Influence of aluminium on the restoration potential of a terrestrial vascular plant,Portulaca Oleracea L. as a biomonitoring tool of fresh water aquatic environments

In the present study, the influence of aluminium on the regeneration potential of leaf and stem-cuttings of Portulaca oleracea was studied in order to identify a terrestrial plant species as an alternate biomonitoring toolof fresh water environment. The leaves and stem cuttings of theterrestrial plant, P. oleracea grew well in the distilled water producing adventitious and lateral roots. The aluminium treated leaves and stem cuttings showed a reduction in the growthof the adventitious and lateral roots and increase in the decay of leaves and stem cuttings with increasing aluminium concentration. The tolerance index calculated for the leaves and the stem cuttings showed that the leaves were more sensitivethan stems to aluminium. Since all the parameters studied showedconcentration dependent changes, the terrestrial plant, P. oleracea can be considered a suitable biomonitoring tool of fresh water environment besides its usage in the Al toxicity testing.     

Effects of Copper Sulfate and Copper Nitrate in Aquatic Medium on the Restoration Potential and Accumulation of Copper in Stem Cuttings of the Terrestrial Medicinal Plant, Portulaca Oleracea Linn

The stem cuttings of the terrestrial, ornamental plant, Portulaca oleracea, grew well in distilled water by producing adventitious roots and leaves. However, when exposed to various concentrations of sulfate and nitrate salts of copper resulted in a suppression of root growth, increase in initiation time of roots and sprouts and decay of stem cuttings from the cut open end, decrease in number of leaves with an increase in concentration of copper in the growth medium. Accumulation of copper increased with increasing concentrations of both copper sulfate and copper nitrate. However, copper accumulation was greater in copper nitrate than in copper sulfate treatment. Hence, copper in the presence of nitrate is more toxic than in the presence of sulfate. The accumulation factors in all treatment concentrations were greater than 1, hence P. oleracea is a copper accumulator.     

Bioconcentration and Phytotoxicity of Cd in Eichhornia crassipes

Plants of Eichhornia crassipes grown at various levels of cadmium ranging from 0.1 to 100 μg ml⁻¹ accumulated Cd in a concentration and duration dependent manner. At all levels, Cd accumulation by various plant tissues followed the order roots shoot leaves. Approximately 80% of total Cd was accumulated by plant at highest concentration (100 μg ml⁻¹) used in the experiment. Cadmium induced phytotoxicity appears at 25.0 μg ml⁻¹ resulting into reduced levels of chlorophyll, protein and in vivo nitrate reductase activity of the plant. However, a slight induction of these physiological variables was obtained at lowest Cd (0.1 μg ml⁻¹) concentration. In contrast, carotenoid content increased at highest Cd concentration i.e., 100 μg ml⁻¹. Similar effects at low and high levels of Cd was obtained with respect to mitotic index and micronuclei in root meristem of the plant. It could be inferred that Cd toxicity in plant is differential depending upon the low and high concentration of Cd in the medium.     

Bioaccumulation and translocation of metals in the natural vegetation growing on fly ash lagoons: a field study from Santaldih thermal power plant, West Bengal, India

A field study was conducted in the fly ash lagoons of Santandih Thermal Power Plant located in West Bengal (India) to find out total, EDTA and DTPA extractable metals in fly ash and their bioaccumulation in root and shoot portion of the naturally growing vegetation. Fly ash sample has alkaline pH and low conductivity. The concentration of total Cu, Zn, Pb and Ni were found higher than weathered fly ash and natural soil, where as Co, Cd and Cr were found traces. Five dominant vegetation namely, Typha latifolia, Fimbristylis dichotoma, Amaranthus defluxes, Saccharum spontaenum and Cynodon dactylon were collected in the winter months (November–December). Bioaccumulation of metals in root and shoot portions were found varied significantly among the species, but all concentration were found within toxic limits. Correlation between total, DTPA and EDTA extractable metals viz. root and shoot metals concentration were studied. Translocation factor (TF) for Cu, Zn and Ni were found less than unity, indicates that these metals are immobilized in the root part of the plants. Metals like Mn have TF greater than unity. The study infers that natural vegetation removed Mn by phytoextraction mechanisms (TF > 1), while other metals like Zn, Cu, Pb and Ni were removed by rhizofiltration mechanisms (TF < 1). The field study revealed that T. latifolia and S. spontaenum plants could be used for bioremediation of fly ash lagoon.     

