Forgot your password?
New user?
New Window Opens on the Secret Life of Microbes: Scientists Develop First Microbial Profiles of Ecosystems
CAS announces the release of SciFinder Scholar for Mac OS X
Press Releases
Press Releases
| Check out our New Publishers' Select for Free Articles |
Archives of Environmental Contamination and Toxicology (v.64, #3)
Quantification of Environmental Tobacco Smoke Contribution on Outdoor Particulate Aliphatic and Polycyclic Aromatic Hydrocarbons by M. Gini; M. Lianou; M. C. Chalbot; A. Kotronarou; I. G. Kavouras; C. G. Helmis (pp. 347-356).
The objective of this study was to identify and quantify the sources of fine particulate aliphatic and polycyclic aromatic hydrocarbons (PAHs) in an urban area in southeastern Europe. A total of 91 urban PM2.5 samples were analyzed by gas chromatography coupled with mass spectrometry for alkanes and PAHs. Exploratory statistical tools were applied to resolve a decreased number of components based on the variation of measurements. Molecular markers and diagnostic ratios were examined to assign retained components to specific sources. The contributions of the sources were estimated by multivariate linear regression. Sources of aliphatic and PAHs hydrocarbons included primary particles from traffic (3.9 ng/m3 for alkanes and 240 pg/m3 for PAHs), evaporative fugitive (4.0 ng/m3 for alkanes and 93 pg/m3 for PAHs), and unburnt fuels and oil residues (1.1 ng/m3 for alkanes and 230 pg/m3 for PAHs). For the first time, we quantified the contribution of environmental tobacco smoke (ETS), which accounted for 5.2 ng/m3 of alkanes and 128 pg/m3 of PAHs. The findings of this study underlined the persistence of ETS and possible exposures to significant quantities of tobacco residues outdoors. Tobacco smoke is known to induce adverse respiratory and cardiovascular illnesses and increased risk for cancer.
Geochemical Characterization of Acid Mine Lakes in Northwest Turkey and Their Effect on the Environment by Deniz Sanliyuksel Yucel; Alper Baba (pp. 357-376).
Mining activity generates a large quantity of mine waste. The potential hazard of mine waste depends on the host mineral. The tendency of mine waste to produce acid mine drainage (AMD) containing potentially toxic metals depends on the amounts of sulfide, carbonate minerals, and trace-element concentrations found in ore deposits. The acid mine process is one of the most significant environmental challenges and a major source of water pollution worldwide. AMD and its effects were studied in northwest Turkey where there are several sedimentary and hydrothermal mineral deposits that have been economically extracted. The study area is located in Can county of Canakkale province. Canakkale contains marine, lagoon, and lake sediments precipitated with volcanoclastics that occurred as a result of volcanism, which was active during various periods from the Upper Eocene to Plio-Quaternary. Can county is rich in coal with a total lignite reserve >100 million tons and contains numerous mines that were operated by private companies and later abandoned without any remediation. As a result, human intervention in the natural structure and topography has resulted in large open pits and deterioration in these areas. Abandoned open pit mines typically fill with water from runoff and groundwater discharge, producing artificial lakes. Acid drainage waters from these mines have resulted in the degradation of surface-water quality around Can County. The average pH and electrical conductivity of acid mine lakes (AMLs) in this study were found to be 3.03 and 3831.33 μS cm−1, respectively. Total iron (Fe) and aluminum (Al) levels were also found to be high (329.77 and 360.67 mg L−1, respectively). The results show that the concentration of most elements, such as Fe and Al in particular, exceed national and international water-quality standards.
Ecotoxicity of Cr, Cd, and Pb on Two Mediterranean Soils by Esther Martí; Jordi Sierra; Joan Cáliz; Genoveva Montserrat; Xavier Vila; María Antonia Garau; Robert Cruañas (pp. 377-387).
