RESEARCH WATCH Health Brain tumor risk. Recent findings suggest that chemicals in flea and tick products may increase risks of brain tumors in infants. (Pagoda, J. M.; Preston-Martin, S. "Household Pesticides and Risk of Pediatric Brain Tumors," Environ. Health Perspect. 1997, 105 (11), 1214-1220)
Measurements Analysis of PAHs in soils. Factors are identified that affect the selectivity of porous-layer solid-phase microextraction for extracting PAHs from water. The technique is demonstrated through the analysis of contaminated soil samples. (Liu, Y.; Lee, M. L.; Hageman, K. J.; Yang, Y; Hawthorne, S. B. "Solid-phase Microextraction of PAHs from Aqueous Samples Using Fibers Coated with HPLC Chemically Bonded Silica Stationary Phases," Anal. Chem. 1997, 69 (24), 5001-5005) Compound enrichment technique. A novel method is demonstrated for enrichment of trace concentrations of phenolic compounds in environmental aqueous samples. Factors affecting the efficiency and performance of the procedure are identified. (Li, N.. Lee, H. K. "Trace Enrichment of Phenolic Compounds from Aqueous Samples by Dynamic Ionexchange Solid-phase Extraction," Anal. Chem. .997, 69 ((4), 5193-5199) New technique for organics. A mass spectrometry system is described that can be used to quantitatively determine parts-per-billion solution concentrations of semivolatile organic compounds such as caffeine in ground coffee and acetylsalicylic or phenoxyacetic acids. (Lauritsen, F. R.; Ketola, R. A. "Quantitative Determination of Semivolatile Organic Compounds in Solution Using Trapand-Release Membrane Inlet Mass Spectrometry," Anal. Chem. 1997, 69 (23), 4917-^1922)
Pollutant sequestration in soils Soil aging, the process by which the bioavailability and extractability of organic pollutants in soils decreases with time, is poorly understood. N. Chung and M. Alexander studied the extent to which this effect depends on soil type for the pollutants phenanthrene and atrazine. The degradation by bacteria and extractability of these compounds was monitored for 200 days in 16 different soils. Results indicate that no simple relationship exists between the decrease in bioavailability and the reduction in extractability of these pollutants during that time. There was no significant correlation between the rate and extent of pollutant sequestration and soil organic matter content. These findings indicate a need for further research into the role played by soil properties during the sequestration of organic contaminants and the consequent impact on contaminant bioavailability and persistence. (Environ. Sci. Technol., this issue, pp. 855-860)
Risk
Soils
Bioavailability of mercury. The bioavailability of mercury could be significantly less than that of mercuric chloride, and this has ramifications for assessment of risks and cleanup costs. (Paustenbach, D. J.; Bruce, G. M.; Chrostowski, R "Current Views on the Oral Bioavailability of Inorganic Mercury in Soil: Implications for Health Risk Assessments," Risk Analysis 1997, 27 (5), 533-543)
Predicting biodegradation rates. An approach for predicting biodegradation rates in soil-water systems, based on a study of sorption's influence on biodegradation kinetics, is described. (Gamerdinger, A. R; Achin, R. S.; Traxler, R. W. "Approximating the Impact of Sorption on Biodegradation Kinetics in SoilWater Systems," Soil Sci. Soc. Am. J. 1997, 61, 1618-1626)
GIS in risk analysis. Regional risk management strategies were developed using GIS and individual shipment tracking records in conjunction with four waste transport routing scenarios. (Lovett, A. A; Parfitt, J. P.; Brainard, J. S. "Using GIS in Risk Analysis: A Case Study of Hazardous Waste Transport," Risk Analysis 1997, 17 (5), 625-633)
Solid-to-solution ratios. The optimal solid-to-solution ratio for linear and Freundlich-type solid-liquid partitioning is derived. (McDonald, L. M., Jr.; Evangelou, V. P. "Optimal Solid-to-Solution Ratios for Organic Chemical Sorption Experiments," Soil Sci. Soc. Am. J. 1997, 61, 16551659)
Toxicology Safety factor requirements. A review of current literature suggests key recommendations for developing and using safety factors in evaluating environmental risks posed by potentially hazardous substances. The precautionary principle is analyzed. (Chapman, P. M.; Fairbrother, A.; Brown, D. "A Critical Evaluation of Safety (Uncertainty) Factors for Ecological Risk Assessment," Environ. Toxicol. Chem. .198,17(1)) 99-108)
1 9 2 A • APRIL 1, 1998 / ENVIRONMENTAL SCIENCE & TECHNOLOGY / NEWS
Pfiesteria piscicida impairs learning ability. For the first time, the toxic marine dinoflagellate has been shown to persistently interfere with the learning process. (Levin, E. D.; Schmechel, D. E.; Burkholder, J. M.; Glasgow Jr., H. B.; Deamer-Melia, N. J.; Moser, V C; Harry, G. J. "Persisting Learning Deficits in Rats after Exposure to Pfiesteria piscicida,, Environ. Health Perspect. .197, ,05 (12), 1320-1325)
0013-936X/98/0932-192A$15.00/0 © 1998 American Chemical Society
