Effects of dietary cadmium exposure on osmoregulation and urine concentration mechanisms of the semi-desert rodent Meriones shawi

Contamination by cadmium in the environment is of great concern because of its toxicity and threats to human and animal health. The current study was conducted to investigate the effects of a cadmium contaminated diet on the osmoregulation and urine concentration mechanisms of the semi-desert rodent Meriones shawi and eventual accumulation of this metal in vital organs such as the kidneys, which are directly implicated in water regulation. Originally, we used Differential Pulse Anodic Stripping Voltammetry (DPASV) to avoid the matrix interference due to the highly organic content in the biological samples. Our results show that Meriones shawi successfully maintained a homeostasis state and presented a special adaptation to regulate urine volume during cadmium exposure by decreasing diuresis and increasing urinary osmolality. The plasma osmolality and hematocrit remained constant throughout the experiment. The stripping signals of cadmium are linear up to 0.3-100 μg L(-1) range, with a detection limit of 0.28 μg L(-1). The DPASV technique was useful for easy, fast, selective and sensitive determination of Cd, which permits working at cellular concentration. This gives us more information about the chemical form in which Cd is introduced into the organ, as well as the intracellular Cd quantities. This study has potential importance if this valuable novel animal model, imitating human and animal environmental chronic exposure to Cd, could serve as an appropriate terrestrial biomonitor for Cd contaminated sites. These results are encouraging in the context of developing a low-cost and fast technology for the detection of pollutants and for studying the impairment caused by their effects.     

Water and sediment quality of dry season pools in a dryland river system: the upper Leichhardt River, Queensland, Australia

This article presents the geochemical characteristics and physicochemical properties of water and sediment from twelve semi-permanent, dryland pools in the upper Leichhardt River catchment, north-west Queensland, Australia. The pools were examined to better understand the quality of sediments and temporary waters in a dryland system with a well-established metal contamination problem. Water and sediment sampling was conducted at the beginning of the hydroperiod in May and September 2007. Water samples were analyzed for major solute compositions (Ca, Na, K, Mg, Cl, SO(4), HCO(3)) and water-soluble (operationally defined as the <0.45 μm fraction) metals (Cd, Cu, Pb, Zn). Sediment samples were analyzed for total extractable and bioaccessible metals (As, Cd, Cu, Pb, Zn), elemental composition and grain morphology. At the time of sampling a number of pools contained water and sediment with elevated concentrations, compared to Australian regulatory guidelines, of Cu (maximum: water 28 μg L(-1); sediment 770 mg kg(-1)), Pb (maximum: water 3.4 μg L(-1); sediment 630 mg kg(-1)) and Zn (maximum: water 150 μg L(-1); sediment 780 mg kg(-1)). Concentrations of Cd and As in pools were relatively low and generally within Australian regulatory guideline values. Localized factors, such as the interaction of waters with anthropogenic contaminants from modern and historic mine wastes (i.e. residual smelter and slag materials), exert influence on the quality of pool waters. Although the pools of the upper Leichhardt River catchment are contaminated, they do not appear to be the primary repository of water and sediment associated metals when compared to materials in the remainder channel and floodplain. Nevertheless, a precautionary approach should be adopted to mitigating human exposure to contaminated environments, which might include the installation of appropriate warning signs by local health and environmental authorities.     

Toxic and essential elements in blood from delivering women in selected areas of São Paulo State, Brazil

