Basic health care in El Salvador

Health care in a conventional war has its own characteristics. Health care in a guerilla war, as exists at present in El Salvador, adds to this some new aspects.     

Book reviews

Frances Sharples is a terrestrial ecologist in the Environmental Science Division of the Oak Ridge National Laboratory in Oak Ridge, Tennessee, operated by Martin Marietta Energy Systems, Inc., under Contract No. DE-AC05-840R21400 with the US Department of Energy. Publication No. 3413, Environmental Sciences Division, ORNL.     

Successful combination of remediation techniques at a former silver factory

A residential area that was formerly part of a silver factory site severely contaminated with chlorinated solvents was remediated using an in situ electro‐bioreclamation technique. Electro‐bioreclamation is a method for heating soil and groundwater combined with soil vapor and low‐yield groundwater extraction and enhanced reductive dechlorination (ERD). During the first two years of remediation in the source area (the intensive phase), a total of 80 kg of volatile organic compounds (VOCs) was removed by heating combined with ERD. After another two years of ERD in the source and plume areas (the attenuation phase), the VOC concentrations were reduced to a level below 100 μg/L in groundwater. Given these satisfying results, electro‐reclamation in combination with ERD turned out to be a successful in situ remediation technique for removing VOCs. © 2006Wiley Periodicals, Inc.     

Dietary selectivity in the field and food preferences in the laboratory for two herbivorous fishes (Cebidichthys violaceus and Xiphister mucosus) from a temperate intertidal zone

Diets and food selectivity of two stichaeid fishes (Cebidichthys violaceus and Xiphister mucosus) from the rocky intertidal zone of the central California coast (USA) were studied at each season of the year by gut content analysis and abundance measurements of potential macrophyte food items. Both fishes, after reaching a standard length of about 44 mm, were almost exclusively herbivorous. The bulk of the diet consisted of 8 to 10 species of chlorophytes and rhodophytes. These main dietary components were chiefly annual seaweeds with high surfaceto-weight ratios (sheetlike forms or small, highly branched forms). Perennial seaweeds were eaten in relatively large amounts only during the winter. Macrophytes eaten in only trace amounts included about 20 species of chlorophytes, chrysophytes, phaeophytes, rhodophytes and a spermatophyte. The small amount of animal material in the diet (never more than 2% by weight) could well have been ingested incidentally while the fishes were feeding on seaweeds. Food preference tests with up to 19 macrophyte species in the laboratory revealed that both fishes chose to eat three annual rhodophytes (Smithora naiadum, Porphyra perforata and Microcladia coulteri) in preference to Ulva lobata, an annual chlorophyte that was more abundant in the diets of field-caught specimens.     

Nitrous oxide emissions from an ultisol of the humid tropics under maize-groundnut rotation

Nitrous oxide (N20) contributes to global climate change and agricultural soils seem to be the major source. Lack of information led to this study on the influence of different amounts and sources of nitrogen on N2O emission from a maize (Zea mays L.)-groundnut (Arachis hypogae L.) crop rotation in an Ultisol of the humid tropics. The treatments were: inorganic N + crop residues (NC), inorganic N only (RN), and half of inorganic N + crop residues + chicken manure (NCM). The corresponding amount of N applied was 322, 180, and 400 kg ha(-1) yr(-1), respectively. The N2O emissions depended on the amounts and types of N. A maximum peak (9,889 +/- 2,106 microg N2O-N m(-2) d(-1)) was detected at 2 wk before maize sowing amended with chicken manure, showing a persistent influence on N transformations and N2O release. The mineral N from either applied source became low by 2 to 4 wk, coinciding with the small N2O fluxes or its consumption to a few isolated instances. The N2O flux significantly correlated with the mineral N and water-filled pore spaces. The direct annual N2O emission was 3.94 +/- 0.23, 1.90 +/- 0.08, and 1.41 +/- 0.07 kg N2O-N ha(-1) from the NCM, NC, and RN treatments, respectively. The corresponding N2O-N loss of the applied N plus N fixed by groundnut was 0.83, 0.49, and 0.59%. Overestimations of direct annual N2O emission using the Intergovernmental Panel on Climate Change (IPCC) methodology suggest a location-specific emission factor for variable N sources to be considered.     

Determination of DDT and its metabolites in cattle dip soil available in aqueous phase after remediation

Soil taken from a former cattle tick dip site in NSW Australia, was remediated with a chemical leaching technology. The pre- and post-remediated soil (20g) was dispersed in water (100mL) and subjected to passive diffusion using polymeric membranes. The remediation reduced tDDT from 1174.3 microg/g to 102.9 microg/g (ash weight basis), which was further reduced to 43.2 microg/g with composting. The membranes accumulated 41.3 microg tDDT/g from the dip soil, 49.2 microg tDDT/g from the chemically leached soil and 3.1 microg tDDT/g from the leached composted soil. The chemical leaching removed over 90% of the tDDT, but released soil bound DDT, which was converted to DDE, while 2.99 microg/g was accumulated by the membranes from dip soil, 37.52 microg/g was accumulated from remediated soil. Composting, however, almost eliminated the availability for passive diffusion by the membranes from 50-60 microg/g in remediated soil to 3 -3.5 microg/g in composted soil. Variability studies of the membranes using eight replicates demonstrated that the accumulation by the membranes was reproducible with an average relative error of 20.3% for p,p'-DDT in soil type two, whilst the lowest average relative error for p,p'-DDE was 4.3%, suggesting that triplicate analyses will achieve acceptable accuracy.     

Public attitudes to nuclear energy: Salience and anxiety

During the last decade there has been a significant increase in public concern about nuclear energy. This paper presents a brief overview of trends and developments in public opinion since the late 1970s. One possible reason for this increased concern is the public's perception of risks. Research has shown a considerable divergence in public and expert assessment of the risks associated with nuclear energy. It will be argued that qualitative aspects of these risks play a crucial role in the public's perception of nuclear energy, and that reactions such as fear and anxiety are the major determinants of attitudes to the building of new nuclear power stations in one's neighbourhood. It is also clear, however, that differences in the perception of these risks do not embrace all the relevant aspects of public acceptance of nuclear energy. Public reaction is also related to more general values and beliefs, and the issue of nuclear energy is firmly embedded in a much wider moral and political domain.     

S-100 protein in amniotic fluid of anencephalic fetuses

S-100 protein, which is found essentially in the astrocytes of the nervous system, was assayed in amniotic fluids by Particle Counting Immuno Assay. It was present in 19 cases of anencephaly out of 26, in 1 case of open spina bifida out of 5 and in each of the 4 cases of fetal death, whereas it was not detected in the 48 control amniotic fluids collected between the 16th and the 35th week of gestation. Thirty-one amniotic fluids from fetuses with other congenital malformations were devoid of detectable S-100. The presence of S-100 in amniotic fluid of anencephalic fetuses can presumably be considered as a biological sign of necrosis of the exencephalic brain and seems specific to damage of the central nervous system accompanied by neural tube defect.     

Canadian perspectives on aluminum

Summary The multi-media approach to aluminum exposure will allow a more informed decision on the inclusion or exclusion of various exposure media in future epidemiological studies.Knowledge of the types of Al (speciation) and their respective bioavailability will enable interpretation of the importance of specific media.