Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Investigation of a Novel Personal Sampler Material for the Identification of Human Exposure To Semivolatile Organic Compounds(2024) Akmermer, Zülfikar; Demirtepe, Hale; Sofuoğlu, Sait CemilSVOCs are widespread indoors, where they occur at high levels. Humans spend most of their time indoors and are regularly exposed to these compounds. Various methods exist to assess human exposure to SVOCs. However, a novel personal sampler material, i.e. silicone wristband, has been used for the last decade. Due to its commencing use, the uptake capacity of silicone wristbands for SVOCs still needs to be discovered. This study aims to investigate the SVOC uptake rate and equilibrium partitioning coefficients of silicone wristbands. To achieve this aim, an analysis method for determining SVOCs in silicone wristbands was developed and validated with wristbands worn by academic personnel of IZTECH. The results showed that among polycyclic aromatic hydrocarbons (PAHs) acenaphthylene, among organophosphate esters (OPEs), tris (2-butoxyethyl) phosphate and among phthalate esters, di(2- ethylhexl) phthalate were found as the dominant SVOCs in silicone wristbands. Then, the uptake capacity of silicone wristbands for PAHs was investigated by deploying them in a school environment for 36 days, together with polyurethane foam passive air samplers. The uptake rates varied three orders of magnitude for compounds reaching equilibrium, i.e. acenaphthene, acenaphthylene, fluorene, phenanthrene, and anthracene (0.010 – 25.93 m3/day), while for fluoranthene, chrysene, and pyrene uptake rates were close to each other (0.17 – 0.50 m3/day). Furthermore, silicone wristband-air partitioning coefficients were in the range of 5.93 to 7.43 for acenaphthene, acenaphthylene, fluorene, phenanthrene, and anthracene. Lastly, daily and chronic toxic exposures and lifetime cancer risk for school children were assessed using PUF-PAS concentrations, and no significant risk was identified.Master Thesis Inhalation Exposure To Polychlorinated Biphenyls in Izmir(Izmir Institute of Technology, 2022) Edebali, Özge; Sofuoğlu, Sait Cemil; Sofuoğlu, AysunPolychlorinated biphenyls (PCBs) are chemicals that are classified as hazardous air pollutants with carcinogenic and chronic-toxic effects on human health. People may be exposed to these chemicals indoors and outdoors via inhalation of indoor and outdoor air. Their production and use were banned worldwide with the Stockholm Convention. Since the Turkish government became an official signatory to the Stockholm Convention in year of 2010, the determination of persistent organic pollutants (POPs) in environmental compartments in Türkiye has gained importance. PCBs are still present in the environment because they are found in materials such as those used in heat transfer, electrical, and hydraulic systems manufactured before the ban due to their persistence to degradation in environment. Industrial processes have an important effect on their environmental concentrations due to unintentional emissions. Therefore, they are still present in air and investigations show that industrial and urban areas have higher levels. The aim of this study was to measure concentrations of PCB compounds in indoor-outdoor air samples collected at homes and schools, and to estimate exposure and associated carcinogenic health risks. Samples were collected at randomly selected sites in urban, semi-urban, and rural areas with polyurethane foam – passive samplers. Samples were analyzed by using gas chromatography–mass spectrometry after Soxhlet extraction. The estimated carcinogenic risks even at the 95th percentile were calculated below the acceptable risk level (10-6), indicating that the population carcinogenic risk associated with inhalation of gas-phase PCBs is not considerable. However, aggregate risks that could be estimated by addition of other plausible exposure pathways would drive the levels above the acceptable level.Master Thesis Long Range Atmospheric Transport of Persistent Organic Pollutants To Izmir(01. Izmir Institute of Technology, 2021) Ayri, İlknur; Sofuoğlu, Sait Cemil; Sofuoğlu, AysunIn this study, passive samplers were placed in 10 provinces and an active sampler in Izmir in order to examine the long-range transport of POPs that are released into the environment due to the effects of the war in countries next to our southeast border. The ten cities were classified into three proximity groups: close, middle, and far. According to correlation analysis, central tendency statistics for various congeners showed an increasing trend with proximity to the war zone. However, support by hypothesis testing with Kruskal-Wallis or ANOVA tests were limited: PBDE-183, Σ45PCB and dieldrin in winter, PBDE-28, PBDE-99, PBDE-154, p,p'-DDE, Σ14PBDE and Σ25OCP in the transition period, and PBDE-28, PBDE-99, PBDE-85, PBDE-154, PBDE-190, PCB-52, Σ45PCB, p,p'-DDE