Accumulation Of Heavy Metals In Soil Research Articles

Sulfur Dioxide (SO2) and Heavy Metals Accumulation in Soils around Oil Refineries: Case Study from Three Southern Oil Refineries in the State of Kuwait

Geochemical and statistical analysis of Sulfur dioxide, Total Organic Carbon (TOC) and heavy metal pollutants (Pb, Cd, Zn, Cu, Ni, Fe, Mn, Cr and V) was conducted to soil samples around major oil refineries (Mina Ahmadi, Mina Abdullah and Shuaiba), industries and scanty residential areas in Al-Ahmadi governorate at the southern region of the State of Kuwait. High level of SO2 was found in soil samples of the adjacent area of the refineries (15,000-23,000) ug g-1 and TOC ranging between 0.01 to 1.62 μg g-1 in the soil samples. Furthermore, trace metal analysis in sediment samples revealed high metal levels in the sequence of Fe (17.153 μg g-1) > Zn (151.08 μg g-1) > Ni (112.78 μg g-1) > Pb (27.71 μg g-1) > Mn (404.27 μg g-1) > Cd (0.08 μg g-1) > Cu (23.79 μg g-1) > Cr (56.23 μg g-1) > V (36.53 μg g-1). Cr and V were within the permissible limit. Accordingly, the soil analysis demonstrated that the area around Mina Abdullah refinery was the most polluted area and Shuaiba refinery was the least polluted area, indicating the significance of pollution due to the increase of emissions from the refineries and factories in the area. The level of pollution is alarming, health effected and environmental monitoring is highly recommended.

Impact of Long-Term Application of Patranala Sewage on Carbon Sequestration and Heavy Metal Accumulation in Soils

There is a gradual decline in good quality irrigation water for crop production. Farmers are forced to use poor quality water for crop production in peri-urban areas. Among the wastewater, sewage water generally contains higher amount of plant nutrients and dissolved organic matter. A case study was conducted to investigate the impact of untreated sewage water application on physicochemical properties and carbon sequestration in soil. For this purpose, peri-urban agricultural lands irrigated with sewage water from Patranala, Bhopal were selected. Such lands around both sides of the Patranala were being irrigated with sewage water for more than last 50 years. The soil samples were collected at various soil depths i.e., 0–15, 15–30, 30–45 and 45–60 cm from these fields; and sampling points were at about 2 km intervals along the channel direction and also at the distance interval of about 0.5, 1.0, 1.5 and 2.0 km away from the sewage carrying channel. The soil microbial population and enzymatic activities were considerably higher in the sewage irrigated fields as compared to those in tubewell irrigated area. Concentrations of heavy metals in surface soils were also higher in sewage irrigated fields. Maximum soil organic carbon (SOC) contents were found in surface layer (0–15 cm), which decreased with depth at all the locations. Net stock of carbon in upper 60 cm of the soil depth was higher in sewage irrigated lands as compared to those irrigated with tubewell water. Thus, long-term application of sewage water for crop production enhanced sequestration of sewage borne carbon in soil profile, which otherwise could pollute the surface water bodies and emit in the atmosphere as greenhouse gases. However, heavy metals build-up in the sewage irrigated area is a major concern.

Reverse flow of urban pollutants in sewage irrigated crops in developing countries

Dwindling fresh water supplies in developing countries have led to increased interest in exploring alternative irrigation water sources including untreated or partially treated wastewater. Wastewater originates from a variety of sources including domestic sewage, mixed with industrial effluents, and stormwater. Wastewater irrigation benefits farmers and other stakeholders through better crop yields owing to reliable water and nutrient supply and pollution reduction of rivers and other surface water bodies. However, it poses health risks to farmers and consumers alike due to pathogens, build-up of chemical pollutants especially heavy metals in soils and groundwater contamination. A very small proportion of sewage water (SW) is treated in a few working sewage treatment plants (STPs) in developing countries. Many existing STPs are running above the capacity and only partially treat SW. Many studies on SW in developing countries show the presence of high metal and metalloid concentrations beyond maximum permissible limits. Likewise, several studies evidence increased concentrations of heavy metals in both groundwater and surface waters in developing countries. Repeated use of SW for irrigation may result in accumulation of heavy metals in soils, which can enter the food chain. Review of pertinent literature demonstrates heavy metal accumulation in soils and eventually in edible portion of crops grown in peri-urban areas. Site specific best management practices aimed at curtailing the bioavailability of pollutants in soil and eventual uptake and translocation to edible parts of the crops are required. New STPs and upgradation of the existing STPs are the need of hour. Developing countries need to develop pretreatment standards for industrial waste discharged to the STP collection systems.

