共查询到20条相似文献,搜索用时 31 毫秒
1.
The geochemical characteristics of arsenic in the soil of the Western Hunan mining area of P.R. China were systematically
studied. The results show that the strata of Western Hunan are rich in arsenic and that Western Hunan is a geochemically abnormal
region for arsenic. The experimental study on speciation in the strata also indicates that the speciation of arsenic in the
Neoproterozoic-Cambrian strata are mainly easily transferred speciation (exchangeable, carbonate-bound, sulfides-bound), which
are approaching or exceed 60%. Arsenic content in the main soil of Western Hunan is in the range of 8.8–22.8 μg g−1, the mean value is 16.1 μg g−1, which is larger than the arsenic background value of Hunan soil. The distribution of rock with high arsenic content or high
easily transferred arsenic speciation is consistent with the distribution of high arsenic content soil. In the mining region,
part soils and river/brook waters were polluted by mine tailings and mining/smelting waste water. The arsenic content in polluted
paddy soils and river/brook water is 46.26–496.19 μg g−1, 0.3–16.5 mgL−1, respectively. The positive abnormality and pollution of arsenic in the soil and water affects the arsenic content of the
crop and the inhabitants’ health. 相似文献
2.
The Salí River Basin in north-west Argentina (7,000 km2) is composed of a sequence of Tertiary and Quaternary loess deposits, which have been substantially reworked by fluvial and
aeolian processes. As with other areas of the Chaco-Pampean Plain, groundwater in the basin suffers a range of chemical quality
problems, including arsenic (concentrations in the range of 12.2–1,660 μg L−1), fluoride (50–8,740 μg L−1), boron (34.0–9,550 μg L−1), vanadium (30.7–300 μg L−1) and uranium (0.03–125 μg L−1). Shallow groundwater (depths up to 15 m) has particularly high concentrations of these elements. Exceedances above WHO (2011) guideline values are 100% for As, 35% for B, 21% for U and 17% for F. Concentrations in deep (>200 m) and artesian groundwater
in the basin are also often high, though less extreme than at shallow depths. The waters are oxidizing, with often high bicarbonate
concentrations (50.0–1,260 mg L−1) and pH (6.28–9.24). The ultimate sources of these trace elements are the volcanic components of the loess deposits, although
sorption reactions involving secondary Al and Fe oxides also regulate the distribution and mobility of trace elements in the
aquifers. In addition, concentrations of chromium lie in range of 79.4–232 μg L−1 in shallow groundwater, 129–250 μg L−1 in deep groundwater and 110–218 μg L−1 in artesian groundwater. All exceed the WHO guideline value of 50 μg L−1. Their origin is likely to be predominantly geogenic, present as chromate in the ambient oxic and alkaline aquifer conditions. 相似文献
3.
Patel KS Shrivas K Brandt R Jakubowski N Corns W Hoffmann P 《Environmental geochemistry and health》2005,27(2):131-145
Arsenic contamination in the environment (i.e. surface, well and tube-well water, soil, sediment and rice samples) of central
India (i.e. Ambagarh Chauki, Chhattisgarh) is reported. The concentration of the total arsenic in the samples i.e. water (n=64), soil (n=30), sediment (n=27) and rice grain (n=10) were ranged from 15 to 825 μg L−1, 9 to 390 mg kg−1, 19 to 489 mg kg−1 and 0.018 to 0.446 mg kg−1, respectively. In all type of waters, the arsenic levels exceeded the permissible limit, 10 μg L−1. The most toxic and mobile inorganic species i.e. As(III) and As(V) are predominantly present in water of this region. The
soils have relatively higher contents of arsenic and other elements i.e. Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu,
Zn, As, Ga, Zr, Sn, Sb, Pb and U. The mean arsenic contents in soil of this region are much higher than in arsenic soil of
West Bengal and Bangladesh. The lowest level of arsenic in the soil of this region is 3.7 mg kg−1 with median value of 9.5 mg kg−1. The arsenic contents in the sediments are at least 2-folds higher than in the soil. The sources of arsenic contamination
in the soil of this region are expected from the rock weathering as well as the atmospheric deposition. The environmental
samples i.e. water, soil dust, food, etc. are expected the major exposure for the arsenic contamination. The most of people
living in this region are suffering with arsenic borne diseases (i.e. melanosis, keratosis, skin cancer, etc.). 相似文献
4.
