Assessment Of Soil Contamination Research Articles

An optical detection module-based biosensor using fortified bacterial beads for soil toxicity assessment.

An optical biosensor module for soil contamination assessment is presented, employing bioluminescent bacterial bioreporters encapsulated in poly-dopamine (PD)-coated alginate microbeads. The PD-coated beads displayed improved mechanical strength and stability, but somewhat delayed responses to the inducing toxicant. Using toluene as a model soil contaminant, two bioluminescent reporter strains were employed for its detection in the ambient light-blocking, temperature-controlled biosensor module. Bioluminescence of strain TV1061 (harboring an inducible grpE::luxCDABE fusion) increased and that of strain GC2 (harboring a constitutive lac::luxCDABE fusion) decreased in the presence of increasing toluene concentrations. In the former case, a maximal effect was observed in the presence of 1% toluene. This simple optical detection biosensor module may potentially be utilized for monitoring soil contamination from areas suspected of chemical pollution such petrochemical industrial zones or petrol stations.

Geochemical anomalies of potentially hazardous elements reflect catchment geology: An example from the Tyrrhenian coast of Italy

Assessing soil contamination by hazardous metals and estimating the extent to which metal concentrations in surficial sediments may pose risks to human health are increasingly important environmental issues. An integrated sedimentological and geochemical study of 57 Holocene beach sands from the shallow subsurface (120–130 cm depth) of the heavily urbanized Tyrrhenian Sea coast of Italy (Tuscany and adjacent coastal stretches) allowed a remarkable compositional heterogeneity to be identified as a function of spatial variations in riverine sediment supply and alongshore sediment dispersal patterns.Concentrations of Cr, Ni, and As exceeding maximum permissible limits for recreational/industrial sites (150 mg/kg, 120 mg/kg, and 20 mg/kg, respectively) reveal spatial trends that fit the petrography of modern beach sands and closely reflect the geology of river catchments, thus indicating a geogenic origin. Extremely high concentrations of Cr (and Ni), even 10 times greater than threshold values, are interpreted to reflect sediment supply from river catchments rich in ultramafic rocks (ophiolite sequences of Cecina and Campiglia areas), with subsequent transport via the longshore drift. On the other hand, high As concentrations in the Campiglia region and along the southern stretch of coast reflect leaching of felsic volcanic and plutonic parent rocks and hydrothermal products related to the Tuscan and Roman magmatic provinces cropping out in the Fiora, Albegna, and Cornia river catchments.This study shows that coastal sediment derived from particular source rocks is likely to contain potentially harmful metals in predictable proportions, which may easily exceed maximum allowable concentrations. Assessing spatial distribution of such metals based on catchment geology and sediment transport pathways may help separate natural concentrations from the anthropogenic contribution, providing a valuable source of information for appropriate remediation strategies and management options.

Comparison of heavy metals contamination and ecological risk between soils enriched with compost and chemical fertilizers in the North of Iran and ecological risk assessment

Background: Nowadays, uncontrolled use of chemical fertilizers in agriculture is one of the reasons for the entry of heavy metals into the environment. In this study, the heavy metals contamination of the soils enriched with compost and chemical fertilizers in the North of Iran and its ecological risk assessment were evaluated. Methods: In this study, 108 soil samples were collected from agricultural soils of some places of Babol in Mazandaran province. An atomic absorption spectrophotometer (PG-990) was used to determine the concentrations of lead, cadmium, and zinc in the soil samples. The assessment of soil contamination was performed by the contamination factor, degree of contamination indices, and the potential ecological risk of the heavy metals. Data were analyzed using SPSS version 22. Descriptive and chi-square tests were used to compare the mean with existing standards. Significant level was considered at P<0.05. Results: The highest lead concentration (35.7 ± 9.5 mg/kg) was observed at 5-cm depth, and the maximum cadmium (1.1 ± 0.2 mg/kg) and zinc (88 ± 22.6 mg/kg) concentrations were observed at 15-cm depth. The results showed that lead, cadmium, and zinc concentrations in the agricultural soils enriched with compost fertilizers were acceptable, but agricultural soils enriched with chemical fertilizers indicated higher content than those enriched with compost fertilizers and higher than the maximum allowable concentration. The maximum contamination degree, pollution index, and potential ecological risk in the agricultural soils enriched with the chemical fertilizers were 15.77, 1.97, and 293.48, respectively, and these soils had low potential pollution and moderate ecological risks. Conclusion: According to the results, it is necessary to use compost fertilizers for the agricultural soils enrichment.

