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Source identification of copper, lead, nickel, and zinc loading in wastewater reclamation plant influents from corrosion of brass in plumbing fixtures Texte intégral
2009
Kimbrough, David Eugene
A natural experiment indicated that a link between the presence and concentration of four elements, copper, lead, nickel, and zinc in the influent to two wastewater reclamation plants to the presence and concentrations of the same four elements in the tap water of residential properties. There were 36 populations of results that were assessed for the normality of their distribution, the difference in their median concentrations, the similarity in the ratios of their median concentrations, and the correlations of the concentrations. The results of this study suggest that brass corrosion is the major source of these four elements in the water reclamation plants influent and that there are two distinct populations of brass sources, those in the early stages of dezincification where the release of the non-copper elements is dominant and those in the later stages where the release of copper dominates and the type of brass that is corroding. Statistical analysis of residential tap waters and water reclamation plant influent showed that metals found in both came from brass corrosion.
Afficher plus [+] Moins [-]Heavy metal deposition in the Italian "triangle of death" determined with the moss Scorpiurum circinatum Texte intégral
2009
Basile, A. | Sorbo, S. | Aprile, G. | Conte, B. | Castaldo Cobianchi, R. | Pisani, T. | Loppi, S.
In this study, a biomonitoring project using the moss Scorpiurum circinatum was carried out to evaluate the deposition and biological effects of heavy metals in the area of Acerra (Naples, S Italy), one of the vertices of the sadly called "Italian triangle of death" owing to the dramatic increase in tumours. The results clearly indicated that the study area is heavily polluted by heavy metals, a large proportion of which is likely present in the atmosphere in particulate form. The ultrastructural organization of exposed samples was essentially preserved, but cell membrane pits, cytoplasm vesicles and concentric multilamellar/multivesicular bodies, probably induced by pollution, were found, which may be involved in the tolerance mechanisms to metal pollution in this moss species. Although severe biological effects were not found at the ultrastructural level in the exposed moss, effects on humans, especially after long-term exposure, are to be expected. The moss Scorpiurum circinatum indicates that the "Italian triangle of death" is heavily polluted by heavy metals.
Afficher plus [+] Moins [-]Application of bioassays to evaluate a copper contaminated soil before and after a pilot-scale electrokinetic remediation Texte intégral
2009
Wang, Quan-Ying | Zhou, Dong-Mei | Cang, Long | Sun, Tian-Ran
Remediation programmes are considered to be complete when human risk-based criteria are met. However, these targets are often unsatisfied with the ecological parameters that may be important with regard to future soil use. Five soil subsamples, collecting along a pilot-scale soil column after electrokinetic treatment, were studied, from which about 42.0%-93.3% soil Cu had been successfully removed. A series of biological assays including soil microbial biomass carbon, basal soil respiration, soil urease activity, earthworm assays, and seed assays were used to evaluate their ecological risks. The results showed that the bioassay data from the treatment variants did not supposedly reflecting the decreased soil Cu concentrations after the electrokinetic treatment, but were highly correlated with some soil physicochemical characteristics. It suggests that bioassays are necessary to assess the ecotoxicity of soil after electrokinetic treatment.
Afficher plus [+] Moins [-]Prediction of Cadmium uptake by brown rice and derivation of soil-plant transfer models to improve soil protection guidelines Texte intégral
2009
Römkens, P.F.A.M. | Guo, H.Y. | Chu, C.L. | Liu, T.S. | Chiang, C.F. | Koopmans, G.F.
Cadmium (Cd) levels in paddy fields across Taiwan have increased due to emission from industry. To ensure the production of rice that meets food quality standards, predictive models or suitable soil tests are needed to evaluate the quality of soils to be used for rice cropping. Levels of Cd in soil and rice grains were measured in 19 paddy fields across the western plains in Taiwan. Cadmium levels in soil range from less than 0.1 mg kg⁻¹ to 30 mg kg⁻¹. Measured Cd levels in brown rice were predicted very well (R² > 0.8) based on Cd and Zinc in a 0.01 M CaCl₂ extract or a soil-plant transfer model using the reactive soil Cd content, pH, and cation exchange capacity. In contrast to current soil quality standards used in Taiwan, such models are effective in identifying soils where Cd in rice will exceed food quality standards. Cadmium uptake by 12 rice cultivars is predicted well by a single soil-plant transfer model based on 0.01 M CaCl₂ or a combination of pH, CEC, and the 0.43 N HNO₃-extractable soil Cd concentration.
Afficher plus [+] Moins [-]Persistence of organochlorine chemical residues in fish from the Tombigbee River (Alabama, USA): Continuing risk to wildlife from a former DDT manufacturing facility Texte intégral
2009
Hinck, Jo Ellen | Norstrom, Ross J. | Orazio, Carl E. | Schmitt, Christopher J. | Tillitt, Donald E.
Organochlorine pesticide and total polychlorinated biphenyl (PCB) concentrations were measured in largemouth bass from the Tombigbee River near a former DDT manufacturing facility at McIntosh, Alabama. Evaluation of mean p,p'- and o,p′-DDT isomer concentrations and o,p'- versus p,p'-isomer proportions in McIntosh bass indicated that DDT is moving off site from the facility and into the Tombigbee River. Concentrations of p,p'-DDT isomers in McIntosh bass remained unchanged from 1974 to 2004 and were four times greater than contemporary concentrations from a national program. Total DDT in McIntosh bass exceeded dietary effect concentrations developed for bald eagle and osprey. Hexachlorobenzene, PCBs, and toxaphene concentrations in bass from McIntosh also exceeded thresholds to protect fish and piscivorous wildlife. Whereas concentrations of DDT and most other organochlorine chemicals in fish have generally declined in the U.S. since their ban, concentrations of DDT in fish from McIntosh remain elevated and represent a threat to wildlife.