Maria do Socorro S. Pereira Eduardo Winter Jose Roberto Guimarães Susanne Rath Anne Hélène Fostier 《Environmental Chemistry Letters》2007,5(3):137-141
Here, we show a fast and sensitive method for the determination of inorganic arsenic in natural waters using differential
pulse cathodic stripping voltammetry. All the arsenite determinations were done in 2.0 mol L−1 HCl + 3.15 × 10−4 mol L−1 Cu(II) supporting electrolyte. 1 × 10−3 mol L−1 sodium thiosulphate was used as As(V) reducing agent. The detection limit was 0.5 μg L−1 for both species. The method has been applied to water samples collected in an arsenic-contaminated region of Brazil, in
particular, to verify the efficiency of the solar oxidation and removal of arsenic process applied to these waters. 相似文献
5.
The influence of naturally occurring uraniferous black shales on cadmium, molybdenum and selenium concentrations in soils
and plants is examined. The possible implications of element concentrations to animal and human health are considered for
the Deog-Pyoung area.
Geochemical surveys have been undertaken within 13 river tributary valleys in the area underlain by uraniferous black shales
and black slates or grey chlorite schists. Sampling of rocks, soils and plants has been carried out along transect lines within
each valley. Samples were analysed for trace elements by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES)
and for uranium by Neutron Activation Analysis (NAA). Soil pH, cation exchange capacity, loss on ignition and particle size
distribution have been measured for selected samples.
Average trace element concentrations of the Okchon uraniferous black shales were 6.3 μg g−1 Cd, 136 μg g−1 Mo and 8.6 μg g−1 Se. Soils derived from these rocks tend to reflect their extreme geochemical composition. Trace element concentrations in
alluvial soils derived in part from these black shales averaged 1.2 μg g−1 Cd, 20 μg g−1 Mo and 1.5 μg g−1 Se. Trace element concentrations in plants were found to be influenced by those of soils. Cadmium accumulated in tobacco
leaves up to 46 μg g−1 (D.M.) and leafy plants such as lettuce contain up to 0.5 μg g−1 Se (D.M.).
In addition to total concentrations in soils, soil pH is a major factor influencing uptake of Mo into crop plants and soil
texture for Se. Concentrations of trace elements in plants also varied between plant species. The relative concentrations
of Cd were found to vary in the order tobacco > lettuce > red pepper > rice grain.
Elevated concentrations of Cd in crop plants and in tobacco may possibly have deleterious effects on human health in this
area. The low Cu:Mo ratio in rice stalk of 2.65:1 may be associated with disturbed Cu metabolism in ruminant animals which
regularly consume this material. 相似文献
6.
H. D. Revanasiddappa B. P. Dayananda T. N. K. Kumar 《Environmental Chemistry Letters》2007,5(3):151-155
We developed a cost-effective and sensitive spectrophotometric method for the determination of arsenic at trace level using
a new reagent, leuco malachite green. Here we show that, arsenic reacts with potassium iodate in acidic conditions to liberate
iodine, and the liberated iodine selectively oxidizes leuco malachite green to malachite green dye. We studied the Beer’s
law at 617 nm, which showed linearity over the concentration range 0.09–0.9 μg ml−1 of arsenic. We show that the molar absorptivity, Sandell’s sensitivity and detection limit of the method are 6.1 × 104 l mol−1 cm−1, 0.0012 μg cm−2 and 0.025 μg ml−1, respectively. We applied the developed method for the determination of arsenic in environmental samples. 相似文献
7.
The cancer risk and the non-cancer hazard index for inhabitants exposed to As, Cd, Cu and Zn in the soils and stream waters
of the abandoned Songcheon Au–Ag mine area were evaluated. Mean concentrations of As, Cd, Cu, Pb and Zn in agricultural soils
were 230, 2.5, 120, 160, and 164 mg kg−1, respectively. Mean concentrations of As, Cd and Zn of the water in the stream where drinking water was drawn was 246 μg
L−1, 161 μg L−1 and 3899 μg L−1, respectively. These levels are significantly higher than the permissible levels for drinking water quality recommended by
Korea and WHO. The resulting human health risks to farmers who inhabited the surrounding areas due to drinking water were
summarized as follows: (1) the non-cancer health hazard indices showed that the toxic risk due to As and Cd in drinking water
were 10 and 4 times, respectively, greater than those induced by the safe average daily dosages of the respective chemicals.
