Measurement campaigns of PM10 and its elemental composition covering different seasons were performed at two sites influenced by the main railway station of Zürich and at a site influenced by a very busy railway line with more than 700 trains per day. Daily samples were taken 10 m from the railway tracks. At the railway line in addition simultaneous samples were taken at 10 m, 36 m and 120 m distance from the tracks with the aim to study the distance dependence of the railway induced PM10 and iron concentrations.

In order to distinguish the railway emissions from the regional background, simultaneous samples were also taken at a near urban background site in Zürich. PM10 concentrations were found to be only moderately higher at the railway influenced sites compared to the urban background site. However, from the iron data it can be seen, that this increase is to a large extent caused by iron. This finding is in line with the expecta-tions, because the most plausible sources of the railway emissions are abrasion particles from tracks, brakes and wheels. It should be noted that in Switzerland trains are operated nearly exclusively by electric locomo-tives and consequently no diesel particle emissions from railways have to be considered.
The concentration differences between the railway exposed sites and the background site Zeughaus show that the railway contribution to the ambient concentrations of PM10 and iron was in the range of 1-2 ug/m3 and is decreasing quite rapidly with increasing distance from the railway tracks. It can thus be concluded that measurable exposition to PM10 caused by railway traffic occurs only in the immediate vicinity of very busy railway lines, consists mainly of iron in the coarse fraction and is quantitatively moderate.

Contact persons:

Robert Gehrig: Tel. ++4144 823 42 34

Nicolas Bukowiecki: Tel. ++4144 823 46 02

Peter Lienemann: Tel. ++4144 823 42 31