Inventory and Emission Factors of Creosote, Polycyclic Aromatic Hydrocarbons (PAH), and Phenols from Railroad Ties Treated with Creosote

Abstract

Inventory, emission factors, and total yearly emissions of creosote, PAH, and phenols from the Swiss railway network were determined based on the analysis of cross sections of selected railroad ties which were in use for up to 46 years. Approximately 9 million wooden railroad ties are installed in Switzerland, each being treated with roughly 15 kg of creosote. During the service time of a typical railroad tie of 20−30 years, about 5 kg of creosote are emitted, corresponding to an emission factor of 208 mg/(m2 × day). PAH emissions occur as emissions of the volatile 2- and 3-ring PAH (such as naphthalene, acenaphthylene, acenaphthene, anthracene, fluorene, phenanthrene; boiling point up to 340 °C). PAH emissions for an average railroad 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 determined to be in the range of 10 g for each tie, corresponding to an emission factor of 0.58 mg/(m2 × day). According to our study, about 1710 t of creosote components are being emitted by the ties of the Swiss railway network, every year. Based on the values reported above, yearly emissions of 2- and 3-ring EPA-PAH add up to 139 t. Cumulated emissions of phenolic compounds are in the order of 4 t per year.

Determination of Benzo[a]pyrene, Benz[a]anthracene and Dibenz[a,h]anthracene in Creosotes and Creosote-Treated Woods

“…Some groups have reported that mechanical shaking and liquid extraction methods are also useful, as is Soxhlet extraction. 13,15,18,21,22) Our group also previously confirmed the usefulness of soak-extraction for the analysis of wood samples. 9) Sonication is thought to enable the rapid extraction of PAHs.…”

“…15,18,21) Here, target PAHs were separated by a solid phase extraction approach using Sep-Pak Plus silica-cartridges. A PAH standard solution (10-20 µg in 0.1 ml) was loaded onto the cartridge, and then was eluted with 10 ml of dichloromethane.…”

“…The PAH profiles regarding the constituents and levels of creosotes in Japan were similar to those for the old type of creosotes used in the EU. 17,18) Improved creosotes, i.e., those in which BaP amounts were reduced by the fractionation of lower boiling-temperature components, were used for the construction of wooden railroad ties in Switzerland. 18) Among the creosotes examined, both samples No.…”

“…A GC system equipped with a capillary column and mass selective-ion-monitoring (SIM) is useful for detecting each chemical selectively and provides sufficient separation for the quantification of the PAHs in a complex. [15][16][17][18][19][20][21][22] Therefore, we used GC-mass spectrometry (GC-MS) for the determination of PAHs in creosotes. With our previous method, the sensitivity of detection was low with respect to the determination of 3-10 µg/g of PAHs in creosote and creosote-treated wood products, 9) and a long period of time was required for GC-MS analysis, i.e., more than 30 min per sample.…”

Functional and transcriptional analyses of the initial oxygenase genes for acenaphthene degradation from Sphingomonas sp. strain A4

“…Acenaphthene, a PAH that possesses a single alicyclic five-membered ring sharing three carbon atoms with two aromatic rings, is an abundant constituent of coal tar and creosote (Wise et al, 1988). Commercial creosotes contain 0?95-6?1 % (w/w) acenaphthene (Kohler et al, 2000). Nevertheless, the biodegradation of the compound has been poorly studied, especially in terms of bacterial catabolic genes.…”