Effect of long-term application of treated sewage water on heavy metal accumulation in vegetables grown in Northern India

Use of industrial and wastewater for irrigation is on the rise in India and other developing countries because of scarcity of good-quality irrigation water. Wastewaters contain plant nutrients that favour crop growth but leave a burden of heavy metals which can enter the food chain and is a cause of great concern. The present study was undertaken on the long-term impact of irrigation with treated sewage water for growing vegetables and the potential health risk associated with consumption of such vegetable. Treated sewage water (TSW), groundwater (GW), soil and plant samples were collected from peri urban vegetable growing areas of Northern India (Varanasi) and analysed to assess the long-term effect of irrigation with TSW on Cd, Cr, Ni and Pb build-up in soils and its subsequent transfer into commonly grown vegetable crops. Results indicate that TSW was richer in essential plant nutrients but contained Cd, Cr and Ni in amounts well above the permissible limits for its use as irrigation water. Long-term application of TSW resulted in significant build-up of total and DTPA extractable Cd, Cr, Ni and Pb over GW irrigated sites. TSW also resulted in slight lowering in pH, increase in organic carbon (1.6 g kg^− 1) and cation exchange capacity (5.2 cmol kg^− 1). The tissue metal concentration and relative efficiency of transfer of heavy metals from soil to plant (transfer factor) for various groups of vegetables were worked out. Radish, turnip and spinach were grouped as hyper accumulator of heavy metals whereas brinjal and cauliflower accumulated less heavy metals. Health risk assessment by consumption of vegetables grown with TSW indicated that all the vegetables were safe for human consumption. However, significant accumulation of these heavy metals in soil and plant needs to be monitored.     

Seed bank of Cu-contaminated topsoils at a wood preservation site: impacts of copper and compost on seed germination

Is identification of seed bank (SB) species useful for sustainable management of vegetation restoration on Cu-contaminated soils? How does Cu contamination of the soil affect the SB and can incorporating compost into Cu-contaminated soils counter the effects of Cu? The topsoil SB was investigated at seven contaminated sub-sites of a wood preservation site. The germination parameters of the seeds were recorded using three substrates: a washed river sand (Sand), the same sand spiked with CuSO₄ to reach the same Cu concentrations as in the soil pore water (0.3 to 3.2 mg Cu/L) (Cu), and the same Cu-spiked sand amended with compost (CPM). The total number of germinated seeds (NGS) was 1,081. The whole seedling dataset enabled 12 plant species and eight families to be identified in the SB. Species richness and Shannon indexes were low. The addition of Cu in the germination substrate enhanced total NGS at one sub-site and the addition of CPM increased plant diversity at three sub-sites. SB composition varied with the sub-site but did not correlate with total soil Cu or with the Cu concentration in the soil pore water. Three species belonging to the Poaceae family dominated. In terms of total NGS, the dominant species were Portulaca oleracea and Agrostis capillaris. Similarities between SB and established vegetation were low but increased when the soil bulk density was reduced. The Cu-tolerant species P. oleracea and A. capillaris dominated in both the SB and the established vegetation. However, the pattern of SB and established vegetation differed and consequently SB was not a sufficient indicator to predict the future vegetation.     

