scholarly journals Arsenic and heavy metal concentrations in agricultural soils in South Savo province

2002 ◽  
Vol 11 (4) ◽  
pp. 285-300 ◽  
Author(s):  
V. MÄNTYLAHTI ◽  
P. LAAKSO

Increasing concentrations of arsenic and heavy metals in agricultural soils are becoming a growing problem in industrialized countries. These harmful elements represent the basis of a range of problems in the food chain, and are a potential hazard for animal and human health. It is therefore important to gauge their absolute and relative concentrations in soils that are used for crop production. In this study the arsenic and heavy metal concentrations in 274 mineral soil samples and 38 organogenic soil samples taken from South Savo province in 2000 were determined using the aqua regia extraction technique. The soil samples were collected from 23 farms.The elements analyzed were arsenic, cadmium, chromium, copper, mercury, nickel, lead and zinc. The median concentrations in the mineral soils were:As 2.90 mg kg –1, Cd 0.084 mg kg –1, Cr 17.0 mg kg –1, Cu 13.0 mg kg –1, Hg 0.060 mg kg –1, Ni 5.4 mg kg –1, Pb 7.7 mg kg –1, Zn 36.5 mg kg –1. The corresponding values in the organogenic soils were:As 2.80 mg kg –1, Cd 0.265 mg kg –1, Cr 15.0 mg kg –1, Cu 29.0 mg kg –1, Hg 0.200 mg kg –1, Ni 5.9 mg kg –1, Pb 11.0 mg kg –1, Zn 25.5 mg kg –1. The results indicated that cadmium and mercury concentrations in the mineral and organogenic soils differed. Some of the arsenic, cadmium and mercury concentrations exceeded the normative values but did not exceed limit values. Most of the agricultural fields in South Savo province contained only small amounts of arsenic and heavy metals and could be classified as “Clean Soil”. A draft for the target values of arsenic and heavy metal concentrations in “Clean Soil” is presented.;

2020 ◽  
Author(s):  
Anne Karine Boulet ◽  
Adelcia Veiga ◽  
Carla Ferreira ◽  
António Ferreira

<p>Conservation of agriculture soils is a topic of major concern, namely through the increase of soil organic matter. SoilCare project (https://www.soilcare-project.eu/) aims to enhance the quality of agricultural soils in Europe, through the implementation and testing of Soil Improving Cropping Systems in 16 study sites. In Portugal, the application of urban sewage sludge amendments in agriculture soils has been investigated. However, this application is a sensitive topic, due to the risk of long term accumulation of heavy metals and consequent contamination of the soil. The recent Portuguese legislation (Decret-Law 103/2015) is more restrictive than the precedent one (Decret-Law 276/2009) in terms of maximum concentrations of heavy metals in agricultural soils. The analytical quantification of heavy metals, however, raises some methodological questions associated with soil sample pre-treatment, due to some imprecisions in standard analytical methods. For example, the ISO 11466 regarding the extraction in Aqua Regia provides two pre-treatment options: (i) sieve the soil sample with a 2 mm mesh (but if mass for analyses is <2g, mill and sieve the sample <250µm is required), or (ii) mill and sieve the soil sample through a 150µm mesh. On the other hand, the EN 13650 requests soil samples to be sieved at 500µm. Since heavy metals in the soil are usually associated with finer particles, the mesh size used during the pre-treatment of soil samples may affect their quantification.</p><p>This study aims to assess the impact of soil particle size on total heavy metal concentrations in the soil. Soil samples were collected at 0-30cm depth in an agricultural field with sandy loam texture, fertilized with urban sludge amendment for 3 years. These samples were then divided in four subsamples and sieved with 2mm, 500µm, 250µm and 106µm meshes (soil aggregates were broken softly but soil wasn’t milled). Finer and coarser fractions were weighted and analyzed separately. Heavy metals were extracted with Aqua Regia method, using a mass for analyze of 3g, and quantified by atomic absorption spectrophotometer with graphite furnace (Cd) and flame (Cu, Ni, Pb, Zn and Cr).</p><p>Except for Cu, heavy metals concentrations increase linearly with the decline of the coarser fraction. This means that analyzing heavy metals content only in the finest fractions of the soil leads to an over estimation of their concentrations in the total soil. Results also show that coarser fractions of soil comprise lower, but not negligible, concentrations of heavy metals. Calculating heavy metal concentrations in the soil based on the weighted average of both fine and coarse fractions and associated concentrations, provide similar results to those driven by the analyses of heavy metals in the <2mm fraction. This indicates that milling and analyzing finer fractions of the soil did not influence the quantification of heavy metals in total soil. Clearer indications on analytical procedures should be provided in analytical standards, in order to properly assess heavy metal concentrations and compare the results with soil quality standards legislated.  </p>


