scholarly journals Lower Douro River basin (Portugal) water quality – Focus on trace element changes and anthropogenic sources of contamination

2014 ◽  
Vol 16 (2) ◽  
pp. 252-268 ◽  

<p>The Douro River lower basin water quality was studied regarding its concentration on 18 trace elements (Be, Al, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Sb, Ba, Tl, Pb and U, measured by ICP-MS). Other physicochemical parameters, such as pH, conductivity, dissolved oxygen and water temperature were also determined in situ.</p> <p>To take into account the expected spatio-temporal changes and to look for anthropogenic influences on trace element levels, samples (n=88) were collected at 11 sampling sites in four sampling campaigns (October 2007; January, March and July 2008), in both low and high tides, in order to evaluate spatial, seasonal and tidal changes.</p> <p>A multivariate approach &ndash; principal component analysis &ndash; was used to investigate interelement correlations and the variability observed in the different data sets.</p> <div> <p>According to aquatic life limits (CCME, 2011), the quality of Douro River water was found acceptable. Except for DO, where a significant number of samples presented levels below 5.0 mg l<sup>-1</sup>, Cr(VI) (mean&plusmn;sd = 3.09&plusmn;1.54; median = 2.82 ppb) and Se (10.9&plusmn;10.1; 7.74 ppb) all the other parameters measured fell well within acceptable limits. Occasional high levels were found for most trace elements, reflecting sporadic and local inputs. Important spatial differences in trace element levels were also found. Except for Be, Al and Mn, most metals tended to increase in the downstream direction. Some trace elements related with agriculture practices (Zn, Cu and Ni) were higher in samples collected on sampling sites located at the middle part of the studied area and were highly correlated, reflecting an eventual common source. Important seasonal differences in trace element levels were also observed, e.g., October samples were generally characterized by higher Ni, Cu, Zn and Pb levels.</p> </div> <p>&nbsp;</p>

2016 ◽  
Vol 61 (1) ◽  
Author(s):  
Beric Michael Gilbert ◽  
Annemariè Avenant-Oldewage

AbstractUsing parasites as sentinel organisms has received increased attention due to their responses toward environmental degradation. In some sections of the Vaal River, South Africa, water quality is altered and biota distribution affected. The aims of this study were to assess and compare infection variables of Paradipolozoon ichthyoxanthonAvenant-Oldewage, 2014 in Avenant- Oldewage et al. (2014) at two sites along the Vaal River and compare the water quality and trace element levels at the sites. Infection variables of the parasite, physico-chemical variables, and sediment and water samples for trace element analysis were collected at each site. Conductivity and trace element concentrations were higher at the Vaal River site than the Vaal Dam. Temporal variances in water quality and parasite prevalence, mean intensity and mean abundance, at intervals over a 14 year period occurred, P. ichthyoxanthon was absent at the Vaal River site though the host fish are present. Prevalence peaks in summer and winter. Comparison of infection data to water quality and trace elements indicated that conductivity and trace element levels negatively affected/correlated with the infection variables. Higher trace elements concentration and conductivity at the Vaal River site are thought to be driving factors responsible for absence of the parasite.


2020 ◽  
Vol 28 (2) ◽  
pp. 138-163
Author(s):  
C.W. Cuss ◽  
C.N. Glover ◽  
M.B. Javed ◽  
A. Nagel ◽  
W. Shotyk

The concentrations of trace elements (TEs) in large boreal rivers can fluctuate markedly due to changing water levels and flow rates associated with spring melt and variable contributions from tributaries and groundwaters, themselves having different compositions. These fluctuating and frequently high concentrations create regulatory challenges for protecting aquatic life. For example, water quality criteria do not account for changes in flow regimes that can result in TE levels that may exceed regulatory limits, and neither do they account for the markedly different lability and bioaccessibility of suspended solids. This review addresses the geochemical and biological processes that govern the lability and bioaccessibility of TEs in boreal rivers, with an emphasis on the challenges posed by the colloidal behaviour of many TEs, and their relationship to the dissolved fraction (i.e., <0.45 μm in size). After reviewing the processes and dynamics that give rise to the forms and behaviour of TEs in large boreal rivers, their relevance for aquatic organisms and the associated relationships between size and lability and bioaccessibility are discussed. The importance of biological variables and different forms of TEs for limiting lability and bioaccessibility are also addressed. Two case studies emphasize seasonal fluctuations and accompanying changes in the distribution of TE amongst different size fractions and associated colloidal species in large boreal rivers: the Northern Dvina and one of its tributaries, the Pinega River, both in Russia, and the Athabasca River in Alberta, Canada. Water quality in the Athabasca River is briefly discussed with respect to Canadian guidelines.


