Quantitative arsenic speciation in two species of earthworms from a former mine site

The relationship between the total arsenic concentration and the chemical speciation of arsenic in two species of earthworm (Lumbricus rubellus and Dendrodrilus rubidus) in relation to the host soil, was investigated for 13 sites of varying arsenic content, including a background level garden soil and a former mine site at the Devon Great Consols, UK. Earthworms were collected with the host soil (As soil concentration range 16-12, 466 mg kg(-1) dry weight) and measured for their total arsenic (concentration range 7-595 mg kg(-1) dry weight) using inductively coupled plasma mass spectrometry (ICP-MS). A methanol-water mixture was used to extract arsenic species from the earthworms prior to determination of the individual arsenic species by a combination of anion and cation exchange high performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC-ICP-MS). A gradient elution anion exchange method is presented whereby nine arsenic species could be measured in one sample injection. Arsenic species were identified by comparison of retention times and sample spiking with known standards and a fully characterised seaweed extract. Arsenic was generally present in the earthworm as arsenate (As(V)) or arsenite (As(III)) and arsenobetaine (AB). Methylarsonate (MA), dimethylarsinate (DMA) and three arsenosugars (glycerol, phosphate, sulfate) were present as minor constituents. These results are discussed in relation to the mechanisms for coping with exposure to soil bound arsenic.     

Arsenic speciation in human hair: a new perspective for epidemiological assessment in chronic arsenicism

The analysis for arsenic in hair is commonly used in epidemiological studies to assess exposure to this toxic element. However, poor correlation between total arsenic concentration in hair and water sources have been found in previous studies. Exclusive determination of endogenous arsenic in the hair, excluding external contamination has become an analytical challenge. Arsenic speciation in hair appears as a new possibility for analytical assessing in As-exposure studies. This study applied a relative simple method for arsenic speciation in human hair based on water extraction and HPLC-HG-ICP-MS. The concentration of arsenic species in human hair was assessed in chronically As(V)-exposed populations from two villages (Esqui?a and Illapata) of the Atacama Desert, Chile. The arsenic concentrations in drinking water are 0.075 and 1.25 mg L(-1), respectively, where As(V) represented between 92 and 99.5% of the total arsenic of the consumed waters. On average, the total arsenic concentrations in hair from individuals of Esqui?a and Illapata were 0.7 and 6.1 microg g(-1), respectively. Four arsenic species, As(III), DMA(V), MMA(V) and As(V), were detected and quantified in the hair extracts. Assuming the found species in extracts represent the species in hair, more than 98% of the total arsenic in hair corresponded to inorganic As. On average, As(III) concentrations in hair were 0.25 and 3.75 microg g(-1) in Esqui?a and Illapata, respectively; while, the As(V) average concentrations were 0.15 and 0.45 microg g(-1) in Esqui?a and Illapata, respectively. Methylated species represent less than 2% of the extracted As (DMA(V)+ MMA(V)) in both populations. As(III) in hair shows the best correlation with chronic exposure to As(V) in comparison to other species and total arsenic. In fact, concentrations of As(total), As(III) and As(V) in hair samples are correlated with the age of the exposed individuals from Illapata (R= 0.65, 0.69, 0.57, respectively) and with the time of residence in this village (R= 0.54, 0.71 and 0.58, respectively).     

