Attenuation of allergic contact dermatitis through the endocannabinoid system

Allergic contact dermatitis affects about 5% of men and 11% of women in industrialized countries and is one of the leading causes for occupational diseases. In an animal model for cutaneous contact hypersensitivity, we show that mice lacking both known cannabinoid receptors display exacerbated allergic inflammation. In contrast, fatty acid amide hydrolase-deficient mice, which have increased levels of the endocannabinoid anandamide, displayed reduced allergic responses in the skin. Cannabinoid receptor antagonists exacerbated allergic inflammation, whereas receptor agonists attenuated inflammation. These results demonstrate a protective role of the endocannabinoid system in contact allergy in the skin and suggest a target for therapeutic intervention.     

Microbial biomass and respiration in soils derived from lignite ashes: a profile study

Microbial biomass C and soil respiration measurements were made in 17–20 yr old soils developed on sluiced and tipped coal‐combustion ashes. Topsoil (0–30 cm) and subsoil (30–100 cm) samples were collected from three soil profiles at two abandoned disposal sites located in the city area of Halle, Saxony‐Anhalt. Selected soil physical (bulk density and texture) and chemical (pH, organic C, total N, CEC, plant available K and P, and total Cd and Cu) properties were measured. pH values were significantly lower while organic C and total N contents and the C : N ratio were significantly higher in the topsoil than in the subsoil indicating the effects of substrate weathering and pedogenic C accumulation. Likewise, microbial biomass C, K₂SO₄‐extractable C, and soil respiration with median values of 786 μg biomass C g^–1, 262 μg K₂SO₄‐C g^–1, and 6.05 μg CO₂‐C g^–1 h^–1, respectively, were significantly higher in the topsoil than in the subsoil. However, no significant difference was observed in metabolic quotient between the topsoil and the subsoil. Metabolic quotient with median values of 5.98 and 8.54 mg CO₂‐C (g biomass C)^–1 h^–1 for the 0–30 cm and 30–100 cm depths, respectively, was higher than the data reported in the literature for arable and forest soils. Microbial biomass C correlated significantly with extractable C but no relationship was observed between it and total N, Cd, and Cu contents, as well as plant‐available K and P. We conclude that the presence of the remarkable concentration of extractable C in the weathered lignite ashes allowed the establishment of microbial populations with high biomass. The high metabolic quotients observed might be attributed to the heavy‐metal contamination and to the microbial communities specific to ash soils.     

Sandwich immunoassays for the determination of peanut and hazelnut traces in foods

People suffering from food allergies are dependent on accurate food labeling, as an avoidance diet is the only effective countermeasure. Even a small amount of allergenic protein can trigger severe reactions in highly sensitized patients. Therefore, sensitive and reliable tests are needed to detect potential cross-contamination. In this paper two fast sandwich immunoassays are described for the determination of peanut (Arachis hypogaea) and hazelnut (Corylus avellana) traces in complex food matrices. Mouse monoclonal antibodies were used as capture antibodies, and labeled rabbit polyclonal antibodies were used as detection antibodies in both assays. The assay time was 30 min in total, and cross-reactivities against a variety of fruits and seeds were found to be in the low 10(-4)% (ppm) level or in some cases not detectable. The recoveries in all tested food matrices ranged from 86 to 127%, and the limits of detection were in the range of 0.2-1.2 mg/kg (ppm) in food for both peanut and hazelnut, respectively.     