(2) the cancer risk of As for exposed individuals through the drinking water pathway was 5 in 1000, exceeded the acceptable
risk of 1 in 10,000 set for regulatory purposes. 相似文献
8.
Eun Jung Choy Qtae Jo Hyo-Bang Moon Chang-Keun Kang Ju-Chan Kang 《Marine Biology》2007,151(1):157-165
The time-course of uptake and elimination of benzo(a)pyrene (BaP) for the Pacific oyster, Crassostrea gigas and reproduction damage and reproductive outputs were studied. Sexually immature C. gigas broodstock were fed for 28 days with live algae grown in four BaP solutions of 0, 50, 500, and 5,000 μg L−1 (hereafter, control, 50, 500, and 5,000 oysters) and were subsequently conditioned to maturation by a feeding with BaP-free
live algae under temperature manipulation for another 28 days. The 5,000 μg L−1 oysters gained a steady state concentration, around 30,000 ng g−1 d.w. for digestive gland, a week earlier compared to the 500 μg L−1 oysters. The earlier gain or longer persistence of the steady state concentration influenced elimination of BaP, with an
eliminating trend for 500 μg L−1 oysters, while no elimination for 5,000 μg L−1 oysters. The maternal persistence of the steady state concentration resulted in significant damages in the reproductive success
and their reproductive outputs in terms of the hatching rate and larval growth, survival, and settlement. The 50 μg L−1 oysters remained far below the steady state concentration, and showed a manifest eliminating behavior during the subsequent
BaP-free 28 day maturation period. The reproductive success and initial larval events of 50 μg L−1 oysters were comparable to those of control. However, the damage potential of the 50 μg L−1 oysters might be more significant if their maternal exposure continued beyond 28 days, since the accumulation profile at this
dose was linear. 相似文献
9.
This paper identifies newer areas of arsenic contamination in the District Kanker, which adjoins the District Rajnandgaon where high contamination has been reported earlier. A correlation with the mobile phase episodes of arsenic contamination has been identified, which further hinges on the complex geology of the area. Arsenic concentrations in both surface and groundwater, aquatic organisms (snail and water weeds) soil and vegetation of Kanker district and its adjoining area have been reported here. The region has been found to contain an elevated level of arsenic. All segments of the ecoysystem are contaminated with arsenic at varying degrees. The levels of arsenic vary constantly depending on the season and location. An analysis of groundwater from 89 locations in the Kanker district has shown high values of arsenic, iron and manganese (mean: 144, 914 and 371 μg L−1, respectively). The surface water of the region shows elevated levels of arsenic, which is influenced by the geological mineralised zonation. The most prevalent species in the groundwater is As(III), whereas the surface water of the rivers shows a significant contamination with the As(V) species. The analysis shows a bio-concentration of the toxic metals arsenic, nickel, copper and chromium. Higher arsenic concentrations (groundwater concentrations greater than 50 μg L−1) are associated with sedimentary deposits derived from volcanic rocks, hence mineral leaching appears to be the source of arsenic contamination. Higher levels of arsenic and manganese in the Kanker district have been found to cause impacts on the flora and fauna. A case study of episodic arsenical diarrhoea is presented. 相似文献
10.
This study was carried out to determine the occurrence, prevalence and contributing factors to the incidence of goitre in
Yewa north local government area of Ogun state, southwestern Nigeria. To achieve these objectives, soil, water, and cassava
tubers were collected from four villages – Igbogila, Egua, Sawonjo and Imoto and from Lagos (about 250 m to the ocean) as
a reference location, in order to determine their iodine concentrations. The results of the analyses indicated a soil mean
iodine range of 2.1–5.8 μg g−1; a cassava mean iodine value of 2.3–3.5 μg g−1 and a drinking water mean iodine value of generally <1.0 μg L−1 in all the four villages. These values of iodine in soil and water of the four villages are considered low when compared
with the soil iodine value of 7.4 μg g−1 and water iodine value of 6.1 μg L−1 obtained from Lagos. The limestone unit of the study area remains an inhibiting factor in the bioavailability of the iodine
because of its alkalinity. Statistical analysis has shown that there was significant difference between iodine concentration
in the soils and the drinking water, and a correlation between the soil iodine and organic matter content at p < 0.05. The correlation between soil iodine and granulometric fractions occurred at p < 0.01. Potential goitrogens in the commonly consumed cassava products might also have contributed to the prevalence of goitre
in the study area. Both the females and the adults (i.e., less mobile groups) were found to be vulnerable to goitre development
in these villages. 相似文献
11.