Arsenic exposure in Hungary, Romania and Slovakia

Inorganic arsenic is a potent human carcinogen and toxicant which people are exposed to mainly via drinking water and food. The objective of the present study was to assess current exposure to arsenic via drinking water in three European countries. For this purpose, 520 individuals from four Hungarian, two Slovakian and two Romanian countries were investigated by measuring inorganic arsenic and methylated arsenic metabolites in urine by high performance liquid chromatography with hydride generation and inductively coupled plasma mass spectrometry. Arsenic in drinking water was determined by atomic absorption spectrometry. Significantly higher concentrations of arsenic were found in both the water and the urine samples from the Hungarian counties (median: 11 and 15 microg dm(-3), respectively; p < 0.001) than from the Slovakian (median: 0.94 and 4.5 microg dm(-3), respectively) and Romanian (median: 0.70 and 2.1 microg dm(-3), respectively) counties. A significant correlation was seen between arsenic in water and arsenic in urine (R(2)= 0.46). At low water arsenic concentrations, the relative amount of dimethylarsinic acid (DMA) in urine was increased, indicating exposure via food. Also, high body mass index was associated with higher concentrations of arsenic in urine (p= 0.03), mostly in the form of DMA. Smokers had significantly higher urinary arsenic concentrations than non-smokers (p= 0.03). In conclusion, elevated arsenic exposure via drinking water was prevalent in some of the counties. Exposure to arsenic from food, mainly as DMA, and cigarette smoke, mainly as inorganic arsenic, are major determinants of arsenic exposure at very low concentrations of arsenic in drinking water.     

Urinary 8-hydroxy-2'-deoxyguanosine in inhabitants chronically exposed to arsenic in groundwater in Cambodia

Arsenic concentrations in hair and urine, and urinary levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage, were examined for inhabitants of the Mekong Basin in Kratie Province, Cambodia. Also, the arsenic levels of tube-well water were determined. Total arsenic concentrations in tube-well water ranged from <1 to 886 microg L(-1), and 44.8% of these exceeded the WHO drinking water guideline of 10 microg L(-1). Elevated levels of arsenic were observed in the human hair and urine, and also a significant positive correlation was observed between the concentrations in hair and urine. These results suggest that the inhabitants are chronically exposed to arsenic through drinking the tube-well water. Levels of urinary 8-OHdG were higher for the subjects with higher arsenic levels in hair and urine, suggesting that induction of oxidative DNA damage was caused by chronic exposure to arsenic in tube-well water for the inhabitants in Kratie Province. To our knowledge, this is the first report on the oxidative DNA damage caused by chronic exposure to arsenic in groundwater for the inhabitants in Cambodia.     

Fractionation of sedimentary arsenic from Port Kembla Harbour, NSW, Australia

The binding of arsenic in sediments of the heavily industrialised Port Kembla Harbour, NSW, Australia, has been investigated. Both dredge and core samples have been used to develop a sieving/sequential extraction (SE) procedure. Dredge samples included oxic surficial and deeper anoxic sediment. The main core sample analysed was 18 cm deep, sliced at 2 cm intervals. Sediment was sieved to three size ranges (<63 microm, 63-250 microm, >250 microm) and each of these was then subjected to a four step SE, sequentially solubilizing arsenic as ion exchangeable, 1 M HCl soluble, NH(2)OH.HCl soluble, and strong oxidising acid soluble. Concentrations of 50-500 mg As kg(-1) were found, elevated well above local background values. The core sample showed elevated concentrations of arsenic within the top 6-8 cm (300-500 mg As kg(-1)), relative to the deeper sediment (100-200 mg As kg(-1)). Substantial portions of the total arsenic present in the 0-8 cm sediments of core and dredge samples, were found to be soluble in 1 M pH 5 phosphate buffer or 1 M HCl. Arsenic in the lower 8-18 cm of the core displayed different solubility, the fourth stage SE strong acid digestion being required to solubilize >90% of the deep sediment arsenic. It appears that diagenesis had resulted in remobilisation of weakly bound arsenic with subsequent diffusion and deposition in surficial layers. Strong acid soluble arsenic present in deeper sediments has two possible origins: sedimented as strongly bound remaining untouched by diagenetic events, or subjected to diagenetic reactions such as pyritization, which lead to more stable crystalline forms of minerals.     