This study was designed to evaluate the degree of environmental contamination and possible exposure of pregnant women to toxic elements in seven selected areas of S?o Paulo State, Brazil. The overall median concentration of Mo in maternal blood was 0.53 μg L?1, highly significant differences found between sites (p < 0.0001). Cd was found to be low overall - 0.09 μg L?1 (0.01-0.58 μg L?1) - with mothers from the Coastal and Rural 1 sites having the highest levels (p < 0.016).Median Hg concentration was 0.60 μg L?1 (0.06 μg L?1-4.35 μg L?1); median Pb level was 16.2 μg L?1 (3.5-57.7 μg L?1) and no differences between sites were observed for both metals. Median Mn level was 16.7 μg L?1 (7.0-39.7 μg L?1), being highest in Urban 2 site (p < 0.016). Concentrations of maternal Co were found to range between 0.06 μg L?1 and 1.1 μg L?1 (median 0.25 μg L?1) and As level was 0.60 μg L?1 (0.10-3.8 μg L?1) overall, with no statistical significance between sites for Co and As. Median Se concentrations were found to be 64 μg L?1 (36-233 μg L?1), with the highest median levels found in Urban 3 site; site differences were statistically significant (p < 0.0001). Correlation for each element (between paired maternal and cord blood) was measured only in Rural site 1; significant correlation was shown for Hg, Pb, Mn and Co (p < 0.05). These findings may be interpreted as indicating low environmental contamination in S?o Paulo State, Brazil. These findings could also indicate that pregnant women have little or no contact with pollutants, possibly due to awareness campaigns carried out by public health practitioners.     

Effects of residual antibiotics in groundwater on Salmonella typhimurium: changes in antibiotic resistance, in vivo and in vitro pathogenicity

An outbreak-causing strain of Salmonella enterica serovar Typhimurium was exposed to groundwater with residual antibiotics for up to four weeks. Representative concentrations (0.05, 1, and 100 μg L(-1)) of amoxicillin, tetracycline, and a mixture of several other antibiotics (1 μg L(-1) each) were spiked into artificially prepared groundwater (AGW). Antibiotic susceptibility analysis and the virulence response of stressed Salmonella were determined on a weekly basis by using human epithelial cells (HEp2) and soil nematodes (C. elegans). Results have shown that Salmonella typhimurium remains viable for long periods of exposure to antibiotic-supplemented groundwater; however, they failed to cultivate as an indication of a viable but nonculturable state. Prolonged antibiotics exposure did not induce any changes in the antibiotic susceptibility profile of the S. typhimurium strain used in this study. S. typhimurium exposed to 0.05 and 1 μg L(-1) amoxicillin, and 1 μg L(-1) tetracycline showed hyper-virulent profiles in both in vitro and in vivo virulence assays with the HEp2 cells and C. elegans respectively, most evident following 2nd and 3rd weeks of exposure.     

Genotoxicity of the sediments collected from Pearl River in China and their polycyclic aromatic hydrocarbons (PAHs) and heavy metals

The accelerated industrialization and urbanization in the last three decades around the Pearl River Delta within Guangdong Province in China have led to serious concerns about the impacts on the aquatic environment. In the present study, the genotoxicity of the sediments collected from the Pearl River was evaluated by micronucleus (MN) assay with Vicia faba root tip cells, and the 16 EPA priority polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs, including Cr, Cu, As, Se, Cd, Hg, and Pb) in the sediments were determined respectively by GC-MS, inductively coupled plasma mass spectrometry, and inductively coupled plasma atomic emission spectrometry. The results showed that there were significant increases of MN frequencies observed in the sediment-exposed groups, compared with the negative group (P?相似文献   

Environmental exposure to POPs and heavy metals in urban children from Dhaka, Bangladesh

Persistent organic pollutants (POPs) and heavy metals are well known environmental pollutants. Even though numerous studies have been carried out to assess human exposures to these compounds, there is still a lack of data on humans from developing countries, especially in underprivileged children. The objective of this study was to assess the exposure to POPs and heavy metals in children from Dhaka, Bangladesh. One specific aim was to investigate whether children working at, or living close to, open waste disposal sites (WDSs) were more heavily exposed than other urban children. In 2008, blood and serum were collected from 73 children aged 7-16 from five neighbourhoods. Some of the children lived and worked at WDSs (N = 31), others lived next to a WDS (N = 17), whereas some children lived far from such sites (N = 25). Blood levels of lead (B-Pb), cadmium (B-Cd), and selenium (B-Se) were determined by ICP-MS for all subjects. The metal levels were high, with B-Pb overall mean 120 μg L(-1) (range 40-220), B-Cd 0.74 μg L(-1) (0.22-4.1), and B-Se 120 μg L(-1) (81-170). There were no marked differences between children from the different neighbourhoods, or between WDS workers and other children. PCB levels were low and with no contrast between neighbourhoods, for CB-153 the overall mean was 7.0 ng g(-1) fat (2.8-51). In contrast, high levels of DDTs were observed in all children, for 4,4'-DDE 1300 ng g(-1) fat (420-4600), and for 4,4'-DDT 326 ng g(-1) fat (44-1400), indicating ongoing exposure. PBDE levels were low, and BDE-209 was quantitated mainly in children working at or living close to WDSs. In conclusion, the high levels of DDTs, lead and cadmium observed in children from Dhaka are of concern. Many children were exposed at levels where health effects have been observed, or at levels without safety margins.     

