Heavy Metal Status Research Articles

Status of heavy metals in agricultural soils as affected by different patterns of land use

This study was conducted to determine status of heavy metals in agricultural soils under different patterns of land use. A total of 38, 40 and 45 soil samples for bare vegetable field, greenhouse vegetable field, and grain crop field were respectively taken from surface layer (0-20 cm) from selected experimental areas away from suburbs of ten counties (or districts or cities) in four provinces or municipalities of Huabei plain in north China. Information of crop production history, including varieties, rotation systems and fertilizer use, at the corresponding sampling sites was surveyed. Soil total Cu, Zn, Cd, Pb, Cr, As and Hg were measured. The results showed that the contents of total Cu, Zn, Cd, Pb, Cr, As, and Hg in the soil samples, especially soil total Cu and Zn contents, were higher in the bare vegetable field and the greenhouse vegetable field than that in the grain crop field. Long-term use of excessive chemical fertilizers and organic manures in the bare vegetable field and the greenhouse vegetable field contributed to the accumulation of Cu, Zn, and other heavy metals in the soils. The contents of total Cu, Zn, and other heavy metals in soils increased with increasing vegetable production history of the research areas. In comparison with the grain crop field, the comprehensive pollution indices of the seven soil heavy metals and the single-factor pollution indices of soil Zn, Cu, Cd, Cr, and Hg based on the second criterion of Environmental Quality Standard for Soils were significantly higher in the bare vegetable field and the greenhouse vegetable field. Soils from the greenhouse vegetable field were slightly contaminated according to the comprehensive pollution index, and soils from the bare vegetable field and the grain crop field were at the warning heavy metal pollution level. The soils were contaminated with Cd according to the single-factor pollution index. The Cd pollution was relatively more serious in the bare vegetable field and the greenhouse vegetable field than that in the grain crop field. The soils selected with different land use patterns were not contaminated with Zn, Cu, Pb, Cr, As and Hg.

Status of minerals and heavy metals in the substance sediments around a landfill in Botswana

Status of minerals and heavy metals in the substance sediments around a landfill in Botswana

Diagnosis of heavy metal contamination in agro-ecology of Gujranwala, Pakistan using cattle egret (Bubulcus Ibis) as bioindicator

The present study investigated the status of heavy metals: Lead (Pb), Cadmium (Cd), Chromium (Cr), Cobolt (Co), Silver (Ag) and Nickle (Ni) residues in egg, regurgitate and sediment samples collected from two colonies of cattle egret (Bubulcus ibis) during the breeding seasons between April and August in 2004 and 2005. The mean concentration of heavy metals in eggs and regurgitates was found higher compared to the maximum residue limit (mrl) standards prescribed by Environmental Protection Agency (EPA). A further comparison was made with a similar study conducted in China. High concentrations of heavy metals have contributed to the altered breeding behaviour of the bird species studied. Based on these findings we suggested a regular monitoring of the spread of these pollutants as these have not yet reached to the sediments.

Pollution assessment of the lower basin of Lakes Kainji/Jebba, Nigeria: heavy metal status of the waters, sediments and fishes

The objective of this investigation was to examine the heavy metal status of the lower basin of Kainji dam (used for hydroelectricity generation), which includes Lakes Kainji/Jebba, Nigeria, and the potential for human exposure to heavy metals from eating fish caught in the lakes. Water, sediments and fish were sampled from the lakes and evaluated for As, Cu, Co, Cr, Fe, Hg, Mn, Ni, Pb, Sb, Ti, V and Zn using the EDXRF technique. Fe and Mn were found to be present at high mean concentrations in the water (13 and 9 microg L(-1)), sediment (7,092 and 376 microg g(-1)) and fish (11.4 and 4.6 microg g(-1)) samples. Sb (3.2 microg L(-1)), Ti (4.1 mug L(-1)), Cr (2.2 microg L(-1)), Co (1.2 microg L(-1)), Cu (1.3 microg L(-1)) and Pb (1.2 microg L(-1)) in the water samples and Sb (29 microg g(-1)), Ti (27 microg g(-1)), V (27 microg g(-1)), Cr (27 microg g(-1)), Co (40 microg g(-1)), Ni (33 microg g(-1)), Cu (25 microg g(-1)), Zn (59 microg g(-1)) and Pb (19 microg g(-1)) in the sediment samples were found to be of medium mean concentrations. The other metals were present at trace levels (<1 microg), including As and Hg in the fish and sediment samples. There was an appreciable increase in metal concentrations in going from the water to the sediment samples. The probable source of the pollutants is anthropogenic, arising from agricultural activities, corrosion/abrasion of the ferrous steel material and additives in the lubricants and insulation used for auxiliary services on the turbine floor of the dam constructed on the lakes. However, natural geological sourcing from the underlying lake rock cannot be totally ignored, particularly the high levels of Fe and Mn in the sediment samples. The potential risk for human exposure to these metals emanates from the fish caught in the lakes and subsequently consumed, as there are already significant levels of these metals in the two fish species analysed, Tilapia (Oreochromis niloticus) and Chrysicthys (Chrysicthys auratus).

