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1.
Rosas  I.  Belmont  R.  Armienta  A.  Baez  A. 《Water, air, and soil pollution》1999,112(1-2):133-149
Arsenic levels were determined in seventy three samples of well water, and in fifty samples of soil, forage and cow's milk collected at the most important dairy farms of the Comarca Lagunera located in Coahuila and Durango, Mexico, region naturally rich in As. The total inorganic arsenic concentration in well water ranged from 7 to 740 μg L-1 and about ninety percent of the total arsenic was found as As(V). The agricultural soil texture of the sampled area was sandy clay loam type with total arsenic levels up to 30 μg g-1, however, the extractable arsenic was not higher than 12% of the total and it was higher in the 0–30 cm depth horizon. In alfalfa, the most important crop, the total aresenic ranged from 0.24 to 3.16 μg g-1, with 40% of it accumulated at the root level. Significant correlations (p=0.05) were obtained between arsenic (III), (V) and total inorganic arsenic in groundwater with arsenic in soil (0–30 cm depth), and with arsenic in alfalfa (leaves and roots). It was also found a good correlation between extractable arsenic in soil with As concentrations in alfalfa (roots). Arsenic concentrations found in milk ranged from <0.9 to 27.4 ng g-1. The cow's milk biotransfer factor for arsenic was up to 6 × 10-4, applying a pharmacokinetic approach. It was associated with the exposure not only to food but also to water arsenic.  相似文献   

2.
Malm  O  Calasans  C.F.  Fernandes  A.P.  Bastos  W.R.  Pfeiffer  W.C. 《Water, air, and soil pollution》1997,97(1-2):185-191
Occupational exposure to Hg vapour was investigated in 78 workers during three periods with different temperatures: August 1991, December 1991, and February 1992. Each individual was sampled twice in each period; before and after a six working days period (with a two free days interval). As an attempt to normalise Hg excretion urine was sampled always after a normal 8 hours night sleeping and immediately frozen. Mineralisation was done with acid and oxidant mixture and determination by cold vapour Atomic Absorption Spectrophotometry (Varian VGA-76 and AA-1475). Analytical accuracy was controlled by routine analysis of certified reference material (Seronorm TM trace elements, Nycome As diagnostics Olso - Norway) and all samples were analysed in triplicates. Of a total of 355 samples analysed 13% were over the maximum limit for occupational exposure (50 µg.l-1 or ppb). From the 78 individuals investigated 13% presented average value smaller than 10 ppb; just 8% had the average over 50 ppb; 64% showed averages smaller than 30 ppb; and 28% were between 30 and 50 ppb. Seasonal variation was observed with the highest values in the hottest periods. High variability was observed in the same individual even within an interval of just few days (seven days). No increase of Hg in urine after the six days of exposure was observed when compared with the values after the two free days interval.  相似文献   

3.
Arsenic pollution in ground water in India and Bangladesh is considered to be the largest contamination problem in the world. About 15?–?18% of the area of West Bengal, India comes under the threat of arsenic (As) contamination and around 5.36 million people are exposed to this hazard. A detailed isoline map corresponding to variations in arsenic concentration and their spatial distribution was prepared for the study area, which comprised two villages Ghentugachi and Gotera in Nadia district, West Bengal and the total area covered was 808 hectares. The pattern of arsenic contamination was highly irregular and diverse. About 11.2% of the study area was affected most (?>?0.50?mg As l?1) with sample As values reaching 0.71 and 0.80?mg?l?1. About 22.5% of the area had As content between 0.20 and 0.50?mg?l?1 and 33.9% of study area had As content below the WHO guideline of 0.01?mg As/l. Thus the local population living around these areas is vulnerable and exposed to arsenic contamination. None of the water samples exceeded the allowable limit (1.0?mg As l?1) of As for water used in irrigation purposes. The spatial distribution map helped to determine zones with different As concentrations, making it possible to identify high-risk zones.  相似文献   

