生物因素所致职业病.ppt

What is the route of exposure? 吸入 inhalation 胃肠道 ingestion Assessment of probability of causation: lung cancer The evaluation is dependent on whether the subject has asbestosis（石棉肺）. If asbestosis is present If asbestosis is not present If asbestosis is present the assessment of probability of causation can be relatively simple, since the association between asbestosis and lung cancer is strong and unequivocal. If a diagnosis of asbestosis is established, no quantitative estimate of exposure is required: epidemiological evidence shows that if asbestosis is present the relative risk (RR) of lung cancer from asbestos exposure is well above 2, so that the probability of causation (PC) can be confidently assessed as above 50% whenever asbestosis is present. Furthermore this judgement can be made irrespective of smoking history. If asbestosis is not present In the absence of asbestosis, and if asbestosis is held not to be a precondition for asbestos related lung cancer (either by statute or on the basis of evidence presented), the probability of causation is contingent on the following: Asbestos exposure history Lung fibre count: a level of 5 million fibres/g of dry lung Time since exposure: It is widely assumed that excess risk of lung cancer will not occur within 10 years of initial exposure to asbestos. Smoking history: multiplicative relationship Assessment of probability of causation: mesothelioma间皮瘤 Unlike lung cancer, however, there is no need to consider whether asbestosis is present, since mesothelioma has been reported at exposures well below levels likely to cause asbestosis, and in most cases asbestosis is not present. The latency period from first exposure is long — up to 40 years or even more being quite common. The species of asbestos. The risk of mesothelioma from chrysotile(温石棉)is estimated to be 1/50th of comparable exposure to crocidolite(青石棉). 职业性皮肤癌 Occupational Skin Cancer 砷 Arsenic,煤焦油 coal tars,矿物油类mineral oils 苯并[a]芘 BENZ