Assessment on heavy metals pollution of agricultural soil in Guanzhong District

The monitored soil samples were collected from Heihui irrigated area, Jiaokou irrigated area, Qianhe river valley and Jinghe river valley (hereafter Heihui, Jiaokou, Qianhe and Jinghe for short respectively) of Guanzhong District. According to the Environment Quality Standard for Soil (GB15618-1995II), we evaluated the pollution status of heavy metals (Cd, As, Cr and Pb) that could seriously endanger soil environment and human health by using single-factor index and synthetic pollution index methods. The results indicate that the synthetic pollution indices Pi of soil heavy metals are less than 0.7 in Heihui, Jiaokou, Qianhe and Jinghe of Guanzhong, the single-factor indices Pi of soil heavy metals of most soil samples are less than 0.7, so the soil environmental quality is in a good condition in Guanzhong on the whole; the enrichment degree of soil heavy metals is in the order of Heihui, Jinghe, Qianhe and Jiaokou; the contaminated degree of soil heavy metals has the feature of Cd > As > Cr > Pb; heavy metals contents in the cultivated horizon soil are generally higher than those in its underlayer soil, heavy metals contents of soil have the characteristic of enriching towards the cultivated horizon; Cd exceeds standard in the soil samples HS07a, b and HS08a, b at the Yangtao orchard in Heihui and in the soil sample QHS01a at the suburban vegetable plot in Qianhe, which was mainly caused by the long-term irrational use of chemical fertilizer and pesticide.

Rapid Plant-Cover Establishment on Gold Mine Tailings in Southern New Zealand: Glasshouse Screening Trials

The use of a short-term vegetation cover to temporarily control the negative environmental effects of inactive tailings ponds is not frequently practiced during operational mining, but could have some merit. This article reports on a glasshouse trial designed to examine some of the issues associated with short-term vegetation: fast germination of a high proportion of seed, the ability of seedlings to survive in unamended substrates, and potentially toxic substrate. Five nonindigenous plant species were tested—barley (Hordeum vulgare), rye corn (Secale cereale), Italian ryegrass (Lolium multiflorum), red clover (Trifolium pratense), and lucerne (Medicago sativa)—in five different types of substrate: unamended tailings, tailings and fertilizer, tailings and greenwaste, biosolid-blend compost, and local topsoil. The nutrient and heavy metal status (As, Cu, Cd, Ni, Pb) of each substrate type was determined. Plant species performance was monitored over 14 wk. Substrate metal concentrations were low except for As, which was elevated in all substrate types. Plants in unamended tailings grew less vigorously than plants in tailings and compost, or in topsoil. Plant performance in tailings and fertiliser was greatly suppressed following a high fertilization rate. Metal uptake in plants was highest for As (0.4–77 mg kg−1 DW) and Cu (5.3–50.3 mg kg−1 DW). Future field trials are necessary to authenticate findings, but barley and rye corn are promising species for a short-term tailings cover.

