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Study of different Chemcatcher configurations in the monitoring of nonylphenol ethoxylates and nonylphenol in aquatic environment
2014
Ahkola, Heidi | Herve, Sirpa | Knuutinen, Juha
The main aim of the European Union Water Framework Directive (WFD) (2000/60/EC) is to protect rivers, lakes, coastal waters and groundwaters (EC 2000). The implementation of the WFD requires monitoring the concentration levels of several priority pollutants such as nonylphenol ethoxylates (NPEOs) and nonylphenol (NP) in the area of EU. The present practices for determining the concentration levels of various pollutants are, in many respects, insufficient, and there is an urgent need to develop more cost-effective sampling methods. A passive sampling tool named Chemcatcher was tested for monitoring NPEOs and NP in aqueous media. These environmentally harmful substances have been widely used in different household and industrial applications, and they affect aquatic ecosystems, for example, by acting as endocrine disrupting compounds. The suitability of different receiving phases which were sulfonated styrene–divinylbenzene reversed phase polymer (SDB-RPS), standard styrene–divinyl benzene polymer (SDB-XC) and C-18 (octadecyl) was assessed in laboratory and field trials. The effect of a diffusion membrane on the accumulation of studied compounds was also investigated. The SDB-XC and C-18 receiving phases collected the NPEOs and NP most effectively. The water flow affected the accumulation factor of the studied substances in the field trials, and the water concentrations calculated using sampling rates were tenfold lower than those measured with conventional spot sampling. The concentration of the analytes in spot samples taken from the sampling sites might be higher because in that case, the particle-bound fraction is also measured. The NPEOs readily attach to suspended matter, and therefore, the total concentration of such compounds in water is much higher. Also, the spot samples were not taken daily but once a week, while the passive samplers collected the compounds continuously for 2- or 4-week time periods. This may cause differences when comparing the results of those two methods as well. Both techniques can be applied for monitoring the concentration levels at different sampling sites, but the calculated and measured analyte concentrations in surrounding water are not necessarily comparable with each other. More experiments are still needed to study the effect of hydrological issues and humic substances on the accumulation of chemicals. However, the Chemcatcher passive sampler gives valuable information about the mean concentration levels of studied compounds during 2- or 4-week sampling period. This is important for comparison of annual monitoring results, especially in sampling sites with rapidly fluctuating concentrations.
Afficher plus [+] Moins [-]Challenges in understanding the sources of bioaccumulated metals in biota inhabiting turbid river systems
2014
Cresswell, Tom | Smith, Ross E. W. | Simpson, Stuart L.
Bioaccumulation of As, Cd, Cu, Pb and Zn by Macrobrachium prawns was observed to occur in the Strickland River downstream of a gold mine at Porgera, Papua New Guinea. This was despite the total metal concentrations of waters and sediments indicating no difference from reference sites within tributaries. To provide information on potential sources and bioavailability of metals to prawns, an extensive range of analyses were made on waters, suspended solids, deposited sediments and plant materials within the river system. Dissolved metal concentrations were mostly sub-micrograms per liter and no major differences existed in concentrations or speciation between sites within the Strickland River or its tributaries. Similarly, no differences were detected between sites for total or dilute acid-extractable metal concentrations in bed sediments and plant materials, which may be ingested by the prawns. However, the rivers in this region are highly turbid and the dilute acid-extractable cadmium and zinc concentrations in suspended solids were greater at sites in the Strickland River than at sites in tributaries. The results indicated that mine-derived inputs increased the proportion of these forms of metals or metalloids in the Strickland River. These less strongly bound metals and metalloids would be more bioavailable to the prawns via the dietary pathway. The results highlighted many of the difficulties in using routine monitoring data without information on metal speciation to describe metal uptake and predict potential effects when concentrations are low and similar to background. The study indicated that the monitoring of contaminant concentrations in organisms that integrate the exposure from multiple exposure routes and durations may often be more effective for detecting impacts than intermittent monitoring of contaminants in waters and sediments.