Risk assessment of soil contamination with heavy metals from sewage sludge and ash after its incineration

Risk assessment of soil contamination with heavy metals from sewage sludge and ash after its incineration

ЦИФРОВАЯ ТЕХНОЛОГИЯ КОМПЛЕКСНОЙ ОЦЕНКИ ЭКОЛОГИЧЕСКОЙ ОПАСНОСТИ И ОХРАНЫ ТРУДА В СЕЛЬСКОМ ХОЗЯЙСТВЕ

The methodology, technique and model of complex assessment of ecological danger and labor protection in agricultural production, which were the basis for creation of a package of programs of digital technology of this process for use by farms in practical activity, are developed on the basis of long-term researches. The program package includes the following blocks: assessment of soil and product contamination by pesticides; assessment of soil and product contamination by heavy metals; assessment of hazard class of waste and by-products; assessment of working conditions in the workplace; assessment of ecological culture and culture of labor protection of workers and the population; assessment of the level of investment in labor protection, environment and environmentally safe products; assessment of the impact of mineral fertilizers on the environment; assessment of the load of cattle on pastures and the ratio of stabilizing and destabilizing factors. The software product developed in accordance with the model of integrated assessment of the environmental and occupational safety, held a pilot production testing in JSC «Malinischi» in Pronsky district of the Ryazan region, in which deviations from the risk indicators from criterion values were determined. On the basis of the obtained data, measures to reduce the impact of negative factors on the environment are developed.

Assessing soil contamination in automobile scrap yards by portable X-ray fluorescence spectrometry and magnetic susceptibility.

A by-product of industrialization and population growth, automobile scrap yards are a potential source of metal contamination in soil. This study evaluated the use of portable X-ray fluorescence (pXRF) spectrometry and magnetic susceptibility (χ) analysis in assessing metal soil contamination in scrap yards located in Brazil. Five automobile scrap yards were selected in Curitiba, Paraná State (CB1, CB2, and CB3) and Lavras, Minas Gerais State (LV1 and LV2). By evaluating metal concentrations and geoaccumulation index values, we verified moderate Cu, Pb, and Zr contamination and moderate to high Zn contamination, primarily in the topsoil (0-10cm). Soil Zn concentrations in automobile scrap yards were on average four times higher than in reference soils, suggesting that galvanized automobile parts may be the primary source of this soil contaminant. Although other elements (i.e., As, Cr, Fe, Nb, Ni, and Y) were slightly increased compared to reference values in one or more soils, concentrations did not constitute contamination. Automobile scrap yard topsoil had higher χ values (5.8 to 52.9 × 10-7m3kg-1) at low frequency (χlf) compared to reference soil (3.6 to 7.5 × 10-7m3kg-1). The highest values of χlf occurred in LV soils, which also represented the highest Zn contamination. Magnetic multidomain characteristics (percent frequency-dependent susceptibility between 2 and 10) indicated magnetic particle contributions of anthropogenic origin. The use of pXRF and χlf as non-destructive techniques displays potential for identifying soil contamination in automobile scrap yards.

Geospatial analysis and assessment of garden soil contamination in New York City

Elevated trace metal concentrations, in particular, lead (Pb), are prevalent in urban soils and it is one of the main hurdles for urban agriculture. The growing popularity of gardening in urban areas could also mean increased public health risk. In this study, the spatial distribution of Pb in New York City gardens was analyzed and visualized by Geographic Information System (GIS) tools. Pollution level and ecological risks of gardens and overall New York City (NYC) were evaluated with different indices. The degree of the contamination factors was ranked as follows: Pb >Cu > Zn > Cr>As>Ni>Cd. The single ecological risk index and potential ecological index indicated that Pb had moderate to significantly high risk to the local garden ecosystems. Based on the pollution load index, soil quality of the majority of NYC gardens were characterized as polluted. Geostatistical, geoprocessing, and spatial tools were used to create color-coded maps to support decision making related to gardening and to estimate potential human health risks from gardening, living, or working in/or near these gardens. These findings have important implications for the development of pollution prevention and mitigation strategies to reduce public health risk from garden soil trace metal contamination.

