low concentrations of malathion (25 and 75 [mu]M), and the combination of VC + VE had a more protective effect than VC or VE alone. These results indicated that the presence of vitamins at concentrations that are similar to the levels found in plasma have no effect on malathion-induced toxicity in erythrocytes at a concentration of malathion (200 [mu]M) that is typically used in pesticides. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 24 Jul 2008 | 5:16 pm CEST

Effects of dietary protein and calcium on thymus apoptosis induced by fluoride in female rats (Wistar rats) Our previous studies showed that excessive fluoride (F) ingestion seriously damaged the nonspecific immune function in rabbits. However, the underlying mechanisms of the F-induced damage to the immune system are unclear. The purpose of this study was to investigate whether F induces thymus apoptosis in female rats and its underlying mechanisms by monitoring ultrastructural changes and DNA fragmentation. The results showed that excessive F induced ultrastructural changes and significantly increased the tail length and tailing ratio in thymus lymphocytes. Protein (Pr) supplementation markedly decreased the tailing ratio in thymus lymphocytes in the case of malnutrition. Furthermore, molecular analysis showed that excessive F ingestion significantly up-regulated the expression levels of caspase-3 and caspase-9 mRNA, whereas Pr and calcium (Ca) supplementation down-regulated the expression levels induced by excessive F in the case of malnutrition. In conclusion, these results indicate that excessive F up-regulates the expression levels of caspase-3 and caspase-9 mRNA and induces thymus apoptosis in female rats. Pr and Ca play key roles in process of F-induced thymus apoptosis in malnourished female rats. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 24 Jul 2008 | 5:15 pm CEST

Degradation of dimethyl carboxylic phthalate ester by Burkholderia cepacia DA2 isolated from marine sediment of South China Sea Abstract   Burkholderia cepacia DA2, isolated from marine sediment of the South China Sea, is capable of utilizing dimethyl phthalate (DMP) as the sole source of carbon and energy. During the transformation of DMP in batch culture, its corresponding degradation intermediates were identified as monomethyl phthalate (MMP) and phthalate acid (PA) sequentially over the time of incubation. The biodegradation biochemical pathway of DMP was DMP to MMP and then to PA before mineralization. Degradation of DMP by B. cepacia DA2 was also dependent upon DMP-induction, and the initial concentrations of DMP affected the degradation rate. Degradation kinetics fit well with the modified Gompertz model. The optimum pH and salinity was 6.0 and <5‰, respectively, for DMP degradation by B. cepacia DA2. This study showed that the indigenous microorganisms of the deep-ocean sediments are capable of DMP degradation completely. Content Type Journal Article DOI 10.1007/s10646-008-0247-4 Authors Yali Wang, Chinese Academy of Sciences Key Laboratory of Tropical Marine Environment Dynamics (LED), South China Sea Institute of Oceanography 164 Xingang Road West Guangzhou 510301 People’s Republic of China Bo Yin, Chinese Academy of Sciences Key Laboratory of Tropical Marine Environment Dynamics (LED), South China Sea Institute of Oceanography 164 Xingang Road West Guangzhou 510301 People’s Republic of China Yiguo Hong, Chinese Academy of Sciences Key Laboratory of Tropical Marine Environment Dynamics (LED), South China Sea Institute of Oceanography 164 Xingang Road West Guangzhou 510301 People’s Republic of China Yan Yan, Chinese Academy of Sciences Key Laboratory of Tropical Marine Environment Dynamics (LED), South China Sea Institute of Oceanography 164 Xingang Road West Guangzhou 510301 People’s Republic of China Ji-Dong Gu, The University of Hong Kong School of Biological Sciences Pokfulam Road Hong Kong SAR People’s Republic of China Journal Ecotoxicology Online ISSN 1573-3017 Print ISSN 0963-9292 Source: Ecotoxicology | 24 Jul 2008 | 11:18 am CEST