Three potentially toxic elements [chromium (Cr), lead (Pb), and cadmium (Cd)] were tested to assess their effects on two soils of different properties and origin. The soils were a granitic soil (Haplic Arenosol), which meets the requirements of OECD ecotoxicity testing, and a calcareous soil (Calcaric Regosol) with properties often found in the Mediterranean areas. The metal concentrations used ranged from 0.001 to 5,000 mg kg−1 soil. The effects on soil microbial activity and community composition (respirometry and polymerase chain reaction–denaturing gradient gel electrophoresis analysis), as well as the effects on plant germination and elongation (Lactuca sativa), were assessed. The toxicity of the soil water extracts was also evaluated by the growth inhibition of algal populations (Pseudokirschneriella subcapitata). Cr showed the highest level of toxicity to soil organisms in the assays performed because this element remains in soil as anionic form and is less retained by the soil solid matrix than Cd and Pb. The lowest observed–adverse effect level for Cr ranged from approximately 0.1 mg kg−1 [substrate induced respiration (SIR) test for the granitic soil] to 10 mg kg−1 (basal respiration and SIR tests for the calcareous soil). For Pb (SIR) and Cd (SIR and alga tests), these levels were approximately 100 mg kg−1. Germination and algal tests showed higher sensitivity in Regosol soil than in Arenosol soil for Cr due to differences in the bioavailability between the soils. In the cases or areas where alkaline soils are abundant, these should also be considered in laboratory ecotoxicity testing to avoid underestimation of ecotoxicological risks.
Metal Contamination Disturbs Biochemical and Microbial Properties of Calcareous Agricultural Soils of the Mediterranean Area by Ana de Santiago-Martín; Natalie Cheviron; Jose R. Quintana; Concepción González; Antonio L. Lafuente; Christian Mougin (pp. 388-398).
Mediterranean climate characteristics and carbonate are key factors governing soil heavy-metal accumulation, and low organic matter (OM) content could limit the ability of microbial populations to cope with resulting stress. We studied the effects of metal contamination on a combination of biological parameters in soils having these characteristics. With this aim, soils were spiked with a mixture of cadmium, copper, lead, and zinc, at the two limit values proposed by current European legislation, and incubated for ≤12 months. Then we measured biochemical (phosphatase, urease, β-galactosidase, arylsulfatase, and dehydrogenase activities) and microbial (fungal and bacterial DNA concentration by quantitative polymerase chain reaction) parameters. All of the enzyme activities were strongly affected by metal contamination and showed the following inhibition sequence: phosphatase (30–64 %) < arylsulfatase (38–97 %) ≤ urease (1–100 %) ≤ β-galactosidase (30–100 %) < dehydrogenase (69–100 %). The high variability among soils was attributed to the different proportion of fine mineral fraction, OM, crystalline iron oxides, and divalent cations in soil solution. The decrease of fungal DNA concentration in metal-spiked soils was negligible, whereas the decrease of bacterial DNA was ~1–54 % at the lowest level and 2–69 % at the highest level of contamination. The lowest bacterial DNA decrease occurred in soils with the highest OM, clay, and carbonate contents. Finally, regarding the strong inhibition of the biological parameters measured and the alteration of the fungal/bacterial DNA ratio, we provide strong evidence that disturbance on the system, even within the limiting values of contamination proposed by the current European Directive, could alter key soil processes. These limiting values should be established according to soil characteristics and/or revised when contamination is produced by a mixture of heavy metals.
Impact of Pesticide Contamination on Aquatic Microorganism Populations in the Littoral Zone by S. Lew; M. Lew; A. Biedunkiewicz; J. Szarek (pp. 399-409).
The effect of pesticide contamination of the littoral zone on the population of bacteria and fungi was analyzed using the example of a eutrophic water reservoir exposed for >30 years to the influence of expired crop-protection chemicals, mainly DDT. For three consecutive years, quantity analyses of bacteria and fungi were conducted and the composition of the microorganism population analyzed against seasonal dynamics. Mold and yeast-like fungi were also isolated and identified. Within the Bacteria domain, in addition to the large groups of microorganisms (Alphaprotobacteria, Betaprobacteria, and Gammaproteobacteria, Actinobacteria, and Cytophaga-Flavobacterium), the analysis also involved the presence of bacteria predisposed to degraded pesticides in natural environments: Pseudomonas spp. and Alcaligenes spp. The quantity dynamics of aquatic microorganisms indicated that bacteria and fungi under the influence of long-term exposure to DDT can adapt to the presence of this pesticide in water. No modifying effect of DDT was observed on the quantity of microorganisms or the pattern of seasonal relationships in the eutrophic lake. Changes were shown in the percentage share of large groups of bacteria in the community of microorganisms as was an effect of contamination on the species diversity of fungi. The data show the effectiveness of aquatic microorganism–community analyses as a tool for indicating changes in the water environment caused by pesticide contamination.
