Copper, zinc, and arsenic in soil surrounding Douglas-fir poles treated with ammoniacal copper zinc arsenate (ACZA)

The levels of copper, zinc, and arsenic in soil surrounding Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] utility poles treated with ammoniacal copper zinc arsenate (ACZA) were investigated at sites in Florida, Virginia, and New York. Copper levels were elevated near the poles and declined with both horizontal distance away from the pole and depth beneath the soil surface. Zinc levels were also elevated next to the poles, but the levels declined more slowly than did those of copper. Arsenic levels were elevated in soil immediately next to the poles but declined to near background levels farther away. The results indicate that metals can leach from ACZA-treated poles, but do not migrate far in the soil, and thus the levels decline sharply with distance from the poles.     

Assessing the pollutional load from nonpoint sources: Planning considerations and a description of an automated water quality monitoring program

Planning considerations to be evaluated early in the design of water quality monitoring programs are reviewed. These criteria emphasize the importance of isolating the study area, parameter section, and type of measurements required to ensure meaningful results. A demonstration automatic water quality monitoring program is described. Details with respect to type of equipment, coordination of component parts, sampling program, and analysis of specific parameters are reviewed. General costs of implementation and maintenance of such programs are presented.     

Modeling the costs and benefits of dam construction from a multidisciplinary perspective

Although the benefits of dam construction are numerous, particularly in the context of climate change and growing global demand for electricity, recent experience has shown that many dams have serious negative environmental, human, and political consequences. Despite an extensive literature documenting the benefits and costs of dams from a single disciplinary perspective, few studies have simultaneously evaluated the distribution of biophysical, socio-economic, and geopolitical implications of dams. To meet the simultaneous demands for water, energy, and environmental protection well into the future, a broader view of dams is needed. We thus propose a new tool for evaluating the relative costs and benefits of dam construction based on multi-objective planning techniques. The Integrative Dam Assessment Modeling (IDAM) tool is designed to integrate biophysical, socio-economic, and geopolitical perspectives into a single cost/benefit analysis of dam construction. Each of 27 different impacts of dam construction is evaluated both objectively (e.g., flood protection, as measured by RYI years) and subjectively (i.e., the valuation of said flood protection) by a team of decision-makers. By providing a visual representation of the various costs and benefits associated with two or more dams, the IDAM tool allows decision-makers to evaluate alternatives and to articulate priorities associated with a dam project, making the decision process about dams more informed and more transparent. For all of these reasons, we believe that the IDAM tool represents an important evolutionary step in dam evaluation.     

The in vitro metabolism of lindane by an enzyme preparation from chicken liver.

The soluble fraction (105,000 x g, 30 min) of chicken liver homogenates contained an enzyme(s), probably a dehydrochlorinase(s), which metabolized lindane in vitro. The reaction was glutathione dependent and took place anaerobically. The enzyme(s) also metabolized the alpha- and delta-isomers but not the beta-isomer. About 66% of the in vitro metabolites were soluble in petroleum ether. From the ether-soluble fraction, o-, p- amd m-dichlorobenzene, 1,2,3- and 1,2,4-trichlorobenzene, gamma-2,3,4,5,6-pentachlorocyclohex-1-ene (gamma-PCCH), 2,3- and 2,4-dichlorophenol and 2,4,6-trichlorophenol were identified by comparison of mass spectra and gas chromatographic data with those of reference compounds. Seven additional metabolites were tentatively identified from their mass spectra data. These metabolites were: chlorobenzene, 2 isomers of trichlorocyclohexene, dichlorocyclohexadienetriol, chlorophenol, trichlorocyclohexenol and trichlorocyclohexanediol. The petroleum ether-extracted aqueous phase contained a number of unidentified conjugated metabolites. It was concluded that the metabolic pathway for lindane in the chicken is quite similar to that in the pheasant.     

Atmospheric xenon radioactive isotope monitoring

The Comprehensive Nuclear Test Ban Treaty (CTBT) organisation is implementing a world-wide monitoring network in order to check that the State Signatories comply with the treaty. One of the monitoring facilities consists of an atmospheric noble gas monitoring equipment. According to the requirements annexed in the treaty, the French Atomic Energy Commission (CEA) developed a device, called SPALAX, which automatically extracts xenon from ambient air and makes in situ measurements of the activities of four xenon radioisotopes (131mXe, 133mXe, 133Xe, 135Xe). The originality of this device is noticeable essentially in the gas sample processing method: thanks to the coupling of a gas permeator and of a noble gas specific adsorbent, it can selectively extract and concentrate xenon to more than 3 x 10 E6. This process is carried out continuously without cryogenic cooling, without any regeneration time. The detection of the xenon radioactive isotopes is done automatically by high spectral resolution gamma spectrometry, a robust technology well-suited for on-field instrumentation. In the year 2000, a prototype was involved in an international evaluation exercise directed by the CTBT organisation (CTBTO). This exercise demonstrated that the SPALAX equipment perfectly met the requirements of the CTBTO for such systems. On the basis of the continuous 24-h resolution record of the atmospheric xenon radioactive isotopes concentrations, the SPALAX system also demonstrated that ambient levels of 133Xe can fluctuate quickly from less than the detection limit to over 40 x 10(-3) Bq m(-3). In order to build an industrial version of this equipment, the CEA entered into a partnership with a French engineering company (S.F.I., Marseille, France), which is now able to produce an industrial version of SPALAX, i.e. more compact and more efficient than the prototypes. The 133Xe minimum detectable concentration is 0.15 x 10(-3) Bq m(-3) air per 24 h sampling cycle.     

Ecological aspects of rodent population control in natural plague foci on the territory of the Russian Federation

A concept of population control is proposed as applied to rodent carriers of plague and other infections with natural focality. The concept is based on the generalization of long-term experience gained in natural plague foci, differentiation of the enzootic territory with respect to the level of epidemic risk, analysis of the current state of rodent populations, and the necessity of biodiversity conservation in natural biocenoses.