4.
Arsenicals have been used extensively in agriculture in the United States as insecticides and herbicides. Mono- and disodium methylarsonate and dimethylarsinic acid are organoarsenicals used to control weeds in cotton fields and as defoliation agents applied prior to cotton harvesting. Because the toxicity of most organoarsenicals is less than that of inorganic arsenic species, the introduction of these compounds into the environment might seem benign. However, biotic and abiotic degradation reactions can produce more problematic inorganic forms of arsenic, such as arsenite [As(III)] and arsenate [As(V)]. This study investigates the occurrences of these compounds in samples of soil and associated surface and groundwaters. Preliminary results show that surface water samples from cotton-producing areas have elevated concentrations of methylarsenic species (>10 microg of As/L) compared to background areas (<1 microg of As/L). Species transformations also occur between surface waters and adjacent soils and groundwaters, which also contain elevated arsenic. The data indicate that point sources of arsenic related to agriculture might be responsible for increased arsenic concentrations in local irrigation wells, although the elevated concentrations did not exceed the new (2002) arsenic maximum contaminant level of 10 microg/L in any of the wells sampled thus far.  相似文献   

5.
Water samples from 78 private potable wells in southern New Jersey were collected for mercury analysis in 1991–1992. Analyses were performed for the quantification of reactive, volatile and methyl mercury species. Relationships of mercury with other water quality parameters were evaluated also. Total mercury concentrations varied from <1 ng L?1 to over 36 Μg L?1. The dominant forms in which mercury occurred in the wells sampled were Hg? and HgCl2?, although methyl mercury was present in some wells and comprised up to 8% of the total mercury in the ground water samples.  相似文献   

6.
Arsenic speciation in farmed Hungarian freshwater fish   总被引：2，自引：0，他引：2  
Arsenic speciation analysis was carried out on freshwater farmed fish collected from an area with elevated groundwater arsenic concentrations in Hungary as well as from outside of the area (control samples). The arsenic species were determined by high-performance liquid chromatography-inductively coupled plasma mass spectrometry on methanol extracts of the muscle tissue from the fish. Catfish (Claries gariepinus) were raised in geothermal water where the average total arsenic concentrations were 167 (contaminated sites) and 15.1 ng As mL(-1) (control); they were all fed an artificial diet containing 2880 microg As kg(-1) total arsenic, mostly present as arsenobetaine. In the catfish, the accumulated total arsenic (2510-4720 microg As kg(-1)) was found mostly in the form of arsenobetaine suggesting that uptake of arsenic was dominated by their diet. Carp (Cyprinus carpio) were cultured in surface lakes with no significant arsenic pollution and had total arsenic concentrations ranging from 62 to 363 microg As kg(-1). The arsenic species found in the carp extracts differed markedly from those in the catfish in that no arsenobetaine was detected. Most samples of carp from the investigated sites contained low concentrations of As(III) (arsenite), As(V) (arsenate), MA (methylarsonate), and DMA (dimethylarsinate), and no other compounds were detected. The four individuals from the control site, however, all contained appreciable levels of oxo-arsenosugar-glycerol and oxo-arsenosugar-phosphate. Indeed, the oxo-arsenosugar-phosphate dominated the speciation pattern for these carp contributing about 75% of the sum of species. The contrast between these two freshwater aquaculture species regarding total arsenic and arsenic species has relevant toxicological aspects in terms of food safety.  相似文献   

7.
This paper reports arsenic speciation in edible seaweed (from the Galician coast, northwestern Spain) produced for human consumption. Chondrus crispus , Porphyra purpurea , Ulva rigida , Laminaria ochroleuca , Laminaria saccharina , and Undaria pinnatifida were analyzed. The study focused on arsenosugars, the most frequently occurring arsenic species in algae. As(III) and As(V) were also determined in aqueous extracts. Total arsenic in the samples was determined by microwave digestion and inductively coupled plasma mass spectrometry (ICPMS). For arsenic speciation, a water extraction especially suitable for arsenosugars was used, and the arsenic species were analyzed by liquid chromatography with both anionic and cationic exchange and ICPMS detection (LC-ICPMS). The total arsenic content of the alga samples ranged from 5.8 to 56.8 mg As kg(-1). The mass budgets obtained in the extracts (column recovery × extraction efficiency) ranged from 38 to 92% except for U. pinnatifida (4%). The following compounds were detected in the extracts: arsenite (As(III)), arsenate (As(V)), methylarsonate (MA), dimethylarsinate (DMA), sulfonate sugar (SO(3)-sug), phosphate sugar (PO(4)-sug), arsenobetaine (AB), and glycerol sugar (Gly-sug). The highest concentrations corresponded to the arsenosugars.  相似文献   