and Σ25OCP in the whole sampling period. Back-trajectory frequency analysis of passive sampling indicated that air masses were transported from the war zone to the close region, but it was limited for middle and far regions deeming support by back-trajectory analysis of active sampling not possible, which show that the main route of air masses were Europe, Russia, and the former Soviet Union countries, and North Africa. Concentrations measured by passive air sampling being relatively higher both in the close-group and far-group especially in winter than in the middle-group. The result of passive sampling indicates that the southwest border of Turkey was impacted by POPs which were transported from the war zone while the west of the country was impacted by those from areas in north and northeast.Master Thesis The Use of Vetiveria Zizanioides (l) Nash and Cyperus Alternifolius L. by Floating Wetland Treatment To Improve Water Quality(Izmir Institute of Technology, 2018) Yücel, Arzu; Sofuoğlu, Aysun; Sofuoğlu, Sait CemilThe olive mill wastewater (OMW), arises during the production process of olive oil, is an important problem in all Mediterranean countries. OMW shows seasonality, and contain high organic pollutant. Eventhough various methods have been studied for the treatment, olive oil producers neither can afford the cost of these methods, nor it can provide the discharge standards. The capacity of phytoremediation of Vetiveria zizanioides (L.) Nash (vetiver) and Cyperus alternifolius L. (umbrella palm) species was evaulated in the treatment of OMW by floating treatment wetland (FTW) method. The 5 and 15% concentrations of OMW (OMW-5 and OMW-15) were remediated by these plants, and unplanted sets as triplicates for 67 days to determine their organic and nitrogen reduction. Therefore, total organic carbon (TOC), total phenol and total nitrogen (TN) in the OMW were measured. The amount of biomass at the beginning of the experiment were 2.5 and 4.0 kg OMW-5 and OMW-15 respectively. The highest biomass growth rate (149%) and total phenol accumulation in plant (439%) were observed in umbrella palm. The results showed that umbrella palm achieved 95%, 99%, 82% removal in TOC, total phenol, TN while these removals were 85%, 93%, 40% in vetiver planted OMW-5 tanks. Similarly, the removal in OMW-15 were comparable with 90, 97, 41 percentages with umbrella palm and 79, 92, and 21 percentages for vetiver respectively. As a result, it seems that umbrella palm and vetiver have potential in diluted OMW treatment by FTW for future.Master Thesis Exposure and Risk Assessment for Arsenic in Simav Plain by Ingestion of Edible Crops(Izmir Institute of Technology, 2017) Terzi, Begüm; Sofuoğlu, Sait Cemil; Gündüz, OrhanIngestion is the main route of exposure to arsenic. The pathways of concern are ingestion of drinking water and arsenic-accumulating plants. Simav plain has been shown to have the natural arsenic conamination of waters and soil. However, foodstuff was not made a subject of investigation. In this study, arsenic exposure via ingestion of edible plants cultivated in Simav plain was investigated based on the modeling of the measured soil concentrations and data collected from the literature, which were for bioconcentration factors, plant consumption rates, background arsenic concentrations in plants, plant root depths, and body weights. Eighteen plant species, which are bean, broccoli, cabbage, carrot, cauliflower, corn, cucumber, eggplant, garlic, lettuce, okra, onion, potato, radish, spinach, sunflower seed, tomato, and wheat were studied. Chronic-toxic and carcinogenic risks associated with the consumption contaminated foodstuff were assessed with two approaches: scenario based point estimates (deterministic approach) and population based estimates (probabilistic approach). Monte Carlo simulation was used to determine chronic-toxic and carcinogenic risks via ingestion of edible plants probabilistically. Wheat was found as the plant variety with the highest non-carcinogenic and carcinogenic risks which was followed by potato, tomato, cucumber, corn, cabbage, eggplant, and onion. Non-carcinogenic risk levels for broccoli, cauliflower, garlic, and radish were below the threshold level. However, their carcinogenic risk levels were considerable. The risk levels estimated in this study are exceptionally high, indicating consumption of the plants cultivated in Simav may pose significant chronic-toxic and carcinogenic health risks.Master Thesis Persistent Organic Pollutants in Turkey's Atmosphere: Spatial Variation(Izmir Institute of Technology, 2015) Çiçek, Tuğba; Sofuoğlu, Sait Cemil; Kurt Karakuş, Perihan BinnurThe objectives of this study was to measure ambient air levels of 43 PCBs and 22 OCPs in 16 cities at urban and background sites by using polyurethane foam discs (PUF) as passive air samplers (PAS), to investigate spatial