Pankaj Kumar Manish Kumar A. L. Ramanathan Maki Tsujimura 《Environmental geochemistry and health》2010,32(2):129-146
Arsenic contamination in groundwater is of increasing concern because of its high toxicity and widespread occurrence. This
study is an effort to trace the factors responsible for arsenic enrichment in groundwater of the middle Gangetic Plain of
India through major ion chemistry, arsenic speciation, sediment grain-size analyses, and multivariate statistical techniques.
The study focuses on the distinction between the contributions of natural weathering and anthropogenic inputs of arsenic with
its spatial distribution and seasonal variations in the plain of the state Bihar of India. Thirty-six groundwater and one
sediment core samples were collected in the pre-monsoon and post-monsoon seasons. Various graphical plots and statistical
analysis were carried out using chemical data to enable hydrochemical evaluation of the aquifer system based on the ionic
constituents, water types, hydrochemical facies, and factors controlling groundwater quality. Results suggest that the groundwater
is characterized by slightly alkaline pH with moderate to strong reducing nature. The general trend of various ions was found
to be Ca2+ > Na+ > Mg2+ > K+ > NH4
+; and HCO3
− > Cl− > SO4
2− > NO3
− > PO4
3− > F− in both seasons. Spatial and temporal variations showed a slightly higher arsenic concentration in the pre-monsoon period
(118 μg/L) than in the post-monsoon period (114 μg/L). Results of correlation analyses indicate that arsenic contamination
is strongly associated with high concentrations of Fe, PO4
3−, and NH4
+ but relatively low Mn concentrations. Further, the enrichment of arsenic is more prevalent in the proximity of the Ganges
River, indicating that fluvial input is the main source of arsenic. Grain size analyses of sediment core samples revealed
clay (fine-grained) strata between 4.5 and 7.5 m deep that govern the vertical distribution of arsenic. The weathering of
carbonate and silicate minerals along with surface-groundwater interactions, ion exchange, and anthropogenic activities seem
to be the processes governing groundwater contamination, including with arsenic. Although the percentage of wells exceeding
the permissible limit (50 μg/L) was less (47%) than that reported in Bangladesh and West Bengal, the percentage contribution
of toxic As(III) to total arsenic concentration is quite high (66%). This study is vital considering that groundwater is the
exclusive source of drinking water in the region and not only makes situation alarming but also calls for immediate attention. 相似文献
12.
Debapriya Mondal Mayukh Banerjee Manjari Kundu Nilanjana Banerjee Udayan Bhattacharya Ashok K. Giri Bhaswati Ganguli Sugata Sen Roy David A. Polya 《Environmental geochemistry and health》2010,32(6):463-477
Remediation aimed at reducing human exposure to groundwater arsenic in West Bengal, one of the regions most impacted by this environmental hazard, are currently largely focussed on reducing arsenic in drinking water. Rice and cooking of rice, however, have also been identified as important or potentially important exposure routes. Quantifying the relative importance of these exposure routes is critically required to inform the prioritisation and selection of remediation strategies. The aim of our study, therefore, was to determine the relative contributions of drinking water, rice and cooking of rice to human exposure in three contrasting areas of West Bengal with different overall levels of exposure to arsenic, viz. high (Bhawangola-I Block, Murshidibad District), moderate (Chakdha Block, Nadia District) and low (Khejuri-I Block, Midnapur District). Arsenic exposure from water was highly variable, median exposures being 0.02 μg/kg/d (Midnapur), 0.77 μg/kg/d (Nadia) and 2.03 μg/kg/d (Murshidabad). In contrast arsenic exposure from cooked rice was relatively uniform, with median exposures being 0.30 μg/kg/d (Midnapur), 0.50 μg/kg/d (Nadia) and 0.84 μg/kg/d (Murshidabad). Cooking rice typically resulted in arsenic exposures of lower magnitude, indeed in Midnapur, median exposure from cooking was slightly negative. Water was the dominant route of exposure in Murshidabad, both water and rice were major exposure routes in Nadia, whereas rice was the dominant exposure route in Midnapur. Notwithstanding the differences in balance of exposure routes, median excess lifetime cancer risk for all the blocks were found to exceed the USEPA regulatory threshold target cancer risk level of 10−4–10−6. The difference in balance of exposure routes indicate a difference in balance of remediation approaches in the three districts. 相似文献
13.
