Semra G. Tuncel

Chemical composition of precipitation near an industrial area at Izmir, Turkey

Abstract Wet and dry deposition samples were collected near an industrial area on the Aegean coast of Turkey. Concentrations of major ions (Cl − , SO 4 2− , NO 3 , H + , Na + , K + , Cat 2+ Mg 2+ and NH 4 + were determined. The pH of the precipitation, calculated from the volume weighted H+ concentration, was found to be 5.6, indicating extensive neutralization of the acidity in the rain. Neutralization was found to be a local process. The main base responsible for the neutralization of acidity was NH 3 from fertilizer used in the region. The CaCO 3 from resuspended soil accounts for 16% of the neutralized acidity. The annual wet deposition of ions was determined by two parameters, namely the precipitation amount and concentrations of ions in the precipitation. Precipitation amount accounted for approximately 70% of the annual wet deposition of ions in the Menemen region, whereas concentrations of ions in precipitation had only a minor influence. Although concentrations decrease with precipitation amount due to dilution in heavy rain, precipitation amount is not the only factor affecting concentrations of ions in precipitation. The main source of ions in wet deposition is the emissions from nearby industries. However, airborne NH 4 NO 3 and (NH 4 ) 2 SO 4 fertilizer particles may also contribute to observed concentrations of SO 2 2− and NO 3 − in rainwater. Dry deposition of most of the ions was higher than their annual wet deposition.

Composition of fine particle regional sulfate component in Shenandoah Valley

Fine fractions of atmospheric particulate samples collected over 3 weeks in July/Aug 1980 in Shenandoah Valley, VA, and previously analyzed by X-ray fluorescence analysis to provide data for many additional elements. Modified factor analysis of the combined data yielded a regional sulfate component containing S, NH/sub 4//sup +/, V, Mn, Zn, Se, As, In, Sb, And Pb. If the component originates mainly from coal combustion, there is modification of the elemental composition pattern during transport from distant mental composition pattern during transport from distant power plants to the receptors, even in the <2.5-..mu..m fraction. The regional sulfate component should be used in receptor-model treatments of areas strongly affected by sulfate from distant sources, as it may account for substantial fractions of several airborne elements, especially Se and Mn. Particulate S/Se mass ratios from this and other work are usually in the vicinity of 3300 in areas not immediately affected by fresh SO/sub 2/ sources, but drop significantly near such sources.

Major ion composition of wet and dry deposition in the eastern Mediterranean basin

Abstract Major ions were analysed in wet and dry deposition samples collected for 1 year (1992), using daily and weekly sampling periods at the Eastern Mediterranean coast of Turkey. The dry deposition fluxes of marine and crustal ions were found to be higher than their corresponding wet deposition. However, wet deposition fluxes of ions with anthropogenic sources, such as SO 4 2− and NO 3 − were found to be higher than their dry deposition rates. The annual average pH of the precipitation was 5.17, with high variability in the observed values due to different source regions. High concentrations of SO 4 2− and NO 3 − measured in samples with high pH indicated extensive neutralization of acidity by alkaline species. Results suggest that more than 70% of the acidity has been neutralized by CaCO 3 which originate both from airborne local soil and dust transported from North Africa.

Rain water chemistry in Ankara, Turkey

Samples of rain water were collected in Ankara for the period between September 1989 and May 1990, by using wet-only sampler. Concentrations of major cations (H+, Na+ K+ Ca2+ and NH4+) and major anions (Cl−, NO3− and SO42−) were determined for the first time in Turkey. The rain water was not acidic owing to high concentrations of alkaline soil particles in the atmosphere. However, the concentrations of acid forming ions, such as SO4− and N03, were higher than the concentrations expected in a typical urban atmosphere. Most of the SO4− in rain water was in the form of CaSO4. Rain-aerosol coupling were examined by simultaneous sampling of aerosols with rain. The ions most efficiently scavenged from the atmosphere were found to be SO42− and Ca2+.

