To investigate fine particulate air pollution generated by public transport and its microenvironment, PM2.5 measurements and particle number counts for six particle size ranges (0.3–0.5 µm, >0.5–1.0 µm, >1.0–3.0 µm, >3.0– 5.0 µm, >5.0–10 µm and >10 µm) were obtained for four public transport modes: bus, metro–bus, car and walking. The measurements were repeated for each transport mode twice a day for 7–10 measurement days. The highest average PM2.5 concentration was measured inside a bus (106 µg/m3) during rush hours. The highest single peak measurement was a concentration of 316 µg/m3 for walking during non–rush hours. The PM2.5 level in a car with the air conditioning fan off was approximately 2.5 times lower than the level with the air conditioning fan on. Moderate correlations were found between PM2.5 concentrations and wind speed. Weak correlations were found between PM2.5 concentrations, relative humidity and temperature. The results showed that the diameters of most of the particles were smaller than 0.5 µm, regardless of the transport mode. The average fine particle number (size range 0.3–0.5) for all transport modes ranged from 54 647 to 209 746 particles/103 cm3 during rush hours and from 49 423 to 184 866 particles/103 cm3 during non–rush hours

An aerosol monitoring study was conducted to measure the fine particulate matter (PM2.5 and PM1) concentrations and composition in the urban area of Istanbul, the most populated city in the north–west of Turkey. The sampling station was located near the D–100 highway. The PARTISOL particulate matter sampler was used during the campaign and operated from 24 April 2009 to 24 May 2009 for PM2.5 and from 11 December 2009 to 9 April 2010 for PM1. Nineteen PM2.5 samples and 17 PM1 samples were collected. The glass fiber filters were weighed before and after sampling to obtain mass concentrations. Then X–ray fluorescence was used to measure the concentration of 23 elements (Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Cu, Zn, As, Rb, Sr, Y, Mo, Ba). PM2.5 concentration ranged between 23.8µg/m3 and 81.5µg/m3 and PM1 concentrations were between 7.6µg/m3 and 30.2µg/m3. As a result of the principal components analysis (PCA), PM2.5 metal emissions were dominated by significant anthropogenic sources, as expressed by high factor loadings in S, Cr, Zn, Cu and K. Crustal elements were likely related to first component (high loadings in Mg, Al, Ba and Si) for PM2.5 and third component for PM1