2018 ◽  
Vol 7 (3) ◽  
pp. 1762
Author(s):  
Diaa SeifSeif ◽  
Mahmoud Nasr ◽  
Mohamed R. Soliman ◽  
Medhat Moustafa ◽  
Walid Elbarki

This study investigated the spatial variation in the water quality parameters of Burullus Lake using multivariate analysis and MIKE21 model. The lake was classified into zone-1 at north-east (Z1), zone-2 at south-east (Z2), zone-3 at north-middle (Z3), zone-4 at south-middle (Z4), zone-5 at north-west (Z5), zone-6 at south-west (Z6), and zone-7 at west (Z7). The obtained parameters were temperature 21.5±5.0 ºC, pH 8.2±0.6, dissolved oxygen (DO) 5.9±1.0 mg/L, biological oxygen demand (BOD) 23.9±5.7 mg/L, NH3-N 2.5±0.3 mg/L, NO2-N 1.9±0.3 mg/L, NO3-N 1.2±0.3 mg/L, PO4-P 1.9±0.3 mg/L, SiO4 3.2±0.1 mg/L, Chlorophyll-a (Chl-a) 88.2±10.8 µg/L, and salinity 3.2±1.0 g/L. Principal component analysis showed that agricultural drainage water was the key factor influencing the water quality characteristics of Burullus Lake. Water quality index (WQI) varied between “Bad” to “Medium”, suggesting that the lake wasn’t suitable for irrigation and fish growth; however, it was appropriate for some aquatic life. A MIKE21 model was developed to provide a recommendation scenario that could be used to enhance the water quality of Burullus Lake. By improving the water quality of precise drains (namely drains 7 and 8), the WQI at Z4 and Z6 modified from “Bad” to “Medium”. The period required to achieve this self-purification was 5 months.  


Author(s):  
Rui Shi ◽  
Jixin Zhao ◽  
Wei Shi ◽  
Shuai Song ◽  
Chenchen Wang

Water quality is a key indicator of human health. Wuliangsuhai Lake plays an important role in maintaining the ecological balance of the region, protecting the local species diversity and maintaining agricultural development. However, it is also facing a greater risk of water quality deterioration. The 24 water quality factors that this study focused on were analyzed in water samples collected during the irrigation period and non-irrigation period from 19 different sites in Wuliangsuhai Lake, Inner Mongolia, China. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were conducted to evaluate complex water quality data and to explore the sources of pollution. The results showed that, during the irrigation period, sites in the middle part of the lake (clusters 1 and 3) had higher pollution levels due to receiving most of the agricultural and some industrial wastewater from the Hetao irrigation area. During the non-irrigation period, the distribution of the comprehensive pollution index was the opposite of that seen during the irrigation period, and the degree of pollutant index was reduced significantly. Thus, run-off from the Hetao irrigation area is likely to be the main source of pollution.


2016 ◽  
Vol 174 (4) ◽  
pp. 425-432 ◽  
Author(s):  
Chantal Zevenbergen ◽  
Tim I M Korevaar ◽  
Andrea Schuette ◽  
Robin P Peeters ◽  
Marco Medici ◽  
...  

BackgroundLevels of thyroid hormone (TH) and trace elements (copper (Cu) and selenium (Se)) are important for development and function of the brain. Anti-epileptic drugs (AEDs) can influence serum TH and trace element levels. As the relationship between AEDs, THs, and trace elements has not yet been studied directly, we explored these interactions.MethodIn total 898 participants, from the Thyroid Origin of Psychomotor Retardation study designed to investigate thyroid parameters in subjects with intellectual disability (ID), had data available on serum Se, Cu, thyroid stimulating hormone (TSH), free thyroxine (FT4), tri-iodothyronine (T3), reverse T3, T4, and thyroxine-binding globulin (TBG); 401 subjects were on AED treatment. Differences in trace elements according to medication usage was investigated using ANOVA, and associations between trace elements and thyroid parameters were analysed using (non-) linear regression models.ResultsStudy participants were not deficient in any of the trace elements analyzed. AED (carbamazepine, valproate and phenytoin) usage was negatively associated with serum Se and showed compound-specific associations with Cu levels. After correction for drug usage, Se was positively associated with TSH levels, negatively associated with FT4levels, and positively with T3levels. Cu was positively associated with T4, T3, and rT3, which was largely dependent on TBG levels.ConclusionThe subjects with ID did not display profound deficiencies in trace element levels. AEDs were associated with serum Se and Cu levels, while serum Se and Cu were also associated with thyroid parameters. Further studies on the underlying mechanisms and potential clinical importance are warranted.