Pistón M Silva J Pérez-Zambra R Dol I Knochen M 《Environmental geochemistry and health》2012,34(2):273-278
A multicommutated flow system was designed and evaluated for the determination of total arsenic and selenium by Hydride Generation
Atomic Absorption Spectrometry (HG-AAS). It was applied to the determination of arsenic and selenium in samples of natural
and drinking water. Detection limits were 0.46 and 0.08 μg l−1 for arsenic and selenium, respectively; sampling frequency was 120 samples h−1 for arsenic and 160 samples h−1 for selenium. Linear ranges found were 1.54–10 μg l−1 (R = 0.999) for arsenic and 0.27–27 μg l−1 (R = 0.999) for selenium. Accuracy was evaluated by spiking various water samples and using a reference material. Recoveries
were in the range 95–116%. Analytical precision (s
r
(%), n = 10) was 6% for both elements. Compared with the Standard Methods, APHA, 3114B manual method, the system consumes at least
10 times less sample per determination, and the quantities of acid and reducing agent used are significantly lower with a
reduction in the generation of pollutants and waste. As an additional advantage, the system is very fast, efficient and environmentally
friendly for monitoring total arsenic and selenium levels in waters. 相似文献
14.
This study evaluated variations in heavy metal contamination of stream waters and groundwaters affected by an abandoned lead–zinc mine, where a rockfill dam for water storage will be built 11 km downstream. For these purposes, a total of 10 rounds of stream and groundwater samplings and subsequent chemical analyses were performed during 2002–2003. Results of an exploratory investigation of stream waters in 2000 indicated substantial contamination with heavy metals including zinc (Zn), iron (Fe) and arsenic (As) for at least 6 km downstream from the mine. Stream waters near the mine showed metal contamination as high as arsenic (As) 8,923 μg L−1, copper (Cu) 616 μg L−1, cadmium (Cd) 223 μg L−1 and lead (Pb) 10,590 μg L−1, which greatly exceeded the Korean stream water guidelines. Remediation focused on the mine tailing piles largely improved the stream water qualities. However, there have still been quality problems for the waters containing relatively high concentrations of As (6–174 μg L−1), Cd (1–46 μg L−1) and Pb (2–26 μg L−1). Rainfall infiltration into the mine tailing piles resulted in an increase of heavy metals in the stream waters due to direct discharge of waste effluent, while dilution of the contaminated stream waters improved the water quality due to mixing with metal free rain waters. Levels of As, Cu and chromium (Cr) largely decreased after heavy rain but that of Pb was rather elevated. The stream waters were characterized by high concentrations of calcium (Ca) and sulfate (SO4), which were derived from dissolution and leaching of carbonate and sulfide minerals. It was observed that the proportions of Ca and SO4 increased while those of bicarbonate (HCO3) and sodium and potassium (Na+K) decreased after a light rainfall event. Most interestingly, the reverse was generally detected for the groundwaters. The zinc, being the metal mined, was the most dominant heavy metal in the groundwaters (1758–10,550 μg L−1) near the mine, which far exceeded the Korean standard of 1000 μg L−1 for drinking water. The decreases in the heavy metals contents in the groundwaters associated with reduced rainfall were quite different from the increases observed for the stream waters, which is not clearly understood at this time and warrants further investigation. 相似文献
15.