Set of enzymatic bioassays for assessment of soil pollution

A concept of the comprehensive assessment of soil contamination is proposed. In this concept, the conclusion regarding the presence of toxic substances in a sample, which is being analyzed, is connected with the inhibition of enzymatic reactions that are responsible for various functions of a live organism, such as luminescence, respiration, etc., these functions are taken as test functions in classical bioassays, which are using live objects (luminous bacteria, daphnia, algae, etc.). The regularities of the impact of different classes of toxicants on the activity of individual enzymes or coupled oligo-enzyme chains have been established. These enzyme reactions are selected as potential test objects - markers of pollution. The set of enzymatic bioassays consists of three enzyme systems with maximum sensitivity to different classes of toxicants: butyrylcholinesterase, NAD(P)H:FMN‑oxidoreductase + luciferase and lactate dehydrogenase + NAD(P)H:FMN‑oxidoreductase + luciferase. The possibility of using enzymes instead of living organisms in the bioassay of natural complex systems is shown.

Assessment of soil and groundwater contamination at a former Tannery district in Dhaka, Bangladesh.

The uncontrolled and unplanned development of leather processing industries in Bangladesh has contaminated land and water, prompting concerns for public health. Hazaribagh, located in the southwestern part of Dhaka, has been the city's principal leather processing zone since the 1960s. In order to alleviate the environmental contamination and public health risks to citizens of Hazaribagh and downstream, a relocation project was launched to remove the tanning industry. However, soil and groundwater quality conditions of the former industrial sites must be assessed and/or remediated for commercial and residential use. Soil was collected from ten sites and tested for concentrations of potentially toxic metals (Pb, Cr, Zn, Cu, Ni and Cd), and groundwater was collected from six sites and analyzed for physiochemical parameters and potentially toxic metals. Concentrations of soil Cr, Zn and Cu exceeded the European Union maximum permissible concentrations. Deep groundwater Cr concentration in one location exceeded the Bangladesh DoE maximum limits; however, deep groundwater is overall of good-to-excellent quality. Spatial variations of soil and groundwater contamination in Hazaribagh indicate that contaminants have not spread laterally. Based on local conditions, current technologies, contamination level, time and cost, and ease of operation, it is suggested that soil flushing, electrokinetics and/or phytoremediation could be options for remediation of affected soil and groundwater in the Hazaribagh district.

Set of Enzymatic Bioassays for Assessment of Soil Contamination.

A concept of the comprehensive assessment of soil contamination is proposed. According to it, the conclusion regarding the presence of toxic substances in the analyzed sample is based on the inhibition of enzymatic reactions responsible for various functions of a living organism, such as luminescence, respiration, etc. These functions are taken as test functions in classical bioassays with the use of living objects (luminous bacteria, daphnia, algae, and others). The regularities of the impact of different classes of toxicants on the activity of particular enzymes or coupled oligo-enzyme chains have been established. These enzyme reactions are selected as potential test objects: markers of contamination. Three enzyme systems with the maximal sensitivity to different classes of toxicants have been chosen for the set of enzymatic bioassays: butyrylcholinesterase, NAD(P)H:FMN-oxidoreductase + luciferase, and lactate dehydrogenase + NAD(P)H:FMN-oxidoreductase + luciferase. The possibility to use enzymes instead of living organisms in the bioassay of natural complex systems has been shown.

Zirconium as a suitable reference element for estimating potentially toxic element enrichment in treated wastewater discharge vicinity.