Technogenic loading of eastern industrial zone of Zhytomyr on vegetation of adjoining ecosystems

The results of investigations of the peculiarities of the heavy metals accumulation in soil and phytomass of wildlife vegetation from the territory exposed to the influence of the Eastern industrial zone in Zhytomyr are presented. The activity of the enterprises of the Eastern industrial zone leads to the inorganic dust entering the atmosphere, which includes toxic compounds and heavy metals that are transferred at considerable distances, settle and are accumulated in the components of the surrounding ecosystems. It has been determined that significant concentrations of Mn, Zn, Pb, Cu, Fe are accumulated in non-localized dust, which determines the elevated levels of these metals in the vegetation of ecosystems as well. The grass cover has accumulated more elements — dust components — in the south-eastern and southern areas, 2–4 times less — in the eastern and north-eastern areas. The accumulation peculiarities of two groups of metals in plant samples of the territory influenced by the enterprises zone of the Eastern industrial zone in Zhytomyr differ in the ability of air migration, depending on the dust fraction they belong to. The activity of the enterprises located in this zone causes the inorganic dust entering into the atmosphere, which includes toxic compounds and heavy metals. It has been found out that further from the Eastern industrial zone Mn, Zn and Fe are accumulated most in the above-ground phytomass. This is due to the high concentration of these elements in the fine dust fraction.

Research on soil heavy metal accumulation and chemical environmental quality evaluation based on environment law

In this paper, it gives research on annual net flux and accumulative amount of the soil heavy mental in the Pearl River Basin on the basis of giving full consideration to environment law, by adopting such methods as theoretical calculation and field test and based on input/output flux model of soil chemical quality evaluation, and it gives heavy metal content warning and rating to paddy field, dry land and orchard in the Pearl River Basin based on heavy metal chemical evaluation warning method. The research conclusion indicates that: the main heavy metal pollution elements of paddy field and dry land in the Pearl River Basin are Cd, Ni and Hg; heavy metal pollution elements of orchard soil are As, Cr and Ni. Soil of the paddy field, dry land and orchard surrounding Guangzhou city is polluted more seriously; soil of the paddy field and dry land surrounding Jiangmen city and Zhongshan city is given severe pollution warning; soil of the paddy field, dry land and orchard surrounding Zhuhai and Zhaoqing is polluted slightly. Soil quality can be evaluated better by utilizing the input/output flux model for soil chemical quality evaluation proposed in this paper.

Effects of different irrigation practices using treated wastewater on tomato yields, quality, water productivity, and soil and fruit mineral contents

Wastewater use in agricultural irrigation is becoming a common practice in order to meet the rising water demands in arid and semi-arid regions. The study was conducted to determine the effects of the full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation practices using treated municipal wastewater (TWW) and freshwater (FW) on tomato yield, water use, fruit quality, and soil and fruit heavy metal concentrations. The TWW significantly increased marketable yield compared to the FW, as well as decreased water consumption. Therefore, water use efficiency (WUE) in the TWW was significantly higher than in the FW. Although the DI and the PRD practices caused less yields, these practices significantly increased WUE values due to less irrigation water applied. The water-yield linear relationships were statistically significant. TWW significantly increased titratable acidity and vitamin C contents. Reduced irrigation provided significantly lower titratable acidity, vitamin C, and lycopene contents. TWW increased the surface soil and fruit mineral contents in response to FW. Greater increases were observed under FI, and mineral contents declined with reduction in irrigation water. Heavy metal accumulation in soils was within safe limits. However, Cd and Pb contents in fruits exceeded standard limits given by FAO/WHO. Higher metal pollution index values determined for fruits also indicated that TWW application, especially under FI, might cause health risks in long term.