Asaad Ahmed Nafees Ambreen Kazi Zafar Fatmi Muhammad Irfan Arif Ali Fujio Kayama 《Environmental geochemistry and health》2011,33(2):203-216
This study was designed to determine the association between chronic arsenic exposure through drinking groundwater and decrement
in lung function, particularly among individuals who do not have signs of arsenic lesions, among an adult population. This
was a comparative cross-sectional study conducted during the months of January to March 2009. One hundred participants ≥15 years
of age in each group, i.e. exposed (≥100 μg/l) and unexposed (≤10 μg/l) to arsenic, determined by testing drinking water samples
(using portable kits), were compared for effects on lung function using spirometry. A structured and validated questionnaire
was administered. Examination for arsenic skin lesions was also done. There was a decline in the mean adjusted FEV1 of 154.3 ml
(95% CI: −324.7, 16.0; p = 0.076), in mean adjusted FVC of 221.9 ml (95% CI: −419.5, −24.3; p = 0.028), and in FEV1/FVC ratio of 2.0 (95% CI: −25.3, 29.4; p = 0.884) among participants who were exposed to arsenic compared to those unexposed. A separate model comprising a total
of 160 participants, 60 exposed to arsenic concentrations ≥250 μg/l and 100 unexposed at arsenic concentrations of ≤10 μg/l,
showed a decrement in mean adjusted FEV1 of 226.4 ml (95% CI: −430.4, −22.4; p = 0.030), in mean adjusted FVC of 354.8 ml (95% CI: −583.6, −126.0; p = 0.003), and in FEV1/FVC ratio of 9.9 (95% CI: −21.8, 41.6; p = 0.539) among participants who were exposed to arsenic in drinking groundwater. This study demonstrated that decrement in
lung function is associated with chronic exposure to arsenic in drinking groundwater, occurring independently, and even before
any manifestation, of arsenic skin lesions or respiratory symptoms. The study also demonstrated a dose-response effect of
arsenic exposure and lung function decrement. 相似文献
16.
Palumbo-Roe B Cave MR Klinck BA Wragg J Taylor H O'Donnell KE Shaw RA 《Environmental geochemistry and health》2005,27(2):121-130
Jurassic ironstones outcropping over parts of eastern England give rise to soils with arsenic concentrations in excess of
the UK soil guideline value of 20 mg kg−1 for residential areas. Total arsenic concentrations were determined for 73 ironstone derived soils and bioaccessible arsenic
determined using an in vitro physiologically based extraction test. The bioaccessible arsenic concentration for these soils was found to be well below
the soil guideline value with a mean concentration of 4 mg kg−1 and a range of 2–17 mg kg−1. The bioaccessible fraction ranges from 1.2 to 33%. Data from a sequential extraction test based on the use of aqua regia
as the main extractant is presented for a subset of 20 of the soils. Chemometric data reduction is used to demonstrate that
the bioaccessible arsenic is mainly contained within calcium iron carbonate (sideritic) assemblages and only partially iron
aluminosilicates, probably berthierine, and iron oxyhydroxide phases, probably goethite. It is suggested that the bulk of
the non-bioaccessible arsenic is bound up with less reactive iron oxide phases. 相似文献
17.
An assessment of exposure to mercury in Changchun city has been undertaken. We estimated Hg exposure to members of the general population based on currently available information and our research. We also studied the Hg concentrations in scalp hair of adults. Adults have an estimated intake of all Hg species via all routes of 6.780 μg day−1 (excluding dental amalgam), which equates to an absorbed dose of 1.718 μg day−1. Fish consumption was the most important exposure route (12% of intake, 43% of absorbed dose). Furthermore, air, cereals and vegetables were important exposure routes, and these exposure were estimated for absorbed dosed at 0.296, 0.209 and 0.318 μg day−1, respectively. The mean Hg concentration in hair was 0.448 μg g−1 (range 0.092–10.463 μg g−1). Hg concentration in the hair of males was 0.422 μg g−1 (0.105–2.665 μg g−1), and was 0.474 μg g−1(0.092–10.463 μg g−1) in the hair of females. Neither place of residence nor age had any significant effect on hair Hg concentrations. 相似文献
18.
M. J. Watts J. O’Reilly A. L. Marcilla R. A. Shaw N. I. Ward 《Environmental geochemistry and health》2010,32(6):479-490
A field method is reported for the speciation of arsenic in water samples that is simple, rapid, safe to use beyond laboratory
environments, and cost effective. The method utilises solid-phase extraction cartridges (SPE) in series for selective retention
of arsenic species, followed by elution and measurement of eluted fractions by inductively coupled plasma mass spectrometry
(ICP-MS) for “total” arsenic. The method is suitable for on-site separation and preservation of arsenic species from water.