Desorption of arsenic from drinking water distribution system solids

Previous work has shown that arsenic can accumulate in drinking water distribution system (DWDS) solids (Lytle et~al., 2004) when arsenic is present in the water. The release of arsenic back into the water through particulate transport and/or chemical release (e.g. desorption, dissolution) could result in elevated arsenic levels at the consumers' tap. The primary objective of this work was to examine the impact of pH and orthophosphate on the chemical release (i.e. desorption) of arsenic from nine DWDS solids collected from utilities located in the Midwest. Arsenic release comparisons were based on the examination of arsenic and other water quality parameters in leach water after contact with the solids over the course of 168~hours. Results showed that arsenic was released from solids and suggested that arsenic release was a result of desorption rather than dissolution. Arsenic release generally increased with increasing initial arsenic concentration in the solid and increasing pH levels (in the test range of 7 to 9). Finally, orthophosphate (3 and 5 mg PO₄/L) increased arsenic release at all pH values examined. Based on the study results, utilities with measurable levels of arsenic present in their water should be aware that some water quality changes can cause arsenic release in the DWDS potentially resulting in elevated levels at the consumer's tap.     

Environmental monitoring of historical change in arsenic deposition with tree bark pockets

ICP-MS analysis recorded historical change (c. 1846 to 2002) in the arsenic concentration of bark included within the trunks (tree bark pockets) of two Japanese oak trees (Quercus crispula), collected at an elevated location approximately 10 km from the Ashio copper mine and smelter, Japan. The arsenic concentration of the bark pockets was 0.016 +/- 0.003 microg cm(-2) c. 1846 (n = 5) and rose 50-fold from c. 1875 to c. 1925, from approximately 0.01 to 0.5 microg cm(-2). The rise coincided with increased copper production in Ashio from local sulfide ores, from 46 tons per year in 1877 to 16,500 tons per year in 1929. Following a decline in arsenic concentration and copper production, in particular during the Second World War, a second peak was observed c. 1970, corresponding to high levels of production from both local (6,000 tons per year) and imported (30,000 tons per year) ores, smelted from 1954. Compared to the local ores, the contribution of arsenic from imported ores appeared relatively low. Arsenic concentrations declined from c. 1970 to the present following the closure of the mine in 1974 and smelter in 1989, recording 0.058 +/- 0.040 microg cm(-2) arsenic (n = 5) in surface bark collected in 2002. The coincident trends in arsenic concentration and copper production indicated that the bark pockets provided an effective record of historical change in atmospheric arsenic deposition.     

Arsenic transformations in terrestrial small mammal food chains from contaminated sites in Canada

Arsenic in terrestrial contaminated sites has the potential to cause harm to residential wildlife. The aim of this study was to determine the arsenic species in wild rodents living in arsenic contaminated habitats, specifically deer mice from Yellowknife, NT and meadow voles from Seal Harbour, NS, along with co-located plants. Methanol : water (1 : 1) extractions were used to optimize the extraction of methylated arsenic(v) species. Total arsenic concentrations were substantially higher in the Yellowknife deer mice (1.7-3.2 μg kg(-1) wet weight in livers) and Seal Harbour meadow voles (0.67-0.97 μg kg(-1) wet weight in livers) living on the contaminated sites with respect to the surrounding background locations (0.12-0.34 μg kg(-1) wet weight in livers). Around 50% of arsenic could be identified in Yellowknife deer mouse tissues, but only <10% was identified in Seal Harbour vole tissues; inorganic arsenic (iii and v) and dimethylarsinic acid were all found. Monomethylarsonic acid was only detected in both the mice and voles living in the contaminated sites. In the Yellowknife food chain, methyl arsenic (v) proportions increased from plants to mouse inner organs, but the trend was not for clear as the Seal Harbour food chain. Seal Harbour voles may be sequestering arsenic in a less mobile form, rather than transforming it.     

