Natural enrichment of topsoils with chromium and other heavy metals, Port Macquarie, New South Wales, Australia

Soil Research ◽  
1997 ◽  
Vol 35 (5) ◽  
pp. 1165 ◽  
Author(s):  
Bernd G. Lottermoser

Total heavy metal concentrations [cobalt (Co), chromium (Cr), copper(Cu), iron (Fe), mangnese (Mn), nickel (Ni), lead (Pb), and zinc (Zn)]were determined in surface soil samples from Port Macquarie, New South Wales,Australia. Composite topsoil samples (0–10 cm depth) had mean values(per kg) of 13 mg Co, 1020 mg Cr, 59 mg Cu, 136·7 g Fe, 719 mg Mn, 149mg Ni, 20 mg Pb, and 47 mg Zn. The topsoils were generally characterised by alow pH (3·8–5·2) and a mineralogy dominated by haematite,magnetite, quartz, and kaolinite. Chromium was predominantly present in thetopsoils as Cr3+ in microcrystalline chromite(FeCr2O4) and, to a lesser degree,in kaolinite and haematite. Differences in Cr soil concentrations with depthwere due to variations in the relative abundance of the various soilcomponents, rather than Cr3+ mobility within the soilprofile. The elevated heavy metal concentrations are the result of soildevelopment over metal-rich bedrock (serpentinite matrix melange) andassociated enrichment of relatively immobile elements (Cr, Fe, Ni) in theresidual soil profile. The ANZECC and NH&MRC (Australian and New ZealandEnvironment and Conservation Council and National Health & MedicalResearch Council) environmental investigation limits were exceeded for100% of the sample sites for Cr, 47% for Cu, 61% for Mn,and 58% for Ni.


2005 ◽  
Vol 45 (4) ◽  
pp. 445 ◽  
Author(s):  
J. L. Cooper

Two forms of biosolids, with and without lime, were applied to acid soils at 2 sites growing wheat and triticale in central New South Wales. The forms of biosolids used were dewatered sewage sludge cake, and N-Viro Soil which is a lime-amended sewage sludge. Dewatered sewage sludge cake was applied at rates of 0, 6, 12 and 24 dry Mg/ha, and N-Viro soil at 0, 1.5, 3.0 and 4.5 dry Mg/ha. The soil was sampled and analysed at 2 points in time to determine the effect of the biosolids on heavy metal concentrations. Vegetative plant material and grain were also analysed for heavy metal and organo-chlorine pesticide levels. Zinc and copper concentrations increased significantly with the addition of biosolids, especially with the highest rates of dewatered sewage sludge cake. However, all soil heavy metals were below the maximum allowable soil contaminant concentrations set by Environment Protection Authority, NSW. Cereal species, the addition of lime, and biosolids each affected heavy metal concentrations in plant material, but the responses differed between sites. Also, the changes in heavy metal concentrations in plant material were smaller and less consistent than the changes in soil heavy metal concentrations. The maximum heavy metal concentrations in grain were all below the maximum permitted concentrations of Food Standards Australia New Zealand. There were no detectable changes in the levels of organo-chlorine pesticides in the grain.



2003 ◽  
Vol 43 (2) ◽  
pp. 163 ◽  
Author(s):  
T. L. Hind ◽  
G. J. Ash ◽  
G. M. Murray

Surveys of petal infestation and stem infection conducted in 1998, 1999 and 2000 indicated that Sclerotinia sclerotiorum poses a threat to the Australian canola industry. Inoculum was present throughout all canola-growing regions of New South Wales and the stem disease was widespread throughout southern New South Wales. Percentage petal infestation increased over the 3 years surveyed with values ranging from 0 to 99.4%. The highest petal infestation values were observed in 2000 (maximum of 99.4%, mean of 82.2%), with lower mean values in 1998 (38.4%) and 1999 (49.6%). Stem infection ranged from 0 to 37.5% and most fields had less than 10% stem infection. Stem rot incidence before harvest did not relate to percentage petal infestation determined during flowering. This indicated that factors other than percentage petal infestation were important in influencing stem rot incidence. While there was no relationship between percentage petal infestation and stem rot incidence, stem infection never occurred without prior petal infestation.



