Determination of real-world emission factors of trace metals, EC, OC, BTEX, and semivolatile organic compounds (PAHs, PCBs and PCNs) in a rural tunnel in Bilecik, Turkey.

A field study was performed in a rural tunnel to determine pollutant concentrations, sources and on road vehicle emission factors (EFs) of particulate matter, trace metals, elemental carbon (EC), organic carbon (OC), benzene, toluene, ethyl benzene and xylenes (BTEX), and polycyclic aromatic hydrocarbons (PAHs). Emission factors (EFs) for polychlorinated naphthalenes (PCNs) and polychlorinated biphenyls (PCBs) were also determined. A 12-day extensive sampling campaign during morning and afternoon periods at inlet and exit stations of the tunnel was conducted. Morphology of the particles was also investigated by Scanning Electron Microcopy (SEM). Correlation analysis, factor analysis and diagnostic PAH ratios were utilized to identify emission sources of trace metals. Identified sources include brake wear (33%), resuspension of road dust (15%), tyre wear (12%), exhaust emissions (10%), and lubricants (9%). Based on the PAH diagnostic ratios, major sources of PAHs were estimated as diesel emissions. EFs were comparable with the literature and varied from 31.5 to 295.4 mg vehicle-1 km-1 with an average of 129.2 ±â€¯80 mg vehicle-1 km-1 for PM2.5. PM2.5-10 EFs varied between 15.9 and 236.1 mg vehicle-1 km-1 with an average of 96 ±â€¯30 mg vehicle-1 km-1. Average EC EFs were 40.3 ±â€¯9.8 mg vehicle-1 km-1 for PM2.5 samples and 19.5 ±â€¯0.5 mg vehicle-1 km-1 for PM2.5-10 samples while OC EFs were 33.7 ±â€¯18 and 15.5 ±â€¯8.4 mg vehicle-1 km-1 for fine and coarse particles, respectively. EFs of elements were generally 2 (Al) to 59 (Mg) times higher than those previously reported in the literature. Compared to literature, relatively higher EFs for Σ13PAHs (range: 48.1-168 µg vehicle-1 km-1, average: 84.3 ±â€¯46.4 µg vehicle-1 km-1) were obtained. BTEX emission factors were in the range of 4.2 ±â€¯4.7 mg vehicle-1 km-1 (m + p-xylene) and 16.7 ±â€¯10.5 mg vehicle-1 km-1 (toluene). Average EFs for ΣPCBs and ΣPCNs were 12.06 ±â€¯5.3 µg vehicle-1 km-1 and 88.9 ±â€¯70.4 ng vehicle-1 km-1, respectively.

Evaluation of air quality by passive and active sampling in an urban city in Turkey: current status and spatial analysis of air pollution exposure.

Concentrations of air pollutants, nitrogen dioxide (NO(2)), sulfur dioxide (SO(2)), ozone (O(3)), particulate matter (PM(2.5) and PM(10)), trace metals, and polycyclic aromatic hydrocarbons (PAHs) were measured in 2008 and 2009 in the city of Eskisehir, central Turkey. Spatial distributions of NO(2), SO(2), and ozone were determined by passive sampling campaigns carried out during two different seasons with fairly large spatial coverage. A basic population exposure assessment was carried out employing Geographical Information System techniques by combining population density maps with pollutant distribution maps of NO(2) and SO(2). It was found that 95 % of the population is exposed to NO(2) levels close to the World Health Organization guideline value. Regarding SO(2), a large proportion of the population (83 %) is exposed to levels above the WHO second interim target value. Concentrations of all the pollutants showed a seasonal pattern increasing in winter period, except for ozone having higher concentrations in summer season. Daily PM(10) and PM(2.5) concentrations exceeded European Union limit values almost every sampling day. Toxic fractions of the measured PAHs were calculated and approximately fourfold increase was observed in winter period. Copper, Pb, Sn, As, Cd, Zn, Sb, and Se were found to be moderately to highly enriched in PM(10) fraction, indicating anthropogenic input to those elements measured. Exposure assessment results indicate the need for action to reduce pollutant emissions especially in the city center. Passive sampling turns out to be a practical and economical tool for air quality assessment with large spatial coverage.