Optimization and field application of a filter pack system for the simultaneous sampling of atmospheric HN03, NH3 AND SO2

Abstract Optimization and field application of a filter pack system for the simultaneous collection of atmospheric gas-phase HN03, NH3 and S02 have been studied. A Teflon prefilter was used to remove particulate matter. Nylon filter, oxalic-acid-treated Whatman 41 filter and sodium-carbonate-treated Whatman 41 filter were used for the collection of HN03, NH3 and S02, respectively. For the collection of gas-phase HN03, nylon filters had better efficiency and capacity as compared to NaCl-impregnated Whatman 41 filters for long sampling periods of more than 30 h. All treated filters and nylon filters worked with the collection efficiencies of greater than 95%. About 2% of the gas-phase ammonia has been retained by the nylon filters during simultaneous collection experiments done in the laboratory but the retained ammonia on the nylon filter sometimes reached to about 25% of the gaseous total ammonia collected on the oxalic-acid-impregnated filter in the field experiments. Other than ammonia no significant retention or volatilization from the filter pack system was observed during the simultaneous experiments carried out in an urban atmosphere.

Study of Trace and Heavy Metals in Rural and Urban Aerosols of Uludağ and Bursa (Turkey)

The concentrations of heavy, trace elements and major ions measuredin the Uludağ and Bursa aerosols were investigated to assess size distributions, spatial and temporal variability, sources and source regions affecting the composition of aerosols in Uludağ and Bursa. A total of 81 samples were collected in two sites, one in Bursa city and another in the Uludağ Mountain during two sampling campaigns. Daily samples were collected using a high volume sampler on Whatman 41 cellulose filters in Uludağ, while three days interval samples were collected in Bursa using an automatic dichotomous sampler on PTFE Teflon filters. Samples were analysed for 15 trace and heavy metals (Al, Fe, Ba, Na, Mg, K, Mn, Ca, Cu), (V, Pb, Cd, Cr, Ni, Zn), and 4 major ions (SO42-, NO3-, Cl-), (NH4+) using ICP-AES, GFAAS, HPLC and UV/VIS Spectrophotometer,respectively. In general, concentrations of the metals measured inUludağ aerosols were lower than those in Bursa. The concentrations of crustal elements were higher in summer than winter, while anthropogenic elements had higher concentrations in winter than summer. Most of the mass of crustal elements was concentrated in the coarse mode while the mass of the heavy metals was concentrated in the fine mode. Factor analysis revealed four factors with sources including crustal, industrial and combustion. Back trajectory calculations were used to determine long range contributions. These calculations showed that contributions were mostly from European countries, former Soviet Union countries, Black Sea and North Africa.

Determination of metal concentrations in lichen samples by inductively coupled plasma atomic emission spectroscopy technique after applying different digestion procedures

Three digestion procedures have been tested on lichen samples for application in the determination of major, minor and trace elements (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, V and Zn) in lichen samples collected in Aegean Region of Turkey by inductively coupled plasma atomic emission spectrometer (ICP-AES). The acid mixture of concentrated HNO(3), H(2)O(2) and HF were used. The instrument was optimized using lichen matrix considering RF power, nebulizer pressure, auxiliary flow rate and pump rate. The accuracy of the overall analyses was first estimated by analysis of two certified reference materials. Good agreement between measured and reference values were found for almost all elements. As the second way of determining the accuracy, results obtained from independent analytical techniques (ICP-AES and instrumental neutron activation analysis (INAA)) were compared for all elements by analyzing real samples. Correlation coefficients of two techniques for the elements ranged between 0.70 (Mg) and 0.96 (Fe). Among the three digestion systems, namely microwave, open vessel and acid bomb, microwave digestion system gave the best recovery results. The method detection limit (MDL) was computed using reagent blanks of microwave digestion system since it provides cleaner sample preparation. Detection limit is adequate for all elements to determine the elements in lichen samples. The precision was assessed from the replicate analyses of reagent blanks of microwave digestion system and was found to be less than 1.5% relative standard deviation (R.S.D.).