Common hydrophytes as bioindicators of iron and manganese pollutions

Sultan Marsh is one of the largest and most important wetlands in Turkey, Middle East and Europe, embodying saline and fresh water ecosystems, which provide a shelter for 426 bird species. The area has begun to contribute much to the tourism of Kayseri state and its environs. However, the sites in the vicinity of the sewerage-sludge and fertilizer plants are highly damaged due to pollution. As such, studies on the heavy metal status of water, sediment and plants were investigated. Concentrations of iron and manganese were measured in bottom sediments, water and Phragmites australis, Typha angustifolia, Potamogeton pectinatus, Ranunculus sphaerosphermus and Groenlandia densa in Sultan Marsh. Analyses of water, bottom sediments and plant samples indicated that all sampling sites in the study area basin are generally more or less polluted when compared with the control sites. It has been found that the tissues of P. pectinatus accumulated heavy metals more than those of G. densa. Therefore, all plants can be used as biological indicators while determining environmental pressures; however, Phragmites australis has proved more appropriate for such studies.

Status and fuzzy comprehensive assessment of combined heavy metal and organo-chlorine pesticide pollution in the Taihu Lake region of China

The status of combined heavy metal and organo-chlorine pesticide (OCPs; i.e. HCH and DDT) pollution was investigated and the soil environmental quality of the Taihu Lake watershed, one of the most developed regions in China, was evaluated using a fuzzy comprehensive assessment. Statistical analyses showed the presence of combined pollution in the soil. At many sampling sites, heavy metal concentrations were above corresponding background values, indicating the effects of extraneous pollutants. It has been over 20 years since China banned the use of OCPs, but they can still be found in soil samples of this region. HCH levels at all investigated sites were below the Chinese Environmental Quality Standard for Soils. Fuzzy comprehensive assessment showed that the overall soil quality in this region could be categorized as class I. Nevertheless, the high coefficients of variation for levels of DDT, Cd and Hg indicated the existence of some point-source pollution. Continuous monitoring and further studies of the region are recommended to prevent pollution of farmland from these sources.

Status of Heavy Metals in Water and Bed Sediments of River Gomti – A Tributary of the Ganga River, India

The concentrations of cadmium, chromium, copper, iron, lead, manganese, nickel, and zinc in water and bed sediments of river Gomti have been studied in a fairly long stretch of 500 km from Neemsar to Jaunpur. Grab samples of water (October 2002-March 2003) and bed sediments (December 2002 and March 2003) were collected from 10 different locations following the standard methods. The river water and sediment samples were processed and analyzed for heavy metals viz., Cd, Cr, Cu, Fe, Pb, Mn, Ni, and Zn, and using ICP-AES. The heavy metals found in the river water were in the range: Cd (0.0001-0.0005 mg/L); Cr (0.0015-0.0688 mg/L); Cu (0.0013-0.0.0043 mg/L); Fe (0.0791-0.3190 mg/L); Mn (0.0038-0.0.0973 mg/L); Ni (0.0066-0.011 mg/L); Pb (0.0158-0.0276 mg/L); and Zn (0.0144-0.0298 mg/L) respectively. In the sediments the same were found in the range: Cd (0.70-7.90 /microg/g); Cr (6.105-20.595 microg/g); Cu (3.735-35.68 microg/g); Fe (5051.485-8291.485 micorg/g); Mn (134.915-320.45 microg/g); Ni (13.905-37.370 microg/g); Pb (21.25-92.15 microg/g); and Zn (1 5.72-99.35 microg/g) of dry weight respectively. Some physico-chemical parameters viz., pH, total solids, total dissolved solids, total suspended solids, dissolved oxygen, biological oxygen demand, chemical oxygen demand, hardness etc. were estimated as these have direct or indirect influence on the incidence, transport and speciation of the heavy metals. Based on the geoaccumulation indices, the Gomti river sediments from Neemsar to Jaunpur are considered to be unpolluted with respect to Cr, Cu, Fe, Mn, and Zn. It is unpolluted to moderately polluted with Pb. In case of Cd it varies from moderately polluted to highly polluted. As far as Ni is concerned the sediment is very highly polluted at Barabanki and Jaunpur D/s. No correlation was found between enrichment factor and geoaccumulation index.