Afficher plus [+] Moins [-]Multilingual education of students on a global scale and perspective—international networking on the example of bioindication and biomonitoring (B&B technologies)
2014
Markert, Bernd | Baltrėnaitė, Edita | Chudzińska, Ewa | De Marco, Silvia | Diatta, Jean | Ghaffari, Zahra | Gorelova, Svetlana | Marcovecchio, Jorge | Tabors, Guntis | Wang, Meie | Yousef, Naglaa | Fraenzle, Stefan | Wuenschmann, Simone
Living or formerly living organisms are being used to obtain information on the quality of the general health status of our environment by bioindication and biomonitoring methods for many decades. Thus, different roads toward this common scientific goal were developed by a lot of different international research groups. Global cooperation in between various scientific teams throughout the world has produced common ideas, scientific definitions, and highly innovative results of this extremely attractive working field. The transdisciplinary approach of different and multifaceted scientific areas—starting from biology, analytical chemistry, via health physics, up to social and economic issues—have surpassed mental barriers of individual scientists, so that “production” of straightforward common results related to the influence of material and immaterial environmental factors to the well-being of organisms and human life has now reached the forefront of international thinking. For the further sustainable development of our common scientific “hobby” of bioindication and biomonitoring, highest personal energy has to be given by us, being teachers to our students and to convince strategically decision makers as politicians to invest (financially) into the development of education and research of this innovative technique. Young people have to be intensively convinced on the “meaning” of our scientific doing, e.g., by extended forms of education. One example of multilingual education of students on a global scale and perspective is given here, which we started about 3 years ago.
Afficher plus [+] Moins [-]Emissions behavior and distribution of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) from cement kilns in China
2014
Chen, Tong | Guo, Ying | Li, Xiaodong | Lu, Shengyong | Yan, Jianhua
The production of cement in China is accompanied by various emissions, such as fine particulate matter, heavy metals, nitrogen oxides, sulfur oxides, carbon dioxide…. Moreover, cement kiln presents a potential health risk to its surroundings, linking to emissions of persistent organic pollutants (POPs), such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), in brief dioxins. Flue gas samples were collected from five typical cement kilns during twelve runs and were used to evaluate the levels and distribution of PCDD/Fs in the emissions from cement kilns. The PCDD/Fs concentrations (136 congeners) and I-TEQ values ranged from 2.3 to >40 ng/m³and 9.3 ∼ 90.8 × 10⁻³ ng I-TEQ/m³, respectively, which were lower than the emission standard in China (0.1 ng I-TEQ/m³). In weight units, the dominant congeners were OCDD, 1,2,3,4,6,7,8-HpCDF, and OCDF; 2,3,4,7,8-PeCDF is the largest contributor (36–66 %) to the total I-TEQ value of twelve runs. HxCDF and TCDF were the first two most abundant homologue groups (12–85 and 4–52 %), and the homologue concentration decreased with rising chlorine number for PCDDs. In addition, there was no marked difference in homologue profiles when solid wastes (refuse-derived fuel and municipal solid waste) and hazardous wastes (DDT and POPs) were combusted as supplemental fuels. The use of various supplemental fuels had no obvious effect on the fingerprint of PCDD/F homologues. Moreover, there was no significant difference in levels of PCDD/Fs emission due to the diversity of production capacity, which were consistent with reported previously. Air pollution control device had effect on the homologue profiles, and cement system with electrostatic precipitators (ESP) had more fractions of octachloro congeners to the total.
Afficher plus [+] Moins [-]Mass loads of dissolved and particulate mercury and other trace elements in the Mt. Amiata mining district, Southern Tuscany (Italy)
2014
Rimondi, V. | Costagliola, P. | Gray, J. E. | Lattanzi, P. | Nannucci, M. | Paolieri, M. | Salvadori, A.
