Suchergebnisse

Abstract
Assessment of nanoparticle exposure is not an established routine among occupational hygienists. One of the discussions is about methods of quantification, if we should use number concentration, surface concentration or mass concentration for assessment, this is however also influenced by the access to proper measurement equipment. In this paper we discuss five available methods for exposure assessment. One is the Discmini from Testo, which has the advantage that it could be used for personal measurements, but on the other hand has some limitation according to measurement principles; used for Chimney sweepers. Another is the Nanoscan SMPS from TSI, which not is portable for personal measurements, but still is battery operated and could be moved around at a workplace, Nanoscan SMPS measure particle size distribution; this instrument have been used for logbook measurements among Ferrosilicon alloy workers. Number three is the Scanning Mobility Particle Sizer and the Fast mobility particle sizers from TSI , which is large, power demanding and only useable for stationary measurements, but on the other hand highly demandable for quantification. Number four is the Fast Mobility Particle Sizer, also from TSI, with the advantage of 1 second measurements, used in Ferroalloy industry and among Fire fighters. The fifth is the ELPI instrument from Dekati, which enable collection of samples for subsequent analysis on electron microscope, used in Ferroalloy industry. In this poster we compare type of results and discuss the advantages and disadvantages with the different methods and how useful they are for exposure assessment.

Abstract
Occupational exposure concentrations are routinely collected using gravimetric samples. However, gravimetric samples typically require a long sampling time, especially when there are low exposure concentrations. While long sampling time may be appropriate to verify compliance with 8-h occupational limit values (OELs), they cannot address exposure's temporal and spatial heterogeneity or provide information on peak exposures present in the work environment. Real-time light scattering sensors enable the possibility of collecting high-resolution, low-cost measurements, quickly identifying peak and short-term concentrations, linking exposure to emission sources, and better understanding within-day variation. These technologies have become increasingly popular also for occupational monitoring purposes. In this presentation, the results of the dust samples collected for a randomized double-blinded controlled human exposure chamber study are presented. In six groups, 24 healthy volunteers were exposed to two common stone minerals, quartz diorite, and rhomb porphyry, in 4-h exposure sessions. To control the exposure in the chamber, personal gravimetric samples of respirable dust and stationary gravimetric samples of total dust, PM2.5, and respiratory dust were collected. Additionally, stationary real-time samples of total dust, respirable dust, PM10, PM2.5, and PM1 were collected continuously using DustTrak TSI model DRX 8533. Despite the many advantages of the real-time sensors, evaluating compliance with OELs should be done with caution. Except for the PM2.5 fraction, a significant difference was observed between the gravimetric and the DustTrak samples. While the DustTrak overestimated the PM2.5 concentrations, the total dust concatenations were underestimated by a factor of almost two compared to the gravimetric samples.