The assessment of sediment screening risk in Venice Lagoon and other coastal areas using international sediment quality guidelines

Background, Aims and Scope  A number of studies carried out in recent years have shown the presence of a wide range of contaminants in the Venice Lagoon. It is important to have a good understanding of the ecological quality of Venice Lagoon sediments, in order to: i) define and locate areas where a threat to the environment is present and therefore an intervention is needed (i.e. in situ assessment and management); and ii) define sustainable and environmentally correct ways of managing sediments which are to be dredged for navigational purposes or in relation to other interventions (i.e., ex situ management). Methods  To examine how various regional and international SQGs ‘classed’ screening risk in Venice Lagoon sediments, data on median contaminant levels in surface sediments in Venice Lagoon resulting from a literature review were compared to a range of local and international sediment quality guidelines (SQGs). Then data on sediment contaminant levels in various areas and sub-basins of Venice Lagoon (main Lagoon, Porto Marghera and Venice City Canals) and in other regional and international transitional and coastal ecosystems with various levels of human impact (urbanization and industrialization) were evaluated based upon a selected consensus-based SQG. Finally, screening sediment quality for all of Venice Lagoon was mapped and contoured, relative to this consensus-based SQG and briefly compared with direct toxicity measurement through a battery of bioassays. Results  SQGs allow the sediment areas to be put in terms of potential, or screening, risk. Although there were some differences depending upon which specific SQGs were applied, the Venice SQGs and other international SQGs provided the same general picture of screening risk in Venice Lagoon despite geographic differences. Venice Lagoon South has the lowest screening risk levels, Venice Lagoon Central/North has the highest (and is nearest to the Porto Marghera and Venice City Canals sites). Discussion  The Venice Lagoon sediments have hazard quotients on the low end of the range of moderately urbanized and industrialized sites and higher than background case studies reviewed. Hg levels in the Venice Lagoon were generally higher than equivalent sites, while other contaminants were either equivalent or lower. In Porto Marghera (PM) and Venice City Canals (VC), for many contaminants of interest, PM, and for some, VC sediments have the highest levels of any case study reviewed. Ranges are high, so in all cases, remedial or disposal decisions should be based upon site-specific (and preferably tiered) data. Conclusions  The use of hazard quotients makes it possible to compare screening risks due to different mixes of contaminants within and between sites, but results should be interpreted with caution. How these sites rank when compared to some of the other highly industrialized sites depends upon how data are synthesized and communicated. Actual risk must be evaluated using a weight of evidence (WOE) approach, as site-specific bioavailability and background levels will differ both regionally and internationally. Recommendations and Perspectives  Whilst there are subtle differences, the current Venice sediment classifications (A, B and C) ‘performed’ in a similar manner to SQGs in similar classes, suggesting that regions of Venice Lagoon would not be classified much differently if other SQGs such as TEL, ERL, PEL, ERM or AET were adopted. The Italian sediment quality objectives, on the other hand, are significantly more conservative than any other SQGs examined, with the exception of the Flemish Reference values. A number of European nations are considering criteria based upon contaminant levels in relatively pristine modern sites, or based upon derivations of historical (pre-anthropogenic) contaminant levels. When used as a standard, such an approach lacks discriminating power, designating almost all sediments within an urbanized or industrialized region as of concern, or even, in many cases, mandating action or prohibiting various management approaches in a large percentage of sediments. While generally based upon the laudable desire to return sites to unimpacted levels, there is a risk that overprotective criteria have the opposite effect: by designating too large a percentage of sediments as requiring management or control, limited resources may be improperly allocated. Which set of SQGs is most ‘appropriate’ for the Venice Lagoon sediments depends upon the questions being asked. However, the Venice classifications are currently being used as pass-fail criteria, without consideration of site-specific conditions. The fact that they performed similarly to SQGs in similar classes suggests that any work to develop more site-specific SQGs (with the same general decision classes) would probably not make much difference in how sediments were ultimately classified and managed unless the fundamental approach was changed from a pass-fail to a tiered and WOE approach integrated in a comprehensive decision framework. For Venice Lagoon, and for other regions, although SQGs should be developed with care, in a scientifically defensible and risk-based manner, an equally or more important issue to be addressed is their role in overall decision frameworks. ESS-Submission Editor: Dr. Marc Babut (marc.babut@cemagref.fr)     

Development, growth and chemical composition of the potato crop (Solanum tuberosum L.). I. leaf and stem

Summary In this first part of a review the development of the potato leaf and stem is described, based on research data and literature. The development over time, the daily changes of fresh and dry matter, the contents of organic and inorganic components (dry matter, starch, sugars, organic acids, ascorbic acid, nitrogenous compounds, nitrate, glycoalkaloids, chlorophyll, P, K, Ca, Mg, Mn, Na, trace elements), and physiological parameters (rate of assimilation and photosynthesis, activity of enzymes) of the leaf and stem are described and discussed for every phenological growth stage of the potato crop.     