Monitoring of heavy metal contaminants using feathers of shorebirds, Korea

This study presents concentrations of iron, zinc, copper, lead and cadmium in the feathers of 3 shorebird species (n = 29) from Okgu Mudflat, Korea in the East Asian-Australian Migration Flyways. Lead concentrations (ANOVA, p < 0.001) in Red-necked Stints (geomean = 9.61 μg g(-1) dry weight) were higher than in Terek Sandpipers (geomean = 5.56 μg g(-1) dry weight) which in turn were higher than in Great Knots (geomean = 2.78 μg g(-1) wet weight). Cadmium concentrations (ANOVA, p < 0.001) were higher in Great Knots (geomean = 2.97 μg g(-1) wet weight) and in Red-necked Stints (geomean = 2.70 μg g(-1) dry weight) than in Terek Sandpipers (geomean = 0.33 μg g(-1) dry weight). Lead (r = 0.574, p < 0.01) and cadmium (r = 0.380, p < 0.05) concentrations between feathers and livers of shorebirds were significantly correlated. Lead concentrations in 65.5% (19 individuals) of shorebirds exceeded a toxicity threshold for feathers (4 μg g(-1) dry weight). Iron, zinc, copper, lead and cadmium concentrations in feathers were within the range of earlier studies for wild birds, but lead concentrations in Red-necked Stints were higher than those reported in other studies. Because lead concentrations in feathers and livers of Red-necked Stints were markedly higher than in other shorebirds, we suggest that Red-necked Stints were exposed to higher lead concentrations than the other shorebirds on their breeding or wintering grounds.     

Toxic metal (Pb, Cd, As and Hg) and organochlorine residue levels in hake (Merluccius merluccius) from the Marmara Sea, Turkey

Toxic metals (Pb, Cd, As and Hg) and organochlorine residue levels were measured in hake (Merluccius merluccius) from the Marmara Sea. Biota samples were collected by a trawling cruise of the R/V ARAR in August and December 2009. The concentrations of toxic metals varied between Pb, 3.23-14.4; Cd, <0.01-2.14; Hg, 0.01-0.18 and As, 0.01-0.21 [Formula: see text]g g(-1) dry wt. Pb levels in the Marmara Sea were found to be higher than the critical limits set by the both Turkish Ministry of Environment for Aquatic Products (1 μg g(-1) wet wt.) and European countries (2.0 μg g(-1), UNEP 1985). In contrast, As and Hg levels were found to be lower than the critical limits for two periods. Cd contents of fish from the Marmara Sea were also comparable to or slightly lower than contents of fish from the Southern Black Sea Shelf. The results of organochlorine residues ranged between total HCH, <0.05 and 99 ng g(-1); endrin, <0.001 and 381 ng g(-1); alpha-endosulphan, <0.05 and 90 ng g(-1); beta-endosulphan, <0.05 and 15.3 ng g(-1); o,p DDE, 3.5 and 52.4 ng g(-1); p,p DDE, 7.4 and 139 ng g(-1); o,p DDD, 1.5 and 90.2 ng g(-1) and p,p DDD, 2.7 and 86 ng g(-1) wet weight. The rivers for the distribution of organochlorine levels in the Marmara Sea ordered from highest to lowest as Dil R. > Susurluk R. > Biga R. > G?nen R. The high levels of o,p and p,p DDE, and o,p and p,p DDD compounds, which are metabolites of DDT, indicate its illegal use. Toxic metal and organochlorine residue levels of fish are significantly higher than levels from the Mediterranean Sea.     

