RESEARCH WATCH Air Aircraft emissions. Current knowledge of atmospheric processes is described, and potential atmospheric effects of aircraft emissions are analyzed. (Brasseur, G. P.; Cox, R. A.; Hauglustaine, D.; Isaksen, I.; Lelieveld, J.; Lister, D. H.; Sausen, R.; Schumann, U.; Warmer, A.; Wiesen, R "European Scientific Assessment of the Atmospheric Effects of Aircraft Emissions," Atmos. Environ. 1998, 32(13), 2329-2418) Particulate matter. Population exposure to particulate matter in all size ranges improved during the period 1940-1990. (Lipfert, F. W. "Trends in Airborne Particulate Matter in the United States," Appl. Occup. Environ. Hyg. 1998, 73(6), 370-384)
Biodegradation Chlorophenols. A newly isolated bacterium was used to successfully biodegrade chlorophenols in water. (Steinle, R; Stucki, G.; Stettler, R.; Hanselmann, K. W. "Aerobic Mineralization of 2,6-dichlorophenol by Ralstonia Sp. Strain Rkl," Appl. Environ. Microbiol. 1998, 64(7), 2566-2571) Sediment effects. The presence of sediments can affect the biodegradation patterns of mixtures of PAHs. (Beckles, D. M.; Ward, C. H.; Hughes, J. B. "Effect of Mixtures of Polycyclic Aromatic Hydrocarbons and Sediments on Fluoranthene Biodegradation Patterns," Environ. Toxicol. Chem. 1998, 17(7), 1246-1251)
Climate change Carbon sinks. The long-term variability of anthropogenic carbon in terrestrial and oceanic uptake was studied. (Joos, E; Bruno, M. "LongTerm Variability of the Terrestrial and Oceanic Carbon Sinks and the Budgets of the Carbon Isotopes 13C and 14C," Global Biogeochem. Cycles 1998, 12{2), 277-295)
Dissolution of cinnabar by DOM Dissolved organic matter (DOM) interacts with cations in natural waters and soils and affects solubility, mobility, and toxicity of many trace metals. M. Ravichandran and coworkers found that organic matter isolated from the Florida Everglades caused a dramatic increase in mercury release from cinnabar (HgS). Hydrophobic acids dissolved more mercury than hydrophilic acids and other DOM nonacid fractions. Possible mechanisms of dissolution include surface complexation of mercury and oxidation of surface sulfur species by the organic matter. DOM enhances mercury release from cinnabar under oxic and anoxic conditions. Enhanced cinnabar solubility has geochemical significance: In mercury-contaminated areas and where conditions favor HgS formation, humic substances could enhance mercury mobilization and affect bioavailability. (Environ. Sci. Techno!., ,his issue, pp. 3305-3311)
Model test. The performance of three global ocean carbon cycle models is evaluated, and deficiencies are noted. (Stephens, B. B.; Keeling, R. E; Heimann, M.; Six, K. D.; Murnane, R.; Caldeira, K. "Testing Global Ocean Carbon Cycle Models Using Measurements of Atmospheric 0 2 and Co2 Concentration," Global Biogeochem. Cycles 1998, 12{2), 213-230) Sensitivity study. A model was used to examine the responses of terrestrial ecosystems to transient changes in atmospheric C0 2 concentration and climate in the 21st century. (Xiao, X.; Melillo, J. M.; Kicklighter, D. W; McGuire, A. D.; Prinn, R. G.; Wang, C; Stone, P. H.; Sokolov, A. "Transient Climate Change and Net Ecosystem Production of the Terrestrial Biosphere," Global Biogeochem. Cycles 1998, 12(2), 345-360)
Contaminants Contaminant accumulation. A review is presented of methods used to measure or predict the accumulation of persistent organic contaminants in plants and animals. (Burnison, B. K. "Review of Bioconcentration, Bioaccumulation and Kow Techniques," Water Qual. Res. J. Can. 1998, 33(2), 213-230) Novel discovery. Compounds that are structurally isomeric with dioxins have been found in thermal process-
5 1 O A • NOV. 1, 1998 / ENVIRONMENTAL SCIENCE & TECHNOLOGY / NEWS
ing streams. (Otto, E; Leupold, G.; Parlar, H.; Rosemann, R.; Bahadir, M.; Hopf, H. "Chlorinated Diphenoquinones: A New Class of Dioxin Isomeric Compounds Discovered in Fly Ashes, Slags, and Pyrolysis Oil Samples by Using HPLC/ELCD and HRGC/MS," Anal. Chem. 1998, 70(4), 2831-2838) Volatile organic compounds. This report reviews the characteristics of various processes that could affect the transport, behavior, and fate of 55 VOCs in streams. (Rathbun, R. E. "Transport, Behavior, and Fate of Volatile Organic Compounds in Streams," U.S. Geol. Surv. Prof. Pap. 1998, 1589, 151 pp.)
Control Bacterial insecticide. Bacterial strains are shown to have use in controlling mosquito larvae. (Orlova, M. V; Smirnova, T A.; Ganushkina, L. A.; Yacubovich, V Y.; Azizbekyan, R. R. "Insecticidal Activity of Laterosporus," Appl. Environ. Microbiol. 1998, 64(7), 2723-2725)
Drinking water Cancer mortality. The results of this study suggest a positive association between chlorinated drinking water consumption and cancer of the rectum, lung, bladder, and kidney. (Yang, C-Y; Chiu, H-E; Cheng, M-E; Tsai, S-S. "Chlorination of Drinking
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