Concentrations Of Elements In Water Research Articles

The incorporation of strontium and barium into the otoliths of the flounder Paralichthys olivaceus at early life stages demonstrates resilience to ocean acidification.

Ocean acidification could modify the bioavailability and chemical properties of trace elements in seawater, which could affect their incorporation into the calcareous structures of marine organisms. Fish otoliths, biomineralized ear stones made by aragonite, are suspended within the endolymph fluid of teleosts, indicating that the elemental incorporation of otoliths might also be susceptible to ocean acidification. In this study, we evaluated the combined effects of CO2-induced ocean acidification (pH 8.10, 7.70, and 7.30, corresponding to ocean acidification scenarios under the representative concentration pathway 8.5 model as projected by the Intergovernmental Panel on Climate Change) and water elemental concentrations of strontium (Sr) and barium (Ba; low, medium, and high) on elemental incorporation into otoliths of the flounder Paralichthys olivaceus at early life stages. Our results revealed that the elemental incorporation of Sr and Ba into otoliths was principally dependent on the corresponding water elemental concentrations rather than on ocean acidification. Moreover, the partition coefficients (DMe) of Sr and Ba may stabilize after dynamic equilibrium is reached as the water elemental concentration increases, but are not affected by ocean acidification. Therefore, the incorporation of Sr and Ba into otoliths of the flounder at early life stages may not serve as an effective indicator of ocean acidification. In other words, the findings suggest that ocean acidification does not impact the incorporation of Sr and Ba incorporation into otoliths when tracing the temperature or salinity experiences of the flounder. Our findings will provide new knowledge for understanding the potential ecological effects of ocean acidification on the recruitment dynamics of fish species.

Density and proximity of oil and gas wells and concentrations of trace elements in urine, hair, nails and tap water samples from pregnant individuals living in Northeastern British Columbia

BackgroundOil and gas exploitation can release several contaminants in the environment, including trace elements, with potentially deleterious effects on exposed pregnant individuals and their developing fetus. Currently, there is limited data on pregnant individuals’ exposure to contaminants associated with oil and gas activity. ObjectivesWe aimed to 1)measure concentrations of trace elements in biological and tap water samples collected from pregnant individuals participating in the EXPERIVA study; 2)compare with reference populations and health-based guidance values; 3)assess correlations across matrices; and 4)evaluate associations with the density/proximity of oil and gas wells. MethodsWe collected tap water, hair, nails, and repeated urine samples from 85pregnant individuals, and measured concentrations of 21trace elements. We calculated oil and gas well density/proximity (Inverse Distance Weighting [IDW]) for 4buffer sizes (2.5 km, 5 km, 10 km, no buffer). We performed Spearman’s rank correlation analyses to assess the correlations across elements and matrices. We used multiple linear regression models to evaluate the associations between IDWs and concentrations. ResultsSome study participants had urinary trace element concentrations exceeding the 95th percentile of reference values; 75% of participants for V, 29% for Co, 22% for Ba, and 20% for Mn. For a given trace element, correlation coefficients ranged from −0.23 to 0.65 across matrices; correlations with tap water concentrations were strongest for hair, followed by nails, and urine. Positive (e.g., Cu, Cr, Sr, U, Ga, Ba, Al, Cd) and negative (e.g., Fe) associations were observed between IDW metrics and the concentrations of certain trace elements in water, hair, and nails. SignificanceOur results suggest that pregnant individuals living in an area of oil and gas activity may be more exposed to certain trace elements (e.g., Mn, Sr, Co, Ba) than the general population. Association with density/proximity of wells remains unclear.