Trace metal bioaccumulation in eight common coastal Australian polychaeta

Whole tissue trace metal concentrations of ten metals in eight common coastal Australian polychaete species collected from uncontaminated locations were measured. The mean concentration range for each trace metal was: Mn: 2.6-13 microg g(-1); Co: 0.8-4.6 microg g(-1); Cu: 3.4-26 microg g(-1); Zn: 47-225 microg g(-1); As: 18-101 microg g(-1); Se: 2.2-20.4 microg g(-1); Ag: 0.03-2.5 microg g(-1); Cd: 0.07-17 microg g(-1); Hg: 0.08-0.88 microg g(-1) and Pb: 0.09-3.2 microg g(-1)dry mass. Principal components analysis of trace metal signatures revealed that the habitat, i.e. exposed coast sand or rock, estuarine sand or estuarine mud substrate in which a polychaete species was found, had a significant influence on the bioaccumulation of six trace metals (Mn, Cu, Zn, Ag, Cd and Pb). However, there is no clear relationship between trace metal concentrations in substrates and polychaetes. The results of the current study contribute to a reference dataset of polychaete species-specific natural background trace metal concentrations for use in determining the extent of trace metal contamination by urban and industrial sources.     

Long-term changes of heavy metal and sulphur concentrations in ecosystems of the Taymyr Peninsula (Russian Federation) North of the Norilsk Industrial Complex

The Norilsk industrial ore smelting complex (Taymyr Peninsula, Russian Federation) has significantly impacted many components of local terrestrial and aquatic environments. Whether it has had a major impact on the wider Russian Arctic remains controversial as studies are scarce. From 1986 to 2004, data on heavy metal (Cu, Ni, Zn, Hg, Cd and Hg) concentrations in fish (burbot), moss, lichens, periphyton, hydric soils and snow in and around Norilsk and the most northern parts of the Taymyr Peninsula were analysed. Very high concentrations of Cu (203 μg L?1 ± 51 μg L?1) and Ni (113 μg L?1 ± 15 μg L?1) were found in the water of the Schuchya River close to Norilsk. Heavy metal concentrations in burbot liver were highest in Lake Pyasino near Norilsk compared to other study regions that were >100 km distant. From 1989-1996, Cu (121 μg L?1 ± 39 μg L?1 SD), Zn (150 μg L?1) ± 70 μg L?1) and Ni (149 μg L?1 ± 72 μg L?1) snow concentrations were greatest in Norilsk, but were low elsewhere. By 2004, these concentrations had dropped significantly, especially for Cu-74 μg L?1 (±18.7 μg L?1 SD), Zn-81.7 μg L?1 (± 31.3 μg L?1 SD) and Ni-80 μg L?1(±18.0 μg L?1 SD). Norilsk and its surroundings are subject to heavy pollution from the Norilsk metallurgical industry but these are absent from the greater Arctic region due to the prevailing winds and the Byrranga Mountains. Pollution abatement measures have been made so further investigations are necessary in order to assess their efficiency.     

A preconcentration procedure for the determination of cadmium in biological material after on-line cloud point extraction

In this paper, a method involving on-line preconcentration with cloud point extraction for the determination of cadmium in biological samples is presented. The procedure is based on the sorption of micelles containing Cd(II) ions and the reagent 4-(5'-bromo-2'-thiazolylazo)orcinol (Br-TAO) in a minicolumn packed with polyester. The surfactant Triton X-114 was used in the formation of micelles. After sorption, the Cd(II) ions were desorbed from the minicolumn with acid eluent and determined by flame atomic absorption spectrometry. Parameters influencing the cloud point extraction were studied. The method showed a detection limit of 0.5 μg l(-1) and an enhancement factor of 27. The accuracy was tested by determination of cadmium in certified reference materials (spinach leaves 1570a and tomato leaves 1573a) from the National Institute of Standards and Technology.     

