Identifying factors influencing trace metal concentrations in urban residential soil using an optimal parameter-based geographical detector model.

Background concentrations of trace metals As, Ba, Cd, Co, Cu, Ni, Pb, Se, and Zn in 214 Florida urban soils: Different cities and land uses

Estimation of the accumulation rates and health risks of heavy metals in residential soils of three metropolitan cities in China

Occurrence of selected trace metals and their oral bioaccessibility in urban soils of kindergartens and parks in Bratislava (Slovak Republic) as evaluated by simple in vitro digestion procedure

To design a rational management system of urban soil pollution, it is necessary to know first the regional soil pollution characteristics and their governing mechanism. In this study, the X-ray fluorescence (XRF) method was selected for quick monitoring of metal concentrations in many solid samples. Soil and plant samples were collected along two streets and at a sports ground in Kyoto City area, and their metal concentrations were determined by the XRF method. Those metal concentrations in soil and plants were analyzed in a stochastic manner. The results obtained in this study can be summarized as follows: (i) The XRF method is useful for quick monitoring of many solid samples because its simple pre-treatment requirement for concentration determination. The practical quantitative detection limits are determined (e.g., 0.010mg g−1 for Zn). (ii) Metal concentrations in surface soils along two streets in Kyoto City showed that the soil contamination was heavier in the central part of the city. (iii) Some metal concentration correlation with sampling distance showed a distance dependent decrease of correlation coefficient, but other metals did not, which suggested random distribution in surface soil of the surveyed area. (iv) Most metal concentrations in grasses had a negative correlation with some element concentration in soil, and some metal concentration in grasses was larger than in soil. These facts indicate that grasses might be used for remediation of polluted soil.

This study presents the current state of heavy metal contents in both urban and forest soils within the city area of Vienna, Austria. Based on a systematic survey of urban soils and on targeted sampling in forest areas, local and regional anomaly thresholds are derived using statistical methods and considering regional distribution patterns. For urban soils, local anomaly thresholds of elements Cu (60 mg/kg), Hg (0.5 mg/kg), Pb (100 mg/kg) and Zn (200 mg/kg) exceed national guideline values for uncontaminated urban soils and according to Austrian legislation fall into the category "anthropogenic contamination present but no damage to plants, animals or humans detectable". In forest soils within the city, thresholds are very similar to reference values for similar geological settings outside the city, apart from higher concentrations of elements Cr and Ni (threshold values of 107 and 64 mg/kg, respectively). Grouping urban soils according to land use reveals that Cd contents are 25 % higher, Pb contents 36 % higher, in traffic and industrial areas than in parks and like Cu, Hg and Zn, these elements can be shown to be at least partly caused by anthropogenic contamination. A dependency between heavy metal concentrations in soils and underlying geological units is shown within the flysch zone at the western city margin where the contents of elements Co, Cr, Cu, Ni and V are controlled by geology and reveal distinct differences between geological units. In built-up areas, no clear dependency between heavy metal contents in soils and geology is evident as urban soils represent accumulations by anthropogenic activity rather than in situ weathering products of underlying sediments.

Trace metals, including heavy metals, can be harmful to the biota and human beings. This leads to study the accumulation of those elements in soils. In the Pampean region (Argentina) this knowledge is scarce. Our objectives were to (i) determine the trace metal concentration in soils of Buenos Aires City and agricultural areas, (ii) start to establish the soil trace metals baseline concentration, and (iii) find relationships between soil properties and those elements Topsoil samples were taken in Buenos Aires City and on farms along an arc 50 to 250 km away from the metropolis. All studied soils were Mollisols. Soil samples were analyzed for their cadmium (Cd), copper (Cu), zinc (Zn), chromium (Cr), cobalt (Co), lead (Pb), and nickel (Ni) contents by acid extraction. Soil properties were determined using standard methods. The soils of Buenos Aires City show the highest average concentrations of Cd, Cu, Pb, and Zn. The further the sampling sites were from Buenos Aires, the lower the metal concentration in the soils. Conversely, there were no differences in Co, Cr, and Ni concentrations from urban to the rural soils. There was a high variability in metal concentrations. We hypothetized that cars are the main source of contamination of Pb and Cd in the urban soils. The measured metals concentrations from rural areas, can be a basis from which to establish the background levels of those soils. Clay content was related to the concentrations of Cd, Cr, Ni. Pb, and Zn in soils.

