Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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Author: search.filters.author.Odabaşı, MustafaSubject: search.filters.subject.Air pollution

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  • Article
    Citation - WoS: 94
    Citation - Scopus: 96
    Short-Term Variation in Ambient Concentrations and Gas/Particle Partitioning of Organochlorine Pesticides in Izmir, Turkey
    (Elsevier Ltd., 2004) Sofuoğlu, Aysun; Çetin, Eylem; Bozacıoğlu, Sevde Seza; Şener, Gaye Devrim; Odabaşı, Mustafa
    Twenty successive daytime and nighttime air samples were collected and analyzed for 23 currently used and/banned organochlorine pesticides (OCPs) between 14 and 23 May 2003 in Izmir, Turkey. Average individual OCP concentrations ranged from 5±4pgm-3 (p,p′- dichlorodiphenyldichloroethane) to 391±306pgm-3 (chlorpyrifos) and they were within the ranges previously measured at different sites. Most of the OCPs did not exhibit strong diurnal cycling. The temperature dependence of gas-phase atmospheric concentrations of OCPs investigated using Clausius-Clapeyron plots was statistically significant for β-HCH and endosulfan sulfate (p<0.1) and was not significant for other compounds (0-21% of the variability in their gas-phase concentrations). In addition to temperature, the effect of wind speed and direction was also investigated using multiple linear regression analysis and these three parameters together explained the 2% (aldrin) to 72% (endosulfan II) of the variability in gas-phase OCP concentrations. Results of the multiple regression analysis indicated that wind speed was a statistically significant factor for most of the OCPs and wind direction was important for some compounds. The temperature-dependent diurnal cycling of most OCPs was probably masked by the higher wind speeds observed during daytime periods with high temperatures, different source sectors and ongoing sources. The lack of correlation for heptachlor, aldrin, p,p′-dichlorodiphenyldichloroethylene (p-p′-DDE), and p,p′-dichlorodiphenyltrichloroethane (p-p′-DDT) with temperature, wind speed and direction suggested that their concentrations were affected by long-range transport. The partitioning of OCPs between particle and gas phases was investigated and compared to KOA (octanol/air partition coefficient) absorption model. The overall agreement between experimental and modeled logKp (gas/particle partition coefficient) values was good (p<0.01, slope=0.94). Prediction of absorption model for particulate percentages was excellent for β-HCH, endosulfan I, and p-p′-DDT. However, the model underpredicted the particulate percentages for α,γ-HCHs, chlorpyrifos, and dieldrin, and overpredicted those for p-p′-DDE.
  • Article
    Citation - WoS: 71
    Citation - Scopus: 76
    Temperature Dependence of Gas-Phase Polycyclic Aromatic Hydrocarbon and Organochlorine Pesticide Concentrations in Chicago Air
    (Elsevier Ltd., 2001) Sofuoğlu, Aysun; Odabaşı, Mustafa; Taşdemir, Yücel; Khalili, Nasrin R.; Holsen, Thomas M.
    The temperature dependence of gas-phase atmospheric concentrations of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides measured in Chicago, IL between June and October 1995 were investigated using plots of the natural logarithm of partial pressures (lnP) vs. reciprocal mean temperatures (1/T). For the eight lowest molecular weight PAHs, temperature dependence was statistically significant (at the 95% confidence level) and temperature accounted for 23-49% of the variability in gas-phase concentrations. The relatively higher slopes for most of the PAHs suggested that volatilization from local sources and short-range transport influenced their concentrations. For pesticides, temperature dependence was statistically significant for DDD and for trans-nonachlor (at the 95% and 90% confidence levels), and was not statistically significant for the other five compounds (2-18% of the variability in their gas-phase concentrations). The relatively lower slopes for individual pesticides suggested that they have mostly non-urban and distant sources.Results of back trajectory analyses suggested that the region, southwest of Chicago, might be an important local or regional source sector for PAHs and organochlorine pesticides. No statistically significant relationship was observed between wind speed and PAH or pesticide concentrations. None of the variables (temperature, wind speed, wind direction, local and regional sources) could fully explain the variation in their concentrations measured in Chicago, therefore, this variation can be attributed to the combined effect of those factors.