Accumulation and tolerance characteristics of cadmium in Chlorophytum comosum: a popular ornamental plant and potential Cd hyperaccumulator

The effects on the growth, physiological indexes and the cadmium (Cd) accumulation in Chlorophytum comosum under Cd stress were examined by pot-planting. The results showed that the tolerance index (TI) of C. comosum were all above 100 in soil Cd concentration of 100 mg kg − 1. The O2·-_{2^{\bullet}}^{-} production rate and electrical conductivity of C. comosum were significantly positively correlated to Cd adding-concentration while the MDA content increased and had significant differences with the control. The activities of SOD, CAT, and POD all rose significantly in lower Cd concentration and the Cd threshold of them were around 10, 50 and 20 mg kg − 1, respectively. The Cd in C. comosum root and aboveground part reached 1,522 and 865·5 mg kg − 1, respectively, in Cd concentration of soil up to 200 mg kg − 1. For the advantages of high tolerance, high accumulation, and high ornamental value, C. comosum may have tremendous application value in the treatment of Cd-contaminated soils.     

流动注射分光光度法测定环境水样中镉

建立了镉-氨水·氯化铵缓冲溶液-对偶氮苯重氮氨基偶氮磺酸-甲醛高灵敏度显色体系下，采用流动注射技术测定环境水样中镉的方法，优化了试验条件，讨论了共存离子与色度的影响及消除办法。方法在6．00μg／L～460μg／L范围内线性良好，检出限为0．1μg／L，实际水样测定的加标回收率为986％～102％。     

Effects of pH and low molecular weight organic acids on competitive adsorption and desorption of cadmium and lead in paddy soils

The bioavailability and ultimate fate of heavy metals in the environment are controlled by adsorption-desorption process. Batch equilibrium experiments were performed to assess the effects of pH and low molecular weight organic acids (LMWOAs) on competitive adsorption and desorption of cadmium and lead in paddy soils from China. The results indicated that both soils exhibited greater sorption capacity for lead (Pb) (1.37-1.61-fold) than cadmium (Cd) as estimated by the maximum sorption parameter (Q) from the Langmuir equation. The Langmuir bonding energy coefficient (b) and distribution coefficient (K (d)) were greater for Pb than for Cd, furthermore, b (binary) and K (d) (single) were greater than b (single) and K (d binary), indicating that competition for sorption sites promote the retention of both metals on more specific sorption sites. Both Cd and Pb desorption as a function of solution pH was characteristic of "S" pattern. The presence of LMWOAs inhibited Cd or Pb desorption at the low concentrations (≤0.1 mmol L(-1)) but promoted Cd and Pb desorption at higher concentrations (≥0.5 mmol L(-1) for citric acid and ≥1 mmol L(-1) for malic and oxalic acid). The two paddy soils had a greater d (Cd) than d (Pb) in the presence of LMWOAs, indicating that Cd desorption was more affected by the presence of LMWOAs in binary metal system.     

Assessment of cadmium exposure for neonates in Guiyu, an electronic waste pollution site of China

This study aimed to determine the levels of placental cadmium (PCd) and cord blood cadmium (CBCd) and the resulting expression of placental metallothionein (MT) in neonates and to investigate cadmium (Cd) exposure levels in neonates and mothers who live in Guiyu, China, an electronic waste (e-waste) pollution site. Among the 423 mothers included in the study from 2004/2005 to 2007, 289 lived in Guiyu (exposed group) and 134 lived in Chaonan, located 10 km away from Guiyu (controls) and had never been exposed to e-waste pollution. CBCd and PCd levels were measured by atomic absorption spectrometry. Placental MT was examined by immunohistochemistry. Information on maternal and neonatal characteristics and exposure conditions was obtained from hospital records and by personal interviews. For the 3 years, the median CBCd was higher for Guiyu neonates than for controls (3.61 vs. 1.25 ??g/L), with 25.61% of Guiyu subjects exhibiting a median CBCd that exceeded the safety limit defined by the World Health Organization (5 ??g/L), as compared with 14.18% of control neonates (p < 0.01). In Guiyu, the mean PCd was higher than that for controls (0.17 ± 0.48 vs. 0.10 ± 0.11 ??g/g, p ?? 0.01). The high levels of CBCd and PCd were significantly associated with parents?? occupational and environmental exposure to e-waste recycling pollutants. Staining for MT was positive and dense for 67.00% (67/100) of Guiyu neonates as compared with 32.69% (17/52) of controls (p < 0.01). Exposure to e-waste recycling pollutants increased Cd exposure in neonates, which was accompanied by increased placental MT expression.     