Estimation of background concentrations of macro- and trace elements in an aquatic plant as a basis for the passive biomonitoring of pollution

Chemical pollution was indicated as a global environmental problem since elevated concentrations of toxic substances were recorded in almost all ecosystems worldwide. Trace elements, released to environment due to industrial, agricultural and urban activities, are of special concern due to their non-degradability, persistence, bioaccumulation in organisms and potential toxicity. Reliable methods for assessing the level of pollution are essential for proper monitoring and control of pollution. A useful tool for this purpose is the geochemical background (GB), which enables to differentiate between unpolluted and polluted areas as well as calculate pollution indices. The study presents the first attempt to estimate the background values for aquatic plants using cosmopolitan submerged aquatic macrophyte Ceratophyllum demersum as a model species. Water and plant samples were collected from 117 water bodies. Contents of 15 elements (As, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, V, Zn) were determined using atomic absorption spectrometry and flame photometry. Four methods were tested for estimation of the background concentrations: Median ± 2Median Absolute Deviation, Iterative 2σ technique, Tukey box-plot, Grouping of data with 60 % coefficient of variation (CV). Wide ranges of element concentrations in water and various values of Contamination Factor indicated to a variety of natural and anthropogenic impacts in the studied area, which confirmed that the database covered a real environmental variability. Very different estimates of background concentrations were obtained depending on the method. The highest background values were usually given by Me±2MAD method. Grouping of data with 60 % CV was most exigent in defining a site as undisturbed, therefore this method was recommended as the most suitable for estimation of the background values for C. demersum. Pollution Load Index validated the use of estimated background concentrations as reliable for bioindication of pollution in aquatic reservoirs.

Accumulation of chemical elements in bivalve molluscs under conditions of changes in their content in the aquatic environment under anthropogenic impact

In the course of the study, an analysis of the ecological situation in the region was carried out, taking into account the influence of various anthropogenic factors on the environment. The authors analyzed the accumulation and concentration of chemical elements in bivalve mollusks, which were collected in water bodies of the analyzed territory. As a result of the study, it was revealed that the concentration of chemical elements in water is steadily increasing under the influence of various kinds of pollution that have a negative impact on the biotic component of aquatic ecosystems.

Determination of Environmental Factors on some Water and Sediments Quality Parameters of Eastern Al-Hammar Marsh

The research aims to identify the most important environmental factors that affect some of the water quality and sediment characteristics of the Eastern Al-Hammar marsh by evaluating their concentrations and comparing them with national and international limits. Water samples and sediments were collected from different sites of Al-Mashab Marsh within the Eastern Al-Hammar marsh during the winter and summer seasons of 2019. The sample sites included some sites affected by the oil activities within the marsh boundaries, and water samples from the Al-Badaa channel, which produces drinking water for Al-Basra Governorate. The field measurements included measurement of the (Temp., pH, TDS, EC, S%, Turb.), while the laboratory measurements included (TSS, COD, OC), and measuring of the concentrations of the heavy elements in water and sediments marsh such as (Pb, Zn, Cu, Cr, Mg, Cd, Ni).The results showed that the water marsh is alkaline (pH more than 7) and has EC; TDS, and salinity that exceed the permissible limits, which indicates it’s unfit for human consumption. Also, this study showed a definite increase in all the measured physical variables in the summer season as a result of the impact of climate changes and the quality of the Main Outfall Drain (MOD) water which supplier some areas of marshes, in addition to the effect of oil installations discharges. The concentrations of heavy elements were within the permissible limits in the water, except for Pb and Cr elements were their increased concentrations in the water are due to the wastewater quality effect of the oil installations that discharge to the marshes, and the impact of human activities and the MOD water quality. The current study indicated evident seasonal changes in heavy element concentrations between the summer and winter seasons. There were high concentrations of heavy elements in the marsh water in the winter (February) compared with the summer season (August) due to the increased activities and works of oil installations in the study area, and rainwater. The concentrations of heavy elements in marsh sediments were higher than the permissible limits, and this means they are contaminated by these measured elements due to what is added to it from the neighboring areas, specifically the nearby oil installation discharges, and also the impact of human activities and the MOD water quality.