2020 ◽  
Vol 10 (27) ◽  
pp. 200911
Author(s):  
Aung Zaw Tun ◽  
Pokkate Wongsasuluk ◽  
Wattasit Siriwong

Background. Artisanal and small-scale mining activities are widely practiced globally. Concentrations of heavy metals associated with gold, such as copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb) can increase in the environment as a result of mining activities, leading to environmental pollution and pose toxicity risks to humans and animals. Objectives. The aim of the present study was to investigate soil concentrations of toxic heavy metals in placer small-scale gold mining operations in Myanmar. Methods. Soil samples were collected from three placer small-scale gold mining sites: Site A located in the Hmawbon public protected forest, Site B and Site C, situated in the Nant-Kyin reserved forest around Nar Nant Htun village. At each site, soil samples were collected from four gold mining stages (ore processing, sluicing, panning, and amalgamation). Atomic absorption spectroscopy was utilized to examine the concentrations of As, Cd, Pb, and Hg. Results. The highest heavy metal concentrations were generally found in the amalgamation stages across all the gold mining sites. Across the three mining sites, the maximum heavy metal concentrations in the amalgamation stage were 22.170 mg.kg−1 for As, 3.070 mg.kg−1 for Cd, 77.440 mg.kg−1 for Hg, and 210.000 mg.kg−1 for Pb. Conclusions. The present study examined the concentrations of As, Cd, Hg and Pb in the soil of several small-scale gold mining sites in Banmauk Township, Myanmar. The results demonstrated the presence of high concentrations of heavy metals in the soil of the gold mining sites. Miners in this area work without proper personal protective equipment, and frequent exposure to heavy metals in the soil may cause adverse health effects. The present study provides baseline data for future risk assessment studies of heavy metal contamination in gold mines. Competing Interests. The authors declare no competing financial interests


2021 ◽  
Vol 47 (3) ◽  
Author(s):  
Ruth Ramos ◽  
Alejandra Verde ◽  
Elia M García

Venezuelan oil exploration and exploitation activities have been taking place since the 18th century. These long-term activities are closely related to heavy metal contamination because of the increasing input of toxic pollutants. Variations in heavy metal concentrations can cause, among other things, changes in metal distribution patterns, alterations in biogeochemical cycles, and increments in environmental and biological risks. The need for a complete baseline on heavy metal concentrations along the Venezuelan coast is critical. For this reason, we present the concentrations, distribution, and degree of contamination of 9 heavy metals (barium, mercury, copper, nickel, chromium, cadmium, zinc, lead, and vanadium) in marine sediments along the Venezuelan coast. We used the enrichment factor, the geoaccumulation index, and the mean effects range median quotients to evaluate the degree of contamination, comparing areas with and without intervention. Our results indicate that higher concentrations of these heavy metals are associated with places with greater anthropic activity, especially on the central and eastern coasts of Venezuela. Only cadmium showed extremely severe enrichment and a high degree of contamination. The biohazard potential was between 12% and 30% and was primarily associated with locations having high oil activity, which suggests that these places must be monitored, given the potential hazard they represent. This work encompasses the distribution and concentration of 9 heavy metals along the Venezuelan coast and takes relevance as a baseline for heavy metal concentrations and pollution indicators in marine sediments for Venezuela and the Caribbean.


