Environmental Engineering / Çevre Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/4321
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Article Citation - WoS: 15Citation - Scopus: 19Brominated Flame Retardants in a Computer Technical Service: Indoor Air Gas Phase, Submicron (pm1) and Coarse (pm10) Particles, Associated Inhalation Exposure, and Settled Dust(Elsevier Ltd., 2019) Genişoğlu, Mesut; Sofuoğlu, Aysun; Kurt Karakuş, Perihan Binnur; Birgül, Aşkın; Sofuoğlu, Sait CemilBrominated flame retardants (BFRs) are found in multi-media indoors, therefore, may pose serious risks to human health. This study investigated the occurrence of BFRs in particulate matter (PM1 and PM10) and gas phase by active and passive sampling, and settled dust to estimate potential exposure in a computer technical service. Polybrominated diphenyl ethers (PBDEs) and their alternatives (novel BFRs, NBFRs) were studied. PM and gas phase were collected on glass fiber filters and polyurethane foam plugs, respectively, and analyzed with a GC/MS after extraction, clean-up, and concentration. Inhalation exposure of the staff was estimated based on the measured concentrations using Monte Carlo simulation. BDE-209 was the dominating PBDE congener in all media while bis(2-ethylhexyl)-3,4,5,6-tetrabromophthalate and 1,2-bis(2,4,6-tribromophenoxy)ethane were those of NBFRs. Submicron particulate matter (PM1) BFR levels constituted about one half of the PM10-associated concentrations, while average PM10 mass concentration (69.9 μg m−3) was nine times that of PM1 (7.73 μg m−3). Calculated log10 dust-gas and PM-gas partitioning coefficients ranged from −5.03 to −2.10, −2.21 to −0.55, and −2.26 to −1.04 for settled dust, PM10, and PM1, respectively. The indoor/outdoor concentration ratios were >1 for all compounds indicating the strength of indoor sources in the service. The estimated potential inhalation exposures, for future chronic-toxic and carcinogenic risk assessments, indicated that the levels of gas-phase and PM1-associated exposures were similar at approximately one half of PM10-associated levels. Results of this study indicate that the occurrence of BFRs in all studied media should be taken into consideration for occupational health mitigation efforts.Article Citation - WoS: 12Citation - Scopus: 14Thermodynamically Designed Target-Specific Dna Probe as an Electrochemical Hybridization Biosensor(Elsevier Ltd., 2020) Can, Faruk; Ökten, Hatice Eser; Ergön Can, Tülay; Ergenekon, Pınar; Özkan, Melek; Erhan, ElifApplications of molecular techniques to elucidate identity or function using biomarkers still remain highly empirical and biosensors are no exception. In the present study, target-specific oligonucleotide probes for E. coli K12 were designed thermodynamically and applied in an electrochemical DNA biosensor setup. Biosensor was prepared by immobilization of a stem–loop structured probe, modified with a thiol functional group at its 5′ end and a biotin molecule at its 3′ end, on a gold electrode through self-assembly. Mercaptopropionic acid (MPA) was used to optimize the surface probe density of the electrode. Hybridization between the immobilized probe and the target DNA was detected via the electrochemical response of streptavidin-horseradish peroxidase in the presence of the substrate. The amperometric response showed a linear relationship with the target DNA concentration, ranging from 10 and 400 nM, with a correlation coefficient of 0.989. High selectivity and good repeatability of the biosensor showed that the thermodynamic approach to oligonucleotide probe design can be used in development of electrochemical DNA biosensors.Article Citation - WoS: 91Citation - Scopus: 95Source Apportionment and Carcinogenic Risk Assessment of Passive Air Sampler-Derived Pahs and Pcbs in a Heavily Industrialized Region(Elsevier Ltd., 2018) Çetin, Banu; Yurdakul, Sema; Güngörmüş, Elif; Öztürk, Fatma; Sofuoğlu, Sait CemilCancer has become the primary reason of deaths in Dilovasi probably due to its location with unique topography under the influence of heavy industrialization and traffic. In this study, possible sources and carcinogenic health risks of PAHs and PCBs were investigated in Dilovasi region by Positive Matrix Factorization (PMF) and the USEPA approach, respectively. PAHs and PCBs were measured monthly for a whole year at 23 sampling sites using PUF disk passive samplers. Average ambient air concentrations were found as 285 ± 431 ng/m 3 and 4152 ± 6072 pg/m 3 , for Σ 15 PAH and Σ 41 PCB, respectively. PAH concentrations increased with decreasing temperature especially at urban sites, indicating the impact of residential heating in addition to industrial activities and traffic. On the other hand, PCB concentrations mostly increased with temperature probably due to enhanced volatilization from their sources. Possible sources of PAHs were found as emissions of diesel and gasoline vehicles, biomass and coal combustion, iron and steel industry, and unburned petroleum/petroleum products, whereas iron-steel production, coal and biomass burning, technical PCB mixtures, and industrial emissions were identified for PCBs. The mean carcinogenic risk associated with inhalation exposure to PAHs and PCBs were estimated to be >10 −6 and >10 −5 , respectively, at all sampling points, while the 95th percentile was >10 −5 at 15 of 23 and >10 −4 at 8 of 23 sampling locations, respectively. Probabilistic assessment showed, especially for PCBs, that a majority of Dilovasi population face significant health risks. The higher risks due to PCBs further indicated that PCBs and possibly other pollutants originating from the same sources such as PBDEs and PCNs may be