RESPIRABLE FIBERS - SURFACTANT COATED FIBERS RELEASE MORE FE3+ THAN NATIVE FIBERS AT BOTH PH 4.5 AND 7.2

Exposure to asbestos is associated with several lung diseases, The car cinogenic action of asbestos is not fully understood but oxidative str ess is considered to play a role, Iron on the surface can lead to Fent on chemistry and the Haber Weiss reaction producing free radicals such as the hydroxyl radical, which is likely to be important. Little is k nown of the pathogenic action of manmade fibres, This study involved t he use of a panel of man-made fibres, some of which Here shown to be p athogenic and others shown to be non-pathogenic in recent animal studi es, A short term assay measuring Fe3+ release from the fibres over a 2 0 hour time period, and also a longer study of 12 weeks, found that pa thogenic and non-pathogenic fibres could not be differentiated accordi ng to Fe3+ release only, Iron release from native fibres was compared with that from surfactant-coated fibres, and in all cases surfactant c oated fibres released more Fe3+ inferring that in vivo lung lining flu id coats native fibres and therefore affects the fibre surface chemist ry and hence reactivity, (C) 1998 Published by Elsevier Science Ltd on behalf of British Occupational Hygiene Society.