Arsenic and Other Metal Contamination of Groundwaters in the Industrial Area of Thessaloniki, Northern Greece

In groundwater, used for drinking water supply in the greater industrial area of Thessaloniki, in Northern Greece, concentrations of total arsenic exceeded the WHO provisional guideline value and the EU maximum contaminant level (MCL) of 10 μg/L. The concentration of total arsenic was in the range between 4–130 μg/L, whereas the median value was 36 μg/L and the average concentration 46 μg/L. Nine out of the eleven wells contained total arsenic at concentration higher than 10 μg/L and it should be stressed that 6 of them contain arsenic at concentrations between 10 (new MCL) and 50 μg/L (previous MCL). The examined groundwaters were found to contain elevated concentrations of manganese and phosphate. Arsenic had a positive correlation with the pH, indicating the possible effect of pH on arsenic mobilisation. These findings emerge the problem of contamination from arsenic, since, according to the EU directive 98/83, all drinking water sources within the European Union should have achieved compliance with the new limits by 12/2003, implying that the situation requires urgent remedial action.     

Simulation of arsenic partitioning in tributaries to drinking water resevoirs

Arsenic released by bottom sediments was determined by experiments in which the sediments were artificially re-suspended using a particle entrainment simulator (PES) to simulate river conditions. Sediment cores were collected from various tributaries to drinking water reservoirs in Connecticut spiked with arsenic, and run in the PES at simulated bed-flow shear stresses from 0.0 to 0.6 N/m². Under equilibrium conditions, the dissolved fraction of arsenic was found to range from 8.3 to 22.1 μg/l, which in most cases exceeded EPA Maximum Contaminant Level (MCL) of 10 μg/l. Experimental results from these simulations have shown that bed-flow shear stress causes an increased concentration of dissolved arsenic, most notably at shear stresses of 0.4, 0.5, and 0.6 N/m². For the solid phase under equilibrium, the concentrations of arsenic ranged between 71 and 275 mg/kg. The average concentration of arsenic on the solid phase as well as partitioning coefficient values (K _p) were highest at initial shear stress. This was attributed to the higher fraction of colloidal material and finer organic particles in the suspended solid mixture. Particles of such nature proved to have higher affinity to arsenic. K _p values were determined from PES data and were found to range from 4,687 to 24,090 l/kg. However, on a mass load basis, the amount of arsenic found in suspended sediment increased with the increase of shear stress. Similarly, the amount of arsenic in the solid phase increased significantly for sites with high Volatile Organic Carbon (VOC) content. Because of the influence of Total Suspended Solids (TSS) and VOC concentrations on K _p, the use of the PES is more appropriate in obtaining K _p values that would be found under real stream conditions when compared to the traditional way of measuring K _p using a jar study technique.     

Arsenic-speciation in arsenate-resistant and non-resistant populations of the earthworm,Lumbricus rubellus

Arsenic speciation was determined in Lumbricus rubellus Hoffmeister from arsenic-contaminated mine spoil sites and an uncontaminated site using HPLC-MS, HPLC-ICP-MS and XAS. It was previously demonstrated that L. rubellus from mine soils were more arsenate resistant than from the uncontaminated site and we wished to investigate if arsenic speciation had a role in this resistance. Earthworms from contaminated sites had considerably higher arsenic body burdens (maximum 1,358 mg As kg-1) compared to the uncontaminated site (maximum 13 mg As kg-1). The only organo-arsenic species found in methanol/water extracts for all earthworm populations was arsenobetaine, quantified using both HPLC-MS and HPLC-ICP-MS. Arsenobetaine concentrations were high in L. rubellus from the uncontaminated site when concentrations were expressed as a percentage of the total arsenic burden (23% mean), but earthworms from the contaminated sites with relatively low arsenic burdens also had these high levels of arsenobetaine (17% mean). As arsenic body burden increased, the percentage of arsenobetaine present decreased in a dose dependent manner, although its absolute concentration rose with increasing arsenic burden. The origin of this arsenobetaine is discussed. XAS analysis of arsenic mine L. rubellus showed that arsenic was primarily present as As(III) co-ordinated with sulfur (30% approx.), with some As(v) with oxygen (5%). Spectra for As(III) complexed with glutathione gave a very good fit to the spectra obtained for the earthworms, suggesting a role for sulfur co-ordination in arsenic metabolism at higher earthworm arsenic burdens. It is also possible that the disintegration of As(III)-S complexes may have taken place due to (a) processing of the sample, (b) storage of the extract or (c) HPLC anion exchange. HPLC-ICP-MS analysis of methanol extracts showed the presence of arsenite and arsenate, suggesting that these sulfur complexes disintegrate on extraction. The role of arsenic speciation in the resistance of L. rubellus to arsenate is considered.     

