In vitro assessment of genotoxic and oxidative effects of zinc borate

Zinc borate is used as flame retardant for plastics and cellulose fibers, paper, rubber, and textiles. Despite its wide industrial use, there is limited information concerning its toxicity. The aim of the present study was to investigate the concentration dependence (0–280 mg L^?1) of its genotoxic activity on cultured human lymphocytes by using sister chromatid exchange and chromosomal aberration assays. Total antioxidant capacity and the extent of oxidative stress were also determined. Zinc borate was found to be non-genotoxic at all tested concentrations. It exhibited antioxidant activity at concentrations lower than 40 mg L^?1, and total oxidative stress levels were not changed at any applied concentration of zinc borate.     

Variation in trace element mobility and nitrogen metabolism of Verbascum olympicum Boiss. under copper stress

The aim of this study was to evaluate the effects of copper (Cu) stress on accumulation and transport of trace elements, nitrogen assimilation, and growth parameters of Verbascum olympicum. Eight-week-old seedlings were grown in Hoagland's solution and exposed to 0, 50, 250, or 500?µM CuSO₄ for seven days in laboratory conditions. Bioaccumulation of trace elements (boron, bismuth, cobalt, Cu, iron, lithium, manganese, molybdenum, nickel, lead, zinc) in the roots and leaves was determined by inductively coupled plasma–mass spectrometry after one, three, and seven days. Chlorophyll content, nitrate reductase, and glutamine synthetase activities, soluble protein content, and biomass were determined. Copper accumulated in the roots and leaves (up to 19609.8 and 256.2?mg?kg^?1 dry weight, respectively). Other trace elements accumulated to higher levels in the roots of Cu-treated plants compared with those of control plants. High Cu concentrations decreased nitrogen-assimilatory enzyme activities. Compared with control plants, those treated with high Cu concentrations showed lower chlorophyll contents, total protein contents, and biomass. Nitrogen assimilation and growth parameters of V. olympicum were negatively affected by Cu treatment but mineral nutrition was not severely disrupted. The results support the suitability of V. olympicum as a candidate for phytoremediation of Cu-contaminated soils.     

Biogeochemical cycle of arsenic and calculating the enrichment factor by using Li element

In this study, the biogeochemical cycle of arsenic in the Bosporus and the Golden Horn, which have a two-layer stratified structure, was investigated and the dominant feature in this cycle was observed to be the anthropogenic (domestic + industrial) activities. On the contrary, in the rural areas which are far from human activities, such as İğneada, the seawater–atmosphere interchange can be observed evidently in the periods covering the primary production.     

Simultaneous determination of estrone and selected pesticides in water medium by GC-MS after multivariate optimization of microextraction strategy

A sensitive and accurate analytical method based on dispersive liquid-liquid microextraction was developed for the simultaneous determination of selected pesticides, hormones, and endocrine disruptors by GC-MS. The optimum conditions of the extraction procedure were determined using an experimental design of factors significantly affecting the extraction output. Analysis of variance (ANOVA) was used to evaluate the main effects of experimental factors and their interactions. The limit of detection values determined for the analytes under optimum experimental conditions were found to be between 0.30–2.0 ng/mL. The linear calibration plot of analytes span across a wide concentration range and low %RSD values from replicate measurements indicated good precision of the developed method. Spiked recovery tests were also performed on municipal wastewater, well water, lake water, sea water, and tap water matrices to determine the method’s accuracy and applicability to water samples. The recovery results obtained were satisfactory for all water samples.     

