Fiber analysis in human lungs: usefulness and limitations
It is often necessary to assess past exposures to asbestos for clinical, epidemiological, occupational health or even legal purposes. The difficulties and uncertainties associated with the assessment of occupational or environmental fiber exposures from occupational histories, job exposure matrixes or calculations from specific exposure databases have led to investigate the capabilities of mineralogical analysis. It relies on the demonstration by light or electron microscopy of elevated levels of asbestos bodies or fibres within lung samples (lung tissue, bronchoalveolar lavage fluid, sputum) as indicators of exposure. Relevant data are sought about the fiber type(s) present (identification), their amount(s) (quantification), their sizes, composition and crystalline structure (characterization) and about their association with lesions (importance as aetiological agent). As the purpose is to assess the fiber burden retained in the lungs at the time of sampling, the measured levels integrate both phenomena of lung deposition and clearance. Technical aspects of fiber analysis were extensively reviewed by a workgroup of the European Respiratory Society and several papers report rules to interpret results (1-5). For reliable interpretation of quantitative results it is crucial that standardized methodologies are used and that comparisons can be made to an adequate reference population analysed by the same laboratory. Several European and American laboratories consider that concentrations exceeding the following values are indicative of nontrivial exposure to asbestos: 1 AB/ml in BAL fluid, 1000 AB/g dry lung tissue, 1 106 amphibole fibres longer than 1μm/g dry lung tissue and 0.1 106 amphibole fibres longer than 5 μm/g dry lung tissue. These levels are seldom exceeded in lifetime white-collar workers.
Pascal Dumortier
Erasme Hospital Chest Department -Laboratory of Mineralogy Route de Lennik, 808
国际会议
北京
英文
71-73
2008-10-29（万方平台首次上网日期，不代表论文的发表时间）