variations, and to generate a baseline database which is the first large-scale nationwide database for POP residues in air of Turkey. Air sampling was conducted from May 2014 to April 2015 with three-month sampling periods. Samples were analyzed by gas chromatography - mass spectrometry after extraction, clean-up, and volume reduction. The one-year overall average Σ43PCBs concentration was 108±132 pg/m3. The one-year average of Σ43PCBs ranged from 14.5±14.3 pg/m3 (Kayseri) to 403±428 pg/m3 (İzmir) at urban sites with a mean of 116±141 pg/m3, and from 19.0±22.7 pg/m3 (Aksaray) to 217±353 pg/m3 (Kastamonu) at rural sites with a mean of 101±122 pg/m3. PCB 118 had the highest mean concentration (26.3±44.6 pg/m3) among the 43 PCB congeners. The PCB homologue group with the highest contribution was penta-CBs with 54.3%. Overall one-year average Σ22OCPs concentration was 341±870 pg/m3 with a range of 55.3±36.5 pg/m3 (Çankırı) and 1294±2153 pg/m3 (Kırklareli). ΣDDT had the highest overall mean level with 134±296 pg/m3 among the OCP groups. The highest concentration OCPs were p’p-DDE (97.6±236 pg/m3), HCB (45.3±197 pg/m3), α-HCH (22.0±92.8 pg/m3), β-HCH (21.8±96.1 pg/m3), and p’p-DDT (21.3±77.4 pg/m3). Principle Components Analysis showed that, in addition to the OCP with the highest concentration (p’p-DDE), parent OCP compounds such as α-endosulfan, α-HCH, HCB, and p’p-DDT differed from the others, and some of the remaining decay products were grouped together indicating similar behavior. Highly chlorinated PCBs were clustered together. Mann-Whitney U test indicated that the difference in the median concentrations of urban and rural sites was not significant. It was also used to test the significance of temperature effect on the median concentrations at a high and a low temperature range. The medians were significantly different for HCB, dieldrin, p’p-DDT, and β-endosulfan at urban sites but not significant for the remaining OCPs and ΣPCBs. The difference in the medians was significant for HCB, heptachlor, dieldrin, endrin, p’p-DDE, Mirex, and ΣPCBs at rural sitesMaster Thesis Ambient Air Persistent Organic Pollutant Monitoring, Backtrajectory Modeling, and Health Risk Assessment(Izmir Institute of Technology, 2015) Güngörmüş, Elif; Sofuoğlu, Aysun; Sofuoğlu, Sait CemilTurkish Government has officially become a party to the Stockholm Convention as of 2010, therefore, determination of POPs in environmental compartments in Turkey is a critical concern. In this study, 22 organochlorine pesticides (OCPs) and 43 polychlorinated biphenyls (PCBs) were measured in gas and particulate phases of ambient air samples collected in Izmir and Istanbul from May to October 2014 on a weekly basis. Gas chromatography–mass spectrometry was used to quantify the targeted pollutants. Potential source regions were assessed by applying back-trajectory and Potential Source Contribution Function (PSCF). Population carcinogenic risk levels associated with inhalation exposure were estimated by using Monte Carlo simulation, for which sensitivity and uncertainty analyses were also conducted. The highest mean concentration compounds were heptachlor (61±126 pg/m3) and p,p’-DDE (54±57 pg/m3) in Izmir and Istanbul, respectively. The mean Ʃ43PCBs concentration was found as 232±224 pg/m3 in Izmir, and 104±48 pg/m3 in Istanbul. Gas phase concentartions of OCPs and PCBs were generally much higher than particle phase. The PSCF results pointed out different potential source regions: Middle East, Eurasia, and Europe. All the estimated carcinogenic risks based on the 95% percentile values for individual OCPs and Ʃ43PCBs were calculated below the acceptable risk levels (10-6), indicating no significant potential health risk via inhalation route.Master Thesis Development of a Hybrid Sorbent Composed of Natural Materials for the Removal of Arsenic From Waters(Izmir Institute of Technology, 2014) Yılmaz, Dilek; Sofuoğlu, Sait CemilA novel sorbent has been developed by immobilizing chitosan onto pumice for As(V) sorption from waters. In order to ensure its functionality, sorption performance was determined by measuring As concentrations in water using hydride generation atomic absorption spectrometry. The success of the immobilization was checked with characterization techniques as scanning electron microscopy, thermal gravimetric analysis, and elemental analysis. Points of zero charges were determined with potentiometric mass titration. Batch type equilibration studies showed that the sorbent can be employed at a wide pH range resulting in quantitative sorption (>90%) at pH 3.0-7.0, and greater than 70% sorption at pH>8.0. These results demonstrate the advantage of immobilizing chitosan onto pumice, because, under the same conditions, pumice displays <20% sorption towards As(V) whereas chitosan gives approximately 90% sorption but only at pH 3.0. The validity of the method was verified through the