Effects of long-term fertilizer applications on peanut yield and quality and plant and soil heavy metal accumulation

The status of essential and potentially toxic trace elements in soils and crops can be affected by long-term fertilization practices. This study aimed to investigate changes in peanut (Arachis hypogaea L.) yield and kernel quality, and changes in copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd) concentrations in soil and peanut kernels after 16 years of continuous cropping with different fertilization treatments. Five fertilization treatments were applied at a red soil site in Southeast China: chemical fertilizer (F) containing nitrogen, phosphorus, and potassium, F + trace elements (FT), pig manure (M), M + effective microorganisms (MB), and MB + trace elements (MBT). Properties of soil and pig manure, heavy metal contents in soil and peanut kernels, and the compositions of amino and fatty acids in kernels were determined. Application of pig manure significantly increased peanut biomass, kernel yield, and crude protein and total amino acid contents in kernels, but led to higher amounts of Cu, Zn, and Cd in soil and higher amounts of Zn and Cd in peanut kernels compared with that of chemical fertilizer. There should be greater concern about potential kernel Cd and Zn contaminations resulting from long-term application of pig manure contaminated with potentially toxic metals as an organic fertilizer.

The Effect of Highway on Heavy Metal Accumulation in Soil in Turfy Swamps, Northeastern China

A detailed investigation was conducted to study the effect of highway on the accumulation of heavy metals in soils of turfy swamps. The concentrations of Cr, Zn, Cu, and Cd showed a decreasing trend with increasing distance from the road, while such trend was not identified in Pb, Ni, Co, and As. The results of factor analysis and cluster analysis indicated that Cr, Zn, Cu, and Cd were in a closer relationship than other metals and might be derived from common sources. The soil samples from JY and LQ sites with the highest traffic volume had the highest heavy metal concentrations of the three highways, while the concentrations of Cr and Cu were significantly positively correlated with traffic volumes (p < 0.05). Contamination levels of traffic-related metals were evaluated using the geo-accumulation index (I geo) and enrichment factor (EF) in turfy soil. The I geo index for Cr, Zn, Cu, and Cd varied from unpolluted to the heavily polluted, and the enrichment factor (EF) ranged from 0.44 (no enrichment) to 8.38 (significant enrichment) at JY and LQ site. For HSD site, the I geo index and EFs of Cr, Zn, and Cd in turfy soils were lower than that in JY and LQ, ranged from uncontaminated to moderate contamination and no enrichment to moderate enrichment, respectively. The I geo index and EFs of Cd were higher than 1 among all three sites. Therefore, Cd should be paid more attention to avoid potential risk to the flora and fauna in turfy swamps. The affected area of traffic-related metals was <30 m from the highway; this may be due to the abundant precipitation and long cold winter in Changbai Mountain area. The heavy metals could move with rainfall runoff and snowmelt in both particulate and dissolved forms.

Health risk assessment of heavy metals in soils and maize (Zea mays L.) from Yushu, Northeast China

ABSTRACTTo investigate heavy metal accumulation in soils and evaluate health risk through maize consumption, a total of 196 soils and 55 maize samples were collected from Yushu, China, one of the most important maize production bases. The mean contents of Cd, Cr, Cu, Zn and Pb were 0.119, 56.51, 19.21, 70.58, and 34.42 mg kg−1 for soils and were 0.014, 0.68, 1.33, 17.15 and 0.02 mg kg−1 for maize, respectively. The contents of Cr, Cu, Zn and Pb in all soil and maize samples did not exceed safety thresholds, but the percentages of Cd content above guideline values of Chinese Environmental Quality Standards for Soil and maximum permissible limits for maize were 6.6% and 1.8%, respectively. The spatial distribution and correlation analysis suggested that Cr and Cu in soil were of lithogenic origin, while Zn and Pb were associated with coal combustion exhausts and chemical fertilizer application. The main source of Cd may be phosphate fertilizer application. The average target hazard quotients were all less than 1 and the average hazard index for adults was 0.065, indicating that there was not a potential health risk through maize.