Arsenic occurrence and accumulation in soil and water of eastern districts of Uttar Pradesh, India

Arsenic in the soil and water of eastern districts of Uttar Pradesh (Ballia and Ghazipur) was estimated. Survey results revealed that arsenic in soil samples ranged from 5.40 to 15.43 parts per million (ppm). In water samples, it ranged from 43.75 to 620.75 parts per billion (ppb) which far exceeded the permissible limit of 10 ppb as recommended by the World Health Organization. Maximum concentration of arsenic in water was found in Haldi village of Ballia (620.75 ppb). However, mean arsenic concentration in water followed the order: Karkatpur (257.21 ppb) < Haldi (310.15 ppb) < Sohaon (346.94 ppb) < Dharmarpur (401.75 ppb). In case of soil, maximum arsenic was detected in soil of Sohaon (15.43 ppm). Mean arsenic levels in soils followed the order: Karkatpur (9.24 ppm) < Haldi (9.82 ppm) < Dharmarpur (11.32 ppm) < Sohaon (14.08 ppm). Arsenic levels were higher in soils collected from 15–30 cm depth than 0–15 cm from the soil surface.     

Biomonitoring of tin and arsenic in different compartments of a limnic ecosystem with emphasis on Corbicula fluminea and Dikerogammarus villosus

Asian clam Corbicula fluminea, the amphipod Dikerogammarus villosus and the macrophyte Nuphar lutea were tested for investigating spatial and temporal variability in the bioavailability of tin and arsenic in the River Lippe, Germany. Samples were collected from September 2002 to May 2003 at a tin polluted site (source pollution) and a reference site. Additional screening sampling was carried out twice in April 2003 to test the extent of As and Sn concentration in periphyton (aufwuchs) samples. Accumulated Sn and As concentrations were measured with ICP-MS after sample processing (dissection, cryo-milling) and digestion. Quality control was performed by parallel analysis of three certified reference materials. Measurable As and Sn contents in plant tissues were only detectable in roots (below 30 microg kg(-1) and 20 microg kg(-1) for As and Sn, respectively). Homogenates from C. fluminea and D. villosus tissues showed site-dependent trace metal contents. Elevated bioavailability of Sn is present downstream of the sewage discharge of the world's biggest producer of tributyltin (TBT) at Luenen (northern Ruhr region). In comparison to C. fluminea, D. villosus shows higher concentrations of tin in samples from both sites. Arsenic concentrations in C. fluminea remain constant with increasing shell size, whereas tin shows a size-dependent accumulation. The results indicate that Corbicula fluminea and Dikerogammarus villosus are suitable passive biomonitoring organisms for Sn, but As levels might be actively regulated. The concentration of tin in the periphyton (aufwuchs) samples was found to be much higher in samples from a contaminated site (428 +/- 63 vs. 1949 +/- 226 microg kg(-1)).     