Study on Chromium-Binding Capacity of Callitriche cophocarpa in an Aquatic Environment by Joanna Augustynowicz; Joanna Kyzioł-Komosińska; Sylwester Smoleń; Andrzej Waloszek (pp. 410-418).
The aim of the present study was to investigate the binding strength of chromium (Cr) ions to aquatic macrophyte Callitriche cophocarpa. Shoots of the plants were incubated in a natural water solution containing Cr(III) or Cr(VI) at a concentration ranging from 0.5 to 4 mM under laboratory conditions. We found that C. cophocarpa has an extremely high capacity to bind Cr. The average level of accumulation reached 28,385 or 7,315 mg kg−1 dry weight for plants incubated with Cr(III) or Cr(VI), respectively. Shoots incubated in a 0.5 mM concentration of Cr(III) for 5 days removed almost 100 % of the metal from solution. The major pool of the bound Cr(III) ions follows the strongest mechanism of metal-binding to an organic matter. In contrast, we found that only 25 % of Cr(VI) ions are bound into the metallo-organic compounds and 57 % of Cr(VI) exists in an easily remobilizable form. Activity of a photosynthetic electron transport (as F V/F M) was evaluated with respect to the Cr-binding mechanism. Our results contribute to the development of knowledge on processes controlling bioremediation of heavy-metallic compounds in aquatic systems.
Assessing the Chronic Toxicity of Atrazine, Permethrin, and Chlorothalonil to the Cladoceran Ceriodaphnia cf. dubia in Laboratory and Natural River Water by Yin Latt Phyu; C. G. Palmer; M. St. J. Warne; R. Dowse; S. Mueller; J. Chapman; G. C. Hose; R. P. Lim (pp. 419-426).
The majority of ecotoxicological data are generated from standard laboratory-based experiments with organisms exposed in nonflowing systems using highly purified water, which contains very low amounts of dissolved organic matter and suspended particulates. However, such experimental conditions are not ecologically relevant. Thus, there is a need to develop more realistic approaches to determining toxicity, including both lethal and sublethal effects. This research provides information on the effect of natural water constituents, such as suspended particulates and dissolved organic matter, in river water (RW) on the chronic toxicity (7-day reproductive impairment) of the pesticides atrazine, chlorothalonil, and permethrin to the freshwater cladoceran Ceriodaphnia cf. dubia. Standard bioassays were conducted under standard laboratory and more environmentally realistic conditions (using RW). The 7-day IC25 (reproduction impairment) values of atrazine, chlorothalonil, and permethrin to C. cf. dubia ranged from 862.4 to >1000, 51.3 to 66.4, and 0.19 to 0.23 μg/L, respectively. Using the Globally Harmonized System of Classification and Labelling of Chemicals, atrazine is classified as moderately to highly toxic, whereas permethrin and chlorothalonil were both highly toxic. The presence of dissolved organic matter and suspended particles in natural RW did not significantly (p > 0.05) change the toxicity of any of the pesticides to C. cf. dubia compared with that tested in laboratory water (LW). For the tested pesticides, toxicity testing in LW provided an adequate estimate of the hazard posed.
Chronic Effects of Carbamazepine on Life-History Strategies of Ceriodaphnia dubia in Three Successive Generations by Kiran Lamichhane; Santos N. Garcia; Duane B. Huggett; Donald L. DeAngelis; Thomas W. La Point (pp. 427-438).
