Fibre exposure

Relatively minimal information is available on cancers associated with fibre exposure. Lechner etal. (1997) summarised these carcinogenesis mechanisms with primary emphasis on the alterations described in human mesotheliomas. Of the known changes, the most frequent are in the tumour-suppressor genes (Kratzke etal. 

Wagner (1997) stressed that the majority of mesotheliomas occurred after prolonged exposure to large quantities of fibre, a situation rarely existing today, and that at least 10 % of these diffuse mesotheliomas occurred without exposure to asbestos dust. Some were reported before the widespread use of asbestos. Peterson et al. (1984) and Pelnar (1988) reviewed mesotheliomas of other causes than asbestos exposure. However, it has not been possible to make a realistic estimate of the frequency of mesotheliomas which are not due to fibre exposure because, in Western countries, everyone is exposed to some fibres and these fibres will be found in the lung at autopsy whether they are the cause of the mesothelioma or not (Elmes 1994). 

J. Bignon, J. Peto, and R. Saracci, eds., Monoccupational Exposure to Mineral Fibres, lARCC Scientific PubHcation No. 90, International Agency for Research on Cancer, Lyon, Prance, 1989. 

The PE fibres are produced by melt spinning a novolak resin of molecular weight ca 1000 and then cross-linking the molecules by exposure to gaseous formaldehyde at 100-150°C for 6-8 h or with a formaldehyde solution. The fibres were introduced under the tradename Kynol by American Kynol Inc., a subsidiary of Carborundum AG. 

The poor stability on exposure to air and water, particularly at elevated temperatures, which results in a reduction in conductivity, also poses problems. In the case of polypyrrole it has been found that conductivity can, however, be maintained either by the drastic measure of storing under the protective layer of the inert gas argon or embedding polypyrrole film in a matrix of an epoxide resin-glass-fibre composite. 

Carbon disulphide control of exposure m the viscose industry Man-made mineral fibres... 

Control limits Maximum exposures to dust levels are set by control limits, (refer to Table 4.34). These are expressed as fibres per millilitre, measured or averaged over 4h[s or 10 min ... 

Brown, G.M., Li, X.Y. and Donaldson, K. (1991a). Secretion of interleukin 1 and tumour necrosis fector by alveolar macrophages following exposure to particulate and fibrous dusts. In Mechanisms in Fibre Carcint nesis (eds. R.C. Brown, J.A. Hoskins and N.F. Johnson) pp. 499-504. Plenum, New York. 

The most popular and efficient are substantive to the fibre typical examples are N,N -diphenylacetamidine (10.179), which tends to yellow on exposure to oxides of nitrogen, and particularly the diphenylated diamines such as N.N -diphenylethylenediamine (10.180), which does not yellow. Non-substantive inhibitors applied by padding and drying, such as triethanolamine (10.126) and melamine (10.181), have also been used despite the fact that they are removed on washing. The demand for and commercial availability of gas-fume inhibitors have declined. 

Donaldson, K., Tran, L., Jimenez, L.A., DufEn, R., Newby, D.E., Mills, N., MacNee, W and Stone, V. (2005) Combustion-derived nanoparticles areview of their toxicology following inhalation exposure. Particle and Fibre Toxicology (2), 10. 

Oberdorster, G. et al. (2005) Principles for characterizing the potential human health effects from exposure to nanomaterials elements of a screening strategy. Particle and Fibre Toxicology, 2 (1), 8. 

Deposition of sensor layers is possible on fibre Flow-through cell allowing the optics, planar waveguides, and test strips simultaneous exposure of the membrane to... 

Batcheller et al. also discuss the influence of the dyeing process on the composition of the fibre s surface. They note that high alkalinity/acidity and extended processing time result in loss of surface lipid. Nevertheless, the dyeing process has limited influence on the ageing process due to light exposure. 

The volatile substances were extracted from portions of 0. lg hair using solid-phase micro extraction (SPME). The method uses a fibre coated with an adsorbent that can extract organic compounds from the headspace above the sample. Extracted compounds are desorbed upon exposure of the SPME fibre in the heated injector port of a gas chromatograph (GC). 

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