冶炼烟气中砷的监测方法改进

金属冶炼烟气中的砷大都以颗粒物的形式存在,对环境造成污染.2010年,国家颁布了《铜、镍、钴工业污染物排放标准》( GB 25467-2010),对于废气中砷的监测,该标准中规定使用《空气和废气砷的测定 二乙基二硫代氨基甲酸银分光光度法(暂行)》( HJ 540-2009).然而该方法中对于烟气中砷的监测方法存在一定问题,高氯酸在高温消解过程中易爆炸,比较危险,另外采用在锥形瓶内加热至产生白烟的排酸方式不能有效地排净硝酸,会导致反应无法进行.为此,就该方法中有组织排放废气中砷的前处理部分提出了改进意见.     

Water quality assessment of Majhiaon block of Garwa district in Jharkhand with special focus on fluoride analysis

Fluoride in groundwater is known to contaminate the water sources globally. Jharkhand, one of the states in the eastern part of India, is known to have excessive fluoride content in groundwater sources. The present work involves assessment of water quality with special reference to fluoride in Majhiaon block of Garwa district in Jharkhand. Iron, nitrate and arsenic were also tested for the water samples collected from site. Eight hundred forty samples were tested for fluoride on site using colourimetry method, and one tenth of the samples were brought to laboratory for iron, nitrate, arsenic and fluoride analysis. Results show that 402 samples were having fluoride above permissible limit. Iron and nitrate were found to be beyond permissible limits in 302 and 286 water samples, respectively. More than 50% of samples collected from school had fluoride levels above permissible limits. Arsenic was well within the limits. However, few samples shown were excessive of iron and nitrate.     

Arsenic and trace metals in river water and sediments from the southeast portion of the Iron Quadrangle, Brazil

The Iron Quadrangle has been one of the most important gold production regions in Brazil since the end of the seventeenth century. There, arsenic occurs in close association with sulfide-rich auriferous rocks. The most abundant sulfide minerals are pyrite and arsenopyrite, yet trace metal sulfides occur in subordinate phases as well. Historical mining activities have been responsible for the release of As and trace metals to both aquatic and terrestrial environments close to mining sites in the region. Therefore, this study was aimed to evaluate the distribution and mobility of As, Cd, Co, Cr, Cu, Ni, Pb, and Zn in streams in the southeast portion of the Iron Quadrangle between the municipalities of Ouro Preto and Mariana, the oldest Brazilian Au mining province. Total concentrations of some trace metals and arsenic in water were determined. The four-stage sequential extraction procedure proposed by the commission of the European Communities Bureau of Reference (BCR) was used to investigate the distribution of these elements in stream sediments. Arsenic concentration in water was >10 ??g L^???1 (maximum limit permitted by Brazilian environmental regulations for water destined for human consumption) at all sampling sites, varying between 36.7 and 68.3 ??g L^???1. Sequential extraction in sediments showed high concentrations of As and trace metals associated with easily mobilized fractions.     

Trace elements and organochlorines in the shoalgrass community of the lower Laguna Madre,Texas

Our objectives were to measure concentrations of seven trace elements and 14 organochlorine compounds in sediment and biota of the shoalgrass (Halodule wrightii) community of the lower Laguna Madre of south Texas and to determine whether chemicals associated with agriculture (e.g. mercury, arsenic, selenium, organochlorine pesticides) were highest near agricultural drainages. Arsenic, mercury, selenium, lead, cadmium, and organochlorines were generally at background concentrations throughout the lower Laguna Madre. Nickel and chromium concentrations were exceptionally high in shrimp and pinfish (Lagodon rhomboides), which is difficult to explain because of no known anthropogenic sources for these trace elements. For sediment and blue crabs (Callinectes sapidus), mercury was highest near agricultural drainages. Also, DDE was more frequently detected in blue crabs near agricultural drainages than farther away. In contrast, selenium concentrations did not differ among collecting sites and arsenic concentrations were lowest in shoalgrass, blue crabs, and brown shrimp (Penaeus aztecus) near agricultural drainages.     

