PAH-losses from glass fiber filters under the conditions of different air volume sampling: results of field evaluations in occupational atmospheres

Summary The estimation of the occupational medical and toxicological risks to workers exposed to PAH depends on sampling these compounds, some of which are carcinogenic, with as little loss as possible in the air of the working environment.A sampling system for the collection of air samples for PAH in field investigations consisting of a glass fiber filter followed by a suction pump has been tested for its efficiency at various suction rates using n=19 specially selected reference substances. The variability of the suction rate obtainable with the pump employed is to be regarded as being of particular significance.A total of 60 determinations made in areas devoted to the manufacture of artificial coal and at road paving operations revealed greatly reduced and pumping rate-dependent recoveries, i.e. correspondingly high losses. With an air throughput of 22 500 l/h an average of 47.8% of the total of 19 PAH was recovered on the glass fiber filter; when a suction pump with a throughput of 2840 l/h was employed 28% of the PAH was not collected and the losses amounted to 15% at a pumping rate of 120 l/h. The losses of 5 PAH compounds chosen for their carcinogenicity were of the same order of magnitude with ca. 51%, 22% and 11%.The influence of the number of rings in the PAH, i. e., its increasing boiling point, plays a decisive role in its recovery rate. Thus, when sampling at a throughput of 120 l/h, the recovery rates of various members of the 4, 5, 6 and 7-ring PAH systems were on average 77.1%, 88.4%, 95.6% and 99.1%, respectively.Glass fiber filters are not suitable for use as the sole collection phase for PAH air sampling, particularly when pumps having a high throughput are employed. A combination of filters as the collection phase for particulate PAH followed by adsorbent tubes of Tenax or XAD-2 for gaseous PAH must be regarded as necessary for the collection of representative samples for determination of the total concentration of polycyclic aromatics.

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PAH-Verluste an Glasfaserfiltern unter den Bedingungen der Probenahme bei unterschiedlichen Luftdurchsätzen: Ergebnisse von Feldauswertungen in Arbeitsbereichen

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Dedicated to Prof. Dr. G. Hesse on the occasion of his 80th birthday