Motor transport affects the state of the natural environment and results in the accumulation of trace metals in roadside soils. The trace metal concentrations in roadside soils depend mainly on the distance from the road and the traffic intensity. The aim of the investigations was to determine the range of the environmental impact of the (Cracow-Zakopane) transport route and the effect of traffic intensity on the concentrations of trace metals in the soil. Three road sections differing in their traffic intensity were selected for this purpose. The concentrations of Cr, Cu, Ni, Pb and Zn in soil samples taken from a depth of 0-30 cm at a distance of 5, 10, 50 and 100 metres from the road were spectrophotometrically determined. The metal concentrations in the surroundings of the Cracow-Myślenice road carrying heavy traffic were found to be several times higher than the ones in the soils near the Łopuszna-Dursztyn local road with low traffic intensity. The largest differences in trace metal concentrations in the soils were found for nickel (four times higher concentrations along the Cracow-Myślenice road) at all the considered distances and for copper (three times higher) at the distances of 5 and 10 metres. In comparison with the reference areas, in the vicinity of the investigated roads the concentrations of Cr, Cu, Ni, Pb and Zn in the soil were found to be elevated. The fact that the concentrations of the trace metals decrease with increasing distance from the road's edge clearly indicates the traffic-related origin of the contaminants.

Impact of informal electronic waste recycling on metal concentrations in soils and dusts

Mining activities often cause important impacts on soil and water quality. The main objective of this study was to evaluate the effect of amendments (compost and technosol made from waste) on metal concentrations in a mine soil planted with Brassica juncea. A greenhouse experiment with cylinder pots was carried out during 11months. The mine soil was collected from the settling pond of the depleted copper mine of Touro (Galicia, Northwest Spain). A series of characteristics were analysed including soil pseudototal metal concentrations, soil CaCl2-extractable (phytoavailable) metal concentrations and metal concentrations in soil pore water. The results showed that at depth 0-15cm SCP (mine soil + compost, grown with B. juncea) had a significantly lower CaCl2-extractable Cu, Pb, Ni and Zn concentration than STP (mine soil + technosol, grown with B. juncea) over the time (P < 0.05). At depths 15, 30 and 45cm, STP and SCP had lower Cu pore water concentration than S over the time. The highest translocation factor (TF) values for all metals (Cu, Pb, Ni and Zn) were observed at time 1 (3months) in the settling pond soils treated with technosol and B. juncea L. The conclusions of this experiment revealed that SCP compared to STP caused a higher reduction on Cu, Pb, Ni and Zn phytoavailable concentrations in the first depths.

&amp;lt;p&amp;gt;Soil contamination by heavy metals causes metal accumulation by plants, which leads to the degradation of plants communities and migration of toxicants with food chains to man. Therefore, the investigation of heavy metal concentration in soils of urban areas is an urgent scientific task. This study aims to examine the translocation of heavy metals from urban soils to herbs in Tyumen (Russian Federation).&amp;amp;#160; Soil surface layer was collected at control site, near the highway as well as from areas with metallurgical, motor building, oil refinery and battery manufactory plants in Tyumen. Meadow grass, red clover, wild vetch, chamomile and coltsfoot were collected at all examined sites. &amp;amp;#160;The mobile and acid-soluble heavy metal fractions in soils, as well as the heavy metal contents in plants, were determined by atomic absorption spectrophotometry. The bioconcentration factor was estimated as the ratio of the amount of heavy metals in soils to that in plants. The study was performed during three-year period from 2017 to 2019. Heavy metal concentrations in urban soils were higher than those at the control site by 20% and by up to 10 times. The greatest heavy metal accumulation in both soils and plants was found at the battery manufacturing and metallurgical plants, exceeding the control levels of Pb and Fe by 2-17 times. The Cu, Fe and Mn contents in soil were positively correlated with those in plants. Heavy metal translocation by the plants was species-specific. The percentages of the mobile heavy metal fractions decreased in the following order: Mn&amp;gt;Zn&amp;gt;Cu&amp;gt;Fe. Heavy metal accumulation in plants in the urban sites compared to that at the control site decreased in the following order: Fe&amp;gt;Zn&amp;gt;Cu&amp;gt;Mn&amp;gt;Pb&amp;gt;Cd. Coltsfoot exhibited the highest Fe, Mn, and Zn accumulation, which exceeded the control levels by 17, 5, and 3.5 times, respectively. The heavy metal bioconcentration factors, indicators of translocation, decreased in the following order: Cu&amp;gt;Zn&amp;gt;Cd&amp;gt;Pb&amp;gt;Mn&amp;gt;Fe. The heavy metal translocation suggests the need to relocate industrial facilities to outside the city. Future monitoring of the study area is needed to ensure its long-term ecological safety.&amp;lt;/p&amp;gt;