Trace quantities of pharmaceuticals are continuously being discharged into the environment through domestic and industrial wastewater effluents, causing concern among scientists and regulators regarding potential long-term impacts on aquatic ecosystems. These compounds and their metabolites are constantly interacting with organisms at various life-cycle stages and may differentially influence the development of embryonic, larval, juvenile, and adult stages. To understand the possible cumulative effects of exposure to carbamazepine (CBZ), a multigenerational approach was taken in which survival, reproduction, respiration, growth, brood size, and biomass of Ceriodaphnia dubia were assessed at sublethal concentrations over the course of three successive generations. CBZ exposure significantly decreased fecundity at 196.7 μg/L in the F0 and F1 generations over 2 weeks and acclimatized at 264.6 μg/L in the F2 generation. Similarly, a significant decrease of neonate dry weight was observed at the 196.7 μg/L CBZ treatment in the F1 generation, and it acclimatized at 264.6 μg/L treatment level in the F2 generation. Median time to first brood release was significantly delayed at 264.6 μg/L in the F2 generation, indicating slower maturation. Results over three successive generations are not different than what one would obtain by testing simply the F0 generation. Furthermore, the effects measured were observed at concentrations two orders of magnitude higher than are environmentally relevant, and it is unlikely that CBZ poses a substantial risk to the environment regarding the end points measured in this study. However, additional research through laboratory and field multigenerational studies may be required to understand the overall risk of CBZ to other nontarget organisms.
Application of a Biomarker Response Index for Ranking the Toxicity of Five Pharmaceutical and Personal Care Products (PPCPs) to the Bivalve Dreissena polymorpha by Marco Parolini; Alessandra Pedriali; Andrea Binelli (pp. 439-447).
Pharmaceuticals and personal care products (PPCPs) have been detected in several aquatic ecosystems during the last two decades, but their potential for biological effects to nontarget organisms is only now being studied. The aim of this study was to compare and rank the cyto-genetic effects induced by 96-hour exposure to an environmental concentration (1 nM) of triclosan (TCS), trimethoprim (TMP), diclofenac (DCF), ibuprofen (IBU), and paracetamol (PCM) on the freshwater bivalve Dreissena polymorpha by integrating biological responses of eight biomarker into a simple biomarker response index (BRI). The application of the BRI decreased the wide biomarker variability and enabled toxicity ranking of the tested PPCPs as follow: TCS > TMP > IBU > DCF = PCM. This approach allowed us to draw an accurate PPCP scale of toxicity of the most dangerous drug and to address further in-depth investigations.
Temporal Trends (2004–2009) of Imposex in Rock Shells Thais clavigera Collected Along the Korean Coast Associated With Tributyltin Regulation in 2003 and 2008 by Minkyu Choi; Hyo-Bang Moon; Jun Yu; HyunSeo Cho; Hee-Gu Choi (pp. 448-455).
We investigated the temporal trend in contamination of butyltin compounds (BTs) along the Korean coast using imposex and tributyltin (TBT) burden in gastropods (Thais clavigera) as a biomonitor. Thais clavigera were collected from 26 locations with different shipping activities between 2004 and 2009 after restrictions on TBT-based antifouling paints were imposed in Korea. In the present study, imposex indices and TBT tissue concentrations significantly decreased over time from 2004 to 2009, confirming the effectiveness of TBT regulation. However, imposex in 2009 samples was still found. Significantly high imposex indices and TBT tissue residues were found in large ports containing commercial and ferry services compared with small ports and background areas. Imposex indices in background areas had decreased to zero, suggesting recovery from imposex caused by BT contamination. These results suggest that recovery from TBT contamination occurs faster in areas with very low maritime activities than areas with high maritime activities.
Effects of Sublethal Dose of Fipronil on Neuron Metabolic Activity of Africanized Honeybees by Thaisa Cristina Roat; Stephan M. Carvalho; Roberta C. F. Nocelli; Elaine C. M. Silva-Zacarin; Mario Sérgio Palma; Osmar Malaspina (pp. 456-466).