Bioavailability of Metals in Fly Ash and Their Bioaccumulation in Naturally Occurring Vegetation: A Pilot Scale Study

A pilot scale study was conducted to find out the different forms of metals if fly ash (FA) and bioaccumulation of these metals in the naturally growing vegetation on FA dumps. The total, acid extractable, bioavailable and water soluble fraction of metals of Fe, Cu, Mn, Zn, Ni, Co and Pb, and their bioaccumulation coefficients (BAC) on naturally growing vegetation were determined. FA samples had a neutral pH, low electrical conductivity, low organic C and trace amounts of N and P. The relative abundance of total metals in FA were found in the order Fe ≤ ≤ Zn ≤ Ni ≤ Co ≤ Cu. The concentration of bioavailable (DTPA) metals depend on the type and nature of coal used in thermal power stations. In the water the extract solution, only Fe and Zn were found above detection limits. After one year only four species of naturally occurring herbaceous vegetation were found growing and Cynodon dactylon (grass) covered almost entire surface of the FA. Iron accumulated to the greatest extent in vegetation followed by Mn, Zn, Cu, Pb, Ni and Co. The sequence of BAC for different metals were Fe (202) ≤ Mn (90) ≤ Zn (63) ≤ Pb (49) ≤ Ni (41) ≤ Cu (24). The experimental study revealed that Cynodon grass could be used for remediation of fly ash without any amendments, as this grass species act as metal excluder type.     

The combined use of electrokinetic remediation and phytoremediation to decontaminate metal-polluted soils: a laboratory-scale feasibility study

The use of a combination of electrokinetic remediation and phytoremediation to decontaminate two metal-polluted soils has been demonstrated in laboratory-scale reactors. One soil was heavily contaminated with copper, the other with cadmium and arsenic (2500 g g^-1 Cu; 300-400 g g^-1 Cd and 230 g g^-1 As, respectively). Test reactors with twoseparated chambers, each with a capacity of 5.25 kg soil, wereconstructed, then the respective chambers were filled with eithera mixture of the polluted soil and a control topsoil (75:25) ortopsoil alone. Reactors were sown with perennial ryegrass (Lolium perenne cv Elka) and a constant voltage of 30 V was applied continually across the soils in each reactor. Soil sampling took place at the start and the end of the test run, whilst plant foliage was sampled after approximately 3 weeks (both reactors) 6 weeks (Cd soil reactor only) and at the conclusion of each test run (98 days Cu soil, 80 days Cd soil). Soil and plant metal concentrations were measured, together withsoil pH. Results showed that in both soils there was a significant re-distribution of metals from anode to cathode in the test reactors, coupled with an enhancement of plant Cu uptakein the cathode region for the Cu soil. Patterns of plant Cd uptake were less clear cut and were not as clearly related to theredistribution of Cd measured in the soil. There was significant acidification of soil at the anode in each test reactor, but soilpH in other parts of the reactor changed little during the courseof the experiment. Plant growth was affected at the anode, but was not affected in other parts of the reactor. There was no visual evidence of metal toxicity in the ryegrass in either polluted soil. Some effects on soil fungi were apparent, with a stimulation of Fusarium infection of ryegrass in the cathode region of all reactors and the appearance of sporophoresof Coprinus in the same location. It is concluded that the combination of the two techniques represents a very promising approach to the decontamination of metal polluted soils that nowrequires validation in field conditions.     

Health risk assessment of heavy metals for edible parts of vegetables grown in sewage-irrigated soils in suburbs of Baoding City,China

With the long-term application of wastewater to vegetable production fields, there is concern about potential health risks of heavy metals contaminating the edible parts of vegetables grown in contaminated soils in the suburban areas of Baoding City, China. The average concentration of elemental Zn in sewage-irrigated soil was the highest (153.77 mg kg⁻¹), followed by Pb (38.35 mg kg⁻¹), Cu (35.06 mg kg⁻¹), Ni (29.81 mg kg⁻¹), and Cd (0.22 mg kg⁻¹) which were significantly higher (P < 0.05) than those in the reference soil. The results showed that long-term sewage irrigation had led to a growing accumulation of heavy metals in the soils, especially for Cd, Zn, and Pb. Furthermore, the concentrations of elemental Cd, Zn, and Ni in vegetables (e.g., Beassica pekinensis L., Allium fistulosum L., Spinacia oleracea L.) collected from the wastewater-irrigated soils exceeded the maximum permissible limits, and this also increased the daily intake of metals by food. However, compared with the health risk index of <1 for heavy metals, the ingestion of vegetables from the soils irrigated with sewage effluent posed a low health risk. Nevertheless, heavy metal concentrations should be periodically monitored in vegetables grown in these soils together with the implementation effective remediation technologies to minimize possible impacts on human health.     

