RESEARCH WATCH Air Quality Mercury emissions. A study is described that aims to develop a sorbent-screening test protocol, to screen potential mercury sorbents in a bench-scale fixed-bed system, and to provide data to support efforts to model mercury capture mechanisms. (Dunham, G. E.; Miller, S. J.; Chang, R.; Bergman, P. "Mercury Capture by an Activated Carbon in a Fixed-Bed Bench-Scale System," Environ. Prog. 1998, 17(3), 203-208)
Historic lead deposits Knowledge of past atmospheric lead deposition is useful for assessing how anthropogenic emissions of lead have perturbed its natural biogeochemical cycle. D. Weiss and coworkers evaluated the atmospheric deposition of lead in Switzerland since the beginning of the industrial revolution. They found lead enrichment relative to the natural background between 1880 and 1920 (enrichments ranging from 40 to 80 times natural background values), and between 1960 and 1980 (enrichments ranging from 80 to 100 times). Data also indicate that although lead emissions from traffic diminished during the last 10 years, this contribution is detectable in modern peat samples and dominates input of lead from other sources. Observations were consistent with other studies. (Environ. Sci. Techno!., this issue, pp. 1340-1352)
Analytical Chemistry Trinitrotoluene. Six prominent trinitrotoluene transformation products were prepared and characterized, three of which (4,4',6,6'-tetranitro-2, 2'-azotoluene, 2,2',6,6'-tetranitro4,4'-azotoluene, and 2-hydroxylamino-4,6-dinitrotoluene) previously had been poorly accessible. (Junk, X; Catallo, W. J. "Environmental Transformation Products of 2,4,6-Trinitrotoluene," Chem. Spec. Bioavail 1998, 10(2), 47-52)
Contaminants Endocrine disruptors. A National Institute of Environmental Health Sciences and Centers for Disease Control and Prevention project to improve human exposure assessment for environmental endocrine disruptors indicates that persistent compounds seem to be decreasing in the U.S. human population. (Manuel, J. "NIEHS and CDC Track Human Exposure to Endocrine Disruptors," Environ. Health Perspect. 1999, 107(1), A16) Persistent organic pollutants. Because production and use data fluctuate and often vary according to source, it can be difficult to determine exactly which countries are producing, using, or exporting the commercially produced persistent organic pollutants that die U.N. Environmental Programme has slated for elimination from the world scene. (Schmidt, C. W.
"Spheres of Influence: No POPS," Environ. Health Perspect. 1999, 107(1), A24-A25)
Groundwater Chromium removal. Different treatment options, including carbon adsorption, ion exchange, chemical treatment, reverse osmosis, and inplace fixation, were tested at a site in California where groundwater is contaminated with hexavalent chromium; an electrochemical treatment proved to be the method of choice. (El-Shoubary, Y.; Speizer, N.; Setii, S.; Savoia, H. "A Pilot Plant To Treat ChromiumContaminated Groundwater," Environ. Prog. 1998, 17(3), 209-213)
Hazardous Waste Exposure. Important concerns revolving around human health, ecology, and quality of life impacts resulting from hazardous waste sites are presented. (Hansen, H.; De Rosa, C. T; Pohl, M. E; Mumtaz, M. M. "Public Health Challenges Posed by Chemical Mixtures," Environ. Health Perspect. 1998, 106(6), 1271-1280)
Measurements Lead levels. A study conducted over an eight-year period of young people living in Edinburgh, Scotland, showed substantial reductions in household-water lead content and blood lead levels. (Macintyre, C; Fulton, M.; Hepburn, W.; Yang, S.;
2 1 4 A • MAY 1, 1999 / ENVIRONMENTAL SCIENCE & TECHNOLOGY / NEWS
Raab, G; Davis, S.; Heap, M.; Halls, D.; Fell, G. "Changes in Blood Lead and Water Lead in Edinburgh: An Eight-Year Follow-up to the Edinburgh Lead Study," Environ. Geochem. Health 1998, 20(3), 157-167)
Methods Hydrocarbon analysis. Automated supercritical fluid extraction using carbon dioxide was tested and optimized for routine analysis of hydrocarbons, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons in marine sediments. (Berg, B. E.; Lund, H. S.; Kringstad, A; Kvernheim, A. L. "Routine Analysis of Hydrocarbons, PCB and PAH in Marine Sediments Using Supercritical C0 2 Extraction," Chemosphere 1998, 38(3), 587-599)
Soils Metal bioavailability. The concept of critical loads, previously applied to acidifying substances, currently is being extended, within the Convention on Long-Range Transboundary Air Pollution, to several metals, including cadmium, copper, lead, mercury, and zinc. (Rieuwerts, J. S.; Thornton, I.; Farago, M. E.; Ashmoret, M. R. "Factors Influencing Metal Bioavailability in Soils: Preliminary Investigations for the Development of a Critical Loads Approach for Metals," Chem. Spec. Bioavail. 1998, 10(2), 61-75)
