Research Watch: Lake microorganisms - Environmental Science


Research Watch: Lake microorganisms - Environmental Science...

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Research Watch

Air Quality

PCDD/Fs in soil and eggs

Phosphine levels. Phosphine was detected in the urban air of Beijing, both as an air pollutant and as a gaseous component of the local phosphorus cycle. Along with other significant sources, paddy fields and water reservoirs were analyzed to understand phosphine's possible biological origins. (Ji-Ang, L., et al. "Phosphine in the Urban Air of Beijing and Its Possible Sources," Water, Air, Soil Pollut. 1999 116 (3-4), 597-604)

PCDD/Fs are persistent and bioaccumulative compounds whose sources and pathways of food chain contamination are unclear. M. Harnly and co-workers investigated their levels in soil and home-produced chicken eggs taken near pentachlorophenol (PCP) sources in Oroville and Stockton, CA, and near a former PCP wood treatment facility. Of egg samples analyzed, 78% had levels above 1 ppt; corresponding soil levels were 6.2 and 6.6 ppt ITEQ. Combined evidence suggested that local industrial sources can contribute to contamination, underscoring broad concern for PCDD/F sources and environmental levels, particularly with respect to human consumption of animal products. {Environ. Sci. Technol., ,his iisue, pp. .143--149)

Atmosphere Ozone reactions. The formation yields of acrolein, l,2-epoxy-3butene, and hydroxyl radicals were measured from the reaction of ozone with 1,3-butadiene at room temperature and atmospheric pressure. The results are discussed in terms of the effect of atmospheric processing on the toxicity of 1,3butadiene. (Kramp, E; Paulson, S. E. "The Gas Phase Reaction of Ozone With 1 3-Butadiene: Formation Yields of Some Toxic Products " Atmos. Environ 1999 34 (1) 35-43) Particle-bound pollutants. Particle size-dependent distributions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polycyclic aromatic hydrocarbons (PAHs) were measured at a rural location in northeastern Bavaria during summer, with the atmospheric particles sampled using cascade impactors and a rotary impactor. (Kaupp, H.; McLachlan, M. S. "Distribution of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans (PCDD/Fs) and Polycyclic Aromatic Hydrocarbons (PAHs) Within the Full Size Range of Atmospheric Particles " Atmos Environ 1999 34 (1) 73-83)

Climate El Niño. Results indicate that the spatial extent of the phytoplankton bloom that followed recovery from El Nino was the largest ever observed for the equatorial Pacific. (Chavez, F. R, et al. "Biological and Chemical Response of the Equatorial Pacific Ocean to the 1997-1998 El Nino," Science 1999, 286 (5447), 2126-2131) Lake microorganisms. Analysis of a portion of a Vostok ice core, which is thought to contain frozen water derived from Lake Vostok, Antarctica, revealed the presence of between 2 x 102 and 3 x 102 bacterial cells/mL and low concentrations of potential growth nutrients. (Karl, D. M., et al. "Microorganisms in the Accreted Ice of Lake Vostok, Antarctica," Science 1999, 286 (5447), 2144-2147) Ocean temperatures. The authors present a high-temporal-resolution record, spanning the past 29,000 years, of sea surface temperatures from the western tropical North Atlantic Ocean that indicates noticeable trends in ocean warming and thermohaline circulation. (Ruhlemann, C , et al. "Warming of the Tropical Atlantic Ocean and Slowdown of Thermohaline Circulation During the Last Deglaciation," Nature 1999 402 (6761), 511-514)

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Health Candles pose risk. Segments of candles having wicks containing a lead metal core were tested in a combustion chamber to assess lead emissions, with results indicating that these candles potentially present highly unacceptable and avoidable risks to human health, (van Alphen, M. "Emission Testing and Inhalational Exposure-Based Risk Assessment for Candles Having Pb Metal Wick Cores " Sci. Total Environ. 1999 243-244 53-65) Mineral water. Bottled mineral waters bought at random all over Europe were analyzed for chemical elements with results showing a wide spread in the chemical composition of the mineral waters and indications that element concentrations for some unwanted constituents (such as Pb) are higher in waters sold in glass bottles than in plastic bottles. (Misund, A., et al. "Variation of 66 Elements in European Bottled Mineral Waters " Sci. Total Environ. 1999 243-244 21-41)

Herbicides Herbicide safeners. This paper examines the potential wide-ranging applications of herbicide safeners and, in particular, their use as pow-