Bioaccumulation of Trace Elements in a Wild Grass Three Years After the Aznalcóllar Mine Spill (South Spain)

In this paper, we surveyed the concentration of nine trace elements (As, Cd, Cu, Fe, Mn, Ni, Pb, Tl and Zn) in bermudagrass (Cynodon dactylon) 3 years after the mine spill in Aznalcóllar (south Spain). The results were compared with those that had been obtained for the same species in a previous study, 18 months after the accident. Three types of soil condition were determined: i) unaffected soils (UN, control); ii) cleaned up and amended soils (A, amended); and (iii) non-amended soils, inaccessible to the clean-up and remediation operations (NA, non-amended). The trace element concentrations in the plants were lower than those reported in the first sampling for both washed (plant tissues) and unwashed plants (as consumed by herbivores). Apart from Cd, trace elements concentrations (plant tissues) were similar in the A and the UN soils. In the NA soils, the Cd, Fe, Mn, Zn and Pb levels in unwashed plants were excessive for animal consumption. This wild grass seems to be suitable as a soil stabilizer for spill affected soils and as a biomonitor for soil pollution by some trace elements (As, Cu and Zn); however, its potential for phytoextraction is negligible.     

Spatial variability of soil total and DTPA-extractable cadmium caused by long-term application of phosphate fertilizers, crop rotation, and soil characteristics

Increasing cadmium (Cd) accumulation in agricultural soils is undesirable due to its hazardous influences on human health. Thus, having more information on spatial variability of Cd and factors effective to increase its content on the cultivated soils is very important. Phosphate fertilizers are main contamination source of cadmium (Cd) in cultivated soils. Also, crop rotation is a critical management practice which can alter soil Cd content. This study was conducted to evaluate the effects of long-term consumption of the phosphate fertilizers, crop rotations, and soil characteristics on spatial variability of two soil Cd species (i.e., total and diethylene triamine pentaacetic acid (DTPA) extractable) in agricultural soils. The study was conducted in wheat farms of Khuzestan Province, Iran. Long-term (27-year period (1980 to 2006)) data including the rate and the type of phosphate fertilizers application, the respective area, and the rotation type of different regions were used. Afterwards, soil Cd content (total or DTPA extractable) and its spatial variability in study area (400,000 ha) were determined by sampling from soils of 255 fields. The results showed that the consumption rate of di-ammonium phosphate fertilizer have been varied enormously in the period study. The application rate of phosphorus fertilizers was very high in some subregions with have extensive agricultural activities (more than 95 kg/ha). The average and maximum contents of total Cd in the study region were obtained as 1.47 and 2.19 mg/kg and DTPA-extractable Cd as 0.084 and 0.35 mg/kg, respectively. The spatial variability of Cd indicated that total and DTPA-extractable Cd contents were over 0.8 and 0.1 mg/kg in 95 and 25 % of samples, respectively. The spherical model enjoys the best fitting and lowest error rate to appraise the Cd content. Comparing the phosphate fertilizer consumption rate with spatial variability of the soil cadmium (both total and DTPA extractable) revealed the high correlation between the consumption rate of P fertilizers and soil Cd content. Rotation type was likely the main effective factor on variations of the soil DTPA-extractable Cd contents in some parts (eastern part of study region) and could explain some Cd variation. Total Cd concentrations had significant correlation with the total neutralizing value (p?<?0.01), available P (p?<?0.01), cation exchange capacity (p?<?0.05), and organic carbon (p?<?0.05) variables. The DTPA-extractable Cd had significant correlation with OC (p?<?0.01), pH, and clay content (p?<?0.05). Therefore, consumption rate of the phosphate fertilizers and crop rotation are important factors on solubility and hence spatial variability of Cd content in agricultural soils.     

