14C-dimethoate residues in olive oil during oil processing

An olive tree was treated twice in the field with 14C-dimethoate (237.7 muCi, 2.4 g) and 14C residues were determined in the olive fruits at harvest. The fruits were crushed and pressed to extract the crude oil, then refined by neutralization, bleaching and deodorization. The crude oil contained 14.1% of the total 14C in the olive fruits. Neutralization resulted in a reduction of 14C by about 50% of the total 14C residues in oil. Bleaching and deodorization processes further reduced the 14C residues and the refined oil contained 31.6% (which corresponds to 4.4% of 14C residues of the total 14C in olive fruits) of the total 14C in the crude oil. Industrially extracted crude oil was fortified with 14C-dimethoate at 1.8 mg kg-1 (0.02 muCi) level and subjected to the same refining process. A sharp decrease in the amount of 14C was observed by neutralization and the amount of 14C remaining in the refined oil was about 7.3% of the total 14C in the crude fortified oil. The data suggest that the 14C residues in the aged and the fortified oil amples were not of the same nature. The terminal 14C residue in the refined oil obtained from the field experiment did not contain dimethoate and/or its oxon.     

Recent mild and wet years in relation to long observation records and future climate change in Sweden

Recent mild and wet years in Sweden were compared with long observation series of temperature, precipitation and runoff. Spatial average series for northern and southern Sweden were constructed and analyzed for the period 1901-2002. Precipitation increased considerably during the period, whereas temperature and runoff increases were weaker. On average, for the whole country, the differences between the period 1991-2002 and 1901-1990 were +0.7 degrees C for temperature, +11% in precipitation and +7% in runoff. The differences in temperature and precipitation, but not runoff, were significant at the 5% level. However, the 1930s were equally mild, and the runoff was almost as high in the 1920s. The characteristic feature of the past decade is the combination of high temperature, precipitation and runoff. The deviation between the most recent decade and the preceding years is consistent with climate scenario projections for Sweden, but there are also differences in the seasonal pattern.     

Symbiotic efficiency of autochthonous arbuscular mycorrhizal fungus (G. mosseae) and Brevibacillus sp. isolated from cadmium polluted soil under increasing cadmium levels

The effect of inoculation with indigenous naturally occurring microorganisms (an arbuscular mycorrhizal (AM) fungus and rhizosphere bacteria) isolated from a Cd polluted soil was assayed on Trifolium repens growing in soil contaminated with a range of Cd. One of the bacterial isolate showed a marked PGPR effect and was identified as a Brevibacillus sp. Mycorrhizal colonization also enhanced Trifolium growth and N, P, Zn and Ni content and the dually inoculated (AM fungus plus Brevibacillus sp.) plants achieved further growth and nutrition and less Cd concentration, particularly at the highest Cd level. Increasing Cd level in the soil decreased Zn and Pb shoot accumulation. Coinoculation of Brevibacillus sp. and AM fungus increased shoot biomass over single mycorrhizal plants by 18% (at 13.6 mg Cd kg(-1)), 26% (at 33.0 mg Cd kg(-1)) and 35% (at 85.1 mg Cd (kg(1)). In contrast, Cd transfer from soil to plants was substantially reduced and at the highest Cd level Brevibacillus sp. lowered this value by 37.5% in AM plants. Increasing Cd level highly reduced plant mycorrhization and nodulation. Strong positive effect of the bacterium on inocula, are important in plant Cd tolerance and development in Cd polluted soils.     

Selective supercritical fluid extraction to estimate the fraction of PCB that is bioavailable to a benthic organism in a naturally contaminated sediment

Selective supercritical fluid extraction (SFE) at 40 degrees C, 120 bar and 60 min was utilised as a means to estimate the bioavailable fraction of PCBs to chironomid larvae in a naturally contaminated limnic sediment. This extraction methodology removed about 50% of the PCBs from the sediment. According to the equilibrium partitioning theory, organisms in that sediment should decrease their uptake from the sediment to the same extent, biota-to-sediment accumulation factors (BSAFs) thus remaining constant. Surprisingly, the BSAFs for 11 PCB congeners decreased some 40% for the selectively extracted sediment as compared to BSAFs for organisms dwelling in untreated sediment. The results were statistically significant at the 0.001 level using a paired t-test. This can only be interpreted so that selective SFE removed easily available PCBs preferentially, leaving more tightly bound PCBs behind. Hence, by fine-tuning extraction conditions, this methodology might be used to estimate bioavailable fractions by chemical means.     