Heavy metal contamination has become a serious ecological problem due to its toxic effects on soils, plants and human. Experimental study was conducted on dumpsite soil to assess the potential of Ricinus communis to accumulate heavy metals from the soil using bioconcentration (BCF) and tanslocation factors (TF). Heavy metals concentration (mg/kg) in dumpsite and control soil before planting were Mn (50.68- 220.08); Zn(29.01- 135.56); Cu (8.92- 86.88), Pb (5.88-48.86), Ni (3.01-7.99) and Co (1.78-6.88) while the concentration in soils after planting were Mn(29.89- 135.21); Zn (15.11-88.21); Cu (3.89-50.22), pb (3.68-31.56), Ni (1.22-3.56) and Co (0.67-2.68) in Mg/kg. Ricinus communis showed BCF greater than 1 for Ni and Co and less than 1 for Mn, Cu, Zn and Pb while TF is greater than 1 for all the determined heavy metals. The dumpsite soils have higher heavy metal concentration than the control soil. The levels of heavy metals concentration in soils and plants are in the order of Mn&gt; Zn&gt; Cu&gt; Pb&gt; Ni. Significant reduction (P&lt;0.05) was observed in the heavy metal concentrations in the soils before and after planting indicating their accumulation in the plants. Results of this study indicate the accumulation of heavy metals in Ricinus communis plants and its potential for effective removal of Cu, Zn, Pb, Ni, Co and Mn from the dumpsite soils.&#x0D; Keywords: Heavy metal accumulation, Ricinus communis, Dumpsite soil, Translocation factor, Remediation

The objective of this study is to determine influence of Treated Sewage Sludge (TSS) rates as organic matter and nutrient resource on temporal variations of some macronutrients and micronutrients and heavy metals concentrations in a Typic Xerofluvent soil. The experiment was conducted in Menemen Plain, in the Western Anatolia Region of Turkey in 2003–2005. Moist TSS was added to the soil at the rates of 0, 30, 60 and 90 Mg ha−1 on May 1, 2003. Peanut (Arachis hypogaea) was planted as the first crop. On the other hand, mixture of green barley (Hordeum vulgare) and common vetch (Vicia sativa L.) was planted as the second crop. During the experiment, soil samples were taken five times. Increasing TSS applications to this soil resulted in significantly increased concentrations of total N, Cu, Pb and Ni, and available P, K, Ca, Fe, Cu, Zn, Mn concentrations in soil. However, concentrations of available Mg and Na, total Fe, Zn, Mn, Cd, Co and Cr in soil did not significantly change. Micronutrients and heavy metals concentrations in soil were found under threshold values in all sampling periods in this study. Available nutrient concentrations in the soil decreased particularly in the last sampling periods because of plant uptake of nutrients from the applied TSS. It is recommended that 90 Mg ha−1 moist TSS can be added once in a 2-year period for improving nutrient concentrations in Typic Xerofluvent soil.

Elevated heavy metal concentrations in urban top soils are principal indicators of environmental pollution; however, relative data on the heavy metal status in soils of Greek island towns, that are regional administrative centers and popular tourist destinations, are missing. A survey was conducted to examine heavy metal concentrations in the urban soils of Ermoupolis, the capital of Syros island and of the prefecture of Cyclades complex in the Aegean Sea. Total (aqua-regia extracted) and available (DTPA extracted) concentrations of Cu, Pb, Zn, Ni, Cr, Sn and Fe were determined in top soil samples collected from green areas and open spaces of the town and in surface samples from inland reference soils of the island. Mean values for the aqua-regia extracted fraction of Cu, Pb and Zn were 117, 155 and 440 mg kg(-1) respectively, up to four times higher than the respective mean values of the reference soils. Enrichment factors (EFs) for these metals indicated high accumulation in the urban top soils and the available to total concentration ratio of Cu, Pb, Zn and Fe was higher for the urban compared to the reference soils, suggesting differences in metal sequestration, resulting in higher metal availability in the urban soils. GIS analysis was used to visualize the spatial distribution of EFs of the studied heavy metals. Factor Analysis and Cluster Analysis, applied to aqua-regia and DTPA data sets, adequately elucidated the origin of metals grouped under each factor or cluster.

Assessment of lead, cadmium, and zinc contamination of roadside soils, surface films, and vegetables in Kampala City, Uganda

Growing safe food crops in urban settings requires soil condition assessment because many sites may be metal contaminated. Of particular concern are trace metals found at urban sites as a result of litter, construction materials, industrial development, and traffic patterns. Although all soils contain trace metals inherited from the parent material, anthropogenic influences can influence and increase metals' plant availability. Different urban activities located on soils derived from three parent materials, marine, glacial marine, and glacial till, were selected in Metro Vancouver to assess trace metal concentrations in the urban soils. Estimates of total (aqua regia) and available (dilute HCl) trace metals (Cu, Mn, Ni and Pb ) were compared among the sites and between the surface soil and the underlying parent material to assess potential environmental risks associated with location of the urban sites. Comparisons were made to metal concentration standards in published government guidelines. Although urban activities do affect metal amounts, parent materials must be considered when assessing anthropogenic effects of trace metals in soils because metal contents vary among different parent materials. Results indicate that surface soil metal concentrations are influenced by geographical location within the urban setting and soil management practices. For a rapid and reproducible determination of potential trace metal concentrations, the use of 0.1 M HCl provides a useful initial assessment.