8.
A purge and trap procedure was used with gas chromatography-mass spectrometry determination to analyze 70 foods for volatile organic compounds (VOCs). The results from analyses over a 5 year period (1996-2000) are reported. VOCs were found in at least one sample of all foods tested, although no single compound was found in each of the foods. The total amount of VOCs found in a single food item over the 5 year period ranged from 24 to 5328 ppb, with creamed corn (canned) the lowest and cheddar cheese the highest. Benzene was found in all foods except American cheese and vanilla ice cream. Benzene levels ranged from 1 to 190 ppb, with the highest level found in fully cooked ground beef. Benzene was found in 12 samples of cooked ground beef, with an average of 40 ppb. Benzene levels above 100 ppb were also seen in at least one sample each of a cola (138 ppb), raw bananas (132 ppb), and cole slaw (102 ppb). This compares to a maximum contaminant level of 5 ppb set by the U.S. EPA for drinking water.  相似文献   

9.
Arsenic (As), which is present in all living tissues, water, and soil, is considered toxic to humans and animals. Because of the presence of arsenic-contaminated sites throughout the world, there is a renewed interest in studying the status of As in water, soil, and plants. Concentrations of As above the permissible limit have been reported in Lower Ganges Plains (West Bengal in India and Bangladesh). The present investigation aimed to examine the concentration of As in water, soil, and rice plants in the Upper/Trans-Ganges Plains covering Punjab in northwestern India. In total, 200 water samples were collected from different locations in Punjab. Corresponding soil, rice grain, and straw samples were collected from the same locations as the water samples had been collected. In addition to deep tube well water (>125 m deep), water samples from shallow hand pumps (<50 m deep) and canals were also collected. The samples were analyzed for total As concentration using an atomic absorption spectrophotometer equipped with a hydride generating system (AAS-HG). The concentration of As in tube well water samples varied from 5.33 to 17.27 μg As L–1, with about 40% samples having As concentrations greater than the permissible limit (10 μg As L–1). None of the hand pump and canal water samples had As concentrations greater than permissible limits. The As concentration of surface soils varied from 1.09 to 2.48 mg As kg–1. There was no trend in the distribution of As with depth of soil. The concentration of As in rice straw varied from 4.05 to 15.06 μg As kg–1 and that of grain from 1.48 to 6.87 μg As kg–1. The concentration of As was lower in edible grain than in inedible straw. There was a positive and significant correlation between As concentration in tube well water and As concentration in surface soils. The buildup of As in soils was directly related to the As concentration of tube well waters. There was a significant correlation between As in water and As in plants. However, a nonsignificant correlation existed between As in soil and As in plants. This indicates that plants absorbed more As from irrigation water than that from soil. This also suggests that irrigation with such waters over a longer period of time may have detrimental effects on soil and on plants, animals, and humans. There is thus a need to continuously monitor the As concentration in undergroundwater.  相似文献   

10.
Rice (Oryza sativa L.), a staple crop for over 50% of the world's population, is also a source of dietary arsenic (As) because of it's efficiencyat accumulating As. Lead–arsenate pesticide was used in agriculture, these soils potentially may be used for rice production. The objective of this study was to determine the effects of compost on total and inorganic As concentrations in rice grown on lead–arsenate contaminated soils. Three lead–arsenatesoils were amended with 10% by weight of compost and planted with rice under flooded and non-flooded conditions. Rice grain yieldwas higher with compost but not flooding. Flooding significantly increased total and inorganic As concentrations. In most cases, rice inorganic Asconcentrations were higher than the limit set by Chinaat 0.2 mg kg?1. Compost at therate used did not reduce rice grain As to safe levels.Lead–arsenate contaminated soils are not recommended for rice production.  相似文献   