The suitability of a reference element or normalizer used in assessing soil contamination levels using enrichment factor (EF) is important for soil quality assessment and monitoring. This study evaluated the results of using three reference elements Ti, Fe, and Zr for EF determination of Rb and Sr in soils within treated wastewater discharge vicinity, Central Botswana. The upper continental crust (UCC), world average values (WAV), and the local background values (LBV) were used in EF assessment of eight pedons. The elemental concentrations of the soils were determined with portable X-ray fluorescence (pXRF) analyzer. Relationships between the elements were strongly significant between Rb and Ti (r = 0.600, p < 0.01), Rb and Fe (r = 0.735, p < 0.01), Sr and Ti (r = 0.545, p < 0.01), and Sr and Fe (r = 0.841, p < 0.01). Second-level correlation analysis between contamination factor (CF) and EF levels showed Zr as the best reference element for Rb and Sr in the soils. Results from this study provide baseline knowledge necessary for contamination assessment and monitoring of soils with similar environmental conditions.

HYGIENIC ASSESSMENT OF THE CONTENT OF CHEMICALS IN THE SOIL OF MINING AREAS OF THE TRANS-BAIKAL REGION

Introduction. Intensive exploration and processing of mineral raw materials in the Trans-Baikal territory has caused the accumulation of considerable amount of industrial mining waste with high content of chemical elements of different classes of hazard. Currently 33 tailings storage facilities (TSF) accumulating approximately 3 milliard tons of different industrial waste are located in the territory of the region. The aim of the research is the hygienic assessment of soil contamination in the residential areas adjacent to TSFs. Material and methods. Atomic absorption spectrophotometry method was used for the determination of heavy metals. The study presents the results of analyses of 444 samples of gross content of lead, zinc, copper, mercury, arsenic, and cadmium in the soil of Khapcheranga, Sherlovaya Gora, Kadaya, Vershino-Darasunsky, and Vershino-Shakhtaminsky mining villages throughout the duration of 2012 - 2015. Results. During the period of the study the total value of soil contamination with Zc calculated by the median concentrations in Khapcheranga Village amounted to 4.7 6.9, in Vershino-Shakhtaminaky - to 6.7 8.8, which corresponds to the «allowable» level of the contamination. Zc calculation by maximum concentrations has shown the soil to be referred to the category from “moderately dangerous” to “extremely dangerous”; this value in Khapcheranga Village amounted to 48.7 - 235.3, in Vershino-Shakhtaminsky Village - to 23.76 - 164.8. Discussion. In the residential areas the allowable degree of soil contamination was determined to be predominantly observed; Khapcheranga and Vershino-Shakhtaminsky villages are the exceptions. The results of the assessment give the evidence of tge increased lead, cadmium and arsenic content throughout the entire area of the villages, while the highest levels of accumulated toxic substances are registered in the areas located near the TSF Conclusion. Thus, several zones of natural and anthropogenous contamination with increased concentrations of heavy metals and arsenic have been formed in the Trans-Baikal Territory. This dictates the need to study the influence of geochemical anomalies on the health of population.

A preliminary assessment of potential ecological risk and soil contamination by heavy metals around a cement factory, western Saudi Arabia

AbstractTwenty surface soil samples (0-10 cm) and shoots of a perennial shrub Zygophyllum coccineum L. were collected around a cement factory on the western coast of Saudi Arabia, in order to assess concentrations of some heavy metals (Cr, Cu, Ni, Pb and Zn). The most noticeable among all heavy metals was Pb that showed an average concentration of 460.15±86.60 μg g-1 followed by Cr (138.67±30.89 μg g-1), Zn (54.41±43.79 μg g-1), Ni (41.22±12.60 μg g-1) and Cu (33.48±12.52 μg g-1). Based on biological concentration factor analysis, Z. coccineum can be considered as an accumulator only for zinc (BCF &gt;1). Estimation of various ecological contamination factors revealed the significant impact of Pb in the environmental pollution in the region. It is also understood that the primary contribution to the ecological risk index (RI) mainly originated from various anthropogenic influences such as industrialization and urbanization. The different statistical analysis further revealed the potential effect of soil characteristics on the occurrence and dispersal of heavy metals in the study area.