Fipronil is a neurotoxic insecticide that inhibits the gamma-aminobutyric acid receptor and can affect gustative perception, olfactory learning, and motor activity of the honeybee Apis mellifera. This study determined the lethal dose (LD50) and the lethal concentration (LC50) for Africanized honeybee and evaluated the toxicity of a sublethal dose of fipronil on neuron metabolic activity by way of histochemical analysis using cytochrome oxidase detection in brains from worker bees of different ages. In addition, the present study investigated the recovery mechanism by discontinuing the oral exposure to fipronil. The results showed that mushroom bodies of aged Africanized honeybees are affected by fipronil, which causes changes in metabolism by increasing the respiratory activity of mitochondria. In antennal lobes, the sublethal dose of fipronil did not cause an increase in metabolic activity. The recovery experiments showed that discontinued exposure to a diet contaminated with fipronil did not lead to recovery of neural activity. Our results show that even at very low concentrations, fipronil is harmful to honeybees and can induce several types of injuries to honeybee physiology.
Levels of Mercury in Muscle and Liver of Star-Spotted Dogfish (Mustelus manazo) from the Northern Region of Japan: A Comparison with Spiny Dogfish (Squalus acanthias) by Tetsuya Endo; Yohsuke Hisamichi; Osamu Kimura; Hideki Ogasawara; Chiho Ohta; Nobuyuki Koga; Yoshihisa Kato; Koichi Haraguchi (pp. 467-474).
We analyzed mercury (Hg) concentrations in muscle and liver samples of star-spotted dogfish (Mustelus manazo) caught off the northern region of Japan and compared them with those of spiny dogfish (Squalus acanthias) caught in the same region. The average body length of male star-spotted dogfish specimens was significantly smaller than that of female specimens, reflecting the slower growth rate of male fish. Hg concentrations in liver and muscle increased with increases in body length and estimated age of both male and female star-spotted dogfish specimens. However, the relationships between Hg concentration in liver or muscle and body length or estimated age of male specimens differed markedly from those of female specimens, reflecting differences in growth rate and cessation of growth on reaching maturity. Marked increases in Hg concentration in liver of male and female star-spotted dogfish specimens were observed slightly later than increases in Hg concentration in muscle of those specimens due to growth cessation. These marked increases in Hg in liver may reflect increases in Hg due to the formation of mercury selenide. Similar results were previously reported in spiny dogfish specimens, except spiny dogfish showed only trace levels of Hg in liver (Endo et al., Chemosphere 77:1333–1337, 2009). The greater lipid content in liver and the larger liver size in spiny dogfish may explain the much lower levels of Hg observed in liver of spiny dogfish compared with those in the star-spotted dogfish.
Alterations in Differentially Expressed Genes After Repeated Exposure to Perfluorooctanoate and Perfluorooctanesulfonate in Liver of Oryzias latipes by Jeong Hwan Oh; Hyo-Bang Moon; Eun Sang Choe (pp. 475-483).
Perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) are considered biologically toxic due to their persistence in the environment. The effects of repeated exposure to these compounds on differentially expressed genes (DEGs) were investigated in liver of the medaka, Oryzias latipes. In this study, seven genes—except for cytochrome P450 3A (CYP450 3A)—were identified as DEGs that were downregulated in response to 15- and 30 days exposures to PFOA and/or PFOS. Four DEGs (c-type lysozyme, EF-1β, complement component C3-1, and NADH dehydrogenase subunit 1) returned to basal levels after 15 days of recovery after 30 days of exposure to the compounds. In contrast, three DEGs (transferrin, alcohol dehydrogenase class VI, and CYP450 3A) were still upregulated by PFOS after 15 days of recovery. In addition, the effect of PFOS showed more accumulation after 15 days of recovery than PFOA. These data suggest that PFOS accumulates more in tissue than PFOA and causes high cellular toxicity by way of suppression of the genes encoding transferrin and alcohol dehydrogenase class VI, whereas there is upregulation of cytochrome P450 3A.
Assessing Mercury Exposure and Biomarkers in Largemouth Bass (Micropterus Salmoides) from a Contaminated River System in California by Daphne B. Gehringer; Myra E. Finkelstein; Kenneth H. Coale; Mark Stephenson; Jonathan B. Geller (pp. 484-493).