Determination of heavy metals and metals levels in five fish species from I??kl? Dam Lake and Karaca?ren Dam Lake (Turkey)

The concentrations of heavy metals and metals (Zn, Pb, Bi, Cd, Ni, Co, Fe, Mn, Mg, Cu, Cr, Ca, Sr, Na, Li, K) were measured in muscle of five species Cyprinus carpio (from I??kl? dam), Scardinius erythrophthalmus (from I??kl? dam), Tinca tinca (from I??kl? dam), C. carpio (from Karaca?ren dam), Carassius carassius (from Karaca?ren dam) caught from I??kl? and Karaca?ren. The highest metal was Na (466.95 μg/g) in C. carassius, while the lowest levels were Fe (0.37 μg/g) and Cu (0.37 μg/g) in C. carpio from I??kl? dam. The mean concentrations μg/g d.w. some of heavy metals in muscle of C. carpio (from I??kl? dam), S. erythrophthalmus (from I??kl? dam), T. tinca (from I??kl? dam), C. carpio (from Karaca?ren dam), C. carassius (from Karaca?ren dam) were as follows: Cd 2.00-2.10-1.95-2.06-2.27, Zn 4.36-2.64-13.13-13.33-24.47, Pb 1.65-1.24-1.90-2.37-2.41, Co 2.46-2.37-2.48-2.58-2.80, Mg 138.51-154.35-218.59-204.58-202.16, Fe 0.37-2.62-3.17-3.01-12.33, respectively.     

Intraspecific variation in cadmium tolerance and accumulation of a high-biomass tropical tree Averrhoa carambola L.: implication for phytoextraction

Averrhoa carambola L., a high-biomass tropical tree, has recently been shown to be a strong accumulator of cadmium (Cd) and has great potential for Cd phytoextraction. In the present study, field studies and a controlled-environment experiment were combined to establish the extent of variation in Cd tolerance and accumulation at the cultivar level using 14 to 19 cultivars of A. carambola. The results indicated that all cultivars tested could accumulate Cd at high but different levels, and that Cd tolerance also varied greatly between these cultivars. It is confirmed that the high Cd tolerance and accumulation capacity are species-level and constitutional traits in A. carambola. However, no correlation was detected between tolerance index and accumulation of Cd in different cultivars, suggesting that the two traits are independent in this woody Cd accumulator. More importantly, cultivar Wuchuan Sweet (WCT) was shown to have the highest Cd-extraction potential; it yielded a high shoot biomass of 30 t ha(-1) in 230 d, and extracted 330 g ha(-1) Cd in the aerial tissues grown in Cd-contaminated field soil, which accounted for 12.8% of the total soil Cd in the top 20 cm of the soil profile.     

Effects of Cadmium (CdCl2) on development and hatching of eggs in European squid (Loligo vulgaris Lamarck, 1798) (Cephalopoda: Loliginidae)

This is the first study related to the effects of cadmium (Cd) on the development and hatching of eggs of Loligo vulgaris. The eggs were exposed to concentrations varying from 10 to 100,000 μg Cd/l for up to 1 month. During the study period natural sea water salinity (37 PSU), ambient temperature (ranging 16.5–21.5°C) and light conditions of 12-h light: 12-h dark for 744-h were used prior to the hatching. For 96-h, mortality rate of 100% of the eggs was found at cadmium concentration of 100,000 μg Cd/l, and the same mortality rate of the eggs were found at 1,000 and 10,000 μg Cd/l for 744-h and 696-h, respectively. Hatching took place between hours 456 and 576 in the control group and between hours 480 and 576 in 10 and 100 μg Cd/l groups. Total hatching rates were calculated to be 98.2 ± 1.6% for control group, 99.4 ± 0.6% for 10 μg Cd/l group and 98.6 ± 1.2% for 100 μg Cd/l group. Hatching successes were estimated as 69.5 ± 13.8% for control group, 84.5 ± 8.2% for 10 μg Cd/l group and 76.9 ± 5.9% for 100 μg Cd/l group. In the 100,000 μg Cd/l treatment, the egg degeneration began from animal pole of the eggs in 16 h, and 50% and 100% of them died in the initial stage at 72-h and 96-h, respectively. In the 10,000 μg Cd/l group, the eggs which reached at stage 19 (IX) were deformed and 50% and 100% of them died at 312-h and 696-h, respectively. In 1,000 μg Cd/l group, however, the eggs developed abnormally from stage 21 (X–XI) and reached at stage 29 (XIX), and 50% and 100% of them died in 624-h and in 744-h, respectively. There were significant differences in survival rates of the eggs among the concentrations (p < 0.05). The current study demonstrated that Cd adversely affects the development, survival and hatching of L. vulgaris eggs; however, no mortality was observed in 10 μg Cd/l and 100 μg Cd/l groups.     