Analysis and prediction of global climate temperature change based on multiforced observational statistics

The response of the climate system to increasing greenhouse gases was simulated by a number of climate model projections. There is an urgent need to verify or falsify these projections against observational climate data. Therefore, in this contribution, surface air temperature data are considered covering on a global average the period 1861-1990 and on a northern hemisphere average 1670-1990 (including proxy data). Based on a multiple correlation and coherence analysis a regression model is evaluated which is simultaneously forced by the observed or reconstructed atmospheric CO(2) or equivalent CO(2) concentration increase, volcanic activity, solar variations, and the ENSO (El Ni?o/southern oscillation) mechanism including phase shifts between cause and effect. This model reveals a greenhouse-gas-induced mean global temperature rise of 0.6-0.8 K since preindustrial time (c. 1800-1990). Following the IPCC business-as-usual scenario (trend extrapolation) this would lead to a hypothetical 3.8 K temperature rise in 2100 (best estimate, uncertainty + 0.7/-0.4 K compared to the 1985 value.     

Home transport and wastage: environmentally relevant household activities in the life cycle of food

In environmental systems analysis of food production systems, the consumer phase (home transport, cooking, storing, and wastage) is an important contributor to the total life-cycle environmental impact. However, households are the least investigated part of the food chain. Information gathering about households involves difficulties; the number of households is large, and food-related activities are embedded in other household activities. In cooperation between researchers from environmental systems analysis and consumer research, Swedish households were surveyed by questionnaire, diary, and interviews. Data on home transport of food and wastage were collected. The average weekly driving distance was 28 to 63 km per household, depending on how trips made in conjunction with other errands are allocated. The wastage of prepared food ranged between 0 and 34% for different food categories, and wastage from storing between 0 and 164% (more food was discarded, e.g. by cleaning out a cupboard, than consumed). In both cases dairy products scored highest.     

Coping with uncertainty: a call for a new science-policy forum

The scientific and policy worlds have different goals, which can lead to different standards for what constitutes "proof" of a change or phenomena, and different approaches for characterizing and conveying uncertainty and risk. These differences can compromise effective communication among scientists, policymakers, and the public, and constrain the types of socially compelling questions scientists are willing to address. In this paper, we review a set of approaches for dealing with uncertainty, and illustrate some of the errors that arise when science and policy fail to coordinate correctly. We offer a set of recommendations, including restructuring of science curricula and establishment of science-policy forums populated by leaders in both arenas, and specifically constituted to address problems of uncertainty.     

Holocene biomass burning and global dynamics of the carbon cycle

Fire regimes have changed during the Holocene due to changes in climate, vegetation, and in human practices. Here, we hypothesise that changes in fire regime may have affected the global CO2 concentration in the atmosphere through the Holocene. Our data are based on quantitative reconstructions of biomass burning deduced from stratified charcoal records from Europe, and South-, Central- and North America, and Oceania to test the fire-carbon release hypothesis. In Europe the significant increase of fire activity is dated approximately 6000 cal. yr ago. In north-eastern North America burning activity was greatest before 7500 years ago, very low between 7500-3000 years, and has been increasing since 3000 years ago. In tropical America, the pattern is more complex and apparently latitudinally zonal. Maximum burning occurred in the southern Amazon basin and in Central America during the middle Holocene, and during the last 2000 years in the northern Amazon basin. In Oceania, biomass burning has decreased since a maximum 5000 years ago. Biomass burning has broadly increased in the Northern and Southern hemispheres throughout the second half of the Holocene associated with changes in climate and human practices. Global fire indices parallel the increase of atmospheric CO2 concentration recorded in Antarctic ice cores. Future issues on carbon dynamics relatively to biomass burning are discussed to improve the quantitative reconstructions.     

Evaluation of the Galega-Rhizobium galegae system for the bioremediation of oil-contaminated soil

The bioremediation potential of a nitrogen-fixing leguminous plant, Galega orientalis, and its microsymbiont Rhizobium galegae was evaluated in BTX (benzene, toluene, xylene)-contaminated soils in microcosm and mesocosm scale. To measure the intrinsic tolerance of the organisms to m-toluate, a model compound representing BTX, G. orientalis and R. galegae were cultivated under increasing concentrations of m-toluate alone and in association with Pseudomonas putida pWWO, a bacterial strain able to degrade toluene-derived compounds. The test plants and rhizobia remained viable in m-toluate concentrations as high as 3000 ppm. Plant growth was inhibited in concentrations higher than 500 ppm, but restituted when plants were transferred into m-toluate-free medium. Nodulation was blocked under the influence of m-toluate, but was restored after the plants were transferred into the non-contaminated media. In the mesocosm assay the Galega plants showed good growth, nodulation and nitrogen fixation, and developed a strong rhizosphere in soils contaminated with oil or spiked with 2000 ppm m-toluate. Thus, this legume system has good potential for use on oil-contaminated sites