Distribution of Metals in the Edible Plants Grown at Jajmau, Kanpur (India) Receiving Treated Tannery Wastewater: Relation with Physico-Chemical Properties of the Soil

The implications of metal contamination of agricultural soils due to long term irrigation with treated industrial wastewater and their subsequent accumulation in the vegetables/crops growing on such soils has been assessed in an area of industrial complex, Jajmau, Kanpur (India). Physico-chemical properties of the soil were also studied. The soil and vegetables/crops were sampled from an area of 2100 acre agricultural land and analyzed for physico-chemical properties and metal accumulation in different parts of the plants. The comparison of the data of physico-chemical properties of control and contaminated soil showed that salinity, electrical conductivity, available phosphorous, sodium and potassium content (both water soluble and exchangeable) were found high in contaminated soil. The analysis of plant available metal content in the soil showed the highest level of Fe, which ranged from 529.02 to 2615 μg g⁻¹ dw and lowest level of Ni (3.12 to 10.51 μg g⁻¹ dw). The analysis of the results revealed that accumulation of toxic metal Cr in leafy vegetables was found more than fruit bearing vegetables/crops. Thus, it is recommended that the leafy vegetables are unsuitable to grow in such contaminated sites. It is important to note that toxic metal, Ni was not detected in all the plants. The edible part of the vegetables (under ground) such as, garlic (19.27 μg g⁻¹ dw), potato (11.81 μg g⁻¹ dw) and turmeric (20.86 μg g⁻¹ dw) has accumulated lowest level of toxic metal, Cr than leafy and fruit bearing vegetables. In some fruit part of vegetables such as, bitter gourd, egg plant, jack tree, maize and okra, the accumulation of Cr was not detected and may be grown in this area.     

Lichens as Bioindicators of Atmospheric Heavy Metal Pollution in Singapore

Lichens have been used as bioindicators in various atmospheric pollution assessments in several countries. This study presents the first data on levels of heavy metals (As, Cd, Cu, Ni, Pb, and Zn) in lichens at different locations in Singapore, Southeast Asia. Singapore is a fully industrialised island nation, with a prevailing tropical climate and a population of 4 million people within a confined land area of less than 700 km². The ubiquitous lichen species, Dirinaria picta was collected from six sample sites across Singapore and analysed for heavy metals using inductively coupled plasma mass spectrometry (ICPMS). No significant relationship existed between metal levels in lichen and soil, indicating that accumulated metals in lichen are primarily derived from the atmosphere. Peak concentrations of zinc (83.55 μg g⁻¹), copper (45.13 μg g⁻¹) and lead (16.59 μg g⁻¹) in lichens were found at Sembawang, Jurong and the National University of Singapore campus which are locations associated with heavy petroleum and shipping industries, and road traffic respectively. The mean heavy metal levels of lichen samples in Singapore were found to be at the upper range of values reported in the literature for temperate countries.     

Variability of total and available copper concentrations in relation to land use and soil properties in Yangtze River Delta of China

The effects of land use and soil properties on total and available Cu concentrations in soils were investigated in this study. A total of 276 surface (0-20 cm) soil samples were collected from seven land uses: industrial area, woodland, vegetable field, dry land, paddy field, tea garden and orchard. The total and available (DTPA extractable) Cu concentrations, pH, organic matter, and total nitrogen contents, and cation exchange capacity were measured for each sample. The correlation and ANOVA analyses showed that land use significantly affected total and available Cu concentrations, and the available ratio of soil Cu (available Cu concentration/total Cu concentration). On total Cu concentration, total nitrogen had significant influence in dry land and paddy field, and CEC in garden land; on available Cu concentration, the four measured soil properties showed significant influence only in paddy field; on the available ratio of Cu, pH had significant effect in paddy field and woodland, and CEC in industrial area. Moreover, the relationship between available Cu concentration and soil properties was constructed in different land uses. Spatial analysis of grain Cu using indicator Kriging showed that most of the study areas were in low risk for arable activities, and 7.94% of the study area and 5.10% of the arable land were in high risk probability.     