Mean percentage accuracies (n = 25) for synthetic solutions of arsenite (AsIII), arsenate (AsV), monomethylarsonic acid (MA), and dimethylarsinic acid (DMA) containing 10 μg l−1 As, were 98, 101, 94, and 105%, respectively. Data are presented to demonstrate the effect of pH and competing anions on
the retention of the arsenic species. The cartridges were tested in the UK and Argentina at sites where arsenic was known
to be present in surface and groundwaters, respectively, at elevated concentrations and under challenging matrix conditions.
In Argentinean groundwater, 4–20% of speciated arsenic was present as MA and 20–73% as AsIII. In UK surface waters, speciated arsenic was measured as 7–49% MA and 12–42% DMA. Comparative data from the field method
using SPE cartridges and the laboratory method using liquid chromatography coupled to ICP-MS for all water samples provided
a correlation of greater than 0.999 for AsIII and DMA, 0.991 for MA, and 0.982 for AsV (P < 0.01). 相似文献
19.
Presence of Alexandrium catenella and paralytic shellfish toxins in finfish, shellfish and rock crabs in Monterey Bay, California, USA 总被引:1,自引:0,他引:1
The central California coast is a highly productive, biodiverse region that is frequently affected by the toxin-producing
dinoflagellate Alexandrium catenella. Despite the consistent presence of A. catenella along our coast, very little is known about the movement of its toxins through local marine food webs. In the present study,
we investigated 13 species of commercial finfish and rock crabs harvested in Monterey Bay, California for the presence of
paralytic shellfish toxins (PSTs) and compared them to the presence of A. catenella and PSTs in sentinel shellfish over a 3-year period. Between 2003 and 2005, A. catenella was noted in 55% of surface water samples (n = 307) and reached a maximum concentration of 17,387 cells L−1 at our nearshore site in Monterey Bay. Peak cell densities occurred in the month of July and were associated with elevated
shellfish toxicity in the summers of 2004 and 2005. When A. catenella was present, particulate PSTs were detected 71% of the time and reached a maximum concentration of 962 ng STXeq L−1. Of the 13 species tested, we frequently detected PSTs in Pacific sardines (Sardinops sagax; maximum 250 μg STXeq 100 g−1), northern anchovies (Engraulis mordax; maximum 23.2 μg STXeq 100 g−1), brown rock crabs (Cancer antennarius; maximum 49.3 μg STXeq 100 g−1) and red rock crabs (C. productus; 23.8 μg STXeq 100 g−1). PSTs were also present in one sample of Pacific herring (Clupea pallas; 13.3 μg STXeq 100 g−1) and one sample of English sole (Pleuronectes vetulus; 4.5 μg STXeq 100 g−1), and not detected in seven other species of flatfish tested. The presence of PSTs in several of these organisms reveals
that toxins produced by A. catenella are more prevalent in California food webs than previously thought and also indicates potential routes of toxin transfer
to higher trophic levels.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
20.
Rosborg I Nihlgård B Gerhardsson L Sverdrup H 《Environmental geochemistry and health》2006,28(3):215-229
The water chemistry of 20 municipal water treatment plants in southern Sweden, representing various bedrock situations, and water qualities, were investigated. Four water samples, raw and treated, were collected from each plant and analyzed by predominantly ICP-OES and ICP-MS at four occasions from June to December, 2001. The concentrations of Ca, Mg, K, Na, HCO3 and a number of micronutrients, varied considerably in treated waters from the studied plants (ranges; Ca: 9.1–53.7 mg L−1, Mg: 1.4–10.9 mg L−1, K: 1.1–4.8 mg L−1, Na; 5.4–75.6 mg L−1, HCO3: 27–217 mg L−1). The elimination of Fe and Mn from raw water was efficient in all treatments investigated, giving concentrations in treated waters below the detection limits at some plants. Softening filters gave waters with Ca-concentrations comparable to the softest waters in this study. Adjustment of pH by use of chemicals like lye, soda or lime, modified the consumer water composition significantly, besides raising the pH. It was estimated that drinking water contributed to approximately 2.2–13% of the daily Ca uptake, if the gastrointestinal uptake efficiency from food and water was estimated to be around 50%. The corresponding figures for Mg was 1.0–7% and for F 0–59%. None of the studied elements showed any significant time trends in raw or treated waters during the follow-up period. The concentrations of potentially toxic metals such as Al, Pb and U were low and did not indicate risks for adverse health effects (ranges; Al: 0.5–2.3 μg L−1, Pb: 0–0.3 μg L−1, U: 0.2.5 μg L−1). 相似文献