1987 ◽  
Vol 38 (5) ◽  
pp. 591 ◽  
Author(s):  
GE Batley

The distribution and bioavailability of heavy metals in waters and sediments from Lake Macquarie (N.S.W.) have been examined. Elevated concentrations of zinc, lead, cadmium and copper detected in surface sediments and waters from the northern end of the lake are attributable to discharges from a lead-zinc smelter on Cockle Creek. The majority of the metals are in bioavailable forms and are shown to be accumulated in seagrasses, seaweeds and bivalves. Calculations indicate that, at the current rates of discharge, the concentrations of bioavailable metals in newly-deposited sediments should not be deleterious. Elutriate tests showed that there will be no significant mobilization of metals during dredging operations to remove the contaminated sediments.



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 ◽  
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



2001 ◽  
Vol 41 (2) ◽  
pp. 187 ◽  
Author(s):  
R. Aldaoud ◽  
W. Guppy ◽  
L. Callinan ◽  
S. F. Flett ◽  
K. A. Wratten ◽  
...  

In 1995–96, a survey of soil samples from subterranean clover (Trifolium subterraneum L.) paddocks was conducted across Victoria, South Australia, New South Wales and Western Australia, to determine the distribution and the prevalence of races of Phytophthora clandestina (as determined by the development of root rot on differential cultivars), and the association of its occurrence with paddock variables. In all states, there was a weak but significant association between P. clandestina detected in soil samples and subsequent root rot susceptibility of differential cultivars grown in these soil samples. Phytophthora clandestina was found in 38% of the sampled sites, with a significantly lower prevalence in South Australia (27%). There were significant positive associations between P. clandestina detection and increased soil salinity (Western Australia), early growth stages of subterranean clover (Victoria), mature subterranean clover (South Australia), recently sown subterranean clover (South Australia), paddocks with higher subterranean clover content (Victoria), where herbicides were not applied (South Australia), irrigation (New South Wales and Victoria), cattle grazing (South Australia and Victoria), early sampling dates (Victoria and New South Wales), sampling shortly after the autumn break or first irrigation (Victoria), shorter soil storage time (Victoria) and farmer’s perception of root rot being present (Victoria and New South Wales). Only 29% of P. clandestina isolates could be classified under the 5 known races. Some of the unknown races were virulent on cv. Seaton Park LF (most resistant) and others were avirulent on cv. Woogenellup (most susceptible). Race 1 was significantly less prevalent in South Australia than Victoria and race 0 was significantly less prevalent in New South Wales than in South Australia and Western Australia. This study revealed extremely wide variation in the virulence of P. clandestina. The potential importance of the results on programs to breed for resistance to root rot are discussed. in South Australia.



1995 ◽  
Vol 2 (4) ◽  
pp. 398 ◽  
Author(s):  
J. C. Noble ◽  
D. J. Tongway ◽  
M. M. Roper ◽  
W. G. Whitford

The effects of prescribed fires on nutrient pools, soil micro-organisms, and vegetation patch dynamics were studied in three semi-arid mallee shrublands in western New South Wales. Repeated sampling of surface soil strata (0–2 and 2–4 cm) was undertaken at strategic times (immediately before and after the fire, after opening autumn rain, mid-season in the winter, and at the end of the spring) in five microsites (inner, middle and outer mallee litter zones, bare soil, and Triodia hummock). These samples were later analysed for pH, electrical conductivity, organic carbon and available nitrogen. The effect of fire on soil micro-organisms in these microsites was also examined by measuring nitrogenase activity and enumerating soil Acari. Carbon and nitrogen levels were consistently higher in the inner mallee microsites whereas bare soil sites provided the lowest values. Significant microsite x soil depth interactions were recorded in two shrubland sites while highly significant (P < 0.001) depth x sampling time interactions were recorded in three sites. The most sensitive soil parameter with respect to microsite was electrical conductivity, particularly in the surface 0–2 cm stratum. Highest values were again recorded from the inner mallee microsites and the lowest from bare soil sites. Nitrogenase activity was highest in soil samples associated with mallee litter and, where litter was removed by fire, activity decreased markedly except in the bare soil samples where activity was higher in the burnt samples. Soil microarthropod populations also declined notably following fire. Mites from the Prostigmata greatly outnumbered those from other suborders, a total of 12 families (15 genera) being enumerated in control sites compared with three families (three genera) only of Cryptostigmata. Nonetheless the most abundant mites were cryptostigmatids (Aphelacarus spp.) found in unburnt hummocks beneath Triodia plants. The ecological and management implications of these spatial and temporal fluxes in soil chemistry and soil biology are discussed in relation to their effects on landscape processes, particularly water and nutrient redistribution.