Evaluation of Pb, Cu, Zn, Cd, Ni and Fe levels in Rosmarinus officinalis labaiatae (Rosemary) medicinal plant and soils in selected zones in Jordan

The concentration of heavy metals including Pb, Cu, Zn, Cd, Ni and Fe in different parts of Rosmarinus officinalis medicinal plant grown in Jordan were evaluated. Medicinal plant samples and soil samples were collected from three different zones in Jordan (Irbid, Al-Mafraq and Ma’an). Samples were analyzed by atomic absorption spectrometry (AAS) after chemical treatments using acid digestion procedures. Heavy metal levels in washed and unwashed in each part of R. officinalis were analyzed and compared statistically. Results show that concentrations of investigated heavy metals were varied from plant part to another part of R. officinalis. For example, Pb, Zn, Cu and Cd in most parts of R. officinalis in the three zones were concentrated in the following order: flowers, leaves, stems, whereas Pb, Ni and Fe were concentrated in order as follows: leaves, flowers and stems. Heavy metal concentrations in soil samples was evaluated and correlated with their levels in R. officinalis. Two standard reference materials of plant (SRM 1790a; spinach leaves and CRM 281; rye grass) and one standard reference materials of soil (GBW 07406) were examined to validate the method used. Results show that high recoveries were obtained.     

Copper availability assessment of Cu-contaminated vineyard soils using black oat cultivation and chemical extractants

Grapevines grown on acid soils with low fertility in southern Brazil are treated with intense foliar applications of copper (Cu) fungicides, resulting in an increased level of Cu in the soil and increased toxicity. The present study evaluated the accumulation and bioavailability of Cu, and soils with varying levels of Cu from the main producing regions of southern Brazil were collected. The forms of Cu present in the soil were assessed using chemical extractants; additionally, oat cultivation was performed, reflecting the use of the plant as an indicator of Cu bioavailability. Cu accumulated in the topsoil, mainly in bioavailable forms, and there was also an increase of Cu up to a depth of 0.4 m. Cu was primarily found in the mineral fraction, with apparent saturation of the soil organic matter functional groups. Inceptisol and Alfisol soils with a long history of cupric fungicide application were found to have levels of Cu toxic to oat plants. Furthermore, accumulated copper in Alfisol soil from the Campanha Gaúcha region of the state of Rio Grande do Sul had higher bioavailability compared to Cu accumulated in Inceptisol soil from the Serra Gaúcha region. In addition, the copper concentration in roots was found to serve as an indicator of Cu bioavailability in soil, but not of copper phytotoxicity in plants.     

Heavy Metal Uptake By Scirpus Littoralis Schrad. From Fly Ash Dosed and Metal Spiked Soils

Scirpus littoralis is a wetland plant commonly found in Yamuna flood plains of Delhi, India. The ability of Scirpus littoralis to take up and translocate five metals- Mn, Ni, Cu, Zn and Pb from fly ash dosed and metal spiked soils were studied under waterlogged and field conditions for 90 days. Scirpus littoralis accumulated Mn, Ni, Cu, Zn and Pb upto a maximum of 494.92, 56.37, 144.98, 207.95 and 93.08 ppm dry wt., respectively in below ground organs (BO) in 90 days time. The metal content ratios BO/soil (B/S) were higher than shoot/soil ratios (T/S) for all the metals, the highest being for Ni. Metal ratios BO/water (B/W) were also higher than shoot/water (T/W) ratios but the B/W ratio was maximum for Zn. The changes in nutrient status (N, P) in soil water and plants were also studied at interval of 30 days. The Pearson's correlation between metal uptake and N, P uptake were calculated. All the metals except Ni showed negative correlation with nitrogen but they were all non-significant. However, P uptake showed positive correlations with all the metals and all were significant at 1% confidence limit.     