Bioaccumulation, Detection and Analyses of Heavy Metal Pollution in Sultan Marsh and Its Environment

Sultan Marsh is one of the largest and most important wetlands in Turkey, Middle East and Europe, embodying saline and fresh water ecosystems, which provide a shelter for 426 bird species. The area has begun to contribute much to the tourism of Kayseri state and its environs. However, the sites in the vicinity of the sewerage – sludge and fertilizer plants are highly damaged due to pollution. As such, studies on the heavy metal status of water, sediment and plants were investigated. Phragmites australis, Ranunculus sphaerosphermus plants and samples of sediments were taken from 13 different stations of this Marsh. All sampling sites in the study area basin were generally more or less polluted when compared with the control sites. Cr concentrations in the roots of the plants were higher than in the sediment. The tissues of Phragmites australis accumulated heavy metals more than those of Ranunculus sphaerosphermus. The heavy metal accumulation in different parts of plants followed the sequence: root > stem > leaf. Both plants can be used as biological indicators while determining environmental pressures; however, Phragmites australis proved more appropriate for such studies.

Assessing the Spatial Uncertainty of Mapping Trace Elements in Cultivated Fields

Many of the cultivated soils in Galicia (NW Spain) consist of grassland areas and, subsequently, cattle density is also considerable. As a result, dispersion of heavy metals into the rural environment associated with manure and slurry applications has been reported. Mapping the spatial distribution of heavy metals in soils is important for soil management; currently, geostatistical methods are used to generate maps of fertilizer and heavy metal contents and also to assess the uncertainty of the predicted concentrations of these elements. The main objective of this study was to assess the spatial variability of trace elements in a small catchment (10.7 ha), where slurry application was intense. Moreover, the use of geostatistical tools for the description and modeling of metal distribution is illustrated. Fifty‐five soil samples were digested by nitric acid in a microwave (U.S.E PA‐SW‐846 3051) method to assess Mn, Zn, Cu, Ni, Pb, and Cd contents by ICP/AES. The pattern of spatial distribution of total metal contents was analyzed by means of different geostatistical techniques and by the inverse distance method. When a pattern of spatial dependence was found, kriging was used to construct contour maps after semivariogram analysis. High statistical variability was observed for the metals studied. Mean Cu content was 28.5 mg kg−1 and that of Zn was 64.7 mg kg−1, the differences between maximum and minimum being 62.3 mg kg−1 and 122.1 mg kg−1 for Cu and Zn, respectively. Also, some hot spots with high levels of Cd (>l3 mg kg−1) with respect to background values were recorded. The spatial distributions of total Zn and Cu contents were characterized using spherical semivariograms with no nugget effect. Ordinary kriging estimates were compared with results obtained by indicator kriging. Sequential simulation was also applied to analyze the spatial distribution of the metals studied. This study reveals that these methods are useful to determine spatial distribution and uncertainty of trace metal contents in cultivated fields and thus to characterize the heavy metal status at the scale studied. In contrast, EDTA‐ and CaCl2‐extractable Zn and Cu contents did not show spatial structure at all; hence, nongeostatistical techniques were used to attempt to interpolate these metal fractions.

Heavy metals deposited from the atmosphere on upland Scottish soils: Chemical and lead isotope studies of the association of metals with soil components

Three soil profiles taken from the Hartwood Research Station in Central Scotland have been analyzed using chemical digestion and extraction techniques to investigate the chemical association of heavy metals deposited from the atmosphere. Total digestion, EDTA extraction and the BCR (Bureau Communitaire de Reference) sequential extraction procedure were used. In addition, lead isotope ratios in the whole soils and in the fractions from the sequential extraction procedure were measured using thermal ionisation mass spectrometry. All the digestion and extraction procedures gave clear indication of enhanced concentrations of heavy metals in surface soils, in particular for lead and zinc. Whereas total digestion gave a good indication of the heavy metal status of the soils, the extraction procedures were necessary to provide information on chemical association of the metals with soil components, information needed to understand the soil processes involved in mobilization of metals. Lead isotope analysis of the whole soils revealed a consistent picture of lower 206Pb/ 207Pb ratios in surface soils (1.140–1.147) than in soils at 20–30 cm depth (1.182–1.190). The steady progression from the lower to higher ratios down the profile was clear indication that anthropogenic lead had penetrated to some degree into the deeper soils. The combination of sequential extraction and lead isotope analysis proved to be a powerful approach to studying this effect in more detail and showed that the fractions extractable from 20 to 30 cm soils contained lead with much lower 206Pb/ 207Pb ratios (1.174–1.178) than the residual fraction (1.196–1.200). As the extractable fractions contained ≥85% of the lead in the soil, a substantial portion of lead at 20–30 cm depth was of anthropogenic origin. The 206Pb/ 207Pb ratios of 1.174–1.178 found in the extractable fractions suggested that the mobile component of the anthropogenic lead was that deposited before the introduction of leaded petrol.

