Annals of Occupational Hygiene Advance Access originally published online on July 20, 2006
Annals of Occupational Hygiene 2006 50(8):805-812; doi:10.1093/annhyg/mel048
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Collection, Validation and Generation of Bitumen Fumes for Inhalation Studies in Rats Part 2: Collection of Bitumen Fumes from Storage Tanks
Fraunhofer Institute Toxikology und Experimental Medicine (Fh-ITEM) Nikolai-Fuchs-Strasse 1, 30625 Hannover, Germany
*Author to whom correspondence should be addressed. Tel: +(49) 511 5350 116; fax: +(49) 511 5350 155; e-mail: pohlmann{at}item.fhg.de
Objectives: The objective of the study described in this and an accompanying series of papers was to develop a laboratory generated exposure atmosphere to be used for chronic inhalation toxicity studies in rats that resembles, as closely as possible, personal exposures seen by workers during road paving operations.
Methods: To achieve this objective, atmospheric workplace samples were collected at road paving worksites and compared analytically with bitumen fume samples collected from the headspace of hot bitumen storage tanks. In Preiss et al. (2006) the collection and analysis of workplaces samples is described. This contribution describes the strategy for the in-line extraction of a suitable fraction of bitumen fume collected from the headspace of a bitumen storage tank and the comparison of the collected condensate to workplace samples.
Results: Results show that is possible to develop a collecting procedure that allows sampling from hot bitumen storage tanks in an operational asphalt mixing plant. The sampling procedure has been optimized to collect material that matches the workplace samples as closely as possible. The comparison to workplace samples has been performed using parameters that can be analyzed in both the workplace samples and the bitumen fume condensate collected from the tanks. Boiling point distribution (BPD), UV fluorescence (UV-Fl) and content of individual polycyclic aromatic hydrocarbons (PAH) were selected as parameters. The BPD of the final collected bitumen fume condensate did not differ by more than 17°C from any point on the average BPD curve of the workplace samples, in the range from 5 to 95%. UV-Fl of the bitumen fume condensate nearly exactly matched the average UV-Fl of the workplace samples. However, the sum of the 17 PAHs analyzed in the test samples, compared to the mass of the condensate, is lower by a factor of
3 than the sum of the 17 PAHs in some personal samples compared to the mass of Total Organic Matter (TOM). It has to be recognised that during the collection of the workplace samples, despite all efforts a number of the workers who carried a personal sampler could not be prevented from smoking.
Keywords: asphalt bitumen fume workplace chemical analysis sampling methods polycyclic aromatic hydrocarbons