Summary
The suitability of radioallergosorbent test (RAST) inhibition to quantify occupational exposure to rat urinary aeroallergen (RUA) has been assessed. When using a constant pool of rat allergic ...sera, the reproducibility of the assay over 1 year was comparable to that reported for other immunoassays; at 50% RAST inhibition the inter‐assay coefficient of variation (CV) was 7.0% and the intra‐assay CV was 3.0%. The assay was highly specific for rat urine; mouse urine was 1100‐fold less potent at inhibiting the rat urine RAST system. Significant inter‐assay variation in the ‘high’ control was not due to batch variation and was relatively small when compared with the variation in RUA concentrations in the occupational environment. Measurement of workplace RUA exposure demonstrated that those directly involved in the care of rats experienced the highest RUA exposure of the nine occupational groups studied (animal technicians GM = 23.10/μg/m3) followed in decreasing order by those working with soiled litter (e.g. cage cleaners GM = 4.20 μg/m3), dead animals (e.g. post mortem GM = 1.60 μg/m3, scientists GM = 0.67 μg/m3) and rat tissue (e.g. slide production GM = 0.04μg/m3). In view of the complexity of rat allergens, RAST inhibition is an appropriate method for the quantification of occupational exposure to rats.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
As part of an epidemiological study among workers exposed to flour total dust and flour aeroallergen concentrations were measured with personal samplers over a workshift in three large bakeries and ...four flour mills and packing stations. In the bakeries geometric means for total dust concentrations ranged from 0.4 mg/m3 in the bread wrapping area up to 6.4 mg/m3 at the dough brake. The flour aeroallergen concentrations ranged from 45.5 micrograms/m3 in the bread wrapping area up to 252.0 micrograms/m3 in the confectionary area. In the flour mills and packing stations the concentrations were higher with geometric means for total dust ranging from 0.5 mg/m3 in the office up to 16.9 mg/m3 for hygiene workers in an old mill. The flour aeroallergen concentrations ranged from 101.5 micrograms/m3 for transport workers up to 1728.2 micrograms/m3 for hygiene workers. The relation between total dust and flour aeroallergen concentrations varied for different areas and depended on the use of products other than flour.
This paper sets out to explain the vital role of an operations strategy in e-business. Suggests, through various research findings, that a firm can employ a number of operations strategies, and that ...they each possess certain core building blocks. Further, when properly combined, these strategies can be customised to a particular situation and offer substantial benefits for an organisation in driving e-business best practices. The paper gives definitions and descriptions of operations management, e-business, e-operations and an operations strategy for e-business. The work is also supported by empirical research data in the form of a small case study.
This paper presents a simple passenger dynamics model built to ascertain the minimum safe stopping distance of a Personal Rapid Transit vehicle carrying a seated but unrestrained passenger. The ...decelerations, under which the passengers would remain in their seats and unharmed, were determined using a simple one degree of freedom mathematical model of a single, seated passenger. The investigation found that the response of passenger depended heavily on their age and sex with an older female passenger being the most easily put in danger. The safe stopping distance had to account for the worst case scenario and the nature of the deceleration profile was crucial with optimum jerk and deceleration rates needing to be determined. These values were found and an "optimum" deceleration profile produced. Initial tests have occurred with encouraging results and development of the model combined with further testing is planned.
As part of a longitudinal study to explore the exposure-response relationship between flour dust exposure and work-related symptoms and skin sensitivity the authors formed exposure groups and ...estimated various components of variability. This paper describes the between-exposure group, the between-worker and the within-worker variation of personal flour dust exposure in bakeries, flour mills and packing stations. In total 346 samples were collected in 13 exposure groups. The geometric means of the exposure groups ranged from 0.3 up to 9.0 mg m-3. Between-worker variances within exposure groups were less than the overall between-worker component although substantial differences in exposure between workers remained in some exposure groups. Overall the largest variance component was the between-exposure group component followed by the considerably smaller between-worker and within-worker components.
As part of an epidemiological study amongst workers exposed to flour we measured peak exposure levels to total dust and flour aeroallergen with personal samplers in bakeries, flour mills and packing ...stations. Short-term tasks which were expected to give rise to high concentrations of exposure (peaks ) were identified . The frequency and duration of these tasks were estimated and their levels of exposure to dust and flour aeroallergen measured. In total 209 samples were taken. The highest exposure concentrations both for dust (geometric mean > 30 mgm-3) and for flour aeroallergen (geometric mean > 500 microgram m-3) were measured during certain operations. Exposure concentrations for the tasks were often much higher than the levels we had measured over a shift in a previous study. This might be important for sensitization and for the development of asthma. Peak exposure concentrations could be used to explore the exposure response relationship more comprehensively. In general average flour aeroallergen concentrations increased linearly with average dust concentrations, although there were some exceptions.
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