Identification of ecologically significant habitats for urban nature conservation: a case study in Turkey

Given the rapid urbanization of Turkey, sustained productivity of natural resources should be an integral part of any urban development policy. The biogeochemical cycles and ecosystem services link urban and rural ecosystems. It is, therefore, essential that ecologically significant habitats along urban-rural continuum be protected to secure public and environmental health. This necessitates their identification and the establishment of administrative and legal foundations for urban nature conservation in the management of urban habitats, should be established Ecological analysis of urban habitats of Kar?iyaka led to the identification of 19 ecologically significant habitats. Nature conservation priority was rated, using rarity, species richness, stratification, site age, and area of the habitats. Ecologically significant habitats made up about 54 ha of the total urban green space of 289 ha in Kar?iyaka. The total number of plant species was estimated to be 273.     

Aniline degradation by electrocatalytic oxidation

The degradation of aniline solution in alkaline medium of pH 11.0 by electrocatalytic oxidation has been studied using an electrochemical reactor containing a SnO₂–Sb₂O₃–PtO anode and a Ti cathode, both of 54 cm² area. Hydroxyl radicals (HO^√) are produced at the anode, being tested with the trace catcher salicylic acid and phenol by spectrophotometery and high performance liquid chromatography. Intermediates dianiline, 4-anilino phenol and azobenzol were detected by gas chromatography–mass spectrometry. The existence of HO^√ produced in the aniline degradation was assayed with scavenger tertiary butanol. The results showed that electrocatalytic oxidation is an effective process for the degradation of aniline. A general reaction pathway that accounts for aniline degradation to CO₂ involving those intermediates is proposed.     

Inoculation of an atrazine-degrading strain,Chelatobacter heintzii Cit1, in four different soils: effects of different inoculum densities

The possibility to improve atrazine degradation in soils by bioaugmentation was studied. The atrazine-mineralizing strain, Chelatobacter heintzii Cit1, was inoculated in four sterile and four non-sterile soils, at varying inoculum densities. Two soils, which had shown enhanced atrazine mineralization, were used to determine which inoculum density was capable of restoring their original mineralizing capacity after sterilization. The two other soils, with intermediate and low capacity to mineralize atrazine, were used in order to demonstrate that atrazine mineralization in such soils could be improved by inoculation. Mineralization kinetics were fitted using the Gompertz model. In the case of soils adapted to atrazine mineralization, inoculation of C. heintzii did not accelerate the rate of atrazine mineralization, which was essentially performed by the indigenous microflora. However, with soils that did not mineralize atrazine, the introduction of 10(4) cfug(-1) resulted in a 3-fold increase of atrazine mineralization capacity.     

Induction of EROD activity in European eel (Anguilla anguilla) experimentally exposed to benzo[a]pyrene and beta-naphthoflavone

The induction of liver ethoxyresorufin O-deethylase (EROD) activity was investigated in the European eel, Anguilla anguilla, collected from a Mediterranean brackish environment and experimentally exposed to benzo[a]pyrene (B[a]P) and beta-naphthoflavone (BNF). Eels were injected intraperitoneally at increasing doses (0.1, 1, 10, and 50 mg/kg wet body weight) using corn oil as a carrier and sacrificed after 7 days. The main objectives of the present study are: (1). to assess of the sensitivity of EROD induction as a biomarker to polycyclic aromatic hydrocarbon (PAH) exposure; (2). to determine an EROD dose-response relationship of the contaminants used; and (3). to compare the efficiency of B[a]P and BNF as inducers of EROD activity. Results showed that both chemicals resulted in a dose-dependent EROD induction, but increases were not linear. EROD activity seemed to reach a plateau at the exposure of 10 mg/kg in both treatment groups; B[a]P was a more potent inducer than BNF was at the higher doses (10 and 50 mg/kg), while the opposite result was observed at the lower ones (0.1 and 1 mg/kg). The greatest induction occurred in eels treated with 10 mg/kg B[a]P, in which a 261-fold increase in EROD activity was observed. Results showed that EROD activity in A. anguilla is significantly induced by B[a]P and BNF exposure, responding to a wide range of concentrations of these contaminants. We infer that this tool may be suited as a diagnostic biomarker for biomonitoring PAHs pollution in Mediterranean brackish environments and further field research is suggested.     