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

&lt;p&gt;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 &lt;2g, mill and sieve the sample &lt;250&amp;#181;m is required), or (ii) mill and sieve the soil sample through a 150&amp;#181;m mesh. On the other hand, the EN 13650 requests soil samples to be sieved at 500&amp;#181;m. 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.&lt;/p&gt;&lt;p&gt;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, 500&amp;#181;m, 250&amp;#181;m and 106&amp;#181;m meshes (soil aggregates were broken softly but soil wasn&amp;#8217;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).&lt;/p&gt;&lt;p&gt;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 &lt;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. &amp;#160;&lt;/p&gt;



1987 ◽  
Vol 67 (4) ◽  
pp. 893-903 ◽  
Author(s):  
M. D. WEBBER ◽  
A. SHAMESS

Studies were conducted to determine: (a) the heavy metal concentrations in Halton Region agricultural soils; and (b) whether a 1984 estimate of at least 39 yr for practicing land application of sludge in the Region was valid. Soil samples were taken on a regular grid pattern from the agricultural area of the Region. In a very large proportion of the samples, heavy metal concentrations were less than the maximum permissible values for sludge application to land in Ontario and in most of the samples, they were less than or approximately equal to the mean values for uncontaminated soils in Ontario. In a small proportion of the samples, heavy metal concentrations exceeded the maximum permissible values for sludge application to land in Ontario. These samples were obtained mainly west of the Niagara Escarpment in the southwest corner of the Region and the offending metals were primarily Pb and Zn. High Pb and Zn concentrations in these soils were not related to sludge application but were naturally occurring and probably were derived from Pb and Zn sulfides in the soil parent material. It was concluded that sludge may be applied on a very large proportion of the agricultural land in Halton Region and that the 1984 estimate of at least 39 yr for continuing this practice was valid. Moreover, in view of recent reductions in annual sludge quantity for land application in the Region and in sludge Cd concentration, the 39-yr estimate was considered to be conservative. Key words: Heavy metals, cadmium, Halton Region, municipal sludge, land application



Author(s):  
N. P. Udeh ◽  
A. C. Ikegwuonu ◽  
O. A. Okeke ◽  
C. Obudulu ◽  
K. P. Okafor ◽  
...  

Soil samples and cassava tubers collected from farmlands within Nnamdi Azikiwe University, Awka vicinity were analyzed for their heavy metal levels using Atomic Absorption Spectrophotometer (AAS) in order to assess their levels of contamination on the environment as a result of excessive fertilizers and automobile emission. Physiochemical properties of the soil samples were determined using standard methods. The soil pH had a mean value of 6.27 ± 0.07, 6.10 ± 0.06 and 6.57 ± 0.03 respectively indicating that the soils were slightly acidic to neutrality. Total organic carbon and nitrate mean values were 105.20 ± 6.20, 95.75 ± 9.57 and 94.6 ± 2.27 and 138.07 ± 12.09, 149.35 ± 14.25 and 149.20 ± 1.17 respectively showing presence of some organic matters. The mean levels of heavy metals in the soil samples were 0.01 ± 0.01, 0.05 ± 0.03 and 0.05 ± 0.03 for lead (Pb), 0.24 ± 0.16, 0.001 ± 0.001 and 0.001 ± 0.000 for cadmium (Cd) and 0.00 ± 0.00, 0.010 ± 0.006 and 0.001 ± 0.001 for chromium (Cr). These metals levels were in the abundance trend of Pb>Cd> Cr. The mean metal concentrations obtained in the cassava tubers respectively were 0.001 ± 0.001, 0.001 ± 0.001 and 0.005 ± 0.005 for lead (Pb), 0.000 ± 0.000, 0.0003 ± 0.0003 and 0.000 ± 0.000 for cadmium (Cd) and 0.002 ± 0.002, 0.000 ± 0.000 and 0.002 ± 0.002 for chromium (Cr). These metals levels were in the abundance trend of Pb> Cr > Cd. For both the soil and cassava samples, there were no significant variations in the heavy metal concentrations and also in physicochemical parameter except for pH; this showed that there is low heavy metal enrichment in the soils studied. Based on the study, the following heavy metals (Pb, Cd, and Cr) falls within the Codex maximum permissible limits 0.1mg/l or ppm expect soil cadmium in science village which is above the Codex limit. The overall results showed that the farmlands (on soils and cassava tuber) appear to be free from poisoning or some metal enrichment and safe for agricultural purposes and also safe for human health and consumption.



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