11.
Ikem  A.  Osibanjo  O.  Sridhar  M. K. C.  Sobande  A. 《Water, air, and soil pollution》2002,140(1-4):307-333
Two industrial and highly populated cities namely Ibadan and Lagos, both located in Southwestern Nigeria have urban migrationproblems and resource limitations. As a result, the development of residential areas near waste sites and the indiscriminate dumping of municipal waste are common in both cities. Orita-Aperin and Oworonsoki neighborhoods in Ibadan and Lagos,respectively, both located near a waste site were studied. The two areas relied on the wells as sources of drinking water hence poor drinking water quality may have health consequences. A totalof 51 ground-water samples (30 wells in Ibadan and 21 wells in Lagos) were monitored seasonally for two years in Ibadan and a year in Lagos. Results from this study revealed that some of theground-water quality constituents determined exceeded the World Health Organization (WHO) standards for drinking water irrespective of source of pollution. Some of the ground-water samples were poor in quality in terms of pH, conductivity, totaldissolved solids, chloride, nitrate, ammonia, COD, Al, Cd, Cr, Fe, Pb, Ni and total coliforms recorded. Thus, ground-water fromsome of these private wells requires further purification to ensure its fitness for human consumption.F-test, one-way parametric analysis of variance (ANOVA), Mann-Whitney `T' test and Kruskal-Wallis H-test applied to upgradient and downgradient concentrations suggest impact ofthe waste sites on ground-water quality. The Mann-Whitney testonly suggests that the downgradient values of Fe (Ibadan: dryseason (1), sulfate (Ibadan: rainy season (2) and pH (Lagos: dry season (2) were significant at 5% level of significance. For Ibadan wells, the Kruskal-Wallis test showed that variances ofspecific conductivity, dissolved solids, and chloride for Ibadanupgradient and downgradient values were unequal. Also variances of specific conductivity and dissolved solids for upgradient anddowngradient values in Lagos were unequal at 5% level of significance. Three downgradient wells in Lagos and four downgradient wells in Ibadan had significant impact due to leachate migration into drinking wells.  相似文献   

12.
The environmental impact of arsenic and heavy metals on a 105 km2 area of the historical and recent mining site of Villa de la Paz-Matehuala, San Luis Potosí (Mexico) was evaluated. Results of soil samples reported concentrations between 19–17 384 mg kg-1 As, 15–7200 mg kg-1 Cu, 31–3450 mg kg-1 Pb and 26–6270 mg kg-1 Zn, meanwhile, the concentrations in dry stream sediment samples were found to vary between 29–28 600 mg kg-1 As, 50–2160 mg kg-1 Pb, 71–2190 mg kg-1 Cu, and 98–5940 mg kg-1 Zn. The maximum arsenic concentration in pluvial water storage ponds (265 μg L-1), near the main potential sources of pollution, exceed by 5 times the Mexican drinking water quality guideline (50 μg L-1). The arsenic concentrations in water storage ponds and stream sediments decrease as distance from the potential sources increase. A special case is the `Cerrito Blanco' area located 5 km east of Matehuala, where the highest arsenic concentration in water was found (>5900 μg L-1), exceeding by 100 times the established guideline, thus representing a severe health risk. The results suggest that arsenic and heavy metal dispersion from their pollution sources (historical and active tailings impoundments, waste rock dumps and historical slag piles), is mainly associated in this site with: (1) fluvial transportation of mine waste through streams that cross the area in W–E direction; and (2) aeolian transportation of mineral particles in SW–NE direction. Finally, control measures for pollution routes and remediation measures of the site are proposed.  相似文献   

13.
Arsenic (As) poisoning of groundwater in Bangladesh has become a major environmental and health issue. The extensive use of groundwater in irrigation of rice has resulted in elevated As in soils and crops. A study was undertaken to determine As concentrations in groundwater, soils, and crops in 16 districts of southwestern Bangladesh. Groundwater samples were collected from shallow-tube and hand-tube wells (STW and HTW) used for irrigation and drinking water. Soil and rice plants were sampled from the command area of the tube wells. Arsenic concentrations were determined using an atomic absorption spectrometer equipped with flow injection hydride generator. Groundwater samples contained <10 to 552 μg As L?1. Arsenic concentrations in 59% of STW samples exceeded 50 μg As L?1, the national standard for As in drinking water. Unlike groundwater, most of the surface water samples contained <10 μg As L?1. Concentrations of As in the soils from the command area of the tube wells ranged from 4.5 to 68 mg kg?1. More than 85% of the soils contained <20 mg As kg?1. The mean As concentration in the rice grain samples was 0.23 mg kg?1, which is much less than the maximum food hygiene standard. A positive relationship was observed between groundwater and soil As, implying that soil As level increases as a result of irrigation with contaminated water. However, irrigation water As did not show any relation with rice grain As. The findings suggest that surface water bodies are a safe source of irrigation water in the As-contaminated areas.  相似文献   