analysis of ultra-pure, bottled drinking, and tap water samples spiked with arsenate; the respective sorption percentages of 93.2 (±0.7), 89.0 (±1.0), and 80.9 (±1.3) were obtained by batch type equilibration. The sorbent was applied in a column for the spiked samples of ultra-pure and tap water. Similar sorption percentages (60% at the 18th fraction) were obtained for ultra-pure water whereas the methodology gave more efficient results for tap water (90% at the 20th fraction) demonstrating the potential of the sorbent for an efficient water treatment system. Arsenic sorption was also examined in the presence of common interfering ions resulting in competing effects of PO43- and NO3- on As(V) adsorption.Master Thesis Monitoring and Assessment of Indoor Air Volatile Organic Compound Concentrations in Primary Schools(Izmir Institute of Technology, 2008) Aslan, Güler; Sofuoğlu, Sait CemilIndoor air quality (IAQ) is important mainly because, poor IAQ may cause variety of adverse health effects and people spend majority of their time indoors. One of the most susceptible groups to air pollution is considered as children. Children spend approximately six to eight hours a day in school buildings, therefore the indoor air quality of school buildings should be given utmost importance. Formaldehyde and volatile organic compounds (VOCs) have been receiving considerable interest in indoor air field studies because of their high emission rates from products used indoor environments. Thus, their concentrations have been measured in school buildings in many different countries.Indoor and outdoor air samples were collected from three primary schools in İzmir (School 1, School 2, and School 3). Sampling was performed in spring and winter terms. Active sampling was applied for VOCs and formaldehyde by using Tenax TA and DNPH silica gel sorbent tubes, respectively. VOCs were analyzed by using a thermal desorption - gas chromatography - mass spectrometry (TD-GC-MS) system.Formaldehyde analysis was performed by using an HPLC instrument.Benzene, toluene, ethyl benzene and xylenes, which have high toxicity, were detected at high concentrations. In addition, the indoor/outdoor (I/O) concentration ratios of VOCs were investigated. Mean Total VOC (TVOC) and formaldehyde concentrations were calculated for the three schools in winter and spring terms. TVOC and formaldehyde concentrations were 104 .g/m3 and 44.36 ./m3 in winter, and 66.42 .g/m3 and 43.73 .g/m3 in spring terms for School 1; and 50.86 .g/m3 and 30.78 .g/m3 in winter, and 32.1 .g/m3 and 35.82 .g/m3 in spring term for School 2, and 51.09 .g/m3 and 36.53 .g/m3 in spring term for School 3 primary schools, respectively. These concentration values are generally higher than or parallel to the values reported in the literature. The TVOC concentrations in kindergartens were higher than the concentrations in classrooms.Master Thesis Seasonal Variation in Disinfection By-Product Concentrations in Izmir Drinking Water(Izmir Institute of Technology, 2007) Baytak, Derya; Sofuoğlu, Sait CemilThe goal of this study was to investigate the seasonal variation in disinfection byproduct (DBP) concentrations in drinking water zmir. In accordance with this aim, drinking water samples were collected from tap water of five sampling points in the distribution system of three different water sources (Tahtalı Reservoir, Balçova Reservoir and ground water) during a 10 month period, from June 2006 to April 2007. The samples were analyzed by GC-ECD according to EPA Method 551.1. In addition, while the organic matter content (measured as NPOC) and bromide ion concentration were measured in samples from Tahtalı and Balçova Water Treatment Plants, other parameters including pH, temperature and chlorine dose were obtained from the treatment plants. These parameters were used as explanatory variables in the multivariate regression analysis to construct statistical models for DBPs. Trihalomethanes were the most abundant DBPs in all samples, followed by haloacetonitriles, chloropicrin and halogenated ketones. The mean total trihalomethanes (TTHMs) concentration of Balçova, Narlıdere and Güzelbahçe was 20.78 ppb while it was 94.71 ppb at Hatay. Concentrations of DBPs in all sampling locations were found to be the highest in spring and lowest in summer and fall. Although TTHM levels in all samples were found to be in accordance with the current drinking water regulations of Turkey, 41 % of the samples from Hatay exceeded the level that will be come into effect in 2012. Multivariate regression analysis suggested that water temperature and total chlorine dose were the most effective parameters for DBPs. In addition, simple regression analysis between total haloacetonitriles and TTHMs revealed a very high correlation (R2.0.83). Logistic regression models were able to predict the probability of exceedance of the selected TTHM thresholds with 76 % efficiency.