2011 ◽  
Vol 347-353 ◽  
pp. 2140-2145
Author(s):  
Qing Wei Zhang ◽  
She Li Chai ◽  
Jing Cai ◽  
Li Na Gao

The objective of this study was to determine the baseline concentrations of trace elements in grassland topsoils from 155 soil sampling sites in West Jilin province, Northeast China, to establish the relationships between the trace metal contents and soil physicochemical properties and major oxide contents and among trace metal concentrations themselves, and to identify the possible sources of trace element in soils. The baseline concentrations of trace elements(mg/kg) were: As 3.12-14.18, B 16.17-49.08, Cd 0.037-0.127, Co 0.96-15.28, Cr 18.87-60.83, Cu 10.81-24.75, Hg 0.004-0.035, Mn 171.25-657.87, Mo 0.08-1.15, Ni 6.79-30, Pb 12.58 -26.08, Se 0.03-0.36, and Zn 18.93-61.03. The upper baseline limits of these elements were all less than the Chinese Environmental Quality Standard for Soils, the Dutch Intervention Values for Soils, implying that trace element contents in the studied soils were of the safety levels.Fe2O3 and Al2O3 had stronger correlations with most trace elements than other oxides, and Co,Cr,Cu,Mn, Ni were highly correlated one another. Three types of geochemical associations were distinguished from this study:the first association involving As,Co,Cr,Cu,Mn,Mo,Ni,Pb,Zn,Al2O3 and Fe2O3 was mainly associated with Al,Fe-Mn oxides and/or with the Al-bearing clay minerals, suggesting that the trace elements were mainly derived from lithogenic and pedogenic processes; the second association including Se, Hg, Cd, CaO and organic carbon was mainly associated with organic matter and calcium oxides, showing that Se,Hg and Cd were mainly contributed by anthropogenic sources; the third association containing B, Na2O, K2O, MgO, pH, and electrical conductivity was mainly associated salinization processes of soils, implying that alkaline pH and high Na contents would enhance B concentration of soils.


2010 ◽  
Vol 33 (3) ◽  
pp. 155
Author(s):  
Nuray Bayar Muluk ◽  
Fulya Yalçınkaya ◽  
Osman Kürşat Arikan ◽  
Özden Çırpar ◽  
Sedat Kaygusuz ◽  
...  

Objectives: To determine whether trace elements that are essential for neural function play a role in the pathophsiology and etiology of auditory neuropathy (AN).. Materials and methods: Patients diagnosed with auditory neuropathy consisted of eight children (two male, six female). The blood tests including the measurement of sodium, potassium, chloride, calcium, phosphorus, iron, copper and magnesium were done in children with AN during their routine care. Results: Of the eight children with AN, many had serum levels outside the normal range: one had low sodium, two had low potassium, one had low chloride, two had high zinc and three had low zinc, two had low calcium and two had higher than normal phosphorus. Conclusion: Although some serum trace element levels in our patients were higher or lower than normal values, the mean values were within normal limits. Thus, we were unable to detect a relationship between serum trace element levels and AN-. In the future, larger studies should be conducted to confirm these findings.


2018 ◽  
Vol 46 (1) ◽  
pp. 5
Author(s):  
Handan Hilal Arslan ◽  
Duygu Tarhan ◽  
Sena Cenesiz ◽  
Fatma Ates Alkan ◽  
Umit Ozcan ◽  
...  