2009 ◽  
Vol 66 (3) ◽  
pp. 361-367 ◽  
Author(s):  
Gustavo Souza Valladares ◽  
Otávio Antônio de Camargo ◽  
José Ruy Porto de Carvalho ◽  
Alessandra Maria Cia Silva

Agricultural management with chemicals may contaminate the soil with heavy metals. The objective of this study was to apply Principal Component Analysis and geoprocessing techniques to identify the origin of the metals Cu, Fe, Mn, Zn, Ni, Pb, Cr and Cd as potential contaminants of agricultural soils. The study was developed in an area of vineyard cultivation in the State of São Paulo, Brazil. Soil samples were collected and GPS located under different uses and coverings. The metal concentrations in the soils were determined using the DTPA method. The Cu and Zn content was considered high in most of the samples, and was larger in the areas cultivated with vineyards that had been under the application of fungicides for several decades. The concentrations of Cu and Zn were correlated. The geoprocessing techniques and the Principal Component Analysis confirmed the enrichment of the soil with Cu and Zn because of the use and management of the vineyards with chemicals in the preceding decades.


Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1840 ◽  
Author(s):  
Lei Huang ◽  
Hongwei Fang ◽  
Ke Ni ◽  
Wenjun Yang ◽  
Weihua Zhao ◽  
...  

In this study, surface sediment samples were taken from the Three Gorges Reservoir (TGR) in June 2015 to estimate the spatial distribution and potential risk of Cu, Zn, Cd, Pb, Cr, and Ni (34 sites from the mainstream and 9 sites from the major tributaries), and correlations with environmental variables were analyzed (e.g., median sediment size, water depth, turbidity, dissolved oxygen of the bottom water samples, and total organic carbon, total nitrogen, and total phosphorus of the surface sediment samples). Results show that the heavy metal concentrations in the sediments have increased over the last few decades, especially for Cd and Pb; and the sites in the downstream area, e.g., Badong (BD) and Wushan (WS), have had greater increments of heavy metal concentrations. The sampling sites from S6 to S12-WS are identified as hot spots for heavy metal distribution and have relatively high heavy metal concentrations, and there are also high values for the sites affected by urban cities (e.g., the concentrations of Zn, Cd, Cr and Ni for the site S12-WS). Overall, the heavy metal concentrations increased slightly along the mainstream due to pollutants discharged along the Yangtze River and sediment sorting in the reservoir, and the values in the mainstream were greater than those in the tributaries. Meanwhile, the heavy metal concentrations were generally positively correlated with water depth (especially for Ni), while negatively correlated with dissolved oxygen, turbidity, and median sediment size. These environmental variables have a great impact on the partition of heavy metals between the sediment and overlying water. According to the risk assessment, the heavy metals in the surface sediments of TGR give a low to moderate level of pollution.


2020 ◽  
Vol 49 (1) ◽  
pp. 68-80
Author(s):  
Tamara Zalewska ◽  
Paulina Brzeska-Roszczyk ◽  
Beata Danowska ◽  
Mariusz Pełechaty

AbstractThe paper presents the first data on the concentrations of heavy metals (Cd, Pb, Zn, Cu, Ni, Cr, Mn) and 137Cs and their contamination ratios (CR) in the most abundant species of macrophytes in the Vistula Lagoon. No significant differences in the concentrations of heavy metals and 137Cs between macrophyte taxa or the influence of rivers flowing into the Vistula Lagoon on heavy metal concentrations in the area were found. The concentrations of heavy metals in macrophyte taxa varied in the following ranges: Cd – 0.1–0.7 mg kg−1 d.w.; Pb – 0.5–5.0 mg kg-1 d.w.; Zn – 29–390 mg kg-1 d.w.; Cu – 2.5–8.3 mg kg-1 d.w.; Ni – 0.4–6.8 mg kg−1 d.w.; Cr – 0.5–2.8 mg kg−1 d.w.; Mn – 380–8500 mg kg−1 d.w. Since the 1990s, a decline or stable state of heavy metal concentrations in bottom sediments has been observed, reflecting changes in the environment of the Vistula Lagoon. The linear sedimentation rate in the Vistula Lagoon was 3.3 mm y−1. The results presented in the paper can serve as a baseline for assessing changes in the environmental status of the Vistula Lagoon, which may occur as a result of future investments, including building a new navigable canal through the Vistula Spit.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Muyun Sun ◽  
Kaiyuan He ◽  
Shi Shu