Effects of local land use on riparian vegetation, water quality, and in situ toxicity

The conversion of riparian forests into agricultural land results in the loss of water quality and aquatic biota health. The objectives of this study were therefore to determine the proportion of land use with emphasis on the type of vegetation cover; evaluate the limnological parameters and concentration of inorganic elements in the water of the São José stream in the Dourados River Basin, Mato Grosso do Sul, Brazil; correlate land use with the concentrations of inorganic elements in water; and evaluate the risk to preservation aquatic biota and in situ toxic effect on Astyanax lacustris. We collected samples from the São José Stream in 2020 and evaluated land use with high resolution aerial images. The inorganic elements in water samples were quantified using inductively coupled plasma optical emission spectrometry. In the surroundings of the São José stream, a reduction in riparian forest was observed with a proportion of only 16.32% of the area and the predominance of agricultural areas with 75.06%. The concentrations of dissolved oxygen (1.510 mg L-1) and P (> 0.235 mg L-1) in the water did not comply with the national legislation. In addition, Al and P indicated risks regarding the conservation of aquatic biota (risk quotient >1). The in situ evaluation of A. lacustris also revealed toxicity in the water. The results indicate environmental imbalance in the São José stream, requiring mitigation measures for its restoration and the sustainable use of its resources.
 Keywords: anthropic action, inorganic contaminants, risks for aquatic biota.

HEAVY ELEMENTS ACCUMULATION IN TOW SUBMERGEDPLANTS (NAJAS MARINA LAND CERATOPHYLLUM DEMARSUMSOUTHERNOF IRAQ)

The content of heavy elements Copper (Cu), Zinc (Zn) and Iron (Fe) were studied in towsubmerged plants species (Najas marina L and Ceratophyllum demarsum) collected seasonally for periods summer 2019 to spring 2020at two site selected along Al-Chibayish Marsh southern of Iraq to determine the ability of these species to accumulate elements from surrounding water and sediment. The result showed that the average concentration of elements in water for the Particulate phase higher than in the dissolved phase. Also, mean concentrations of particulate phase higher than their mean concentration in total sediments samples except for Fe concentration which was in sediments samples was higher than in particulate part of water. The uptake of totalelements by two studied aquatic plants showed that the highest uptake of elements by the C.demersum spices excepted Fe which higher concentration in N.marina. Also, Bioconcentration factor (BCF) for different elements were calculated and according to these factor data, the orderof heavy elements accumulation in two species were Fe > Zn> Cu.

Potentially toxic elements contamination and its removal by aquatic weeds in the riverine system: A comparative approach

Thamirabarani river acquires large untreated sewage effluents from the Tirunelveli and Thoothukudi districts of South Tamil Nadu. This study examined the concentration of trace elements in water, sediment, and phytoaccumulation potential of aquatic weeds viz., A. cristata, E. crassipes, S. natans, and P. stratiotes, growing along Srivaikundam dam of Thamirabarani river. The Pb, As, Hg, Cd, and Ni concentrations in water were slightly higher than the US Food and Drug Administration (USFDA) drinking water guidelines; however, their accumulation in sediment was below WHO's sediment quality guideline. This study concludes that the phytoaccumulation factor (PAF) and translocation factor (TF) was >1 in E. crassipes and A. cristata, representing them as hyperaccumulators, suitable for phytoremediation in polluted localities. E. crassipes, A. cristata, and S. natans accumulated (100–500 fold) higher trace elements concentrations than that present in the water. Also, the concentrations of trace elements found in the aquatic weeds were below the recommended levels for the critical plant range (CRP). These selected aquatic weeds are more suitable for plant hybridization to be modified as superbug plants.

Metals and metalloids in a first order stream of the Atlantic rainforest: abiotic matrices, bioaccumulation in fishes and human health risk assessment