Background: Cutaneous papillomas are benign proliferative neoplasms. The aetiology and pathogenesis of the disease are very complex. Papillomatosis lesions can be detected anywhere on the body, frequently appearing on the surface of the head, neck, teats, udder, external genital mucosa and upper part of the gastrointestinal tract. The disease is not life threatening but due to loss of productivity, owners often cull animals with papillomatosis. The relationships between trace elements, heavy metals and cancer are still researching. The aim of this study was the evaluation of the relationships between trace elements and antioxidant metabolism, and cutaneous papillomatosis, in cattle.Materials, Methods & Results: Eleven cattle with cutaneous papillomatosis and 10 healthy cattle constituted the study group and control group, respectively. Clinical examinations were performed on all animals. Blood samples were collected and Cr, Cu, Fe, Mg, Mn, Se, Zn, As, B, Ni, Si and Co levels were determined. The analyses were conducted with an inductively coupled plasma-optical emission spectrophotometer. In addition, catalase (CAT), glutathione (GSH), malondialdehyde (MDA) and ceruloplasmin (Cp) concentrations were measured. The Ni, Si and MDA levels of the study group were significantly higher than those of the control group (P < 0.05) but the Se levels of the study group were significantly lower than in the control group (P < 0.05). The normality of the data was determined with the Shapiro-Wilk Test and the Independent Samples t-Test or Mann-Whitney U test was used for statistical comparison of the groups.Discussion: Trace elements are essential components of biological systems. The levels of trace elements, such as Cu, Co, I, Se, Zn and Mn, which are affected by grazing activity, influence ruminants’ reproductive performance and other production parameters. The elements Al, As, Cr, Ni and Sn are also presumed to be essential for ruminant metabolism, although sufficient research data are not available. In the present study, Cr, Cu, Fe, Mg, Mn, Zn, As, B and Co levels were not significantly different between the papilloma and control groups. Se is an important trace element for skin health. This study revealed a mean serum Se level in animals with papillomatosis that was significantly lower than in the healthy group. Although the mode of anticancer activity of Se is not clear, some factors, such as antioxidant protection, improved immune system surveillance, carcinogen detoxification, modulation of cell proliferation and inhibition of tumour cell invasion and angiogenesis, are important. Ni is classified as a toxic heavy metal. In addition, it could be carcinogenic to humans. Ni level was two times higher in the papillomatosis group than in the healthy animals, in the present study. This result may indicate that Ni has a role in the genesis of papillomatosis in cattle. Si injection can cause inflammation, granulomas and cancer. There are few reports about Si levels in animals and the significant difference in the Si levels in cattle with cutaneous papillomatosis reported in this study may be a new indicator for the disease. The skin contains antioxidant molecules that include GSH, alpha-tocopherol or vitamin E, ascorbic acid or vitamin C, glutathione peroxidases, glutathione reductase, glutathione S-transferases (GSTs), superoxide dismutases (SODs), CAT and quinine reductase. There is strong interaction between ROS and/or their oxidant products and antioxidant molecules in the skin. In this study, although MDA levels were higher in the study group than in the control group, there was no significant difference between the groups in their CAT levels, and also in the GSH and CP levels. In conclusion, these results may evidence the systemic effects of papillomatosis on trace element levels and on oxidant metabolism in cattle.


2015 ◽  
Vol 77 (1) ◽  
Author(s):  
Ahmad Firdaus Kamaruddin ◽  
Mohd Ekhwan Toriman ◽  
Hafizan Juahir ◽  
Sharifuddin Md Zain ◽  
Mohd Nordin Abdul Rahman ◽  
...  

The spatial water quality data (281x22) obtained from 12 sampling stations located along the Terengganu River and its main tributaries were evaluated with environmetric methods. Principal component analysis was used to investigate the origin of each variable due to land use and human activities based on the three clustered regions obtained from the hierarchical agglomerative cluster analysis. Six principal components (PCs) were obtained, where six varimax factor (VF) of values more than 0.70 that considered strong loading are discussed. The possible pollution sources identified are of anthropogenic sources, mainly municipal waste, surface runoff, agricultural runoff, organic pollution and urban storm runoff. As a conclusion, the application of environmetric methods could reveal important information on the spatial variability of a large and complex river water quality data in order to control pollution sources.


2013 ◽  
Vol 12 ◽  
pp. CIN.S10770
Author(s):  
P.T. Krishna Kumar ◽  
P.T. Vinod ◽  
Vir V. Phoha ◽  
S.S. Iyengar ◽  
Puneeth Iyengar

Cancer risk management involves obliterating excess concentration of cancer causing trace elements by the natural immune system and hence intake of nutritious diet is of paramount importance. Human diet should consist of essential macronutrients that have to be consumed in large quantities and trace elements are to be consumed in very little amount. As some of these trace elements are causative factors for various types of cancer and build up at the expense of macronutrients, cancer risk management of these trace elements should be based on their initial concentration in the blood of each individual and not on their tolerable upper intake level. We propose an information theory based Expert System (ES) for estimating the lowest limit of toxicity association between the trace elements and the macronutrients. Such an estimate would enable the physician to prescribe required medication containing the macronutrients to annul the toxicity of cancer risk trace elements. The lowest limit of toxicity association is achieved by minimizing the correlated information of the concentration correlation matrix using the concept of Mutual Information (MI) and an algorithm based on a Technique of Determinant Inequalities (TDI) developed by the authors. The novelty of our ES is that it provides the lowest limit of toxicity profile for all trace elements in the blood not restricted to a group of compounds having similar structure. We demonstrate the superiority our algorithm over Principal Component Analysis in mitigating trace element toxicity in blood samples.


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