Despite the extensive attention paid to the transport of heavy metals in sludge landfills, the processes of transporting these pollutants from a landfill to the underground environment are quite complicated and subject to significant uncertainty. In this study, the transport of typical heavy metal pollutants in a sludge landfill through saturated and unsaturated soil zones during rainfall was investigated via numerical modeling. The objectives of the study are to evaluate the heavy metal pollution risk from a sludge landfill under rainfall infiltration conditions and to propose several management suggestions. The results indicate that, during rainfall, heavy metal concentrations at the top of the unsaturated sludge layer decrease rapidly, but they decrease more gradually at the bottom of the layer. The maximum concentration appears in vertical distribution and decreases gradually through the saturated zone. Nickel is the first heavy metal pollutant to break through the low-permeability natural silt barrier. The transport parameters not only influence the simulated time for heavy metal pollutants to break through the silt layer and cause underground environmental pollution but also affect the extent to which the heavy metal pollutants in pore water exceed the guidelines. On the basis of these results, for dredged sludge with heavy metal concentrations significantly exceeding the standard, the concentration of heavy metals in pore water should be reduced before the sludge is landfilled, and a covering layer should be established on the sludge surface to control rainfall infiltration.


2018 ◽  
Vol 3 (1) ◽  
pp. 32-37 ◽  
Author(s):  
Mohammad Kazem Souri ◽  
Neda Alipanahi ◽  
Mansoure Hatamian ◽  
Mohammad Ahmadi ◽  
Tsehaye Tesfamariam

Abstract Heavy metal accumulation in vegetable tissues often poses a great risk for human health. In the present study, accumulation of heavy metal in green leafy vegetable crops of coriander, garden cress, lettuce and spinach were evaluated under waste water irrigation in fields located in Kahrizak, on the southern edge of the metropolitan city of Tehran, Iran. Atomic absorption spectrophotometery was used for determination of heavy metal concentrations in leaf tissue. The results showed that heavy metal concentrations in soil and irrigation water were significantly high than allowable levels. Analysis of plant leaf tissue showed that spinach and garden cress accumulated higher concentrations of heavy metals compared to coriander and lettuce plants. Central leaves of lettuce showed the lowest heavy metal concentration compared to outer leaves or leaves of other vegetable crops, and can be the safer product for fresh consumption. The results indicate that the vegetables produced in the region are not suitable for fresh consumption and the agricultural activities should change towards ornamental or industrial crops production.


2011 ◽  
Vol 49 (No. 9) ◽  
pp. 402-409 ◽  
Author(s):  
K. Gondek ◽  
B. Filipek-Mazur

Sewage sludge application in agriculture is the simplest method of its management. Its content of organic and inorganic toxic components is a barrier to such management. Particular attention should be paid to the content of heavy metals whose presence in sewage sludge and later in soil poses hazard for plants, animals and people. The investigations aimed to determine the effect of vermicomposts obtained from tannery sludge on development of the root system and biomass of shoots as well as heavy metal concentrations in these organs. In the first year after the vermicomposts application their effect on the maize biomass increase was equal to the farmyard manure treatment but significantly worse than the mineral fertilization. The consecutive fertilizer effect of vermicomposts of tannery sludge ted on the increase in biomass of the shoots and roots of winter rape, sunflower and oats was comparable with the farmyard manure effect but notably better than the mineral fertilization. Heavy metal concentrations in individual plants were diversified; in the plants from vermicompost treatment they were as a rule lower than in the plants from mineral or farmyard manure treatment. Absorbed heavy metals accumulated primarily in the root systems, whereas the extremely high chromium content in vermicomposts did not cause its excessive accumulation in the cultivated plants.


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