Sorption, desorption, and degradation of (4-chloro-2-methylphenoxy)acetic acid in representative soils of the Danubian Lowland, Slovakia

Herbicide leaching through soil into groundwater greatly depends upon sorption-desorption and degradation phenomena. Batch adsorption, desorption and degradation experiments were performed with acidic herbicide MCPA and three soil types collected from their respective soil horizons. MCPA was found to be weakly sorbed by the soils with Freundlich coefficient values ranging from 0.37 to 1.03 mg^1−1/n kg⁻¹ L^1/n. It was shown that MCPA sorption positively correlated with soil organic carbon content, humic and fulvic acid carbon contents, and negatively with soil pH. The importance of soil organic matter in MCPA sorption by soils was also confirmed by performing sorption experiments after soil organic matter removal. MCPA sorption in these treated soils decreased by 37-100% compared to the original soils. A relatively large part of the sorbed MCPA was released from soils into aqueous solution after four successive desorption steps, although some hysteresis occurred during desorption of MCPA from all soils. Both sorption and desorption were depth-dependent, the A soil horizons exhibited higher retention capacity of the herbicide than B or C soil horizons. Generally, MCPA sorption decreased in the presence of phosphate and low molecular weight organic acids. Degradation of MCPA was faster in the A soil horizons than the corresponding B or C soil horizons with half-life values ranging from 4.9 to 9.6 d in topsoils and from 11.6 to 23.4 d in subsoils.     

PCDDs, PCDFs, dioxin-like PCBs and indicator PCBs in soil from five selected areas in Slovakia

There is a lack of information regarding persistent organic pollutants (POPs) in soil from Slovakia. This paper reports the concentrations of 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), 12 dioxin-like polychlorinated biphenyls (dl-PCBs) and 6 indicator PCBs associated with 32 soil samples collected in 2007 from areas in the vicinity up to several kilometres from four selected industrial PCDD/F sources in Slovakia and one background area.The results show that the total WHO₁₉₉₈-PCDD/F/dl-PCB-TEQ concentrations varied from 0.34 to 18.05 pg g⁻¹ dry weight (dw) and the average total TEQ concentrations in samples collected at the Šala, Košice, Krompachy and Dubová areas were 3.18, 2.64, 7.80, and 3.19 pg g⁻¹ dw respectively. The average of the total WHO₁₉₉₈-TEQ values in three soil samples representing the background Starina area was 0.66 pg g⁻¹ dw. The predominant contaminants among 2,3,7,8-substituted PCDD/Fs, dl-PCB, and indicator PCBs was OCDD, PCB 118, and PCB 153 respectively. The major contributors to the TEQ were 2,3,4,7,8-PeCDF, PCB 126, 1,2,3,7,8-PeCDD, PCB 156 and 1,2,3,4,7,8-HxCDF + 1,2,3,4,7,9-HxCDF in descending order.     

Exergy efficiency analysis of a refurbished dwelling: a case study in Ljubljana,Slovenia

Buildings contribute almost half of the world's carbon dioxide (CO₂) emissions. Energy and water consumption are some of the largest and fastest growing pressures on the global environment. The use of energy is mainly attributed to the heating and cooling of buildings. The type of materials used in the construction of buildings plays a significant role in the life-cycle emissions of each dwelling. Changing the material use in the construction of an existing building and adding insulation could have a major impact on energy use and the environment of the building in its entire life cycle. This paper investigates the amount of exergy savings and the decrease in CO₂ emissions resulting from the refurbishing of an existing building in Ljubljana. This study results from the growing awareness that in the choice of building materials, the designer must consider not only the requirements of the owner and occupier of the building, but also the resulting energy savings, the resource base and the effects of the manufacturing and processing of building materials on the environment. The exergy efficiency of the material use is calculated and the environmental impact assessment of energy and material use is accounted for.     

Integrated evaluation of aerogenic pollution by air-transported heavy metals (Pb, Cd, Ni, Zn, Mn and Cu) in the analysis of the main deposit media

The composition of the ambient air is constantly changing; therefore, the monitoring of ambient air quality to detect the changes caused by aerogenic pollutants makes the essential part of general environmental monitoring. To achieve more effective improvement of the ambient air quality, the Directive 2008/50/EC on ‘Ambient Air Quality and Cleaner Air for Europe’ was adopted by the European Parliament and the European Council. It informed the public and enterprises about a negative effect of pollution on humans, animals and plants, as well as about the need for monitoring aerogenic pollutants not only at the continuous monitoring stations but also by using indicator methods, i.e. by analysing natural deposit media. The problem of determining the relationship between the accumulation level of pollutants by a deposit medium and the level of air pollution and its risks is constantly growing in importance. The paper presents a comprehensive analysis of the response of the main four deposit media, i.e. snow cover, soil, pine bark and epigeic mosses, to the long-term pollution by aerogenic pollutants which can be observed in the area of oil refinery influence. Based on the quantitative expressions of the amounts of the accumulated pollutants in the deposit media, the territory of the oil refinery investigated in this paper has been referred to the areas of mild or moderate pollution.     