Afficher plus [+] Moins [-]Mercury cycling and species mass balances in four North American lakes Texte intégral
2009
Qureshi, Asif | Macleod, Matthew | Scheringer, Martin | Hungerbuhler, Konrad
A mass balance model for mercury based on the fugacity concept is applied to Lake Superior, Lake Michigan, Onondaga Lake and Little Rock Lake to evaluate model performance, analyze cycling of three mercury species groups (elemental, divalent and methyl mercury), and identify important processes that determine the source-to-concentration relationship of the three mercury species groups in these lakes. This model application to four disparate ecosystems is an extension of previous applications of fugacity-based models describing mercury cycling. The model performs satisfactorily following site-specific parameterization, and provides an estimate of minimum rates of species interconversion that compare well with literature. Volatilization and sediment burial are the main processes removing mercury from the lakes, and uncertainty analyses indicate that air-water exchange of elemental mercury and water–sediment exchange of divalent mercury attached to particles are influential in governing mercury concentrations in water. Any new model application or field campaign to quantify mercury cycling in a lake should consider these processes as important.
Afficher plus [+] Moins [-]An exposure study with polybrominated diphenyl ethers (PBDEs) in female European starlings (Sturnus vulgaris): Toxicokinetics and reproductive effects Texte intégral
2009
Steen, Evi van den | Eens, Marcel | Covaci, Adrian | Dirtu, Alin C. | Jaspers, Veerle L.B. | Neels, Hugo | Pinxten, Rianne
We exposed female European starlings to a pentabromodiphenyl ether (Penta-BDE) mixture through subcutaneous implants, and examined levels and profiles of polybrominated diphenyl ethers (PBDEs) together with reproductive effects. Sum PBDE levels increased significantly in the serum of the exposed females from 218 ± 43 to 23,400 ± 2035 pg/ml. Sum PBDE concentrations in the eggs of the exposed group ranged from 130 ± 12 to 220 ± 37 ng/g wet weight (ww). The profile in serum after egg laying was very similar to that in eggs. There were no detectable levels of HO-PBDEs in both serum and eggs. Fewer females of the exposed group initiated egg laying compared to the control group, although the difference was not significant. In addition, egg weight and volume were significantly higher in the exposed group. These results suggest that, at the investigated exposure levels (150 μg sum PBDEs/bird), PBDEs may have a negative effect on reproductive performance.
Afficher plus [+] Moins [-]Sampling atmospheric pesticides with SPME: Laboratory developments and field study Texte intégral
2009
Wang, Junxia | Tuduri, Ludovic | Mercury, Maud | Millet, Maurice | Briand, Olivier | Montury, Michel
To estimate the atmospheric exposure of the greenhouse workers to pesticides, solid phase microextraction (SPME) was used under non-equilibrium conditions. Using Fick's law of diffusion, the concentrations of pesticides in the greenhouse can be calculated using pre-determined sampling rates (SRs). Thus the sampling rates (SRs) of two modes of SPME in the lab and in the field were determined and compared. The SRs for six pesticides in the lab were 20.4-48.3 mL min-1 for the exposed fiber and 0.166-0.929 mL min-1 for the retracted fiber. In field sampling, two pesticides, dichlorvos and cyprodinil were detected with exposed SPME. SR with exposed SPME for dichlorvos in the field (32.4 mL min-1) was consistent with that in the lab (34.5 mL min-1). SR for dichlorvos in the field (32.4 mL min-1) was consistent with that in the lab (34.5 mL min-1). The trends of temporal concentration and the inhalation exposure were also obtained.
Afficher plus [+] Moins [-]Bags with oven-dried moss for the active monitoring of airborne trace elements in urban areas Texte intégral
2009
Giordano, S. | Adamo, P. | Monaci, F. | Pittao, E. | Tretiach, M. | Bargagli, R.
To define a harmonized methodology for the use of moss and lichen bags as active monitoring devices of airborne trace elements in urban areas, we evaluated the element accumulation in bags exposed in Naples in different spring weather conditions for 6- and 12-weeks. Three different pre-exposure treatments were applied to moss and lichen materials: water-washing, acid-washing and oven-drying. During the different exposure periods in the Naples urban environment the moss accumulated always higher amounts of elements (except Hg) than lichens and the element accumulation increased during wetter weather and higher PM10 conditions. The oven pre-treatment did not substantially modify the morphology and element composition of moss and the exposure in bags of this material for 6-weeks was sufficient to detect the pattern of airborne trace elements.
Afficher plus [+] Moins [-]Individual, population and community level effects of subtle anthropogenic contamination in estuarine meiobenthos Texte intégral
2009
Rubal, Marcos | Guilhermino, Lúcia M. | Medina, Matías H.
The study presented here searched for the level of taxonomic resolution required to detect the effects of low-level chronic pollution on estuarine meiobenthic communities. Meiofauna from two sites, with special attention to harpacticoid copepods, was analysed at different taxonomic levels of aggregation using uni- and multivariate methods. Adaptation processes that could buffer biodiversity disruptions were also considered through the analysis of fitness-related and tolerance traits in the harpacticoid copepod Paronychocamptus nanus. Results showed that uni- and multivariate analyses could be inadequate when assessing subtle anthropogenic contamination. Instead, the assessment of inter-population differences in tolerance to the main source of stress rises as a required procedure if potential effects of this type of contamination are being investigated. Specifically, a 96 h acute toxicity test performed with populations from the affected site appears as a faster and reliable general tool to assess impacts of low-level chronic pollution in estuaries.
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