an important issue for the region.Article Citation - WoS: 108Citation - Scopus: 113Spatial and Seasonal Variations, Sources, Air-Soil Exchange, and Carcinogenic Risk Assessment for Pahs and Pcbs in Air and Soil of Kutahya, Turkey, the Province of Thermal Power Plants(Elsevier Ltd., 2017) Dumanoğlu, Yetkin; Gaga, Eftade O.; Güngörmüş, Elif; Sofuoğlu, Sait Cemil; Odabaşı, MustafaAtmospheric and concurrent soil samples were collected during winter and summer of 2014 at 41 sites in Kutahya, Turkey to investigate spatial and seasonal variations, sources, air-soil exchange, and associated carcinogenic risks of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). The highest atmospheric and soil concentrations were observed near power plants and residential areas, and the wintertime concentrations were generally higher than ones measured in summer. Spatial distribution of measured ambient concentrations and results of the factor analysis showed that the major contributing PAH sources in Kutahya region were the coal combustion for power generation and residential heating (48.9%), and diesel and gasoline exhaust emissions (47.3%) while the major PCB sources were the coal (thermal power plants and residential heating) and wood combustion (residential heating) (45.4%), and evaporative emissions from previously used technical PCB mixtures (34.7%). Results of fugacity fraction calculations indicated that the soil and atmosphere were not in equilibrium for most of the PAHs (88.0% in winter, 87.4% in summer) and PCBs (76.8% in winter, 83.8% in summer). For PAHs, deposition to the soil was the dominant mechanism in winter while in summer volatilization was equally important. For PCBs, volatilization dominated in summer while deposition was higher in winter. Cancer risks associated with inhalation and accidental soil ingestion of soil were also estimated. Generally, the estimated carcinogenic risks were below the acceptable risk level of 10− 6. The percentage of the population exceeding the acceptable risk level ranged from < 1% to 16%, except, 32% of the inhalation risk levels due to PAH exposure in winter at urban/industrial sites were > 10− 6.Article Citation - WoS: 36Citation - Scopus: 42Speciated Arsenic Concentrations, Exposure, and Associated Health Risks for Rice and Bulgur(Elsevier Ltd., 2014) Sofuoğlu, Sait Cemil; Güzelkaya, Hilal; Akgül, Özlem; Kavcar, Pınar; Kurucaovalı, Filiz; Sofuoğlu, AysunArsenic species were determined in rice and bulgur samples that were collected from 50 participants who also supplied exposure related information through a questionnaire survey. Speciation analysis was conducted using an HPLC-ICP-MS system. Ingestion exposure to arsenic and associated health risks were assessed by combining the concentration and questionnaire data both for individual participants and the subject population. Inorganic arsenic dominated both in rice and bulgur but concentrations were about an order of magnitude higher in rice (160. ±. 38. ng/g) than in bulgur. Because participants also consumed more rice than bulgur, exposures were significantly higher for rice resulting in carcinogenic risks above acceptable level for 53% and 93% of the participants when the in-effect and the proposed potencies were used, respectively, compared to 0% and 5% for bulgur. An inorganic arsenic standard for rice would be useful to lower the risks while public awareness about the relation between excessive rice consumption and health risks is built, and bulgur consumption is promoted.Article Citation - WoS: 42Citation - Scopus: 50Occurrence, Oral Exposure and Risk Assessment of Volatile Organic Compounds in Drinking Water for Izmir(Elsevier Ltd., 2006) Kavcar, Pınar; Odabaşı, Mustafa; Kitiş, Mehmet; İnal, Fikret; Sofuoğlu, Sait CemilConcentrations of volatile organic compounds (VOCs) were measured in the drinking water in Province of İzmir, Turkey, and associated health risks due to ingestion of these compounds were investigated using population weighted random samples. A total of 100 houses were visited in different districts of İzmir and drinking water samples were collected from consumers' drinking water source. Questionnaires were administered to one participant in each house to determine demographics and drinking water consumption rates. Oral exposure and risks were estimated for each participant and İzmir population by deterministic and probabilistic approaches, respectively. The four trihalomethane (THM) species (i.e., chloroform, bromodichloromethane, dibromochloromethane, and bromoform), benzene, toluene, p-xylene, and naphthalene were the most frequently detected VOCs with concentrations ranging from below detection limit to 35 μg/l. The risk estimates were found to be less than the values reported in the literature with few exceptions. Noncarcinogenic risks attributable to ingestion of VOCs for İzmir population were negligible, whereas the mean carcinogenic risk estimates for bromodichloromethane and dibromochloromethane were above the de minimis level of one in a million (10-6). For all VOCs, the concentrations measured in metropolitan area were greater than those in other districts. All THM species were detected in higher concentrations in tap water, whereas nontap water contained more benzene, toluene, p-xylene, and naphthalene. Therefore, the concentrations of the latter four compounds and associated risks increased with increasing income and education level since bottled water was used in larger proportions within these subgroups. The results of this study showed that oral exposure to drinking water contaminants and associated risks may be higher than the acceptable levels even if the concentrations fall below the standards.