Source identification and exchangeability of heavy metals accumulated in vegetable soils in the coastal plain of eastern Zhejiang province, China

Vegetable production in China is suffering increasingly heavy metal damages from various pollution sources including agricultural, industrial and other activities. It is of practical significance to understand the effects of human activities on the accumulation and exchangeability of soil heavy metals in vegetable fields. In this study, seventy-two arable layer samples of vegetable soils were collected from the Shaoxing coastal plain, a representative region of the coastal plain of eastern Zhejiang province, China for characterizing the effects of fertilization methods on accumulation and exchangeable heavy metals in soils (Exchangeable heavy metals in the soil samples were extracted by 0.01molL−1 CaCl2). The different origins of heavy metals in the vegetable soils were investigated by multivariate statistical techniques, including principal component analysis (PCA) and cluster analysis (CA). Marked increases were noted for soil heavy metals due to long-term manure or chemical fertilizer application. Three significant components were extracted by PCA, explaining 78.86% of total variance. Mn, Co, Ni, Fe, and Al were associated in lithogenic components, while an anthropogenic origin was identified for Cu, Cr, Pb, Zn, Cd, Hg. However, As level was due to the geochemical background and was not linked to soil management. The results obtained by cluster analysis elucidated individual relationships between metals and agreed with PCA. Cu, Cr, Pb, and Zn in the soils that were mainly associated with the application of chemical fertilizers, organic manures or other activities regarding soil management. Although the origin of Cd, Hg, and As was also attributed to soil management, other sources like vehicle exhaust or aerial depositions were not discarded as possible contributors. Soil amended with organic fertilizer contained more Cu, Pb, Zn and Cr; whereas the soil amended with chemical fertilizer had more Cd. Application of fertilizers also had significant effect on the concentrations of exchangeable heavy metals. Higher mean concentrations of exchangeable Cd and Pb were found in the soils amended with chemical fertilizers, while those of exchangeable Cu and Zn were found in the soils amended with organic fertilizers.

Effects of urbanization on heavy metal accumulation in surface soils, Beijing

Urbanization processes affect the accumulation of heavy metals in urban soils. Effects of urbanization on heavy metal accumulation in soils were studied using Beijing as an example. It has been suggested that the ecological function of vegetation covers shifting from natural to agricultural settings and then to urban greenbelts could increase the zinc (Zn) concentrations of soils successively. The Zn concentration of urban soils was significantly correlated to the percentage of the impervious land surface at the 500m×500m spatial scale. For urban parks, the age or years since the development accounted for 80% of the variances of cadmium (Cd) and Zn in soils. The population density, however, did not affect the heavy metal distributions in urban soils. To conclude, the urban age turned out to be a notable factor in quantifying heavy metal accumulation in urban soils.

Spatial distribution and risk assessment of heavy metals in soil near a Pb/Zn smelter in Feng County, China

A large scale survey and a small scale continuous monitoring was conducted to evaluate the impact of Pb/Zn smelting on soil heavy metals (HMs) accumulation and potential ecological risk in Feng County, Shaanxi province of China. Soil parameters including pH, texture, CEC, spatial and temporal distribution of HMs (Cd, Cu, Ni, Pb and Zn), and BCR fractionation were monitored accordingly. The results showed the topsoil in the proximity of smelter, especially the smelter area and county seat, were highly polluted by HMs in contrast to the river basins. Fractionation of Cd and Zn in soil samples revealed higher proportion of mobile fractions than other HMs. The soil Cd and Zn contents decreased vertically, but still exceeded the second level limits of Environmental Quality Standard for Soils of China (EQSS) within 80cm. The dominated soil pollutant (Cd) had higher ecological risk than Cu, Ni, Zn and Pb. The potential ecological risk (PER) factor of Cd were 65.7% and 100% in surrounding county and smelter area, respectively. The long-term smelter dust emission mainly contributed to the HMs pollution and posed serious environment risk to living beings.

Space-time quantitative source apportionment of soil heavy metal concentration increments

Assessing the space-time trends and detecting the sources of heavy metal accumulation in soils have important consequences in the prevention and treatment of soil heavy metal pollution. In this study, we collected soil samples in the eastern part of the Qingshan district, Wuhan city, Hubei Province, China, during the period 2010–2014. The Cd, Cu, Pb and Zn concentrations in soils exhibited a significant accumulation during 2010–2014. The spatiotemporal Kriging technique, based on a quantitative characterization of soil heavy metal concentration variations in terms of non-separable variogram models, was employed to estimate the spatiotemporal soil heavy metal distribution in the study region. Our findings showed that the Cd, Cu, and Zn concentrations have an obvious incremental tendency from the southwestern to the central part of the study region. However, the Pb concentrations exhibited an obvious tendency from the northern part to the central part of the region. Then, spatial overlay analysis was used to obtain absolute and relative concentration increments of adjacent 1- or 5-year periods during 2010–2014. The spatial distribution of soil heavy metal concentration increments showed that the larger increments occurred in the center of the study region. Lastly, the principal component analysis combined with the multiple linear regression method were employed to quantify the source apportionment of the soil heavy metal concentration increments in the region. Our results led to the conclusion that the sources of soil heavy metal concentration increments should be ascribed to industry, agriculture and traffic. In particular, 82.5% of soil heavy metal concentration increment during 2010–2014 was ascribed to industrial/agricultural activities sources.Using STK and SOA to obtain the spatial distribution of heavy metal concentration increments in soils.Using PCA-MLR to quantify the source apportionment of soil heavy metal concentration increments.