Background and aimMetals and metalloids have been found in several streams and rivers from the Atlantic Rainforest (ARF), one of the world´s leading biodiversity hotspot, which may represent a risk for environmental and human health. The aims of this study were: 1) to evaluate the accumulation and distribution of 24 trace elements in water, sediments and fish tissues (muscle and gills) of sixteen species from the Atlantic Rainforest, 2) to explore bioaccumulation patterns in fish tissues and abiotic matrices, and 3) to assess the impact of metal and metalloids on the human health from water and fish consumption. MethodsWater, sediments and fish samples were collected from Ramos Stream (Misiones Province, Argentina). The concentrations of Ag, Al, As, Ba, Be, Cd, Co, Cr, Cs, Cu, Fe, Ga, Hg, Li, Mg, Mn, Ni, Pb, Se, Sr, Ti, U, V and Zn were determined by Quadrupole Inductively Coupled Plasma Mass Spectrometry. Bioaccumulation factors (BAFs) were used to evaluate bioaccumulation of metals and metalloids in relation to water and sediment. The Hazard Quotient (HQ), Hazard Index (HI) and Target Hazard Quotient (THQ, general and fisherman populations) were calculated to assess the non-carcinogenic human health risk from water and fish consumption. ResultsThe concentrations of several elements in water and sediment were higher than the international guidelines for aquatic biota protection. Levels of As, Pb and Zn in muscle and gills were above national and international guidelines for human consumption. The bioaccumulation factors ranged from 749 to 13,029 being higher in gills than in muscle. The HQ and HI ranged from 0.001 to 0.015. The THQ for each element and total THQ values were lower than 0.1. ConclusionBioaccumulation factor suggests that several species have a moderate capacity to incorporate some metals and metalloids from the abiotic matrices. According to the HI and THQ values found, there is no risk to human health from consumption of water and fish.

The impact of sediment, fresh and marine water on the concentration of chemical elements in water of the\xa0ice-covered lagoon

The common use of chemical elements by man has been contributing to their extraction for centuries. As a consequence, they have been directly or indirectly introduced into the biogeochemical cycle. In the framework of many conventions, mining and processing of elements are currently subject to many restrictions. However, their large load that has already been deposited in the soil and bottom sediments can be remobilised and enter the food chain. The identification of factors favouring this process is very important, especially during the period of adopting new legal regulations on limiting the emission of pollutants. It became possible in February 2018 during the persistence of ice cover on the lagoon’s surface. This allowed observation of processes, the effect of which in the absence of ice is blurred by wind mixing water. Therefore, an investigation of sources of 25 elements in a lagoon of the southern Baltic has been undertaken, based on the example of the Vistula Lagoon. The results point to the remobilisation of chemical elements (including the toxic ones) from land and bottom sediments, where they have been deposited for decades. These processes led to the accumulation of metals in certain areas of the lagoon. It may result in their uptake and accumulation in the benthic organisms inhabiting the lagoon and further transfer in the food chain. It is of major importance as the lagoons in the southern Baltic fulfil many essential functions in the scope of tourism, economy, and fishery. Thanks to restrictions on the quality of wastewater and the emission of pollutants, it has been noticed a substantial “purifying” effect of rivers, too.

Trace element concentrations in water and Clupeonella cultriventris caspia in the Southern Caspian Sea and Assessment of Potential Risk to Human Health.

Despite the fishing pressure on common kilka (Clupeonella cultriventris caspia) and the importance of the Caspian Sea, there are little data on trace element levels in those. Therefore, the concentrations of 27 trace elements were measured in water (n=15) and C. cultriventris (n=1050) collected from the southern Caspian Sea. The concentrations of Cd, Hg, and Zn in the water exceeded permissible limits and posed potential ecological risks to the aquatic biota, especially in the southeastern region of the Caspian Sea. The estimated daily intakes of As, Cd, Co, Hg, Mn, Pb, Sb, and V from the consumption of C. cultriventris were higher than the acceptable daily intake recommended by the JECFA and USEPA. However, the target hazard quotients and hazard index values were lesser than one. It appears that C. cultriventris provides a small amount of essential element nutrition for consumers. In conclusion, this study revealed that consumers are exposed to As, Co, Hg, Mn, Mo, Sb, and, V through the consumption of C. cultriventris. Also, the concentrations of Cd, Hg, and Zn in water showed significant ecological risk.

Dynamics of Trace Element Composition of Bratsk Reservoir Water in Different Periods of Anthropogenic Impact (Baikal Region, Russia).

