tainty in Risk Assessments," /. Envi­ron. Eng. 1999,125 (7), 660-666)

TMDL calculations. A decision sup­port system was developed to calcu­late total maximum daily loads of various pollutants for water quality-limited sections within a river basin. (Chen, C. W.; Hen, J.; Ziemelis, L.; Goldstein, R. A; Olmsted, L. "Deci­sion Support System for Total Maxi­mum Daily Load," /. Environ. Eng. 1999, 125 (7), 653-659)

MODELING Climate change. An atmospheric gen­eral circulation model reveals greater cooling than the CLIMAP project in the equatorial current systems of the eastern Pacific and tropical Adantic Oceans. (Hostetier, S. W; Mix, A. C. "Reassessment of Ice-Age Cooling of the Tropical Ocean and Atmosphere," Nature 1999,399 (6737), 673-677)

α-Hexachlorocyclohexane. In both model results and observations, the dramatic decrease in global emis­sions of oc-hexachlorocyclohexane is reflected in rapidly decreasing con­centrations in the atmosphere and seawater, except in the Arctic Ocean. (Wania, E; Mackay O.; Li, Y.-E; Bidle-man, T. E; Strand, A. "Global Chemi­cal Fate of a-Hexachlorocyclohex­ane. 1. Evaluation of a Global Distribution Model," Environ. Toxi­col. Chem. 1999,18 (7), 1390-1399)

α-Hexachlorocyclohexane. Modeling results provide a comprehensive glo­bal historical picture of the global be­havior of a-hexachlorocyclohexane, which, after being used in huge amounts in the early 1980s, has since been essentially eliminated. (Wania, E; Mackay, D. "Global Chemical Fate of a-Hexachlorocyclohexane. 2. Use of a Global Distribution Model for Mass Balancing, Source Apportionment, and Trend Prediction," Environ. Toxi­col. Chem. 1999 18 (7)) 1400-1407)

S O I L S Mercury presence. It is proposed that erosion of deforested soils following human colonization constitutes a ma­jor disturbance of the natural mercurv

cycle and may explain the increase of mercury burdens in Amazonian aquatic ecosystems in newly colo­nized watersheds. (Roulet, M., et al. "Effects of Recent Human Coloniza­tion on the Presence of Mercury in Amazonian Ecosystems," Water, Air, SoilPollut. 1999,112 (3-4), 297-313)

Heavy metal accumulation Little is known about interactions of metals with individual benthic mi­crobes in nature because of the technical difficulty of studying such small-scale processes in complex, heterogeneous sedimentary eco­systems. T. Jackson and coworkers used energy-dispersive X-ray micro­analysis (EDXM) and transmission electron microscopy (TEM) to inves­tigate the accumulation of Cu and other elements by the cell walls, cytoplasm, cytoplasmic inclusions, fibrils and mineral coatings of indi­vidual bacterial cells in the sedi­ments of a lake polluted with heavy metals This represents the first aDDlication of modern EDXM and TEM techniques to the systematic quantitative analysis of statistically meaningful numbers of individual bap4.prj„l cpils \A/ith separate analv

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WASTEWATER Disinfection-resistant bacteria. It is suggested that the oxidation towers of a wastewater treatment plant in Wil­liamsburg, Va., supported growth or recovery of fecal coliform bacteria and that this bacterial subpopulation seem­ed to increase resistance to routine chlorine disinfection. (Scully, E E., Jr., et al. "Development of Disinfection-Resistant Bacteria During Wastewater Treatment," Water Environ. Ress.999, 71 (3)) 277-281)

Reuse practices. The status of wastewater reclamation and reuse around the Mediterranean basin is presented with a discussion of exist­

ing guidelines and regulations, as well as the possibility of developing uniform wastewater reuse standards. (Angelakis, A. N.; Marecos Do Monte, M.H.E; Bontoux, L.; Asano, T. "The Status of Wastewater Reuse Practice in the Mediterranean Basin: Need for Guidelines," Water Res. 1999,33 (10), 2201-2217)

WATER Contaminated fish. In a survey con­ducted among anglers in New Jersey's Newark Bay Complex, it was found that although 60% of the anglers had heard about fish consumption adviso­ries, they either did not believe them or were unconcerned about health effects from eating contaminated spe­cies. (Pflugh, K. K.; Lurig, L.; Von Ha-gen L. A; Von Hagen; Burger, J. "Ur­ban Anglers' Perception of Risk From Contaminated Fish" Sci. Total Envii

1999 228 (2-3), 203-218)

Humic substances. Results from a variety of spectroscopic techniques suggest the incorporation of light carbon sources in the humification process, rather than 13C enrichment due to trophic effects. (Schulten, H.-R.; Gleixner, G. "Analytical Pyroly-sis of Humic Substances and Dis­solved Organic Matter in Aquatic Systems: Structure and Origin," Wa­ter Res. 1999, 33 (11), 2489-2498)

Membrane filtration. Transport mea­surements of natural organic matter (NOM) rejection and flux are de­scribed consistently using a resistanc-es-in-series model that considers membrane characteristics and NOM properties. (Cho, J.; Amy, G; Pelle-grino, J. "Membrane Filtration of Nat­ural Organic Matter: Initial Compari­son of Rejection and Flux Decline Characteristics With Ultrafiltration and Nanofiltration Membranes" Water Res. 1999 33 (11) 2517-2526)

Pesticide contamination. In a study in which the ecological risks of mod­ern pesticides related to different Eu­ropean river/estuary systems are com­pared, it is found that pesticides exert a significant pressure on the aquatic system. (Steen, R.J.CA., et al. "Ecologi­cal Risk Assessment of Agrochemicals in European Estuaries," Environ. Toxi­col. Chem. 1999,18 (7), 1574-1581)

NOVEMBER 1, 1999 / ENVIRONMENTAL SCIENCE & TECHNOLOGY / NEWS » 4 7 1 A