Arsenic content in ground and canal waters of Punjab, North-West India

Groundwater is the primary source of drinking water for more than 95% of the population in Punjab. The world health organization and US Environment Protection Agency recently established a new maximum contaminant level of 10 ppb for arsenic in drinking water. The arsenic concentration of deep water tube wells located in Amritsar city used for domestic supply for urban population ranged from 3.8 to 19.1 ppb with mean value of 9.8 ppb. Arsenic content in hand pump water varied from 9 to 85 ppb with a mean value of 29.5 ppb. According to the safe limit of As, 54% and 97%, water samples collected from deep water tube wells and hand pumps, respectively, were not fit for human consumption. Arsenic content in canal water varied from 0.3 to 8.8 ppb with a mean value of 2.89 ppb. Canal water has got higher oxidation potential followed by deep tube well and hand pump water. The present study suggests the regular monitoring of arsenic content in deep tube well and shallow hand pump waters by water testing laboratories. The consumption of water having elevated concentration of As above the safe limit must be discouraged. In south-western districts of Punjab, it recommends the use of canal water for drinking purposes and domestic use by rural and urban populations than ground water sources.     

Monitoring of copper,arsenic and antimony levels in agricultural soils impacted and non-impacted by mining activities,from three regions in Chile

This paper reports a comparative study of the concentration of three important environmental elements that are often found together in mineral deposits and then associated with mining activities; copper, arsenic and antimony. These elements were determined in 26 different agricultural soils from regions I, II and V in Chile, zones where the most important and biggest copper industries of this country are located. As background levels of these elements in soils have not been well established, in this study, both, impacted and non-impacted agricultural soils from different regions were considered. The relationships between the concentrations of these elements in soils were also examined. The concentration ranges for copper, arsenic and antimony were 11-530; 2.7-202 and 0.42-11 mg kg(-1) respectively. The copper concentrations in non-polluted soils from the north and central zone of Chile were similar. However, three sites from the north region have copper concentration as higher as 100 mg kg(-1), values that exceed the critical concentration for copper in soils. The concentration of arsenic and antimony in the north soils were higher than in non-impacted ones and, in the case of arsenic, greatly exceeded the world average concentration reported for this element in soils. The highest arsenic and antimony concentrations were found in Calama and Quillagua soils, two different sites in the Loa valley. The arsenic/antimony concentration ratio was higher in Quillagua soil. The high concentrations of three elements determined in impacted soils from region V (Puchuncaví and Catemu valleys) clearly shows the impact produced in this zone by the industrial and mining activities developed in their proximities. At Puchuncaví valley a clear decrease was observed in copper, arsenic and antimony concentrations in soils on the function of the distance from the industrial complex "Las Ventanas", and all concentrations exceeded the reported critical values for this matrix. Instead at Catemu valley, only the copper concentration was higher than this value. Statistically significant correlation was found for Cu-Sb in all soils; more significant Cu-As, Cu-Sb and Sb-As correlations were evaluated for soils from Puchuncaví and Catemu valleys, corroborating that high concentrations of copper, arsenic and antimony in these soils coming from the same pollution sources, the copper industry and the thermoelectric power plant.     

Arsenic concentration and speciation of the marine hyperaccumulator whelk Buccinum undatum collected in coastal waters of Northern Britain

European whelks (Buccinum undatum) have shown to accumulate high levels of arsenic. Since the accumulation process is not well understood it is necessary to gain information about the geographical variability of the arsenic concentration in them. Here we show that the mean arsenic concentrations of the whelks are site specific and vary by a factor of 3.5 in ten different geographical locations. At fishing grounds where whelks exhibited low arsenic concentrations the arsenic concentration increased linearly with size, whereas the whelks with high arsenic levels from a different location showed no correlation. Although the overall arsenic concentration in the whelks differed between 45 and 655 mg kg(-1) d.w., the inorganic arsenic concentration did not exceed 0.4 mg kg(-1) d.w. The main arsenic compound is arsenobetaine, which is widely considered as non-toxic. The exposure to toxic inorganic arsenic when eating whelks cannot be estimated from their size or their total arsenic concentration.