Efficiency of sewage sludge biochar in improving urban soil properties and promoting grass growth

It is meaningful to quickly improve poor urban soil fertility in order to establish the green land vegetation. In this study, a series rates (0%, 1%, 5%, 10%, 20% and 50%, in mass ratio) of biochar derived from municipal sewage sludge was applied into an urban soil and then turf grass was grown in pots. The results showed that biochar amendment induced significant increases in soil total nitrogen, organic carbon, black carbon, and available phosphorus and potassium by more than 1.5, 1.9, 4.5, 5.6 and 0.4 times, respectively. Turf grass dry matter increased proportionally with increasing amount of added biochar (by an average of 74%), due to the improvement in plant mineral nutrition. Biochar amendment largely increased the total amounts of soil heavy metals. However, 43–97% of the heavy metals in the amended soil were concentrated in the residual fraction with low bioavailability. So the accumulation of heavy metals in turf grass aboveground biomass was highly reduced by the addition of biochar. These results indicated that sewage sludge biochar could be recommended in the poor urban raw soil as a soil conditioner at a rate of 50%. However, the environmental risk of heavy metal accumulation in soil amended with sewage sludge biochar should be carefully considered.

Using Nonconventional Water in Irrigation of Olive Trees and Its Effect on Olive Oil Properties

The response of olive orchard with same age and type to irrigation with treated municipal wastewater and freshwater was investigated in three years. Physical and chemical properties of the treated municipal wastewater reuse in agriculture (the effluent) produced by the Sheikh Ejleen wastewater treatment plant in Gaza Strip, freshwater, soil, and olive oil were determined and compared with Palestinian and international standards. The biological oxygen demand (BOD) of Sheikh Ejleen effluent is 60 mg·l-1, which indicates low quality effluent. The results indicate that most of olive oil quality parameters—including heavy metals and trace elements for both fruits irrigated with treated wastewater or irrigated with freshwater—fall within the acceptable standard limit values. Moreover, soil analysis shows that organic content and cation exchange capacity were improved in soil irrigated with treated wastewater in comparison with that irrigated with freshwater. The results also show that there is no trace elements or heavy metals accumulation in soil.

Impact of Land Use and Agrochemicals on Quality Potential of Wetland Soils of Odeda Farm Institute, Eweje, Ogun State, Nigeria

A study was conducted to examine the impact of land use and agrochemicals on wetland soil quality of Odeda Farm Institute, Eweje, Ogun State, Nigeria. The land use types studied were maize, plantain, rice, vegetable, and fallow. Five profile pits were dug, four at agrochemicals applied fields and one at fallow field as control. The results showed that soil texture was not influenced by land use and agrochemicals. The particle size distribution data showed that the soils consisted of high sand content (>600 g/kg). Soil pH, organic carbon and total nitrogen were low at agrochemicals applied fields when compared with the fallow field. The reverse is the trend for available P which is low at the fallow field due to non application of phosphate fertilizer. The heavy metals (Cd, Cu, Fe, Mn, Pb and Zn) results differed significantly (p<0.05) between the agrochemicals applied fields and the fallow field. Soil nutrients depletion and heavy metal accumulation were very prominent under agrochemicals applied fields. However, the impact of land use and agrochemicals which mostly accounted for major changes in the soil quality indicators can be immediate or long term, and wetland users should take into consideration long effect of current land decisions.