Spatial and Temporal Variations in Trace Metal Concentrations in the Cockle, Austrovenus Stutchburyi from Otago, New Zealand

This is the first comprehensive study of sources of variation in metal concentrations within the whole tissues of a shallow burrowing, filter-feeding intertidal clam, Austrovenus stutchburyi. Samples were collected from 12 sites in April, August, November and February in 1993–1994 in the vicinity of Otago Harbour and Peninsula, New Zealand. Total tissue trace metal concentrations (μg g⁻¹ dry weight) were measured in individual animals for the essential metals : Mn, Cu, Zn, Ni and the non-essential Cr using trace-metal clean acid-digestion and ICP-OAES techniques. Average metal concentrations were 3–60 μg g⁻¹ for Cu, 40–118 μg g⁻¹ for Zn, 2–12 μg g⁻¹ for Mn, 5–35 μg g⁻¹ for Ni and 1–44 μg g⁻¹ for Cr. These levels decreased with body weight and differed amongst sites except for Cr in February (mid-summer). Highest concentrations occurred at sites close to a city (Dunedin) and within the central harbour region although the Cu, Zn, Ni and Cr concentrations did not correlate with the environmental gradient or season. At one coastal site, samples of both the blue mussel Mytilus galloprovincialis and cockles gave similar trends in trace metal levels. These results suggest that the cockle could be a useful trace metal biomonitor within NZ estuaries.     

Long-term variability of metals from fungicides applied in amended young vineyard fields of La Rioja (Spain)

The long-term variability of total Cu content from fungicides applied in a certified wine region of Spain (La Rioja) and of other metals (Cd, Cr, Ni, Pb, and Zn) was evaluated in three young vineyard soils and subsoils unamended and amended with spent mushroom substrates (SMS) over a 3-year period (2006–2008). SMS is a promising agricultural residue as an amendment to increase the soil organic matter content but may modify the behaviour of metals from pesticide utilisation in vineyards. Fresh and composted SMS was applied each year at a rate of 25 t ha⁻¹ (dry-weight). Copper concentrations in the three unamended soils were 21.2–88.5, 25.5–77.1, and 29.4–78.4 mg kg⁻¹. They exceeded natural Cu concentrations of the region and reference sub-lethal hazardous concentration for soil organism. The concentrations of Cd, Ni, Pb, and Zn were largely below the sub-lethal limits. Thus, although Cu levels were lower than those of established vineyards, vine performance, and productivity might be affected. The variation in behaviour between different amendments for each soil was high, so a generic conclusion could not be drawn. The amendment practice seemed to have caused temporarily Cu mobilization respect to untreated soils. Total zinc concentrations fall within the range of the natural soil of La Rioja and were significantly affected (p < 0.05) especially by fresh state SMS addition, with increasing up to 75% respect to untreated specimen. The results indicated a build-up of fresh sites for metal retention at both surface and subsurface level, although no accumulation of metals was observed in the short-term period. However, the benefit for soils and the negative effects need to be monitored in the long run.     

Levels of PAHs in the soils of Belgrade and its environs

Polycyclic aromatic hydrocarbons (PAHs) were analysed in 39 soil samples (0–10 cm upper layer) collected in Belgrade, the capital of Serbia. The sampling sites were randomly selected from urban, urban/recreational and rural areas; the samples were collected in April and December 2003 and July and October 2004. The sum of the 16 PAHs corresponding to the recreational zone (298 μg/kg) was close to the urban zone (375 μg/kg). Mean soil ΣPAH concentration from rural areas was 18 μg/kg dry weight. Comparing to values observed in the urbanized locations around the world, the overall levels of PAHs in this study are low. The PAH ratios obtained pointed to a domination of pyrogenically formed PAHs in the examined soils. The dominant PAHs in soil samples in urban zones were fluoranthene, benz[a]anthracene, phenanthrene and pyrene, mostly emitted from noncatalyst vehicles which are still in use in Serbia. The total carcinogenic potency for each sampling site was calculated. Regardless of the used carcinogenic activity factors, carcinogenic potency of 7 sites were 3–9 times higher than the reference ones indicating the increased carcinogenic burden of soils from these sites.