Risk assessment of trace metals in an extreme environment sediment: shallow,hypersaline, alkaline,and industrial Lake Acıgöl,Denizli, Turkey

The major and trace element component of 48 recent sediment samples in three distinct intervals (0–10, 10–20, and 20–30 cm) from Lake Ac?göl is described to present the current contamination levels and grift structure of detrital and evaporate mineral patterns of these sediments in this extreme saline environment. The spatial and vertical concentrations of major oxides were not uniform in the each subsurface interval. However, similar spatial distribution patterns were observed for some major element couples, due mainly to the detrital and evaporate origin of these elements. A sequential extraction procedure including five distinct steps was also performed to determine the different bonds of trace elements in the <?60-μ particulate size of recent sediments. Eleven trace elements (Ni, Fe, Cd, Pb, Cu, Zn, As, Co, Cr, Al and Mn) in nine surface and subsurface sediment samples were analyzed with chemical partitioning procedures to determine the trace element percentage loads in these different sequential extraction phases. The obtained accuracy values via comparison of the bulk trace metal loads with the total loads of five extraction steps were satisfying for the Ni, Fe, Cd, Zn, and Co. While, bulk analysis results of the Cu, Ni, and V elements have good correlation with total organic matter, organic fraction of sequential extraction characterized by Cu, As, Cd, and Pb. Shallow Lake Ac?göl sediment is characteristic with two different redox layer a) oxic upper level sediments, where trace metals are mobilized, b) reduced subsurface level, where the trace metals are precipitated.     

Assessment of heavy metal pollution of seston from freshwater resources poured into the Northeast Mediterranean region

This study was carried out to determine the accumulation levels of heavy metals (Zn, Cd, Pb, Cu, Fe, Cr) in seston to three different freshwater resources poured into the Iskenderun Bay. Seasonal averages of physico-chemical parameters measured at stations, Arsuz Stream, Payas Stream, and Ceyhan River, are classified as Class III—contaminated water according to the temperature parameter in the summer. Payas Stream has been determined to be Class III—polluted water according to pH parameters during the summer season. Ceyhan River was found to be Class III—contaminated water according to the dissolved oxygen parameter in the autumn season. Heavy metal accumulation levels in the seston were determined Fe?>?Cr?>?Zn?>?Cu?>?Pb?>?Cd in Arsuz Stream, Fe?>?Zn?>?Pb?>?Cr?>?Cu?>?Cd in Payas Stream, and Fe?>?Zn?>?Cr?>?Cu?>?Pb?>?Cd in Ceyhan River. The results in this study showed that high accumulation levels in seston were determined for Fe while low accumulation levels for Cd.     

Precipitation Modeling by Polyhedral RCMARS and Comparison with MARS and CMARS

Climate change is becoming an ever important issue due to the possibility that it may result in extreme weather events such as floods or droughts. Consequently, precipitation forecasting has similarly gained in significance as it is a useful tool in meeting the increasing need for the efficient management of water resources as well as in preventing disasters before they happen. In the literature, there are various statistical and computational methods used for this purpose, including linear and nonlinear regression, kriging, time series models, neural networks, and multivariate adaptive regression splines (MARS). Among them, MARS stands out as the better performing precipitation modeling method. In this article, we used a recently developed method called robust conic mars (RCMARS), based on MARS (also on CMARS), to forecast precipitation owing to its ability to model complex uncertain data. In CMARS, which was developed as a powerful alternative to MARS, the model complexity is penalized in the form of Tikhonov regularization and studied as a conic quadratic programming. In RCMARS, on the other hand, CMARS is refined further by including the existence of uncertainty in the future scenarios and robustifying it with a robust optimization technique. To evaluate the performance of the RCMARS method, it was applied to build a precipitation model constructed as an early warning system for the continental Central Anatolia Region of Turkey, where drought has been a recurrent phenomenon for the last few decades. Furthermore, the performance of the RCMARS precipitation model was also compared to that of MARS and CMARS. The results indicated that RCMARS builds more accurate, precise, and stable precipitation models compared to those of MARS and CMARS. In addition to these advantageous features of the RCMARS precipitation model, it also provided a good fit to the data. As a result, we propose its use in precipitation forecasting for the region studied.     