Effects of organic acids on copper and cadmium desorption from contaminated soils

A study was conducted to investigate the effect of organic acids on Cd and Cu desorption from natural contaminated soils (NCS) with permanent contamination by metal smelters and from artificial contaminated soils (ACS) derived from an artificial amendment of Cd to three representative zonal soils in Central China. Results showed that the desorption of Cd in either NCS or ACS, with the increment of tartrate or citrate concentration in desorption solution, can be characterized as a valley-like curve. The presence of tartrate or citrate at a low concentration (< or =0.5 mmol/l) inhibited Cd desorption from these two types of soils, whereas the presence of organic acids at high concentrations (> or =2 mmol/l for citrate and about > or =15 mmol/l for tartrate) apparently promoted Cd desorption. The desorption curve of Cu by tartrate solution with different tartrate concentrations can also be characterized as a valley-like curve, while the desorption of Cu in the presence of citrate was directly enhanced with the increment of citrate concentration. With the enhancement of initial pH value from 2 to 8 in the presence of citrate, Cu desorption ratio decreased at the first stage, then increased, and then decreased again. A valley and a peak sequentially appeared in the Cd or Cu desorption curve with initial pH value increment. Compared with citrate, the desorption ratio of Cd or Cu from NCS or ACS was directly decreased in the presence of tartrate, with the enhancement of the pH value from 2 to 8. Cd or Cu desorption was clearly enhanced when the electrolyte concentration of KNO3 or KCl increased in the presence of 2 mmol/l tartrate. Moreover, a higher desorption ratio of Cd or Cu was shown with KCl electrolyte than with KNO3 electrolyte with the same concentration. Based on these observations, we suggest that bioavailabilities of heavy metal can be promoted with selected suitable types and concentrations of organic acid amendment and reasonable field condition.     

Detection of 210Po on filter papers 16 years after use for the collection of short-lived radon progeny in a room

Radon gas was allowed to accumulate in its radium source and then injected into a 36 m(3) test room, resulting in an initial radon concentration of 15 kBq m(-3). Filter papers were used to collect the short-lived radon progeny and thus to measure the Potential Alpha Energy Concentration (PAEC) in-situ in the year 1984 at different times and conditions according to the experimental design. The radon progeny collected on the filter papers were studied as a function of aerosol particle concentration ranging from 10(2)-10(5) particles cm(-3) in three different experiments. The highest aerosol particle concentration was generated by indoor cigarette smoking. Those filters were stored after the experiment, and were used after 16 years to study the activity of the radon long-lived alpha emitter progeny, (210)Po (T(1/2)=138 days). This isotope is separated from the short-lived progeny by (210)Pb beta emitter with 22.3 years half-life. After 16 years' storage of these filters, each filter paper was sandwiched and wrapped between two CR-39 nuclear track detectors, to put the detectors in contact with the surfaces of different filters, for 337 days. Correlation between the PAEC measured using filter papers in the year 1984 and the activity of long-lived alpha emitter (210)Po on the same filter papers measured in the year 2000 were studied. The results of the (210)Po activity showed a very good correlation of 0.92 with the PAEC 16 years ago. The results also depict that the PAEC and (210)Po activity in indoor air increased with the increase of aerosol particle concentration, which shows the attachment of short-lived radon progeny with the aerosol particles. The experiment proves that indoor cigarette smoking is a major source of aerosol particles carrying radon progeny and, thus, indoor cigarette smoking is an additional source of internal radiation hazard to the occupants whether smoker or non-smoker.     

Sorption of selenium anionic species on apatites and iron oxides from aqueous solutions

The sorption of selenite and selenate ions from aqueous solutions was investigated on hydroxyapatite, fluorapatite, goethite and hematite, in order to simulate the behavior of radioactive selenium in natural or artificial sorbing media. Correlation studies with acido-basic properties and solubility of the solids were also performed. The sorption is pH dependant, but these solids are very efficient for retaining selenite at pH values generally encountered in natural waters, with however higher K(d) values for oxides than apatites. Selenate ions are much less sorbed than selenite. Several methods such as electron microscopy and spectroscopic techniques were used to identify the sorption mechanisms. In the case of hydroxyapatite, sorption proceeds by substitution of phosphate groups in the lattice of the apatite crystal in the superficial layers of the solid. In the case of goethite and hematite, sorption can be interpreted and modeled by a surface complexation process, but there is a discrepancy between sorption site densities for selenite and for protons.     