Total dissolved and particulate mercury (Hg), arsenic (As), and antimony (Sb) mass loads were estimated in different seasons (March and September 2011 and March 2012) in the Paglia River basin (PRB) (central Italy). The Paglia River drains the Mt. Amiata Hg district, one of the largest Hg-rich regions worldwide. Quantification of Hg, As, and Sb mass loads in this watershed allowed (1) identification of the contamination sources, (2) evaluation of the effects of Hg on the environment, and (3) determination of processes affecting Hg transport. The dominant source of Hg in the Paglia River is runoff from Hg mines in the Mt. Amiata region. The maximum Hg mass load was found to be related to runoff from the inactive Abbadia San Salvatore Mine (ASSM), and up to 30 g day⁻¹of Hg, dominantly in the particulate form, was transported both in high and low flow conditions in 2011. In addition, enrichment factors (EFs) calculated for suspended particulate matter (SPM) were similar in different seasons indicating that water discharge controls the quantities of Hg transported in the PRB, and considerable Hg was transported in all seasons studied. Overall, as much as 11 kg of Hg are discharged annually in the PRB and this Hg is transported downstream to the Tiber River, and eventually to the Mediterranean Sea. Similar to Hg, maximum mass loads for As and Sb were found in March 2011, when as much as 190 g day⁻¹each of As and Sb were measured from sites downstream from the ASSM. Therefore, the Paglia River represents a significant source of Hg, Sb, and As to the Mediterranean Sea.
Afficher plus [+] Moins [-]Source apportionment of the carcinogenic potential of polycyclic aromatic hydrocarbons (PAH) associated to airborne PM10 by a PMF model
2014
Callén, M. S. | Iturmendi, A. | López, J. M. | Mastral, A. M.
In order to perform a study of the carcinogenic potential of polycyclic aromatic hydrocarbons (PAH), benzo(a)pyrene equivalent (BaP-eq) concentration was calculated and modelled by a receptor model based on positive matrix factorization (PMF). Nineteen PAH associated to airborne PM10 of Zaragoza, Spain, were quantified during the sampling period 2001–2009 and used as potential variables by the PMF model. Afterwards, multiple linear regression analysis was used to quantify the potential sources of BaP-eq. Five sources were obtained as the optimal solution and vehicular emission was identified as the main carcinogenic source (35 %) followed by heavy-duty vehicles (28 %), light-oil combustion (18 %), natural gas (10 %) and coal combustion (9 %). Two of the most prevailing directions contributing to this carcinogenic character were the NE and N directions associated with a highway, industrial parks and a paper factory. The lifetime lung cancer risk exceeded the unit risk of 8.7 × 10⁻⁵per ng/m³BaP in both winter and autumn seasons and the most contributing source was the vehicular emission factor becoming an important issue in control strategies.
Afficher plus [+] Moins [-]Histopathological and ultrastructural perturbations in tilapia liver as potential indicators of pollution in Lake Al-Asfar, Saudi Arabia
2014
Abdel-Moneim, Ashraf M.
Lake Al-Asfar (Al-Hassa, Saudi Arabia) is under threat from contaminants released through human activities such as agriculture and urban and industrial developments. In the present study, histopathologic and ultrastructural changes in liver of tilapia Oreochromis niloticus were analyzed to monitor the possible impact of pollution in Al-Asfar estuary. Heavy metals such as Ni, Fe, Zn, Co, Ba, Pb, and Cd were predominant in the lake water and far exceeded the international permissible limits. In fish samples, high prevalences of preneoplastic changes (50 %) and one case of cholangiocarcinoma were revealed in liver tissues. Cytological damage in fish hepatocytes included glycogen exhaustion, deformation of nuclear envelope, heterochromatin condensation, mitochondrial degeneration, vesiculation of rough endoplasmic reticulum, augmentation of smooth endoplasmic reticulum, and lysosomal proliferation. In conclusion, the observed biomarker responses were potential indicators of health impairment or disease in field fish populations, although there was no direct proof of a simple cause–effect relationship. This is the first biological effect assessment in Lake Al-Asfar using tilapia as suitable target species.
Afficher plus [+] Moins [-]Toxic effects of hexaflumuron on the development of Coccinella septempunctata
2014
Yu, Caihong | Fu, Maoran | Lin, Ronghua | Zhang, Yan | Yongquan, Liu | Jiang, Hui | Brock, Theo C. M.
