Self-supply with home-produced vegetables is very common in urban areas, where cadmium is a characteristic pollutant due to its anthropogenic origin. It has a harmful effect on human health. People are exposed to cadmium in different ways. One of the most common is through consumption of contaminated food, such as home-produced vegetables. However, different vegetables accumulate cadmium in different concentrations and as such pose different risk to human health. In this research 6 species of vegetables were sampled: endive, chicory, courgettes, tomato, onion and carrot. Vegetables (edible parts) were sampled in gardens of the Municipality of Celje, which is the third largest city in Slovenia. In some areas soils in the city and its vicinity are polluted with heavy metals (e.g. cadmium, lead, zinc) due to past industrial activities. Sampling area was stratified into 6 zones according to Slovenian legislation and the level of soil pollution with cadmium (mg/kg DW): 12. Additionally, vegetables were purchased in local shops, markets and supermarkets in order to compare concentrations of cadmium in vegetables grown in gardens and in purchased vegetables. The main goal of this research was to determine whether purchased vegetables contain significantly lower concentration of cadmium than vegetables produced on gardens of the Municipality of Celje. Results showed that the significant difference between the average concentrations of cadmium in purchased and garden vegetables was observed in vegetables produced in gardens with soil cadmium content above 2 mg/kg DW. Therefore, the recommendation of rather to purchase vegetable than to produce it at home garden is justified in areas where the contamination of soil with cadmium is whether above 2 mg/kg DW, when producing carrot, chicory and endive or above 4 mg/kg DW, when producing courgettes, tomato and onion.

Original paper can be found at: http://www.ask-eu.com/default.asp?Menue=149&AnbieterID=586 [Full text of this paper is not available in the UHRA]

Nitrate concentrations in groundwater strongly depend on denitrification rates in soil and sediments. The objective of this study was to derive denitrification rates in different soil layers in a Eutric Fluvisol. Four intact soil cores were incubated under anaerobic conditions after adding 0, 19-78, 58-116, and 97-115 mg N-NO3 L-1, respectively. The effect of adding 250 mg(-1); glucose C was tested at a nitrate nitrogen concentration of 58-116 mg L-1. Soils were incubated for seven days at a temperature of 18 degrees C. The denitrification rate varied at soil depths of 10-20 cm, 30-40 cm, 50-60 cm, and 90+ cm, which correspond to soil horizons A(p), A(1,2), A(buried) and C between 0.23 +/- 0.005 to 3.23 +/- 0.7, between 0.042 +/- 0.003 to 1.63 +/- 0.20, between 0.15 +/- 0.04 to 1.7 +/- 0.1 and between 0.004 +/- 0.001 to 1.05 +/- 0.09 mg N-NO3 kg(-1) of dry soil (or parent material in the last case) per day respectively. The added nitrate and glucose induce a greater increase denitrification rate in the parent material than in the upper soil layer. The relative increase of denitrification rate induced by added nitrate is more enhanced that relative increase induced with additional glucose in almost all soil layers of observed soil.

Inoculation of a mixture of household organics and shredded wood with inocula from the active phase of composting enhanced mineralization of organic matter and yielded a biologically stabilized product with a more favorable C/N ratio than in a non-inoculated treatment. Analysis of phospholipid fatty acids was used to determine total viable microbial biomass and relative amounts of bacteria, Gram positive and Gram negative bacteria, actinomycetes, fungi, thermophiles and nonthermophiles in compost. The initial viable microbial biomass was 6-fold higher in inoculated than in noninoculated compost. The thermophilic phase occurred immediately after inoculation and the total viable biomass afterwards followed the course of temperature. The ratio of viable (sum of phospholipid fatty acids) to dead (sum of diglyceride fatty acids) microbial biomass during this period was generally higher at lower composting temperatures in both inoculated and noninoculated compost. During composting, fluctuations in total viable microbial biomass and in the relative amounts of indicator PLFAs of all microbial groups except Gram negative bacteria was more intensive in noninoculated compost.

A Pb, Zn and Cd contaminated soil was amended with synthetic apatite and EDTA. The change of bioavaiability of heavy metals was determined in the plant uptake study with Brassica rapa as a test plant. EDTA addition promoted translocation of heavy metals from the roots to the green parts of the test plant. Apatite amendment decreased concentration of Pb in the leaves and concentration of Pb, Zn and Cd in the roots. The subsequent addition of EDTA to apatite-amended soil significantly increased Pb content in the leaves. Sequential extractions indicated that addition of apatite reduced the share of a partly bio-available Pb carbonate fraction in the soil. However, subsequent addition of EDTA increased the share of a readily bio-available, exchangeable Pb fraction.