Bratsk water reservoir is a part of the unified Baikal-Angara water system, the world's largest reservoir of surface drinking water. This study intends to assess the water quality of Bratsk reservoir by examining the spatial and temporal variability of trace element concentrations over periods of changing by the anthropogenic impact. The water samples were collected along the length of the reservoir in 2003, 2008, 2012, and 2018 and analyzed for 12 trace elements (Al, Cr, Mn, Fe, Cu, Zn, As, Cd, Cs, Pb, U, and Hg). The results show that in the zone of maximum anthropogenic impact the concentrations of these elements increased as follows: Al 781.0µg L-1; Cr 1.43µg L-1; Fe 1052.4µg L-1; Cu 3.34µg L-1; Zn 15.52µg L-1; Cd 0.691µg L-1; Cs 0.070µg L-1; U 1.74µg L-1; Hg 0.0505µg L-1. The trace element concentrations in Bratsk reservoir water did not exceed levels set by the international drinking water quality standards. At the same time, the uniqueness of the reservoir requires the use of stricter criteria for water quality control. The trace element concentrations in the water from the source of the Angara river (the only run-off from Lake Baikal) used as reference levels indicate higher levels of metal contamination and pollution indices in Bratsk reservoir water. Over different periods of observation, the contamination factor (CF) showed very high contamination for Al, Mn, Cd, and Cs. PLI indices for 2003 and 2018 classify the majority of water samples as polluted. The NPI values were indicative of severe water contamination by Mn and Pb (all years), Cu (2009), Fe and Cd (2003), Al, Cr, Zn, Cs, and Hg (2003, 2009, 2018). The obtained results showed the importance of using water quality criteria with a view to strengthening the requirements of environmental protection measures in the Baikal region.

A Switchable Solvent-Based Liquid Phase Microextraction Method for the Detection of Cadmium in Water Samples with Flame Atomic Absorption Spectrometry

The natural concentration of trace elements in water and soil depends on the geological, geomorphological, and climate characteristics of the region. The rapid increase of technology in recent years has increased concentrations of trace elements in nature. Separation and enrichment methods are needed to detect trace amounts of heavy metals that cannot be detected due to the detection limit of the instruments or the matrix effect in samples. Recently, low hazard solvents compatible with green chemistry have been used in preconcentration/separation studies of Cd(II). Switchable solvent-based liquid phase microextraction is an environmentally-friendly, simple, and fast procedure for the determination of Cd(II) ions in environmental samples combined with flame atomic absorption spectrometry (FAAS). The switchable polarity solvent was prepared with N,N-dimethyl-n-octylamine. 2-(5-Bromo-2-pyridylazo)-5-(diethylamino) phenol was used as the complexing agent. Important parameters such as pH, amount of switchable polarity solvent and NaOH, as well as ligand and sample volume, all of which might affect the microextraction efficiency were optimized. Under optimal experimental conditions, linear range was found to be between 5 and 500 µg/L. The limit of detection, preconcentration factor, and relative standard deviation were 0.89 μg/L, 150, and 3.2%, respectively. The accuracy of our method was confirmed by the analysis of certified reference material SPS-WW1 Batch 106 (Waste Waters). The developed procedure was successfully applied to determine the cadmium contents of environmental water samples. We believe that this environmentally-friendly method will be useful in detecting Cd(II) ions in water samples.

Concentration of some Heavy Elements in Water , Sediment and Plants in Al-Gharraf River in Thi-Qar Province –South of Iraq

The present study was included to estimate the Concentration and distribution of selected Heavy elements Cadmium, Lead, Nickel and Zinc from water, sediment and two species of plant ( Phragmites australis and Ceratophyllim demersum). Also same physical characteristic of this river in water , samples were collected of three stations in Al-Gharraf River in order to investigates the possibility of pollution in this area with these elements .three station (Al-Fajr districts , Qal'at Sukkar districts and Al-Rifa'I districts) were chosen to execute this study during the period from May 2018 until February 2019. And the high temperature was recorded (13 ٥C in winter to 30 ٥C in summer), pH (7.44 to 7.8) and Turbidity (2.41 to 10.2)NTU. and salinity (0.01 to 0.069) ppt. Also all the heavy metals recorded a significant increase in water and Ceratophyllin demersum plant samples in the winter higher than summer and in the sediments and Phragmites australis plant the rise in the winter was only in the elements nickel and zinc, but in cadmium and lead were concentration low or do not make a big difference in the winter compared to the summer , Where the highest percentage of nickel and zinc in the sediments in the second and third stations respectively reached 86.2 mg / kg dry weight . The lowest concentration of cadmium concentration in water samples at the first station for the summer was 0.0021 mg / L . Where there is a positive relationship between the increase in concentrations.