Crop contamination by selected trace elements

Goal and Background The regulatory limit for the allowable concentration of heavy metals (HM) in agricultural soils should be based both on HM status and on soil parameters that influence HM mobility. In this paper, a soil categorization scheme is proposed which is based on the main factors that influence HM mobility in soils. The scheme also makes use of the existing regulatory limits for total concentrations of trace elements in Slovak soils but additionally takes into account the potential ability of the soils to mobilize trace elements. A map of the Slovak Republic showing the soil categorization using this scheme is presented.

Status of persistent organic pollutants and heavy metals in surface water of Arctic region

Trace pollutants in the surface water of the Arctic region have been analyzed by the capillary gas chromatography with the micro-electron capture detector (GC-μECD), the gas chromatography-mass spectrometry (GC-MS) and the inductively coupled plasmas-mass spectrometry (ICP-MS). Compared with previously reported studies, concentrations of OCPs in these regions are much lower than those in the last decades. The ratio of α-/γ-HCH indicates the different pesticide composition between these two regions and is the potential marker for the source of the OCPs. Many other OCPs with different residue patterns have also been found for the first time in the two regions. No heavy metal contaminant was found in the investigation regions.

The distribution and dynamics of chromium and nickel in cultivated and uncultivated semi-arid soils from Nigeria

Growing concern about heavy metal contamination of agricultural lands under long-term application of inorganic fertilizers and organic wastes makes periodic risk assessment of heavy metal accumulation in arable lands imperative. As a part of a much larger study to systematically document the status of heavy metals in savanna soils this study investigated the distribution and dynamics of Cr and Ni in a savanna soil after 50 years of continuous cultivation and application of inorganic fertilizers and organic manures. The cultivated fields were fertilized with inorganic fertilizers (NPK), farmyard manure (FYM), FYM+NPK for 50 years and a control plot under continuous cultivation for 50 years but did not receive either FYM or NPK. Two uncultivated or natural sites were sampled as reference conditions for assessing the dynamics of Cr and Ni induced by cultivation and management practices. The distribution of Cr and Ni in the soil profiles exhibited eluvial–illuvial patterns. Sand and clay fractions explained between 62 and 90% of the variance in Cr and Ni concentration and distribution in the soil profiles. Mean Cr concentrations ranged from 17 to 59 mg kg −1, while Ni varied from <1 mg kg −1 in the topsoil to 16 mg kg −1 in the subsoil. Mass balance calculations showed a loss of 10% Cr and 17% Ni in the FYM field, and approximately 4% Cr and 11% Ni in the NPK field compared to the natural site after 50 years of cultivation. The control and FYM+NPK field had, however, a positive balance of Cr and Ni. In general, it was concluded that existing soil management practices in this region are unlikely to lead to Cr and Ni build-up probably because of low rates of application of inorganic fertilizers, farmyard manure and other organic wastes to the soils.

Can Oxybutynin Cause Peripheral Neuropathy?