241Am on the territories adjacent to the Belarusian sector of the Chernobyl NPP resettlement zone: soil contamination, foodstuffs and population internal dose assessment

241Am is the only radionuclide of Chernobyl radioactive fallout the content of which until 2058 continues to increase. The purpose of this work is to assess the 241Am internal exposure doses of residents of settlements on the territory adjacent to the resettlement lands of the Chernobyl nuclear power plant. To achieve this goal the current levels of 241Am and accompanying 137Cs content in the soil and foodstuffs were determined at the private settlements of the Bragin district of Gomel region of Belarus. 241Am (Eγ 59.6 keV) content in soil samples and 137Сs (Eγ 661 keV) content in soil/food samples were determined by gamma spectrometry. Determination of 241Am specific activity in food samples was performed by the radiochemical method using selective extraction-chromatographic resins. With an average level of 1.3 kBq/m2 , the maximum soil contamination density of 241Am can reach 3.6 kBq/m2 , and for 137Cs it is one or two orders of magnitude higher and ranges from 50 kBq/m2 to 350 kBq/m2 . The maximum specific activity of 241Am in products is determined in samples of leafy parsley – 33 mBq/kg, and in samples of potatoes, beets, onions per feather – not exceed 5 mBq/kg. The content of accompanying 137Cs in samples of plant products is in the range of 3-12 Bq/kg. In estimation of the internal dose of exposure by the food chain it is conservatively assumed that the population receives all the main components of the diet in their own farmstead. Calculation of the dose of internal exposure during inhalation is made under the assumption that the population performs work in the garden 4 hours a day for 7 months. The total expected dose of internal exposure from 241Am residents of settlements is dominated by the inhalation component, while the oral route is dominant in the formation of the total dose of internal exposure from concomitant 137Сs, which is 20 or more times higher than 241Am.

Оценка загрязненности почв тяжелыми металлами вокруг Дашкесанского горно-обогатительного комбината

The article is devoted to the results of the determination and assessment of the content of heavy metals (HM) in the soil around the Dashkesan mining and processing factory of the Azerbaijan Republic. Combine open-pit mining method produces iron ore with its subsequent enrichment by flotation. Quarry blasting, transportation and crushing of ore by flotation swallowing; open pit and waste rock dumps after ore concentration (heaps) are the main sources of environmental pollution. Air currents and meltwaters contaminants HM fall into the soil. By the method of atomic absorption spectrometry in soil, the total content of Pb, Co, Cd, Cr, Cu, Zn was determined. The assessment of soil contamination by heavy metals was carried out by the Clarke number, the MPC and the total amount (Zc) of the TM. According to the Pb, Cd, Cu, Zn content, the soils are estimated as unpolluted, and according to the Co and Cr content - extremely polluted (MPC exceedance is more than 4 times). According to the total content of HM (Zc), soils are also assessed as extremely polluted. There is no regularity in the distribution of HM content in the soil around the source of pollution. As the distance from the source of contamination increases, the HM content in the soil changes spontaneously, which is a result of the influence of orographic and geological factors.

The ecological risk assessment of soil contamination with Ti and Fe at military sites in Ukraine: avoidance and reproduction tests withFolsomia candida

The aim of this research was to assess the effect of soil contamination with titanium (Ti) and iron (Fe) at military sites in Ukraine using the avoidance and reproduction tests with Folsomia candida (springtail). The soil used for the tests was sampled in 2017 from Dolyna, Ivano-Frankivsk region, Ukraine from two plots, namely a contaminated and a control site. The sample site is a former military site previously used for tank training. At the control site mainly the concentrations of Ti and Fe were exceeded. The control soil was free from contamination. The avoidance test and reproduction test were conducted with the use of springtail species F. candida. The following nine levels of contamination with heavy metals were established: 1%, 1.5%, 5%, 10%, 15%, 25%, 50%, 75% and 100%. The duration of the avoidance test was 7 days, and that of the reproduction test was 28 days. Overall, the results show that the avoidance and reproduction tests with collembolans have the potential to be used as screening tools in an ecological risk assessment of heavy metals. In the avoidance test, the concentrations from 1.5 to 100% significantly decreased the number of F. candida in the contamination site in comparison to the control site. At the same time, avoidance was not observed in the first concentration (1%). According to the reproduction test, the negative effect on the number of F. candida juveniles was observed beginning at the 10% dose. The half maximal effective concentration (EC50) for the avoidance test was 50.12%, while that for the reproduction test was 22.39%. The contamination with heavy metals at the military areas indicated the short- and long-term toxicity risk on the springtail F. candida.