14.
The arsenic contamination of Bangladesh groundwater involves heavy arsenic inputs to irrigated rice fields. Beside adsorption on soil colloids, iron–arsenic co-precipitation phenomena can affect arsenic retention in soils. In paddy fields of Satkhira District, Bangladesh, the study of the arsenic and iron forms in the irrigation waters and in soils at different times and distances from the irrigation well evidenced that a higher Fe/As ratio in the well water was related to a faster oxidation of Fe(II) and As(III) in water and to a close Fe–As association in soils, together with a greater accumulation of arsenic and poorly ordered iron oxides. The concentration of arsenic and of labile iron forms decreased with the distance from the well and with the depth, as well as the reversibility of arsenic binding. The fate of the arsenic added to the soils by irrigation hence resulted strongly influenced by iron–arsenic co-precipitation, depending on the Fe/As ratio in water. Irrigation systems favouring the sedimentation of the Fe–As flocks could help in protecting the rice from the adverse effects of dissolved arsenic.  相似文献   

15.
Rice has a much enhanced arsenic (As) accumulation compared with other cereal crops. How As is transported in xylem exudates of rice growing in soil remains unknown. We quantified the chemical species of As in xylem exudates of rice growing in arsenic-contaminated soil (62.5 mg As per kg soil) under flooded and aerobic conditions. In the aerobic treatment, the predominant species of As in the xylem sap was arsenate [As(V)], accounting for 64–88%, and the remainder was arsenite [As(III)]. In the flooded treatment, dimethylarsinic acid (DMA) was detected in the xylem sap besides As(III) and As(V), and the percentages of the three species As was 11–20%, 26–77%, and 12–54%, respectively. As speciation in the soil solution was dominated by As(V) under aerobic conditions, and dominated by As(III) under flooded conditions. DMA was detected at low concentrations in some of the flooded solution samples. Our results show that As speciation in the xylem sap differs in different water management regimes and correlate with As speciation in the soil solution strongly.  相似文献   

16.
The concentrations of 9 chlorinated pesticides in the water sources and tap waters of Istanbul, Turkey, were determined by gas chromatographic methods following the enrichment through adsorption and elution techniques. The observed organochlorine pesticides were α- and γ-HCH and aldrin which had been banned from use. The contents of α- and γ-HCH in raw waters were in the range of 0.34–1.7 ppb and not detected-0.077 ppb, respectively. Aldrin was observed at the concentration of 0.03 ppb in some samples. The residue levels of organochlorine pesticides in drinking water supplies of Istanbul were found significantly under the maximum permissible levels of standards. The effectiveness of potable water treatment processes and the importance of maintenance and back- washing of sand filters in pesticide removal were observed. Improper and delayed back-washings of filters caused an increase in the pesticide residues in the distributed water. In older water distribution lines, higher concentrations of some organochlorines were also observed.  相似文献   

17.
A pot study was conducted to screen different basmati rice varieties for their accumulation of arsenic (As). Different amounts of arsenic (0–800 µg/L) were applied through irrigation water to four basmati rice varieties (Pusa basmati-1121, Pusa Punjab basmati-1509, Punjab basmati-2, and Punjab basmati-3). Highest arsenic concentration was found in the grains of Punjab basmati-3 and lowest in the grains of Pusa Punjab basmati-1509. In all varieties, grain As concentration ranged from 0.038 to 0.288 mg/kg, which was within the permissible limit of 1.0 mg/kg in rice grain recommended by World Health Organization (WHO). In husk, highest As concentration was found in Pusa basmati-1121 and lowest in Punjab basmati-2. Among the four varieties, highest content of As was accumulated in roots and straw of Pusa Punjab basmati-1509, whereas least was accumulated in Punjab basmati-2. The distribution of arsenic among plant parts was found in the order: roots > straw > husk > grain. The mean arsenic concentrations in grain, husk, straw, and root of basmati rice varieties increased with increasing concentration of arsenic in irrigation water. Highest grain yield was obtained in Pusa Punjab basmati-1509 variety due to lesser accumulation of arsenic compared with other varieties. Rice yield, plant height, root weight, straw weight, test weight, effective tiller, and filled grain per panicle decreased with increase in arsenic concentration in irrigated water.  相似文献   