Chemical characteristics of atmospheric aerosols in a rural site of northwestern Anatolia

Abstract Aerosol samples were collected daily at a rural mountainous site of northwestern Anatolia during September 1993–April 1994. Concentrations of SO 4 2− , NO 3 − , Cl −1 , NH 4 + , Na + , K + , Ca 2+ and Mg 2+ have been determined. Sulfate made up the 30% analyzed aerosol mass with a 2.14 μm −3 average concentration. Measured concentrations were comparable with other rural area data except Ca 2+ which was higher in our station with an average concentration of 1.12 μg m −3 Monthly concentrations of major ions fluctuate depending on meteorological factors, seasons and source strengths. Saharan dust storms affected the sampling site especially in autumn and spring seasons. Wind sector analysis indicated that the most important source regions were located both to the south and north of the station. However, air masses from southerly direction at which a power plant is located have been concluded to bring the greatest amount of anthropogenic pollutants to the sampling site.

Sources and Wet Deposition Fluxes of Polycyclic Aromatic Hydrocarbons (PAHs) in an Urban Site 1000 Meters High in Central Anatolia (Turkey)

Wet-only precipitation samples were collected using an Andersen wet only sampler (Andersen Samplers, Inc., Atlanta, GA, USA), between December 2000 and June 2002, in Ankara, Turkey. Polycyclic aromatic hydrocarbons (PAHs) were first pre-concentrated using solid phase (SPE) and ultrasonic extraction procedures. They were then analyzed using gas chromatography–mass spectrometry (GC–MS). Phenanthrene (Phe), fluoranthene (Flt), benzo (b+k) fluoranthene (B (b+k) F) and pyrene (Pyr) were the major components of ∑ 14PAH concentrations during both winter and summer seasons. Concentrations of PAHs did not show a statistically significant relation with meteorological parameters, such as mixing height, wind speed, and wind direction. However, they showed a strong linear relation with the ventilation coefficient (VC), signifying the importance of local sources on measured PAH concentrations. Concentrations of PAHs in winter season were higher than their corresponding concentrations in summer season due to seasonal variations in meteorology and emissions. Sources of PAHs in rainwater were apportioned using principal component analysis. Three factors with eigenvalues > 1.0 were extracted. The two factors that explained the largest fraction of system variance represented coal and gas combustion whereas the third factor represented motor vehicles. Half of the rain events accounted for approximately 90% of the wet deposition fluxes of PAHs, demonstrating the highly episodic nature of wet PAH deposition.

Inhalation and dermal exposure to atmospheric polycyclic aromatic hydrocarbons and associated carcinogenic risks in a relatively small city.

The aim of this study was to conduct a carcinogenic risk assessment for exposure to polycyclic aromatic hydrocarbons (PAHs) via routes of inhalation and dermal contact. Concentrations of 19 PAH species were determined during a heating period at a site in the city of Balikesir, Turkey. Two questionnaires were administered to a sample of inhabitants to determine time-activity budgets and demographic information. The assessment was conducted for each participant and Balikesir population by deterministic and probabilistic approaches, respectively. Monte Carlo simulation was implemented to determine the population exposure-risk probability distributions. The estimates were based on benzo[a]pyrene equivalent (BaPeq) total PAH concentrations calculated using toxic equivalency factors. The mean and median BaPeq concentrations of gaseous and particulate phases were 3.25 and 1.34, and 38.5 and 34.0ng/m(3), respectively. Carcinogenic risk for inhalation exposure route was estimated by using two different slope factor values (3.9 and 304.5(mg/kg-day)(-1)), recommended by two different organizations, resulting in two (order(s) of magnitude apart) population risk ranges: 1.32×10(-7)-2.23×10(-4), and 1.61×10(-5)-7.95×10(-3), respectively. The population risks associated with dermal exposure were lower compared to those of inhalation, ranging from 6.58×10(-9) to 2.57×10(-6). The proportion of the population with risks higher than the general acceptable level (1.0×10(-6)) was estimated as >99 percent, for inhalation, and as 28 percent for dermal exposure route.