Snail survival as bioindicator of cadmium contaminated soils under semi-realistic field conditions

Juvenile brown garden snails (Helix aspersa Müller) were exposed to Cd-contaminated soils for 60 days under semi-realistic field conditions. The soils were contaminated with increasing concentrations of cadmium chloride (0–2900 mg kg-1 Cd2+/solution CdCl2). The snails were housed in terrariums and were fed exclusively with nettle leaves. The experiments were carried out in Timisoara on 1000 snails.The survival rates differed significantly for different Cd treatments. Only higher cadmium concentrations (> 1000 mg kg-1 Cd2+/solution CdCl2) had a significant influence on survival curves of snails exposed to Cd-contaminated soils. The maximal death rate reached 81.00±9.9% for snails exposed to soils contaminated with 2900 mg kg1 Cd /solution CdCl2. We found dose-dependent survival rates, whereas the half maximal effective concentration was 1365 mg kg-1 Cd2+/solution CdCl2. Our results suggested that longer-term studies are required for assessing the real potential of snail survival rate as bioindicator of Cd-contaminated soils in field conditions

Development of a Pattern Recognition Methodology for Determining Operationally Optimal Heat Balance Instrumentation Calibration Schedules

The goal of the project is to enable plant operators to detect with high sensitivity and reliability the onset of decalibration drifts in all of the instrumentation used as input to the reactor heat balance calculations. To achieve this objective, the collaborators developed and implemented at DBNPS an extension of the Multivariate State Estimation Technique (MSET) pattern recognition methodology pioneered by ANAL. The extension was implemented during the second phase of the project and fully achieved the project goal

High-level dietary cadmium exposure is associated with global DNA hypermethylation in the gastropod hepatopancreas

5-methylcytosine (5mC) is a key epigenetic mark which influences gene expression and phenotype. In vertebrates, this epigenetic mark is sensitive to Cd exposure, but there is no information linking such an event with changes in global 5mC levels in terrestrial gastropods despite their importance as excellent ecotoxicological bioindicators of metal contamination. Therefore, we first evaluated total 5mC content in DNA of the hepatopancreas of adult Cantareus aspersus with the aim to determine whether this epigenetic mark is responsive to Cd exposure. The experiment was conducted under laboratory conditions and involved a continuous exposure, multiple dose- and time-point (14, 28, and 56 days) study design. Hepatopancreas cadmium levels were measured using Flame Atomic Absorption Spectrometry and the percentage of 5-mC in samples using an ELISA-based colorimetric assay. Snail death rates were also assessed. Our results, for the first time, reveal the presence of 5mC in C. aspersus and provide evidence for Cd-induced changes in global 5mC levels in DNA of gastropods and mollusks. Although less sensitive than tissue accumulation, DNA methylation levels responded in a dose- and time-dependent manner to dietary cadmium, with exposure dose having a much stronger effect than exposure duration. An obvious trend of increasing 5mC levels was observed starting at 28 days of exposure to the second highest dose and this trend persisted at the two highest treatments for close to one month, when the experiment was terminated after 56 days. Moreover, a strong association was identified between Cd concentrations in the hepatopancreas and DNA methylation levels in this organ. These data indicate an overall trend towards DNA hypermethylation with elevated Cd exposure. No consistent lethal effect was observed, irrespective of time point and Cd-dosage. Overall, our findings suggest that the total 5mC content in DNA of the hepatopancreas of land snails is responsive to sublethal Cd exposure and give new insights into invertebrate environmental epigenetics

Statistical evaluation of heavy metal content in some capsicum varieties available on the Romanian market

The aim of this study is to emphasis the heavy metals content in seven capsicum varieties of capsicum of the specie Capsicum annuum L., available on the Romanian market. From the analyzed Capsicum fruit samples, three Capsicum assortments were cultivated in Romania and the other four were imported from Italy and Turkey. The studied heavy metals (copper, zinc, manganese, iron, cobalt, lead, nickel, cadmium and chromium) have normal concentration values that are not of any risk to human health. Cadmium is not detectable in all studied samples. The heavy metal content associated with statistical analysis programs permits the identification of characteristics specific to the origin of products and the graphical chemical fingerprint of the studied capsicum species. The chemical fingerprinting of a plant demands the determination of a large number of elements (DJINGOVA ET AL., 2004). The study is revealing similar distribution pattern