Ecological and Geochemical Features of the Underground Waters of the Semipalatinsk Test Site

The results of the study of ecological and geochemical features and assessment of the water quality of water sources located on the territory of the Semipalatinsk test site are presented. The studied waters are diverse in chemical composition: 14 % of the samples had hydrocarbonate, 69 % – sulfate, and 17 % – chloride types of waters. On the basis of the revealed features of the elemental composition of the underground waters of the Semipalatinsk test site, decreasing series of excess of the average concentrations of elements in water in relation to the composition of waters of the zones of hypergenesis and continental salinization were constructed: U14> Mo8> Sr8> V3(hypergenesis zone), U5> Mo3> Sr3> V2(zone of continental salinization). For the groundwater of the Semipalatinsk test site, specific elements were identified, such as U, Mo, Sr and V. The water quality was assessed for the studied chemical components based on comparison with the standards of the Republic of Kazakhstan and the World Health Organization (SaNPiN No. 209, WHO 2011).

Health risk assessment of toxicants in Meriç River Delta Wetland, Thrace Region, Turkey

In the current research, water quality of Meric River Delta was evaluated using some toxic element risk assessment indices. Samples were collected from 24 locations and nickel (Ni), chromium (Cr), arsenic (As), zinc (Zn), lead (Pb), copper (Cu) and cadmium (Cd) accumulations in delta components were read using an ICP-MS. Water quality index (WQI), heavy metal pollution index (HPI), heavy metal evaluation index (HEI) and degree of contamination index (Cdeg) were applied to detected data for assessing the water quality. Also, the toxic element concentrations in water were assessed in terms of public health using some health risk assessment methods including hazard index (HI), hazard quotient (HQ) and cancer risk (CR). According to the results of WQI, HPI, HEI and Cdeg, Ni and As were recorded as most dangerous toxicants among the investigated elements and Gala Lake was recorded as most effected delta component. According to the results HQs and CR, As was recorded as the most dangerous toxicant among the investigated elements and Gala Lake and Ergene River were recorded as the most effected delta components.

Temporal correspondence of selenium and mercury, among brine shrimp and water in Great Salt Lake, Utah, USA

The specific source of high burdens of selenium (Se) and mercury (Hg) in several bird species at Great Salt Lake (GSL) remain unknown. Frequent co-located water and brine shrimp samples were collected during 2016 through 2017 to identify potential correlations of element concentrations among brines and brine shrimp, a keystone species in the GSL. Like many aquatic systems, GSL is characterized by elevated methylmercury (MeHg) in deep waters. However, in contrast to thermally-stratified aquatic systems, biota in the salinity-stratified GSL do not reside in its deep waters, obscuring the presumed relationship between elevated MeHg in biota and in the deep brine. Brine shrimp and water column (shallow and deep, filtered and unfiltered) samples were collected from six sites spanning the South Arm of GSL approximately every other month. Mercury concentrations in brine shrimp (on average 89% of which is MeHg) were correlated only with total mercury in surface filtered water, and displayed little spatial variability, but consistent seasonal trends across the two sampled years. In contrast to Hg, temporal correspondence was observed between Se concentrations in brine shrimp and those in all water samples regardless of filtering and depth, with maxima and minima at higher-than-seasonal frequency.The data suggest a spatially diffuse source of bioavailable mercury to the shallow brine that responds to seasonal influences, for which the underlying deep brine, surficial sediments, and overlying atmosphere were evaluated in terms of potential temporal correspondence to shallow brine and brine shrimp Hg concentrations, as well as potential to mix across the extent of the shallow brine. Bioaccumulation factors were at the low end of those reported for marine systems, and decreased at higher trace element concentrations in water.