A survey on the temporal and spatial distribution of perchlorate in the Potomac River

Samples of river water and treated drinking water were obtained from eight sites along the Potomac River between western Maryland and Washington DC. Samples were collected each month from October 2007 to September 2008 and analyzed for perchlorate by ion chromatography/mass spectrometry. Data on anions were also collected for seven of the twelve months. Data were analyzed to identify spatial and temporal patterns for the occurrence of perchlorate in the Potomac. Over the year of sampling, the largest monthly increase occurred from June to July, with levels then decreasing from July to September. Samples from the period between December and May had lower perchlorate concentrations, relative to the remainder of the study year. Spatially, higher levels of perchlorate were found at sites located in west-central Maryland, the eastern panhandle of West Virginia, and central northern Virginia, with levels decreasing slightly as the Potomac approaches Washington DC. Within the sampling boundaries, river (untreated) water perchlorate concentrations ranged from 0.03 μg L(-1) to 7.63 μg L(-1), averaged 0.67 ± 0.97 μg L(-1) over the year-long period and had a median value of 0.37 μg L(-1). There was no evidence that any of the existing drinking water treatment technologies at the sampling sites were effective in removing perchlorate. There were no correlations found between the presence of perchlorate and any of the anions or water quality parameters examined in the source water with the exception of a weak positive correlation with water temperature. Results from the summer (June-August) and fall (September-November) months sampled in this study were generally higher than from the winter and spring months (December-May). All but one of the locations had annual average perchlorate levels below 1 μg L(-1); however, 7 of the 8 sites sampled had river water perchlorate detections over 1 μg L(-1) and 5 of the 8 sites had treated water detections over this level.     

Development of a novel solid-phase extraction element for the detection of nonylphenol in the surface water of Hangzhou

Nonylphenol (NP) is a representative environmental endocrine-disrupting chemical and persistent toxic pollutant. Previous studies have shown that the average concentration of NP in environmental waters was approximately tens to hundreds of ng L(-1) and it could even reach up to tens of μg L(-1). A simple, fast and accurate method employing a novel solid-phase extraction element named "Magic Chemisorber" (MC) followed by high-performance liquid chromatography (HPLC) using a fluorescence detector (FLD) was used for detecting NP. The most important parameters that affect the extraction process, including extraction time, desorption time, desorption solvent and repeatability, were optimized. The MC-HPLC method showed good linearity with concentrations of NP from 10 to 200 μg L(-1), a correlation coefficient of 0.9995 and the limit of detection (LOD) and limit of quantification (LOQ) of this method was 0.44 and 1.47 μg L(-1), respectively. Compared to commercial polydimethylsiloxane (PDMS) glass fiber, MC had both higher capacity and recovery and it could be used repeatedly. Using the MC-HPLC method we found that the concentration of NP in river water from Hangzhou city ranged from 8.54 ± 1.23 μg L(-1) (Qiantang River) to 65.77 ± 3.69 μg L(-1) (Tiesha River), which was similar to that of international regions heavily polluted with NP and higher than that of Bohai Bay, the Yellow River and the Pearl River Delta in China. This level of NP pollution is possibly related to the rapid development of the textile, printing and paper industries of Zhejiang province.