Carbon sequestration. Evidence from studies in nine forests indicates that elevated nitrogen deposition is unlikely to be a major contributor to the sequestration of carbon in temperate forests. (Nadelhoffer, K. J.; Emmett, B. A.; Gundersen, P.; Kjonaas, O. J.; Koopmans, C. J.; Schleppi, P.; Tietema, A.; Wright, R. F. "Nitrogen Deposition Makes a Minor Contribution to Carbon Sequestration in Temperate Forests," Nature 1999, 398(6723), 145-148)
Contaminants Plastic contaminant. Results provide an assessment of the leaching of bisphenol A (used in plastic manufacturing as a stabilizer) from plastic waste into water. (Yamamoto, T.; Yasuhara, A. "Quantities of Bisphenol A Leached From Plastic Waste Samples," Chemosphere 1999, 38(11), 2569-2576) Silver. Although silver has been regulated since the 1960s, EPA has downgraded this metal from a primary to a secondary maximum contaminant level because the exposure effects of silver were judged to be cosmetic. (Purcell, T. W; Peters, J. J. "Historical Impacts of Environmental Regulation of Silver," Environ. Toxicol. Chem. .999, ,8(1), 3-8)
Health Health effects. Human health effects resulting from environmental contaminants and how these compounds may interact with each other are discussed. (Carpenter, D. O.; Arcaro, K. E; Bush, B.; Niemi, W. D.; Pang, S.; Vakharia, D. D. "Human Health and Chemical Mixtures: An Overview," Environ. Heallh Perspect. 1998,106(6), 1263-1270)
Sediments Approximation methods Analytical chemists are often required to evaluate data quality using limits of detection and quantification methods that are often computationally complex. Where feasible, it is desirable to use less rigorous methods. M. E. Zorn and coworkers evaluated approximate computational methods that use data at multiple spiking concentrations, are iterative, can be derived from either prediction intervals or statistical tolerance intervals, and require at a minimum ordinary least-squares regression for calculating the intercept and slope. Results indicate that although exact methods should be employed whenever possible aooroximate methods can provide detection and quantification limits that are sufficiently tions IFnviron ^ri Tprhnol this 2291-229'i)
of water chemistry on silver speciation and toxicity to freshwater and marine fish. (Wood, C. M.; Playle, R. C; Hogstrand, C. "Physiology and Modeling of Mechanisms of Silver Uptake and Toxicity in Fish," Environ. Toxicol. Chem. .999, ,8(ll) 711 83)
Remediation Bioremediation potential. During an investigation of bioremediation potential in a gasoline-contaminated aquifer, iron and sulfur species were evaluated along with the aqueous ions of 0 2 , N03_, Fe2+, and S042", showing that when mineral data are included, most of the hydrocarbon spill at this site was naturally attenuated. (Kennedy, L. G.; Everett, J. W; Dewers, T; Pickins, W; Edwards, D. "Application of Mineral Iron and Sulfide Analysis To Evaluate Natural Attenuation at Fuel-Contaminated Site " /. Environ. Eng. (Reston Va.) 1999 125(1) 47-56)
Methylmercury. Researchers compared studies on the health effects of methylmercury at a November workshop sponsored by the White House Office of Science and Technology Policy and the National Institute of Environmental Health Sciences and suggested testing of additional systems besides neurodevelopmental ones for use in establishing thresholds. ("MeetWaste treatment. A prototype reacing of the Minds on Mercury," Envitor for the Photo-Fenton method ron. Health Perspect. 1999,107(1), A12) was evaluated for processing highly contaminated wastewaters. (Krutzler, Modeling T; Bauer, R. "Optimization of a Photo-Fenton Prototype Reactor," Silver toxicity. Modeling to calculate Chemosphere 1999, 38(11), 2517silver interactions at biological sur2532) faces is used to illustrate the effects 2 8 4 A • JULY 1, 1999 / ENVIRONMENTAL SCIENCE & TECHNOLOGY / NEWS
Sediment mercury. Watershed areato-lake area ratio was found to be more important than site-specific factors in governing the concentration of sediment mercury in lakes without industrial input. (French, K. J.; Scruton, D. A.; Anderson, M. R.; Schneider, D. C. "Influence of Physical and Chemical Characteristics on Mercury in Aquatic Sediments," Water, Air, Soil Pollut. 1999,110(3-4), 347-362)
Soils Contaminant deposition. The separated and combined effects of moderate levels of acid load and coppernickel deposition on humus microbial community structures were examined six growing seasons after the start of an artificial irrigation experiment. (Pennanen, T; Perkiomaki, J.; Kiikkila, O.; Vanhala, R; Neuvonen, S.; Fritze, H. "Prolonged, Simulated Acid Rain and Heavy Metal Deposition: Separated and Combined Effects on Forest Soil Microbial Community Structure," FEM) Microbioll Ecol. 1998,27(3) 291-300)
Technology Sensor technology. Barriers are examined that impede development and deployment of novel chemical sensor and biosensor technologies. (Weetall, H. H. "Chemical Sensors and Biosensors Update What, Where, When and How," Biosens. Bioelectron. 1999, 14(2), 237-242)
Water Metal-sulfide complexation. New data and calculations confirm the potential importance of sulfide as a complexing ligand in seawater, where sulfide is more important than major anions and competes effectively with natural organic ligands. (Al-Farawati, R.; Van den Berg, C.M.G. "MetalSulfide Complexation in Seawater," 1999, 63(3-4), 331-352)
Wetlands Assessment techniques. With further refinement and development, rapid methods of monitoring aquatic community assemblages are potentially useful tools for early detection of wetland degradation. (Van Dam, R. A.; Camilleri, C; Finlayson, C. M. "The Potential of Rapid Assessment Techniques as Early Warning Indicators of Wetland Degradation: A Review," Environ. Toxicol. Water Qual. 1998 i3(4), 297-312)