Graphical chemical fingerprints of parsley, dill and lovage leaves

The aim of this study is to emphasis the use of thermo gravimetrical water content and trace metals analysis to identify the chemical graphical fingerprints of parsley, dill and lovage leaves. Copper, zinc, manganese, iron, nickel and lead have normal concentration values that are not of any risk to human health. Cobalt, chromium and cadmium were not detectable in all studied samples. The water and present trace metals contents associated with mathematical models permits the identification of characteristics specific to the studied vegetable leaves as well as the graphical chemical fingerprints. The study is revealing similar distribution pattern

Changes in the structure of actinomycete populations in the rhizosphere of vicia sativa species

It is a known fact that species of legumes improve the soil they are grown on, but at the same time, they produce the so-called rhizosphere effect or rhizodeposit that has a selective effect on the microorganisms which are considered "fertility effectors" for soil. From the three studied area the highest number of actinomycetes was found in edaphosphere and the lowest number in the area influenced by roots. Among the few factors under research for the purpose of this paper, humus and potassium were observed to have the strongest impact on this group. Humidity is a factor that could change the competition between soil microorganisms and plants in the soil for N and it could affect the stability of aggregates

Vegetables, fruits, honey and pollen, a natural source of zinc

This work aimed to evaluate zinc content in six common vegetables (parsley, carrot, dill, onion, cucumber and beans), three common fruits (apples, raspberry and dog rose), bees honey and pollen. Determination of zinc content in soil, raw vegetables and fruits, as well as in bees honey and pollen from local apiaries were carried out by FAAS. All experiments and analyses were performed in triplicate. Overall, the highest zinc concentration was found in the leaves (carrot 48.07 mg kg-1, parsley 46.62 mg kg-1, dog rose leaves 36.13 mg kg-1) and beans crops (41.26 mg kg-1). According to our study the highest content occurs in the plants of the Apiaceae Family and in Rosa canina leaves

Seasonal variation in nutrient content of some leafy vegetables from Banat County, Romania

The aim of this study is to investigate the effect of seasonal variation of the moisture content and trace metal composition of spinach, butter lettuce and parsley leaves. The content of bioactive compounds in green leafy vegetables at harvest has beneficial effects on human health. It was found that moisture, macro and microelement content vary from one season to another. Water content measured by thermo-gravimetric method is presenting small variation during the seasonal change, revealing the lowest value for spinach, butter lettuce and parsley leaves, in June. Calcium, magnesium and potassium concentrations in leaves are decreasing in spinach, lettuce and parsley from April to September, but the variations are small. Copper is accumulating mostly in parsley leaves and less in lettuce and spinach. Knowing the concentration of important nutrients in different seasons helps do decide the harvesting period in according to the richness of the diet for each individual

Snail survival as bioindicator of cadmium contaminated soils under semi-realistic field conditions

Juvenile brown garden snails (Helix aspersa Müller) were exposed to Cd-contaminated soils for 60 days under semi-realistic field conditions. The soils were contaminated with increasing concentrations of cadmium chloride (0–2900 mg kg-1 Cd2+/solution CdCl2). The snails were housed in terrariums and were fed exclusively with nettle leaves. The experiments were carried out in Timisoara on 1000 snails.The survival rates differed significantly for different Cd treatments. Only higher cadmium concentrations (> 1000 mg kg-1 Cd2+/solution CdCl2) had a significant influence on survival curves of snails exposed to Cd-contaminated soils. The maximal death rate reached 81.00±9.9% for snails exposed to soils contaminated with 2900 mg kg1 Cd /solution CdCl2. We found dose-dependent survival rates, whereas the half maximal effective concentration was 1365 mg kg-1 Cd2+/solution CdCl2. Our results suggested that longer-term studies are required for assessing the real potential of snail survival rate as bioindicator of Cd-contaminated soils in field conditions

Short-term effects of very low dose cadmium feeding on copper, manganese and iron homeostasis:A gastropod perspective

The available information on the interplay between low-dose cadmium intake and copper, manganese, and iron homeostasis in invertebrates is limited. We have currently studied the accumulation of these trace metals in the hepatopancreas of adult snails, Cantareus aspersus, following 14 and 28 days of exposure to low doses of dietary cadmium, up to 1 mg/kg dw (dry weight). The cadmium dose, but not the duration of exposure, had a significant effect on hepatopancreas copper deposition, the values being significantly elevated compared to controls. A significant peak in manganese levels at 14 days was found in snails administered the lowest cadmium dose. These increases occurred even in the absence of cadmium increase in the hepatopancreas. Our data suggest that low dose cadmium feeding can produce a transient disturbance in hepatopancreas copper and manganese homeostasis. Such responses may serve as early biomarkers of physiological changes occurring during the initial stages of cadmium intoxication