Research Watch: Molecular-level studies - Environmental Science

Research Watch: Molecular-level studies - Environmental Science...

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Hayward, D. G.; Stephens, R. D.; Stenstrom, M. K. "Dioxins and Furans Urban Runoff," /. Environ. Eng. 1999, 125(2), 185-191)

Measurements Sulfur gases. A continuous monitorsulfur chemiluminescence measurement system demonstrated a linear dynamic range exceeding 5 orders of magnitude and equimolar sensitivity to the most prevalent atmospheric sulfur gases. (Mactaggart, D. L.; Farwell, S. O.; Burdge, J. R.; Cai, Z-T.; Haakenson, T. J.; Bamesberger, W. L. "A Continuous Monitor-Sulfur Chemiluminescence Detector System (CMSCDS) for the Measurement of Total Gaseous Sulfur Species in Air," Atmos. Environ. 1999, 33(4), 625-632)

Methods Bromate in drinking water. Ion chromatography-inductively coupled plasma mass spectrometry can be used to detect bromate in drinking water matrixes down to concentrations of 0.3 ng/g. (Creed, J. T.; Brockhoff, C. A. "Isotope Dilution Analysis of Bromate in Drinking Water Matrixes by Ion Chromatography With Inductively Coupled Plasma Mass Spectrometric Detection," Anal. Chem. 1999, 71(3), 722-726) Toxicity testing. It is suggested that toxicity tests should isolate the specific component of the reproductive system most sensitive to endocrine disruption and that disruption may occur at levels well below those which cause mortality or visible signs of stress. (Kime, D. E. "A Strategy for Assessing the Effects of Xenobiotics on Fish Reproduction," Sci. Total Environ. 1999, 225(1-2), 3-11)


Streambed sediment quality A comprehensive, internally consistent set of data for trace elements in streambed sediments is needed to help answer cause-and-effect questions related to their presence. K. C. Rice studied trace-element (arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, and zinc) concentrations in 541 streambedsediment samples collected from 20 study areas across the conterminous United States as part of the National Water-Quality Assessment Program. The sum of concentrations of trace elements characteristic of urban settings—copper, mercury, lead, and zinc—was well correlated with population density, nationwide. The median concentrations of seven trace elements (all nine examined except arsenic and selenium) were enriched in samples collected from urban settings relative to agricultural or forested settings. Forty-nine percent of the sites sampled in urban settings had concentrations of one or more trace elements that exceeded levels at which adverse biological effects could occur in aquatic biota. (Environ. Sci. Techno!., this issue, pp. 2499-2504)

semiquantitative reverse transcriptasepolymerase chain reaction technique for screening estrogenicity by assaying mRNA induction of the estrogenic biomarker vitellogenin in vitro. (Kloas, W; Lutz, I.; Einspanier, R. "Amphibians as a Model To Study Endocrine Disrupters: II. Estrogenic Activity of Environmental Chemicals In Vitro and In Vivo," Sci. Total Environ. 1999, 225(1-2), 59-68)

Endocrine disrupters. The radioreceptor assay for [3H]-E2 binding in Xenopus laevis liver cytosol is useful in screening estrogen receptor binding of pure compounds or complex mixtures of them, which is the prerequisite for causing either estrogenic or antiestrogenic effects. (Lutz, I.; Kloas, W "Amphibians as a Model To Study Endocrine Disrupters: I. Environmental Pollution and Estrogen Receptor Binding," Sci. Total Environ. 1999, 225(1-2), 49-57)

Organic pollutants. An overview of die existing models for estimating the reactivity of organic compounds with tropospheric free radicals is presented, and the limitations of these models, as well as their applicability, are discussed. (Gusten, H. "Predicting the Abiotic Degradability of Organic Pollutants in the Troposphere," Chemosphere 1999, 38(6), 1361-1370)

Endocrine disrupters. For the first time, results demonstrate the use of a

Endocrine disrupters. The transactivational potential of xenoestrogens



and phytoestrogens has been evaluated in a yeast test system. (Graumann, K.; Breithofer, A; Jungbauer, A. "Monitoring of Estrogen Mimics by a Recombinant Yeast Assay: Synergy Between Natural and Synthetic Compounds?" Sci. Total Environ. 1999, 225(1-2), 69-79)

Sediments Polycyclic aromatic hydrocarbons. The sedimentary record of polycyclic aromatic hydrocarbons in San Francisco Bay shows that anthropogenic inputs have increased since the turn of the century, presumably as a result of increasing urbanization and industrialization around the Bay area. (Pereira, W. E.; Hostettler, F. D.; Luoma, S. N.; van Geen, A.; Fuller, C. C; Anima, R. J. "Sedimentary Record of Anthropogenic and Biogenic Polycyclic Aromatic Hydrocarbons in San Francisco Bay, California," Mar. Chem. 1999, 64(1-2), 99-113)

Toxicity Molecular-level studies. Using neural networks, a model based on 20 variables (mainly size and electronic characteristics) predicts the toxicity of compounds not in the training set. (Okey, R. W; Martis, M. C. "Molecular-Level Studies on the Origin of Toxicity: Identification of Key Variables and Election of Descriptors," Chemosphere 1999, 38(6), 1419-1427)

Wastewater Virus removal. A reverse osmosis unit reduced virus concentrations below the detection threshold at a Los Angeles treatment plant, but microfiltration membranes consistently reduced virus concentrations by