Lumbricids species diversity and heavy metal amounts in lumbricids on soil monitoring sites in Saxony-Anhalt (Germany)

This paper will contribute to an evaluation of soil monitoring sites. Abundance, biomass and species diversity of lumbricids was evaluated on 68 differently used sites (fields, grassland, deciduous forest, coniferous forest, mine spoil). Eight of the 68 studied soil monitoring sites showed increased amounts of heavy metals. Apart from the assessment of the abundance, of the biomass and the species diversity, the heavy metal accumulation in lumbricids was measured and evaluated. Earthworms are ideal bioindicators for heavy metals in the soil. Additional soil properties (organic matter content, pH, heavy metals) were measured that could explain differences in the bioavailability of the metal burdens of polluted sites. Metal concentrations in lumbricids showed considerable variation between land use type and the individual lumbricid species.     

Microbial biomass phosphorus contributions to phosphorus solubility in riparian vegetated buffer strip soils

This study tests the hypothesis that microbial biomass phosphorus (P) makes a significant contribution to P solubility in riparian buffer strip soils. In 36 soils collected from buffer strips within three UK soil associations, water-extractable inorganic P solubility was most strongly related to NaHCO₃ extractable inorganic P. However, within individual soil associations where soil pedological properties and management were similar, water-extractable inorganic P was most strongly related to microbial biomass P. These results highlight the difficulty in predicting dissolved P leaching risk based on agronomic soil P tests alone and the dissolved P leaching risk presented by having soils high in organic matter and microbial biomass P in close proximity to surface waters.     

Desorption behaviour of polycyclic aromatic hydrocarbons after long-term storage of two harbour sludges from the port of Rotterdam, The Netherlands

Purpose

The desorption behaviour of 16 polycyclic aromatic hydrocarbons (PAHs) in sludges from two sites of the port of Rotterdam, The Netherlands, which are designated to be stored in a subaqueous sludge depository, was investigated after a storage time of 14 years at 4 °C under anaerobic conditions in the dark, mimicking depository conditions. Such long-term storage is believed to effect the desorption of the PAHs.

Materials and methods

Batch desorption experiments over a time period of 130 days were performed with the brackish Beerkanaal (BK) sludge and the freshwater Beneden Merwede River (BMR) sludge. The organic carbon–water partitioning coefficient (K _OC) values were calculated and compared to values of a previous study on the same sludges after a storage time of 3 years and to values obtained from calculations based on octanol–water partitioning coefficient (K _OW) values. Additionally, the organic matter of the sludges was characterised by C and N elemental analysis and solid-state ¹³C nuclear magnetic resonance spectroscopy.

Results and discussion

Only desorption of low molecular weight PAHs up to pyrene was detected. Several K _OC values were higher compared to the values from the previous study, and all were increased compared to values based on K _OW values. It is assumed that the increase in K _OC was an effect of the prolonged contact time, causing slow intradomain diffusion of PAHs into the condensed carbon domains. Desorption was higher in BK than in BMR, which is explained by differences in organic matter composition because BMR (containing predominantly aromatic carbon) and BK (which was dominated by lipids) contained the same amount of organic carbon. It is inferred that lipids compete with PAHs for sorption sites on the aromatic carbon, so that lipids block these sorption sites, and the PAHs are adsorbed to the lipids.

Conclusions

Since the amounts of PAHs desorbed from both sludges in this study were so low, it is supposed that long-term storage of these sludges in subaqueous depositories will likely result in increased sorption and thus a reduced release of these contaminants into the environment over time.