18.
An enzyme-linked immunosorbent assay (ELISA) for fipronil was developed by using polyclonal antibodies (pABs) or monoclonal antibodies (mABs), and its suitability of the determination of this analyte in spiked water samples was studied. The pABs-based assay showed I50 = 17.95 ppb, I90 = 203.40 ppb, and I10 = 0.066 ppb, whereas the mABs-based assay showed I50 = 5.99 ppb, I90 = 485.40 ppb, and I10 = 0.074 ppb. The recoveries of fipronil from tap water samples by pABs-based ELISA were 93.00-124.00% in the range of 0-500 ng/mL, and those obtained from the samples by mABs-based ELISA were 94.70-108.00%. Different types of water from pool, river, and sea were spiked at different levels (ranging form 0.1 to 10 microg/L) and were assayed by the indirect ELISA with mABs. The recoveries of fipronil by this ELISA were in the range of 80-120%. The results demonstrate that this assay is suitable for the quantitative detection of fipronil at trace levels in water samples.  相似文献   

19.
This study was conducted to examine the spatial variability of groundwater quality factors and to determine soil physicochemical properties in order to distinguish their relationships with pistachio yield in the Rafsanjan area, Iran. One hundred fifty-seven water samples from the wells of the studied area were evaluated for electrical conductivity (EC), sodium (Na+), calcium (Ca2+), magnesium (Mg2+), sulfate (SO4 2–), bicarbonate (HCO3 –), chloride (Cl–), total hardness, and sodium adsorption ratio (SAR). Groundwater levels of the wells were also recorded. The EC and SAR values of groundwater for some of the wells separately compared with pistachio yield in the orchards irrigated with these wells. Six pistachio gardens with the same management but in different parts were selected, and each garden was divided in two (desired and undesired) parts. In each part of these orchards, soil samples were randomly taken in three replicates from depths of 0–40 and 40–80 cm to determine soil properties. One soil profile was also excavated for soil classification in each part of these gardens. Groundwater in most of the area had EC > 8 dS m–1 and SAR ≥ 13 (meq L–1)0.5. The lowest qualities of groundwater were found in the eastern, southern, and the northern parts of the area, where water's negative effects on pistachio yield have been reported. Statistical results for selected gardens showed that pistachio yield was affected considerably by salinity and clay content of the soils. Modern irrigation techniques and mixing high-quality water with poor-quality water in the area is necessary to prevent the reduction of the water table in the area. Preparing continuous soil salinity and texture maps are recommended for proper pistachio management in the area.  相似文献   

20.
Arsenic and antimony concentrations in water and sediment samples collected from Prestea, a gold mining town in the Western Region of Ghana and its environs were studied. The concentrations of these elements were measured using instrumental neutron activation analysis (INAA). INAA was preferred to other modern analytical techniques because of its relatively higher selectivity, sensitivity and high precision. Beside its multi-elemental nature, INAA is very fast and thus presents a very good analytical tool for the determination of elemental concentrations in various samples including water and sediment. The samples were irradiated using a 30 kW tank-in-pool Ghana Research Reactor-1 (GHARR-1) operating at a thermal neutron flux of 5 × 1011 n s?1 cm?2. The samples were irradiated and counted without any chemical treatment. Elevated levels of As and Sb were found in both water and sediment. Generally, As and Sb concentrations in the water samples ranged from 0.90–8.25 ppm and 0.09–0.75 ppm respectively. These values far exceed the WHO recommended values for As and Sb in water, 0.01 ppm and 0.005 ppm respectively. The levels of As in sediment ranged from 942–10,200 ppm, and that of Sb was 8.5–90.4 ppm. Arsenic concentrations in both water and sediment were generally higher than Sb concentrations. This is, however, not surprising as arsenopyrites (FeAsS2) are among the major pathfinder minerals associated with gold mined from Ghana. Our results show that the study area is polluted as far as the levels of As and Sb in water and sediment are concerned.  相似文献   

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