Determination of the effects of temporal change in urban and agricultural land uses as seen in the example of the town of Akhisar, using remote sensing techniques

Today, as a result of erratic and unplanned urbanization, towns are rapidly becoming a mass of concrete and town-dwellers are suffocated by their busy and stressful professional lives. They feel a need for places where they can find breathing-space in their free time. Green areas within towns are important spaces where townspeople are able to carry out recreational activities. These places form a link between townspeople and nature. The importance of urban green areas is increasing with every passing day due to their social, psychological, ecological, physical and economic functions and their impact on the quality of towns. In this study it has been attempted to demonstrate the pressures of urban development on agricultural land by determining the changing land use situation over the years in the district of Akhisar. In this research, an aerial photograph from year 1939 and satellite images of the town from the years 2000 and 2007 were used. Land use changes in the region were determined spatially. As a result of this study, which aims to determine in which direction urbanization is progressing in the district, the importance of town planning emerges. This study will be informative for the local authorities in their future town planning projects. With its flat and almost flat fertile arable land, the district of Akhisar occupies an important position within the province of Manisa. From the point of view of olive production the region is one of Turkey's important centres. Fifty-five percent of the olive production in the province of Manisa is realized in Akhisar. However, the results of the present study show that while agricultural areas comprised 2.5805 km(2) in 1939, these had diminished to 1.5146 km(2) in the year 2000 and had diminished to 1.0762 km(2) in the year 2007 and residential area (dense) 0.449 km(2) occupied in 1939, in the year 2000 this had risen to 1.9472 and 2.3238 km(2) in the year 2007. This planless urbanization in the study area has led to great losses of farmland.     

Response of lake water quality to wastewater inputs from land-based fish farm located on Yuvarlakçay Creek in Köyceğiz–Dalyan Specially Protected Area, Turkey

Köyce?iz Lake is located in the south-western part of Turkey. The area between the Köyce?iz Lake and the Mediterranean Sea is covered with four small lakes and several canals. The surroundings of the lake, canals and forests have a great potential as a reproduction areas for Mediterranean Sea turtles (Caretta caretta) and sheltering place for various animals. In the vicinity of this system there are agricultural areas and small settlements. In this region the most important economic activities are tourism and fisheries. However, the lake is currently threatened by pollution because of (1) non-point source pollution (agriculture); (2) point sources (land-based fish farms); (3) inefficient sewerage systems; (4) uncontrolled soil erosion in its drainage basin; (5) inappropriate flood control measures; and (6) channel traffic. This study evaluates the influence of its influent creeks namely Namnam and Yuvarlakçay Creek on the water quality of Köyce?iz Lake, mainly because the creeks are believed to be responsible for the major pollutant load reaching the lake. Accordingly, this study demonstrates (1) change in the water quality of Köyce?iz Lake from 2006 to 2007; (2) the water quality classification of the major influent creeks feeding Köyce?iz Lake; and (3) how land-based fish farm influences Yuvarlakçay Creek water quality in a Köyce?iz–Dalyan Specially Protected Area.     

Heavy metal concentrations in water, suspended matter, and sediment from Gökova Bay, Turkey

The contents of heavy metals (Fe, Mn, Pb, Cu, Cd, and Hg) dissolved in water and suspended solids of Gökova Bay—partly and fully sampled in 2005 and 2006, respectively—are quite higher than the average values encountered in uncontaminated sea water. The high concentrations are associated with terrestrial inputs from the mining zones and anthropogenic (domestic + industrial) sources. Moreover, the distribution of Fe and Cu is affected by primary production because these elements function as nutrients in biological activities. The Cr, Ni, and Fe concentrations of surface sediments are above the shale average. The Cr and Ni contents of surface sediments representative of river mouths strongly correlate with total phosphorus contents. In a sulfide-poor environment, Pb and Cu were concentrated at a higher ratio in surface sediments than Cd, probably due to higher stabilities of their surface complexes with amorphous iron oxides and clay minerals existing as major components in the sediments. The exceptional enrichment of Zn may be attributed to double oxide formation with amorphous iron oxides in sediments. The high metal values are most probably caused by terrestrial inputs from anthropogenic sources and the mining zones at the southeast part of the bay. The Al, Mn, Pb, Cu, Zn, and Hg contents are below the shale average. The low values have possibly originated from the coarse-grained sandy sediments having a low affinity for metals. There are no distinct differences in the metal distributions in water and suspended matter between the years 2005 and 2006 in the bay, probably due to low sedimentation rates.