Multivariate Statistical Characterisation of Soil Quality in the Lower Danube River Riparian Areas

Increasing anthropogenic influences on the environment has caused negative changes in natural ecosystems and soil contamination with potentially toxic metals has become a worrying issue at global level, due to the negative impact on the environment and human health. For the purpose of assessing soil contamination in the riparian areas of the Lower Danube River, a number of 144 soil samples were collected twice a year, in the period of June 2013 � December 2016, from 9 monitoring locations, from 0.05 m and 0.3 m depths, and the following indicators: Cr, Cu, Mn, Ni, Pb, Zn, including Ca, Mg, Corg, SO42- and humus content have been monitored. The soil was sampled, conserved and analysed according to the European standards in force. Metal concentrations were determined using flame (FAAS) and graphite furnace (GFAAS) atomic absorption spectrometry after �aqua regia� digestion of dried, homogenised and 0.5 mm sieved soil sub-samples. Comparing the average concentration values of the analysed potentially toxic metals, a decreasing tendency following the order Cr]Pb]Ni]Cu]Zn]Mn was observed and by reporting the average values at the normal limits, the order Zn]Cu]Mn]Ni]Pb]Cr of magnitude was obtained. To investigate possible correlations and interdependencies of potentially toxic metals content in the riparian soil, multivariate statistical methods were used. After applying Principal Component Analysis (PCA), 3 main components were identified, with a combined share of about 74 % of the original data-set variance. It was observed that during the monitoring period the average values of the all monitored elements from the studied soils were slightly below the normal reference values, according to the national legislation.

Source and background threshold values of potentially toxic elements in soils by multivariate statistics and GIS-based mapping: a high density sampling survey in the Parauapebas basin, Brazilian Amazon.

A high-density regional-scale soil geochemical survey comprising 727 samples (one sample per each 5 × 5km grid) was carried out in the Parauapebas sub-basin of the Brazilian Amazonia, under the Itacaiúnas Basin Geochemical Mapping and Background Project. Samples were taken from two depths at each site: surface soil, 0-20cm and deep soil, 30-50cm. The ground and sieved (< 75µm) fraction was digested using aqua regia and analyzed for 51 elements by inductively coupled plasma mass spectrometry (ICPMS). All data were used here, but the principal focus was on the potential toxic elements (PTEs) and Fe and Mn to evaluate the spatial distribution patterns and to establish their geochemical background concentrations in soils. Geochemical maps as well as principal component analysis (PCA) show that the distribution patterns of the elements are very similar between surface and deep soils. The PCA, applied on clr-transformed data, identified four major associations: Fe-Ti-V-Sc-Cu-Cr-Ni (Gp-1); Zr-Hf-U-Nb-Th-Al-P-Mo-Ga (Gp-2); K-Na-Ca-Mg-Ba-Rb-Sr (Gp-3); and La-Ce-Co-Mn-Y-Zn-Cd (Gp-4). Moreover, the distribution patterns of elements varied significantly among the three major geological domains. The whole data indicate a strong imprint of local geological setting in the geochemical associations and point to a dominant geogenic origin for the analyzed elements. Copper and Fe in Gp-1 were enriched in the Carajás basin and are associated with metavolcanic rocks and banded-iron formations, respectively. However, the spatial distribution of Cu is also highly influenced by two hydrothermal mineralized copper belts. Ni-Cr in Gp-1 are highly correlated and spatially associated with mafic and ultramafic units. The Gp-2 is partially composed of high field strength elements (Zr, Hf, Nb, U, Th) that could be linked to occurrences of A-type Neoarchean granites. The Gp-3 elements are mobile elements which are commonly found in feldspars and other rock-forming minerals being liberated by chemical weathering. The background threshold values (BTV) were estimated separately for surface and deep soils using different methods. The '75th percentile', which commonly used for the estimation of the quality reference values (QRVs) following the Brazilian regulation, gave more restrictive or conservative (low) BTVs, while the 'MMAD' was more realistic to define high BTVs that can better represent the so-called mineralized/normal background. Compared with CONAMA Resolution (No. 420/2009), the conservative BTVs of most of the toxic elements were below the prevention limits (PV), except Cu, but when the high BTVs are considered, Cu, Co, Cr and Ni exceeded the PV limits. The degree of contamination (Cdeg), based on the conservative BTVs, indicates low contamination, except in the Carajás basin, which shows many anomalies and had high contamination mainly from Cu, Cr and Ni, but this is similar between surface and deep soils indicating that the observed high anomalies are strictly related to geogenic control. This is supported when the Cdeg is calculated using the high BTVs, which indicates low contamination. This suggests that the use of only conservative BTVs for the entire region might overestimate the significance of anthropogenic contamination; thus, we suggest the use of high BTVs for effective assessment of soil contamination in this region. The methodology and results of this study may help developing strategies for geochemical mapping in other Carajás soils or in other Amazonian soils with similar characteristics.