Relevance of the Paraná River hydrology on the fluvial water quality of the Delta Biosphere Reserve

The increasing frequency of extreme events in large rivers may affect not only their flow, but also their water quality. In the present study, spatial and temporal changes in fluvial physico-chemical variables were analyzed in a mega-river delta during two extreme hydrological years (La Niña-El Niño) and related to potential explanatory factors. Basic water variables were evaluated in situ at 13 points (distant 2–35 km from each other) in watercourses of the Delta Biosphere Reserve (890 km²) in the Lower Paraná River (Argentina) in nine surveys (October 2008–July 2010) without meteorological tides. Samples for laboratory analyses were collected from each main river. Multivariate tests by permutations were applied. The period studied was influenced by a drought, within a long period dominated by low flows combined with dry weather and wildfires, and a large (10 years of recurrence) and prolonged (7 months) flood. The hydrological phase, followed by the season and the hydrological year (according to the ENSO event) were the principal explanatory factors of the main water quality changes, whereas the drainage sub-basin and the fluvial environment (river or stream) were secondary explanatory factors. During the drought period, conductivity, turbidity, and associated variables (e.g., major ions, silicon, and iron concentrations) were maximal, whereas real color was minimal. In the overbanking flood phase, pH and dissolved oxygen concentration were minimal, whereas real color was maximal. Dissolved oxygen saturation was also low in the receding flood phase and total major ion load doubled after the arrival of the overbanking stage. The water quality of these watercourses may be affected by the combination of several influences, such as the Paraná River flow, the pulses with sediments and solutes from the Bermejo River, the export of the Delta floodplain properties mainly by the flood, the season, and the saline tributaries to the Lower Paraná River. The high influence of the hydrology of this large river on the Delta fluvial water quality emphasizes the relevance of changes in its flow regime in recent decades, such as the seasonality attenuation. Considering that the effects of extreme events differ among and within fluvial systems, specific ecohydrological evaluations and powerful appropriate statistics are key tools to gain knowledge on these systems and to provide bases for suitable management measures in a scenario of climate change and increasing human alterations and demands.     

Detection of Listeria monocytogenes in ready-to-eat food by Step One real-time polymerase chain reaction

The aim of this study was to follow contamination of ready-to-eat food with Listeria monocytogenes by using the Step One real time polymerase chain reaction (PCR). We used the PrepSEQ Rapid Spin Sample Preparation Kit for isolation of DNA and MicroSEQ® Listeria monocytogenes Detection Kit for the real-time PCR performance. In 30 samples of ready-to-eat milk and meat products without incubation we detected strains of Listeria monocytogenes in five samples (swabs). Internal positive control (IPC) was positive in all samples. Our results indicated that the real-time PCR assay developed in this study could sensitively detect Listeria monocytogenes in ready-to-eat food without incubation.     

Mycobiota and mycotoxins in bee pollen collected from different areas of Slovakia

Contamination by microscopic fungi and mycotoxins in different bee pollen samples, which were stored under three different ways of storing as freezing, drying and UV radiation, was investigated. During spring 2009, 45 samples of bee-collected pollen were gathered from beekeepers who placed their bee colonies on monocultures of sunflower, rape and poppy fields within their flying distance. Bee pollen was collected from bees’ legs by special devices placed at the entrance to hives. Samples were examined for the concentration and identification of microscopic fungi able to grow on Malt and Czapek-Dox agar and mycotoxins content [deoxynivalenol (DON), T-2 toxin (T-2), zearalenone (ZON) and total aflatoxins (AFL), fumonisins (FUM), ochratoxins (OTA)] by direct competitive enzyme-linked immunosorbent assays (ELISA). The total number of microscopic fungi in this study ranged from 2.98 ± 0.02 in frozen sunflower bee pollen to 4.06 ± 0.10 log cfu.g^?1 in sunflower bee pollen after UV radiation. In this study, 449 isolates belonging to 21 fungal species representing 9 genera were found in 45 samples of bee pollen. The total isolates were detected in frozen poppy pollen 29, rape pollen 40, sunflower pollen 80, in dried poppy pollen 12, rape pollen 36, sunflower 78, in poppy pollen after UV radiation treatment 54, rape 59 and sunflower 58. The most frequent isolates of microscopic fungi found in bee pollen samples of all prevalent species were Mucor mucedo (49 isolates), Alternaria alternata (40 isolates), Mucor hiemalis (40 isolates), Aspergillus fumigatus (33 isolates) and Cladosporium cladosporioides (31 isolates). The most frequently found isolates were detected in sunflower bee pollen frozen (80 isolates) and the lowest number of isolates was observed in poppy bee pollen dried (12 isolates). The most prevalent mycotoxin of poppy bee pollen was ZON (361.55 ± 0.26 μg.kg^?1), in rape bee pollen T-2 toxin (265.40 ± 0.18 μg.kg^?1) and in sunflower bee pollen T-2 toxin (364.72 ± 0.13 μg.kg^?1) in all cases in frozen samples.     

Toxicity of metalaxyl,azoxystrobin, dimethomorph,cymoxanil, zoxamide and mancozeb to Phytophthora infestans isolates from Serbia

A study of the in vitro sensitivity of 12 isolates of Phytophthora infestans to metalaxyl, azoxystrobin, dimethomorph, cymoxanil, zoxamide and mancozeb, was conducted. The isolates derived from infected potato leaves collected at eight different localities in Serbia during 2005–2007. The widest range of EC₅₀ values for mycelial growth of the isolates was recorded for metalaxyl. They varied from 0.3 to 3.9 μg mL^?1 and were higher than those expected in a susceptible population of P. infestans. The EC₅₀ values of the isolates were 0.16–0.30 μg mL^?1 for dimethomorph, 0.27–0.57 μg mL^?1 for cymoxanil, 0.0026–0.0049 μg mL^?1 for zoxamide and 2.9–5.0 μg mL^?1 for mancozeb. The results indicated that according to effective concentration (EC₅₀) the 12 isolates of P. infestans were sensitive to azoxystrobin (0.019–0.074 μg mL^?1), and intermediate resistant to metalaxyl, dimethomorph and cymoxanil. According to resistance factor, all P. infestans isolates were sensitive to dimethomorph, cymoxanil, mancozeb and zoxamide, 58.3% of isolates were sensitive to azoxystrobin and 50% to metalaxyl. Gout's scale indicated that 41.7% isolates were moderately sensitive to azoxystrobin and 50% to metalaxyl.