We evaluated mercury (Hg) exposure and two biomarkers, metallothionein (MT) gene expression and histopathological alterations in a wild fish species, largemouth bass (Micropterus salmoides), collected from the Sacramento-San Joaquin Delta, CA, a region polluted with Hg from historic mining activities. Hg is highly toxic and can disrupt multiple physiological systems in vertebrate species, including the immune system. Total mercury (THg) concentration in muscle tissue ranged from 0.12 to 0.98 ppm (wet weight) and was not related to body condition (r 2 = 0.005, p = 0.555). Using linear regression analysis, we found a positive relationship between MT gene expression (as determined using quantitative polymerase chain reaction) and copper, zinc, manganese, aluminum, and nickel (decreased to one variable by way of principal component analysis) (r 2 = 0.379, p = 0.044), a negative relationship with selenium (r 2 = 0.487, p = 0.017), and a weak, negative relationship with THg concentrations (r 2 = 0.337, p = 0.061). Juvenile largemouth bass collected from Hg-contaminated areas displayed histopathological features of immunosuppression compared with those collected from less contaminated areas as evidenced by significantly lower macrophage density in kidney and liver tissue (p = 0.018 and 0.020, respectively), greater trematode density in liver tissue (p = 0.014), and a greater number of adult trematodes. Our results suggest that largemouth bass may be experiencing sublethal effects from chronic Hg exposure. Furthermore, our findings illustrate the utility of examining multiple sublethal markers of effect to assess the impacts of contaminant exposure on physiological function in wild species.
Toxicological Effects of the Antibiotic Oxytetracycline to an Indian Major Carp Labeo rohita by T. R. Ambili; M. Saravanan; M. Ramesh; D. B. Abhijith; R. K. Poopal (pp. 494-503).
Oxytetracycline (OTC), an antibacterial agent, is extensively used in aquaculture practices all over the world. Despite its use, the toxicity of OTC to freshwater fish has been scarcely investigated. In this study, Labeo rohita were exposed to different concentrations (20, 40, 60, 80, 100, and 120 mg L−1) of OTC. Based on the survival-to-mortality ratio, an 80 mg L−1 concentration was selected for sublethal toxicity analysis. Fish were exposed to the above-mentioned concentration for a period of 25 days, during which fish were killed at the end of every 5 days to analyse certain hematological and enzymological parameters. During the exposure period, a mixed trend was observed in hemoglobin (Hb), hematocrit, mean cell volume, mean cellular Hb, and mean cellular Hb concentration, whereas decreased red blood cell count and increased white blood cell was noted. A biphasic trend was observed in the enzymatic levels of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase in the vital organs (gill, liver and muscle) of fish. The alterations of these parameters lead to the conclusion that these parameters may be used as biomarkers in monitoring OTC toxicity in aquaculture and fisheries farms.
Dietary Selenomethionine Exposure Induces Physical Malformations and Decreases Growth and Survival to Metamorphosis in an Amphibian (Hyla chrysoscelis) by Laura Lockard; Christopher L. Rowe; Andrew Heyes (pp. 504-513).
Selenium (Se) is an essential micronutrient with a narrow therapeutic concentration range. The relative toxicity of Se increases as it is biotransformed into organic compounds, primarily selenomethionine (SeMet), within the aquatic food chain. Effects of aquatic Se contamination are well quantified for many freshwater fish and aquatic bird species, but impacts on amphibians are not well known. This study investigated the responses of larval Cope’s gray tree frogs (Hyla chrysoscelis) fed a diet enriched with one of two concentrations of SeMet (50.1 and 489.9 μg Se g−1 dw [low and high groups, respectively]) by way of a food-limited (ration) or ad libitum (ad lib) feeding regimen. The high dose caused 100 % mortality during the larval period independent of resource provision levels. Regardless of feeding regimen, the low dose decreased larval survival and successful metamorphosis relative to control treatments. The low dose also induced rear limb deformities in ≤73 % of individuals initiating metamorphosis. Providing low-dose food by way of a rationed feeding regimen decreased observed toxicity, likely because of decreased dietary exposure to SeMet relative to the low ad lib treatment. Individuals from the low ration treatment had decreased wet mass at initiation and completion of metamorphic climax (Gosner stages 42 through 46) compared with those from the control ad lib treatment, indicating that resource limitation combined with Se exposure might negatively affect energy stores after metamorphosis. However, lipid content analyses of recently metamorphosed individuals did not reveal any influence of treatment or resource provision on energy stored as lipids. The mean tissue Se concentration of individuals that received the low dose and completed metamorphosis was significantly greater than that of control ad lib or ration individuals at the same developmental stage. This study demonstrates that larval exposure to dietary SeMet can decrease growth and survival and induce deformities in a developing amphibian. Furthermore, retention of Se body burdens through metamorphosis suggests that surviving individuals can transport Se accumulated from contaminated aquatic environments into terrestrial food webs.