Studying the toxic risk of pesticide exposure to ladybird beetles is important from an agronomical and ecological perspective since larval and adult ladybirds are dominant predators of herbivorous pest insects (e.g., aphids) in various crops in China. This article mainly deals with the long-term effects of a single application of the insect growth regulator hexaflumuron on Coccinella septempunctata. A 72-h and a 33-day toxicity test with hexaflumuron (single application) were performed, starting with the second instar larvae of C. septempunctata. Exposure doses in the long-term experiment were based on the estimated 72-h acute LR₅₀(application rate causing 50 % mortality) value of 304 g active ingredient (a.i.) ha⁻¹for second instar larvae of C. septempunctata. The long-term test used five hexaflumuron doses as treatment levels (1/50, 1/100, 1/200, 1/400, and 1/800 of the 72-h acute LR₅₀), as well as a solvent control and blank control treatment. The measurement endpoints used to calculate no observed effect application rates (NOERs) included development time, hatching, pupation, adult emergence, survival, and number of eggs produced. Analyzing the experimental data with one-way analysis of variance showed that the single hexaflumuron application had significant effects on C. septempunctata endpoints in the 33-day test, including effects on development duration (NOER 1.52 g a.i. ha⁻¹), hatching (NOER 3.04 g a.i. ha⁻¹), pupation (NOER 3.04 g a.i. ha⁻¹), and survival (NOER 1.52 g a.i. ha⁻¹). These NOERs are lower than the reported maximum field application rate of hexaflumuron (135 g a.i. ha⁻¹) in cotton cultivation, suggesting potential risks to beneficial arthropods.
Afficher plus [+] Moins [-]Alteration of cholinesterase activity as possible mechanism of silver nanoparticle toxicity
2014
Šinko, Goran | Vinković Vrček, Ivana | Goessler, Walter | Leitinger, Gerd | Dijanošić, Adriana | Miljanić, Snežana
Due to their broad-spectrum antimicrobial activity, silver nanoparticles (AgNPs) have been used in a large number of commercial and medical products. Such proliferated AgNP production poses toxicological and environmental issues which need to be addressed. The present study aimed to investigate the effects of AgNPs on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), important enzymes in areas of neurobiology, toxicology and pharmacology. Three different AgNPs, prepared by the chemical reduction using trisodium citrate, hydroxylamine hydrochloride (Cl-AgNPs), and borohydride following stabilization with poly(vinyl alcohol), were purified and characterised with respect to their sizes, shapes and optical properties. Their inhibition potential on AChE and BChE was evaluated in vitro using an enzyme assay with o-nitrophenyl acetate or o-nitrophenyl butyrate as substrates, respectively. All three studied AgNPs were reversible inhibitors of ChEs. Among tested nanoparticles, Cl-AgNP was found to be the most potent inhibitor of both AChE and BChE. Although the detailed mechanism by which the AgNPs inhibit esterase activities remains unknown, structural perturbation of the enzyme may be the common mode of ChE inhibition by AgNPs.
Afficher plus [+] Moins [-]Hexavalent chromium removal by a novel Serratia proteamaculans isolated from the bank of Sebou River (Morocco)
2014
Tahri Joutey, Nezha | Bahafid, Wifak | Sayel, Hanane | Ananou, Samir | El Ghachtouli, Naïma
The novel Serratia proteamaculans isolated from a chromium-contaminated site was tolerant to a concentration of 500 mg Cr(VI)/l. The optimum pH and temperature for reduction of Cr(VI) by S. proteamaculans were found to be 7.0 and 30 °C, respectively. The Cr(VI) reduction rate decreased with the increase in Cr(VI) concentration from 100 to 400 mg/l, suggesting the enzymatic chromium reduction. Resting and permeabilised cell assays provided the better evidence that chromate reduction in S. proteamaculans is enzymatic. Reduction by cell-free filtrate shows no extracellular chromate-reducing activity, revealing that this activity may be associated to membrane fraction and/or cytosolic fraction. Assays conducted with cytosolic and particulate fraction of S. proteamaculans confirmed the role of membrane-bound proteins in Cr(VI) reduction. Furthermore, chromium reduced by heat-treated cells suggests that membrane-associated chromate reductase activity of S. proteamaculans is preceded by its adsorption on the cell surface.
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