Assessment of pesticides in soil from obsolete pesticides stores: a Caribbean case study.

The fate of highly hazardous or persistent pesticides in soils and their potential for environmental and health risks depends on the physical and chemical properties of the pesticide, soil properties including biological health and climatic conditions. Assessing the fate and impact of pesticides in soil is complicated in the Caribbean due to the high diversity of soils and duality of climate. The FAO supported national competent authorities from 11 countries in the Caribbean in the assessment of obsolete stocks and potentially contaminated soil. The Environmental Management Tool Kit (EMKT) prioritised Fond Cole and Camden Base as the only critical sites. Preliminary site investigations that utilised the rapid environmental assessment (REA) methodology identified that contamination was restricted to an impervious layer at the Camden site. Pesticide properties varied across groups, with the organochlorides exhibiting greater sorptive capacity and lower leaching potential relative to the organophosphates. All tested soils were non-saline with alkaline pH and notably sandy in texture with low adsorptive capacity. Analysis of pesticide levels revealed low to undetected quantities across contaminated sites. Traces of Endrin and Dieldrin were found in Marienburg, Suriname. Overall, assessment of soil contamination from stored obsolete pesticides revealed minimal contamination, however, detailed assessment considering contamination gradients should be performed where pesticides were identified.

Profile Distribution and Source Identification of Potentially Toxic Elements in North Nile Delta, Egypt

ABSTRACTVertical distribution and source appointment of potentially toxic elements (PTEs) provide a deeper vision for soil contamination. Contamination factor (CF), contamination degree (CD), enrichment factor (EF), principal component analysis (PCA), and cluster analysis (CA) were used for soil contamination assessment in north Nile Delta, Egypt. Twenty-one soil profiles representing main geomorphic units were dug, and 63 soil samples were collected at three depth intervals (0–30, 30–60 and 60–90 cm). Mean values of the three layers showed that Al, Fe, Mn, Cr, Cu, Pb, Mo, and V did not exceed average natural content of the Earth’s crust, while As, Cd, Co, Ni, and Zn exceeded that limit, except in the sand sheets unit. The studied elements showed irregular vertical distribution trend, except Cr, Ni, and Mo. Both Cr and Ni showed a downward migration, while Mo accumulated in the topsoil. Based on mean values, the CF indicated low contamination with Cr, Cu, Pb, Mn, Mo and V, moderate contamination with Cd and Zn, considerable contamination with As, Co, and Ni, while the CD was low to considerable. Furthermore, the EF indicated safe degree for Cr, Cu, Pb, Mo and V, deficiency to a minimal degree for Cd and Zn, while moderate degree for As, Co, and Ni. The PCA and CA indicated that soil parent materials controlled Al, Fe, Mn, Cu, Cr, Co, Pb, Ni, Mo, and V, while agricultural activities controlled As, Cd and Zn. Similar investigations should be considered in various regions in Egypt to verify potential sources of PTEs and to manage pollution of agricultural fields.