Phytotoxic effects of cyanobacteria extract on Lemna minor and Myriophyllum spicatum phyto-tolerance and superoxide dismutase activity The research on the effects of microcystins on aquatic plants has increased. Some aquatic plants have some tolerance to microcystins but the mechanism of the tolerance is still unknown. In this experiment, we used microcystins of different concentrations to study the toxic effect in Lemna minor and Myriophyllum spicatum. Experiments were carried out with a range of microcysitns levels (equivalent to 0, 0.1, 0.5, 1.0, and 4.3 mg/L). The growth of L. minor (as fresh weight) and chlorophyll a content were significantly reduced and superoxide dismutase (SOD) activity was significantly decreased at microcystins concentration up to 0.5 mg/L. The growth of M. spicatum was affected, only weakly, by microcystins and 0.5 mg/L and these treatments caused significant decrease in chlorophyll a content. Besides, the SOD activity of M. spicatum positively correlated to microcystins concentration (P < 0.01). The result indicated that M. spicatum was more tolerant to microcystins than L. minor and the induced SOD activity may contribute to the tolerance. The experiment also indicated that catalase (CAT) activity was not significantly influenced by microcystin for both the two tested aquatic plants. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 11 Jul 2008 | 1:31 pm CEST

In vitro study on influence of nano particles of CuO on CA1 pyramidal neurons of rat hippocampus potassium currents The effects of nano particles of CuO on voltage-dependent potassium currents were studied in acutely isolated CA1 pyramidal neurons of rat hippocampus using the whole-cell patch-clamp techniques. Nano particles of CuO had small effects on transient outward potassium current (IA, no statistical significance) and mainly inhibited delayed rectifier potassium current (IK) in the concentration of 5 × 10-5 g/mL. Nano particles of CuO didn't shift the steady-state activation curve of IK and IA but negatively shifted the inactivation curve of IK. The effects on inactivation curve of IA had no statistical significance. These results suggested that blockades of K+ currents by nano particles of CuO could be preferential for Ik for the first time. This may interfere with the normal function of nerve cells. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 11 Jul 2008 | 12:58 pm CEST

Effects of ibuprofen on the viability and proliferation of rainbow trout liver cell lines and potential problems and interactions in effects assessment Under some conditions ibuprofen was either cytotoxic or cytostatic to rainbow trout cell lines: RTL-W1 (liver) and RTH-149 (hepatoma). Ibuprofen at up to 15 [mu]g/mL was not cytotoxic, regardless of dosing protocols, exposure conditions, viability endpoints, or cell lines. Responses to higher ibuprofen concentrations depended on the test methodology. No cytotoxicity was seen when stock ibuprofen solutions had been prepared in ethanol. For stock solutions in dimethylsulfoxide (DMSO), ibuprofen from 50 to 1500 [mu]g/mL elicited little cytotoxicity in cultures in which the final DMSO concentration was 0.05% (v/v), but was consistently cytotoxic after 24 h for cultures with 0.5% DMSO (v/v). Cytotoxicity was evaluated with alamar Blue (AB) and carboxyfluoroscein diacetate acetoxymethyl ester (CFDA-AM) as measures respectively of metabolic activity and membrane integrity. Effective concentrations (EC50s) for ibuprofen with AB and CFDA-AM depended on whether the stock solution was dosed directly into a culture well or mixed in medium prior to being added to a well. For indirect dosing, ibuprofen was more cytotoxic in medium without fetal bovine serum (FBS), whereas for direct dosing ibuprofen was equally cytotoxic in medium with or without FBS. As judged by AB and CFDA-AM EC50s, dosing ibuprofen was directly 10 to 30 times more cytotoxic. In FBS-containing cultures, which was dosed with increasing ibuprofen and DMSO at 0.05% (v/v), cell proliferation was impaired at 50 and 150 [mu]g/mL ibuprofen. Lipopolysaccharide (LPS) at 50 [mu]g/mL had little influence on these cytotoxic and cytostatic effects of ibuprofen in medium with FBS. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 18 Jun 2008 | 3:05 pm CEST

Comparison of R-metalaxyl and rac-metalaxyl in acute, chronic, and sublethal effect on aquatic organisms: Daphnia magna, Scenedesmus quadricanda, and Danio rerio Chiral pesticides are used widely in the world, and at present, older racemic products are being replaced by enantiopure products because of accelerated development of asymmetry synthesis techniques. Pesticides as xenobiotic released into environment impose a great stress on nontarget organisms. Although it is a necessary procedure for pesticides to have a registration based on toxicological data from nontarget organism, until now ecological risk assessment about metalaxyl only depend on racemic products. Hence, we investigated the acute, chronic, and sublethal toxicity of R-metalaxy and rac-metalaxyl on aquatic organisms such as D. magna (Daphnia magna), algae (Scenedesmus quadricanda), and adult zebrafish (Danio rerio). The results showed a significant difference in toxicity between R-metalaxyl and rac-metalaxyl. R-Metalaxy was about 20-fold more toxic to algae than rac-metalaxyl with IC50 of 222.89 ± 1.18 mg/L and 19.95 ± 1.12 mg/L, respectively. Similarly, R-metalaxyl was about fourfold toxic to D. magna than rac-metalaxyl according to the individual 24-h-LC50 values, and sixfold toxic than rac-metalaxyl based on 24-h-EC50 values. In the light of 48-h-LC50 and EC50, this difference in toxicity was more significant. As for adult zebrafish, there was no pronounced difference in acute toxicity, in addition, at sublethal level a different pattern in inducing Na+,K+-ATPase activity between them was found. In general, R-metalaxyl seemed more toxic to aquatic organisms than rac-metalaxyl. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 18 Jun 2008 | 3:04 pm CEST