Direct Trace Element Determination in Oil and Gas Produced Waters with Inductively Coupled Plasma‐Optical Emission Spectrometry: Advantages of High‐Salinity Tolerance

Waters co‐produced during petroleum extraction are the largest waste streams from oil and gas development. Reuse or disposal of these waters is difficult due to their high salinities and the sheer volumes generated. Produced waters (PWs) may also contain valuable mineral commodities. While an understanding of produced water trace element composition is required for evaluating the associated resource and waste potential of these materials, measuring trace elements in brines is challenging due to the dilution requirements of typical methods. Alternatively, inductively coupled plasma‐optical emission spectrometry (ICP‐OES) has shown promise as being capable of direct measurements of trace elements within PWs with minimal dilution. Here, we evaluate direct ICP‐OES trace element quantification in PWs for seventeen trace elements (As, Al, Ba, Be, Cd, Cr, Co, Cu, Hg, Mo, Ni, Pb, Rb, Sb, U, V and Zn) within fifteen PWs from five U.S. continuous reservoirs. The total analytical uncertainties associated with the trace element levels determined using ICP‐OES were estimated to be better than ± 30% (2s) except for Rb, which could not be determined due to ionisation interferences. The ICP‐OES results are compared with trace element levels determined using inductively coupled plasma‐mass spectrometry from the same samples. Our results demonstrate the potential for direct analysis of high‐salinity waters using ICP‐OES with minimal dilution and provide trace element concentrations in waters from several important U.S. petroleum‐generating reservoirs where available data are sparse.

The heavy metal contamination history during ca 1839–2003 AD from Renuka Lake of Lesser Himalaya, Himachal Pradesh, India

The Himalayan lakes are facing an acute problem of survival due to increased concentration of toxic elements in water and sediments. In the present study, the heavy metal contamination history of Renuka Lake during the calendar year (ca) 1839–2003 AD has been performed using 137Cs and 210Pb radionuclide-dated core sediment sample and Inductively-Coupled Plasma Mass Spectrometry (ICP-MS). The concentration of heavy metals (Mn, Cr, Cu, Zn, Ni, Pb and Co) during the said time period is found to have significant variations and suggested a contribution of both natural and anthropogenic factors like surrounding rocks, burning of fossil fuels, sewage and agro-chemicals. The highest concentration of Mn is observed during ca 1847, which is 4–5 times more than ca 2003. The Cr is found to be highest during ca 1962; whereas Cu, Zn, Ni and Pb are observed highest during 1883. Similarly, Co is determined highest during ca 1939. The contamination factor (Cf) indicated low to the considerable level of contamination, whereas the degree of contamination (Cd) revealed a low level of contamination in the lake. However, the geo-accumulation index (Igeo) marked the lake uncontaminated to moderately contaminated and on the other hand, the pollution load index (PLI) showed some signs of contamination in the Renuka Lake. The present study has been compared with other lakes and the background concentration of average shale, upper crust, crustal average and carbonate rocks. Although, keeping in view historical contamination, there is a need of stringent steps for the preservation of the Renuka Lake.

Interactive effects of strontium and barium water concentration on otolith incorporation in juvenile flounder Paralichthys olivaceus.

Although the relationship between the incorporation of an element into otoliths and the concentration of the element in water has been extensively investigated in many fish species, the interactive effects of multiple elements in water on the otolith incorporation of an element are not adequately explored or well understood. In this study, 16 treatments in triplicate using strontium (Sr; 1, 2, 3 and 4 times the ambient baseline, 6.5 mg l-1) and barium (Ba; 1, 2, 4 and 6 times the ambient baseline, 40 μg l-1) as categorical variables in an orthogonal design were established to evaluate the relative or interactive effects of water elements on otolith elemental incorporation in juvenile flounder Paralichthys olivaceus (from 15 to 116 days post hatching). The results revealed that otolith incorporation (Me:CaOtolith) of Sr and Ba were positively dependent on the concentrations of the elements in water (Me:CaWater). Overall, Sr was incorporated into otoliths more efficiently than was Ba, and the partition efficiency (DMe) of both elements decreased with increasing water elemental concentrations. Increasing Sr concentrations in water appeared to negatively affect the uptake of Ba into otoliths rather than facilitate it, as previously reported in fish reared in freshwater and brackish water, or showed no effect on fish in seawater. Conversely, the Ba concentration in water did not influence the otolith uptake of Sr, which agrees with the findings for other fish species. When applying otolith microchemistry to fish ecology studies, it is essential to cautiously address the interactive effects of multiple elements in the environment on otolith elemental incorporation.