Effect of Immature Compost on Available Nutrient Capability and Heavy Metal Accumulation in Soil for Lettuce (Lactuca sativa L.) Cultivation

The aim of this study was to evaluate effects of immature compost on the amount of nutrient content, heavy metal concentration, and application rate that were used for lettuce cultivation. The characteristics of the two composts (Compost A (CA) was immature compost and Compost B (CB) was mature compost) were evaluated upon mixing with commercial soil at 0%, 25%, 50%, and 75% (w/w). The poor chemical characteristics were appeared by use of immature compost as soil amendment; the 50% and 75% rates were weakly acidic at pH 5.39 and 5.50, respectively. The total carbon content at using of 75% of the immature compost and mature compost increased the most to 14.5 and 6.5% and it significantly increased concentrations of the total nitrogen and phosphorus compared to control. As for 75% mature compost rate increased significantly the concentrations of Cu (128 ㎎ ㎏ -1 ), Zn (260 ㎎ ㎏ -1 ), Pb (0.32 ㎎ ㎏ -1 ) and, Cd (0.48 ㎎ ㎏ -1 ) compared to control, and the highest As concentration increased significantly at 75% and 50% (6.69 and 6.28 ㎎ ㎏ -1 ) including in 25% immature compost as 6.48 ㎎ ㎏ -1 . However, all of the high compost rates significantly decreased the shoot biomass of lettuce. The immature compost was potentially amended at an application rate of 25% due to a slight salinity and low risk to heavy metal uptake on lettuce growth. This use may be available if the rate is lower than that used in this trial.

Phyto-Assessment of Soil Heavy Metal Accumulation in Tropical Grasses

Phyto-Assessment of Soil Heavy Metal Accumulation in Tropical Grasses

Heavy Metal Pollution in a Soil-Rice System in the Yangtze River Region of China.

Heavy metals are regarded as toxic trace elements in the environment. Heavy metal pollution in soil or rice grains is of increasing concern. In this study, 101 pairs of soil and rice samples were collected from the major rice-producing areas along the Yangtze River in China. The soil properties and heavy metal (i.e., Cd, Hg, Pb and Cr) concentrations in the soil and rice grains were analyzed to evaluate the heavy metal accumulation characteristics of the soil-rice systems. The results showed that the Cd, Hg, Pb and Cr concentrations in the soil ranged from 0.10 to 4.64, 0.01 to 1.46, 7.64 to 127.56, and 13.52 to 231.02 mg·kg−1, respectively. Approximately 37%, 16%, 60% and 70% of the rice grain samples were polluted by Cd, Hg, Pb, and Cr, respectively. The degree of heavy metal contamination in the soil-rice systems exhibited a regional variation. The interactions among the heavy metal elements may also influence the migration and accumulation of heavy metals in soil or paddy rice. The accumulation of heavy metals in soil and rice grains is related to a certain extent to the pH and soil organic matter (SOM). This study provides useful information regarding heavy metal accumulation in soil to support the safe production of rice in China. The findings from this study also provide a robust scientific basis for risk assessments regarding ecological protection and food safety.

A proposed method for the assessment of the interactive heavy metal accumulation in soils

&lt;p&gt;A method is proposed for the assessment of the interactive accumulation of heavy metals in soils. Sixty surface soil samples were collected from fifteen sites, at a depth of 0-30cm, evenly distributed, within the 30,700ha comprising the study area.&lt;/p&gt; &lt;p&gt;It was found that at least&amp;nbsp; some of these metals were significantly contributed to soil, i.e. Mn 9.53, Fe 8.06, Zn 0.86, Pb 0.29, Cd 0.033, Co 0.112 and Ni 0.125 kg/ha, respectively.&lt;/p&gt; &lt;p&gt;Similarly considerable levels of plant nutrients were accumulated in the studied soil such as P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; 8.6, or 3.75 kg P/ha, K&lt;sub&gt;2&lt;/sub&gt;O 52.92 or 43.94 kg K/ha, and Ca 78.98 kg/ha. As expected, the heavy metals accumulated in lower concentrations than those of plant nutrients and in non toxic levels. Nevertheless, the toxicity of these metals must be considered in relation to long term accumulation.&lt;/p&gt; &lt;div&gt; &lt;p&gt;It was shown that the proposed method, based on the quantification of the elemental interactions contribution in heavy metals, could be used as a tool for the quantitative assessment of their accumulation and for the prediction of the &amp;laquo;silent&amp;nbsp; pollution&amp;raquo; that gradually occurs in soils with these metals.&lt;/p&gt; &lt;/div&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;