In vivo genotoxic potential of microcystin-LR: A cyanobacterial toxin, investigated both by the unscheduled DNA synthesis (UDS) and the comet assays after intravenous administration Microcystin-LR (MC-LR) is a toxin produced by freshwater cyanobacteria and is a potential threat to human health. MC-LR has been shown to be both a specific inhibitor of serine/threonine protein phosphatases PP1 and PP2A and a potent tumor promoter in rat liver. However, the genotoxic potential of MCs remains unclear. In this article, we investigated the ability of MC-LR to induce DNA damage on rat hepatocytes following intravenous (iv) administration by using two in vivo genotoxicity assays: the unscheduled DNA synthesis (UDS) and the comet assays. The UDS assay measures DNA synthesis induced from the excision repair of DNA damaged regions and the comet assay is a very sensitive technique for detecting various forms of DNA damage. After an exposure time of 2-4 h or 12-16 h and a dose ranging from 12.5 to 50 [mu]g/kg bw, no DNA damage could be observed in both assays on rat hepatocytes following iv administration. These findings have been discussed and compared with recently published genotoxic results obtained in other organs from mice after oral and intraperitoneal treatments to better understand the mechanism of action of this toxin in relation with its cancerogenicity potential. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 17 Jun 2008 | 1:57 pm CEST

Effects of methyl parathion exposure on development and reproduction in the viviparous fish Girardinichthys multiradiatus Methyl parathion (MeP), an insecticide commonly used in Mexico, has been detected in water bodies adjacent to agricultural crops and is accumulated in the tissue of the amarillo (Girardinichthys multiradiatus), a viviparous fish unique to Central Mexico. Evidence of MeP accumulation in a G. multiradiatus population prompted assessment of the consequences of exposure to MeP during the gestation period and adult life. We exposed adult fish to MeP in the diet at concentrations ranging from 0.001 to 0.165 [mu]g/g dry weight of food. Fish accumulated MeP at concentrations from 0.21 to 5.87 [mu]g/g of fish and exhibited a significant reduction in weight and growth rate. We also evaluated the effects on broods of pregnant females exposed to 0.005, 0.01, and 0.1 [mu]g/g dry weight of food. Although these pregnant females were not affected, their offspring showed an increase in spinal cord malformation and a reduction in survival to adulthood. Finally, we sampled seven localities inhabited by G. multiradiatus; this revealed the presence of MeP in two water bodies at concentrations of 0.0036 and 0.037 [mu]g/mL respectively. Our results suggest that low MeP concentrations affect immature fish with possible consequences later in life. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 17 Jun 2008 | 1:55 pm CEST

Effect of long-term exposure to simazine on histopathology, hematological, and biochemical parameters in Cyprinus carpio We investigated if residues of simazine in the natural waters would cause histological, hematological, and biochemical alterations in carps from contaminated areas in Badajoz (Spain). Some necrotic foci in kidney and liver, hepatitis, and hepatic steatosis were detected. No changes on measured hematological and biochemical parameters between fish from reference and contaminated ponds were observed. To assess if simazine exposure was the cause of these observations carps were exposed in the laboratory to simazine (45 [mu]g/L) for 90 days. Some results obtained in the field were confirmed in laboratory, such as necrosis in kidney and liver and hepatic steatosis. Globular eosinophilic foci in kidney and a slight decrease of the hematocrit were also detected. These changes were moderate and indicative of an adaptation of the fish to the toxic stress caused by exposure to low simazine concentrations. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. Source: Environmental Toxicology | 17 Jun 2008 | 1:48 pm CEST