The commonly used antispasmodic oxybutynin is an antimuscarinic agent that inhibits bladder contractions, relieving spasms induced by various stimuli. The drug can be used for urinary incontinence, urgency and frequency, unstable bladder conditions such as idiopathic detrusor instability and neuropathic bladder disorders. The most frequently reported side effects of oxybutynin are dry mouth, constipation, blurred vision, nausea, abdominal discomfort and facial flushing. Less commonly, the drug may cause urinary retention, headache, dizziness, drowsiness, skin rash, angioedema, diarrhea, arrhythmias, restlessness, disorientation, hallucinations and convulsions.1 The side effects are thought to be dose dependent.2 To our knowledge we report the first case of peripheral neuropathy associated with oxybutynin therapy. CASE REPORT A 70-year-old women who presented with gross hematuria and associated bladder spasm was treated with bladder irrigation and oxybutynin (2.5 mg. twice daily increased to 2.5 mg. 3 times daily). The patient underwent cystoscopy followed by transurethral resection of bladder tumors with no postoperative complications. Two weeks following bladder tumor resection she complained of progressive numbness in both feet (sensory paresthesia in the L5 to S1 distribution with no motor deficit). Causes for peripheral neuropathy (for example diabetes, vitamin B12 deficiency, thyroid function, syphilis serology, heavy metal status, medication) were extensively ruled out from the history or by investigation. The oxybutynin had been overlooked during this period and was stopped. The symptoms resolved spontaneously 2 days later. A week later the patient complained of symptoms suggestive of bladder spasm (suprapubic tenderness and urgency). Oxybutynin was restarted at a higher dose (5 mg. 3 times daily), and the neuropathy returned within 48 hours. The oxybutynin was stopped and the neurological symptoms again resolved 2 days later. This finding was reported to the Committee on Safety of Medicines (United Kingdom) and the manufacturer, neither of whom had known of this side effect previously. DISCUSSION

Status of heavy metals in agricultural soils of Vietnam

Status of Cd, Cr, Cu, Ni, Pb, and Zn in agricultural soils of Vietnam was examined. The six heavy metals were selected from the viewpoint of public concern in the country. The concentration of Cd was low and independent of that of the parent rocks from which the soils were derived. The concentrations of Cr, Cu, Ni, Pb, and Zn more or less varied with the parent rocks. Among them, the concentration was, in general, in the sequence of sandstone < alluvium < limestone < basalt for Cr and Ni and of sandstone < alluvium < basalt < limestone for Cu and Zn. The Pb concentration, however, tended to be the lowest for basalt followed by sandstone. The concentrations of the six heavy metals in the soils derived from alluvium, sandstone, and basalt were generally within and around the concentration ranges reported for the respective parent rocks, except for the possible Zn pollution in the rice-vegetable field in Hanoi. In contrast, the heavy metal concentrations in the soils derived from limestone were much higher than those reported for limestone except for Cd.

Heavy Metal Status of Upland Soils in Jilin Province, Northeast China

Heavy Metal Status of Upland Soils in Jilin Province, Northeast China

A flexible methodology for the characterisation of soils: a case study of the heavy metal status of a site at Dornach

The sampling scheme devised to study the site at Dornach was successful in identifying most of the features and element distributions in the site using only 15 composite samples. The scheme was based on dividing the area into six individual sampling units each of which represented a different combination of land use and soil type. The three-dimensional information was obtained by taking samples at different depths, either on a fixed depth basis for cultivated soils or according to soil horizons for undisturbed soils. In each sampling unit the composite samples were bulked from 12 individual samples. The sampling point for each individual sample was chosen according to a stratified random plan. Key features of the scheme were the flexibility which required the use of experienced personnel and the fact that the sole task of the sampling exercise was to characterise the site with no preconceptions of possible outcomes. The results showed that the high concentrations of Cd in the soil probably resulted from the high concentrations of Cd in the underlying limestone and not primarily from atmospheric inputs. Higher levels of copper were found in soils close to fruit trees probably as a result of using sprays on the trees. The concentrations of Pb and Zn were relatively uniform throughout the site although there was some evidence of increased Zn concentrations with depth analogous to the Cd distributions. The fact that these findings were in agreement with the known characteristics of the site indicates the successful application of the chosen methodology in this study.

Distribution of heavy metals in wheat, mustard, and weed grown in field irrigated with industrial effluents.

In recent years, research has been focused on accumulation of heavy metals in crop plants and naturally growing weeds. As most studies are based on the work done in laboratory conditions, information is scanty on status of heavy metals in soils and standing plants receiving industrial effluents ( Beckett and Davis 1977; Jarvis 1978; Miles and Parker 1979; Singh and Mishra 1987; Ray and Barman 1988; Ray et al. 1988; Ray and Saha 1988; Ray 1990; Szymczak et al. 1993; Barman 1994; Barman and Lal 1994; Sharma and Sharma 1997; Kaer et al. 1998).