Nandrolone Decanoate Induces Genetic Damage in Multiple Organs of Rats by Renan Pozzi; Kelly Rosseti Fernandes; Carolina Foot Gomes de Moura; Raquel Agnelli Mesquita Ferrari; Kristianne Porta Santos Fernandes; Ana Claudia Muniz Renno; Daniel Araki Ribeiro (pp. 514-518).
To evaluate the impact potential of nandrolone decanoate on DNA damage in multiple organs of Wistar rats by means of single-cell gel (comet) assay and micronucleus test. A total of 15 animals were distributed into three groups of five animals each as follows: control group = animal not exposed to nandrolone decanoate; experimental group = animals exposed to nandrolone decanoate for 24 h at 5 mg/kg subcutaneously; and experimental group = animals exposed to nandrolone decanoate for 24 h at 15 mg/kg subcutaneously. Significant statistical differences (p < 0.05) were noted in peripheral blood, liver, and heart cells exposed to nandrolone decanoate at the two doses evaluated. A clear dose–response relationship was observed between groups. Kidney cells showed genetic damage at only the highest dose (15 mg/kg) used. However, micronucleus data did not show remarkable differences among groups. In conclusion, the present study indicates that nandrolone decanoate induces genetic damage in rat blood, liver, heart, and kidney cells as shown by single-cell gel (comet) assay results.
Exposure Assessment of Organochlorine Pesticides, Arsenic, and Lead in Children From the Major Agricultural Areas in Sonora, Mexico by Maria M. Meza-Montenegro; Ana I. Valenzuela-Quintanar; José J. Balderas-Cortés; Leticia Yañez-Estrada; Maria L. Gutiérrez-Coronado; Alberto Cuevas-Robles; A. Jay Gandolfi (pp. 519-527).
There is a lack of information of exposure to organochlorine pesticides (OCP) and some metals, such as lead (Pb) and arsenic (As), both of which were used as arsenicals pesticides, in children living in the major agricultural areas of Mexico. The objective of this study was to assess the exposure of children to different OCP, As, and Pb in the Yaqui and Mayo valleys of Sonora to generate population baseline levels of these toxins. A cross-sectional study was undertaken in 165 children (age 6–12 years old) from 10 communities from both valleys during 2009. Blood samples were analyzed for OCP and Pb and first morning void urine for inorganic As (InAs). All of the blood samples had detectable levels of dichlorodiphenyltrichloroethylene (p,p′-DDE) ranging from 0.25 to 10.3 μg/L. However lindane, dichlorodiphenyltrichloroethane (p,p′-DDT), aldrin, and endosulfan were detected in far less of the population (36.4, 23.6, 9.1, and 3 %, respectively). Methoxychlor and endrin were not found in any sample. The average value of Pb in this population was 3.2 μg Pb/dL (range 0.17–9.0) with 8.5 % of the samples having levels <5.0 μg Pb/dL. Urinary As levels ranged from 5.4 to 199 μg As/L with an average value of 31.0 μg As/L. Levels > 50 μg/L were observed in 12.7 % of the samples. Our results show that is important to start a risk-reduction program to decrease exposure to these toxins in Mexican communities. In addition, the results can be used to establish the baseline levels of exposure to these toxins in this agricultural region and may be used as a reference point for regulatory agencies.