Barbieri Pietro Gino, Somigliana Anna, Girelli Roberto, Lombardi Sandra, Sarnico Michela, Silvestri Stefano
nessuna.
Med Lav. 2016 Mar 24;107(2):141-7.
Malignant mesothelioma cases among primary school teachers are usually linked with asbestos exposure due to the mineral contained in the building structure. Among the approximately 12,000 cases of mesothelioma described in the fourth report of the National Mesothelioma Register, 11 cases of primary school teachers are reported, in spite of the fact that the "catalogue of asbestos use" does not describe circumstances of asbestos exposure other than or different to that due to asbestos contained in the buildings. Four cases in the Brescia Provincial Mesothelioma Register are identified as teachers, without this circumstance of exposure.
To characterize the asbestos concentration and fibre type retained in the lungs of a teacher reported as a new mesothelioma case and preliminarily classified as of unknown asbestos exposure.
The mesothelioma case presented here was diagnosed at age 78 and malignant mesothelioma was confirmed at autopsy; the patient was interviewed directly for occupational history. Samples of lung parenchyma from necropsies were collected, stored and analyzed by scanning electron microscope (SEM) and samples of DAS paste were analyzed by SEM to detect asbestos fibre content.
It was possible to confirm past exposure to DAS paste in forming and finishing dry items and toys during school recreational activity almost every day from the mid-60s to about the mid-70s. Subsequent SEM analysis showed: i) chrysotile fibres were found in an old and unused pack of DAS paste; ii) a lung burden of 1,400 asbestos bodies, 310.000 total asbestos fibres (33% chrysotile, 67% amphibole) and 210.000 talc fibre per gr/dry lung tissue was detected from necropsies performed on the subject. These results seem to be in agreement with an occupational exposure to asbestos due to past use of DAS paste. After the investigation, this case was reclassified from "unknowun" to " sure" occupational asbestos exposure. The occupational origin of the tumour was recognized by the Italian Workers' Compensation Authority (INAIL).
This case suggests i) the need to carry out any possible detailed studies of the circumstances and exposure sources whenever any mesothelioma case is classified as "asbestos exposure unknown", according to the guidelines of the National Mesothelioma Register, ii) handling of DAS paste can be considered as sure asbestos exposure and iii) it should be borne in mind that mesothelioma cases can occur even after cumulative low, occupational exposure, even only to chrysotile.
小学教师中的恶性间皮瘤病例通常与建筑结构中所含矿物质导致的石棉暴露有关。在国家间皮瘤登记处的第四次报告中描述的约12000例间皮瘤病例中，报告了11例小学教师病例，尽管“石棉使用目录”并未描述除建筑物中所含石棉之外或与之不同的石棉暴露情况。布雷西亚省间皮瘤登记处有4例被确定为教师，但不存在这种暴露情况。
对一名被报告为新的间皮瘤病例且初步分类为石棉暴露不明的教师肺部留存的石棉浓度和纤维类型进行特征描述。
此处呈现的间皮瘤病例在78岁时被诊断出，尸检时确诊为恶性间皮瘤；直接对患者进行职业史访谈。从尸检中采集肺实质样本，储存后通过扫描电子显微镜（SEM）进行分析，并对DAS糊剂样本进行SEM分析以检测石棉纤维含量。
有可能证实该患者在60年代中期至70年代中期期间，几乎每天在学校娱乐活动中参与干燥物品和玩具的成型及修整过程时接触过DAS糊剂。随后的SEM分析显示：i）在一包旧的、未使用的DAS糊剂中发现了温石棉纤维；ii）从对该受试者进行的尸检中检测到，每克干燥肺组织中有1400个石棉小体、310000根总石棉纤维（33%为温石棉，67%为闪石类石棉）以及210000根滑石纤维。这些结果似乎与过去使用DAS糊剂导致的职业性石棉暴露相符。调查后，该病例从“不明”重新分类为“确定”职业性石棉暴露。意大利工伤赔偿管理局（INAIL）认可了该肿瘤的职业起源。
该病例表明：i）根据国家间皮瘤登记处的指导方针，每当任何间皮瘤病例被分类为“石棉暴露不明”时，都需要对情况和暴露源进行尽可能详细的研究；ii）接触DAS糊剂可被视为确定的石棉暴露；iii）应牢记，即使是累积的低剂量职业暴露，即使仅接触温石棉，也可能发生间皮瘤病例。