137Cs in marine samples from the Brazilian southeastern coastal region

The present work presents the results of ¹³⁷Cs concentration in seawater, fish and sediments samples collect in 11 sampling points, crossing the Brazilian Southeastern coastal region, from Vitória (ES) to Santos (SP), on a routine basis from 1997 to 2002. This monitoring program was carried out by the Instituto de Radioproteção e Dosimetria (IRD/CNEN/MCT), in cooperation with the Instituto de Estudos do Mar Almirante Paulo Moreira (IEAPM/Brazilian Navy), aiming at determining artificial radionuclides in marine samples. Additionally to the ¹³⁷Cs results, ⁹⁰Sr concentrations in fish samples from 1998 to 2002 are also reported.The ¹³⁷Cs in seawater follows a lognormal distribution, with a geometric mean of 1.8 Bq m^-3 and a geometric standard deviation of 1.4 (n=54), decay corrected to June/2002. For ¹³⁷Cs levels in fish samples a geometric mean of 0.19 Bq kg⁻¹ and a geometric standard deviation of 2.9 (n=39), decay corrected to June/2002, with a range of 0.03 to 1.7 Bq kg⁻¹, were obtained. Based on the ¹³⁷Cs mean concentration in fish as well as in seawater, a transfer factor of 1 × 10² was calculated, which is quite in agreement with the recommended value found in the Safety Report Serie 19.     

Honeybees and their products as potential bioindicators of heavy metals contamination

The concentrations of three representative heavy metals(cadmium, chromium and lead) were measured by atomic absorptionspectroscopy in honeybees and in apiary's products (honey,pollen, propolis, and wax). Samples were collected from fivedifferent sampling points: four from areas surrounding the cityof Rome, and the fifth in the city center which receives intensevehicular traffic. All apiaries employed for this study werespecifically constructed without any metal part in order toavoid the risk of contamination of the assayed materials.Sample collection was conducted over a 3-month period (6samplings for honey and pollen, 3 sampling for propolis and wax,2 samplings for honeybees, all of which were collected in duplicate). Experimental data revealed, in general,statistically significant differences between the backgroundlevels of heavy metals recorded from the reference sites and thelevels measured in the site located in the center of the city ofRome.These results indicate that honeybees and, to a lesser extent,some of their products (pollen, propolis, wax, but not honey),can be considered representative bioindicators of environmentalpollution.     

Synchronous variation in water chemistry for 80 lakes in Southern Sweden

Variation in water chemistry was studied in 80 lakes in southern Sweden. The lakes had forest dominated catchments. The length of the time series was 14 years. Synchrony was calculated as Pearsons product moment correlation coefficients for all combinations of lakes, i.e. 3160 lake-pairs. The chemical variables studied were non-marine sulphate (SO₄ ^*), non-marine calcium (Ca^*), absorbance and acid neutralising capacity (ANC). Statistically significant synchrony occurred in 93% of all lake-pairs for SO₄ ^*, and between 58 and 67% for absorbance, Ca^* and ANC. In 70% of all lake-pairs, the synchrony was \s>0.71 for SO₄ ^*, which means that more than half of the variation in one lake could be explained by the variation in the other lake. For absorbance, Ca^* and ANC, about 25% of the lake-pairs had a synchrony \s>0.71. The relatively high synchrony for SO₄ ^* occurred during an overall downward trend in SO₄ ^* concentration.The degree of synchrony in our study was at a level comparable to other studies in northern America and England. However, our study included lakes in a much larger area, with distances of up to 500 km between the lakes, while earlier studies were made on small lake districts with lakes located within approximately 50 km. In contrast to these earlier studies, there was no correlation between synchrony and distance, lake characteristics or catchment characteristics. However, when a small subset of 15 lakes in the southeast of Sweden was selected, such relations were found.