| Abstract
| - Inventory, emission factors, and total yearly emissions ofcreosote, PAH, and phenols from the Swiss railway networkwere determined based on the analysis of cross sectionsof selected railroad ties which were in use for up to 46years. Approximately 9 million wooden railroad tiesare installed in Switzerland, each being treated withroughly 15 kg of creosote. During the service time of atypical railroad tie of 20−30 years, about 5 kg of creosoteare emitted, corresponding to an emission factor of 208 mg/(m2 × day). PAH emissions occur as emissions of the volatile2- and 3-ring PAH (such as naphthalene, acenaphthylene,acenaphthene, anthracene, fluorene, phenanthrene;boiling point up to 340 °C). PAH emissions for an averagerailroad tie were found to be about 0.5 kg (sum of 16 EPA-PAH), corresponding to an emission factor of 20.3 mg/(m2 ×day). Emissions of phenolic compounds were determinedto be in the range of 10 g for each tie, corresponding to anemission factor of 0.58 mg/(m2 × day). According to ourstudy, about 1710 t of creosote components are being emittedby the ties of the Swiss railway network, every year.Based on the values reported above, yearly emissions of2- and 3-ring EPA-PAH add up to 139 t. Cumulated emissionsof phenolic compounds are in the order of 4 t per year.
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