RESEARCH WATCH Air Suspended particulates. Measurements show that the concentration of airborne particulate matter is higher at 0.81 m above street level than at 2.88 m. (Micallef, A.; Colls, J. J. "Variation in Airborne Particulate Matter Concentration Over the First Three Meters From Ground in a Street Canyon: Implications for Human Exposure," Atmos. Environ. 1998, 32(21), 3795-3799)
Soil remediation Phytoremediation may be a feasible, inexpensive means of decontaminating large areas of soil surface layers polluted by radiocesium. ' "Cs is tightly bound to soil exchange sites, has low bioavailability, and therefore has the potential to be retained in the soil for long periods. S. Dushenkov and co-workers investigated the use of soil amendment procedures that convert "'Cs to more bioavailable forms, which subsequently can be taken up by accumulating plants. In plot studies, ammonium salts were much more effective in mobilizing
,3
'Cs than were surfactants or
organic acids. Amaranth cultivars were the species most capable of accumulating the released
,3
'Cs Although the methodology was not very successful on a field
scale, further developments may result in a feasible large-scale method. [Environ. Sci. Technol., this issue, pp. 469-475)
Urban aerosols. A new combined lidar/scanning electronic microscopy/X-ray microanalysis technique simultaneously gives access to the size distribution, composition, and spatial, as well as temporal dynamics of concentrations of nonvolatile components of urban aerosols. (Kasparian, J.; Frejafon, E.; Rambaldi, R; Yu, J.; Vezin, B.; Wolf, J. P.; Ritter, P.; Viscardi, R "Characterization of Urban Aerosols Using SEMMicroscopy, X-ray Analysis and Lidar Measurements" Atmos. Environ. 1998 32(17) 2957-2967)
Lewis, J. W; McCreedy, R. L.; Tuhovak, D. R.; Weston, A. F. "Characterization of Emissions of Dioxins and Furans From Ethylene Dichloride, Vinyl Chloride, and Polyvinylchloride Manufacturing Facilities in die United States. 1. Resin, Treated Wastewater, and Ethylene Dichloride," Chemosphere 1998, 37(9/12), 1957-1972)
L. "Volatilization of Chemicals From Drinking Water to Indoor Air: The Role of Residential Washing Machines," /. Air Waste Manage. Assoc. 1998, 48, 907-914) Tobacco smoke. Reversible sorption impacts human exposures to compounds mat are emitted intermittently (such as from periodic cigarette combustion) and interact strongly with surfaces. (Van Loy, M. D.; Nazaroff, W W; Daisey, J. M. "Nicotine as a Marker for Environmental Tobacco Smoke: Implications of Sorption on Indoor Surface Materials," /. Air Waste Manage. Assoc. 1998, 48, 959-968)
Chlorocarbon exposure. Clinical data show that continued and enhanced efforts should be directed toward identifying and controlling sources of environmental input for polychlorinated dioxins, furans, and biphenyls. (Brouwer, A.; Ahlborg, U. C.; Rolaf Van Leeuwen, E X; Feeley, M. M. "Report of the WHO Working Group on the Assessment of Health Risks for Human Infants From Exposure to PCDDs PCDFs and PCBs," Chemosphere 1998 37(9/12), 1627-1643)
Phosphate removal. The microbiological and biochemical aspects of the enhanced biological phosphate removal process (EBPR), microorganisms responsible for EBPR, isolation of polyphosphate-accumulating organisms (PAOs), microbial diversity of EBPR sludge, biochemical metabolism of PAOs, energy budget in PAO metabolism, PAO denitrification, and glycogen accumulating nonpoly-P organisms are reviewed. (Mino T.' Van Loosdrecht M. C. M.; Heijnen J. J. "Microbiology and Biochemistry of the Enhanced Biological Phosphate Removal Process " Water Res 1998 32(11) 3193-3207)
Dioxin/furan emissions. The contribution of ethylene dichloride, vinyl chloride monomer, and polyvinylchloride from manufacturing facilities constitutes substantially less dian 1% of estimated U.S. annual dioxin releases to the environment. (Carroll, W. E, Ir.; Berger, T. C ; Borrelli, E E.; Garrity, P. J.; Jacobs, R. A.;
Indoor Air
Food crops. Several assumptions for phytotoxic metals in EPA's risk assessment under the' Clean Water Act 503 regulation have been challenged as scientifically unsound. (McBride, M. B. "Growing Food Crops on Sludge-Amended Soils: Problems Witii the U.S. Environmental Protection Agency Method of Estimating Toxic Metal Transfer," Environ. Toxicol. Chem. 1998, i 7 ( l l ) , 2274-2281)
Chemical volatilization. To better understand the extent and impact of chemical emissions from tap water, 26 experiments were conducted using a residential washing machine and a mix of chemical tracers representing a wide range of physiochemical properties. (Howard, C; Corsi, R.
Air quality. A Lagrangian particle-incell air quality model facilitated study of source contributions to atmospheric fine elemental carbon and fine primary total carbon particle concentrations. (Gray, H. A.;
Assessment
8 8 A • FEB. 1, 1999 / ENVIRONMENTAL SCIENCE & TECHNOLOGY / NEWS
Metals
Modeling
