Corn M, Crump K, Farrar D B, Lee R J, McFee D R
Department of Environmental Health Sciences, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, Maryland 21205.
Regul Toxicol Pharmacol. 1991 Feb;13(1):99-114. doi: 10.1016/0273-2300(91)90044-v.
A total of 473 air samples from 71 schools scheduled for abatement (328 indoor static samples, 51 personal samples, and 94 outdoor samples) were analyzed by transmission electron microscopy techniques. Six measures of asbestos-in-air concentration were considered: (1) total asbestos structures per cubic centimeter: (2) chrysotile structures per cubic centimeter; (3) amphibole structures per cubic centimeter; (4) structures per cubic centimeter at least 0.5 micron long and at least five times wide; (5) structures per cubic centimeter at least 5 microns long; and (6) structures per cubic centimeter at least 5 microns long and at least 0.2 micron wide. The average concentration of chrysotile structures in indoor air samples was 0.017 structures/cm3; the average concentration of amphibole structures was 0.0015 structure/cm3. Ninety-five percent of structures found were chrysotile. The average concentrations of all structures were significantly higher indoors than outdoors (P less than 0.001). The average concentration of structures more than 5 microns long indoors was 0.00023 structure/cm3. None of the following factors were significantly correlated with asbestos concentrations in air: type of asbestos-containing materials (ACM) present, condition of ACM, accessibility of ACM to students, whether ACM were covered, air flow, or whether sweeping was noted during sample collection. In addition, asbestos-in-air concentrations were not significantly different in different types of schools (high, intermediate or elementary) or in schools constructed in different time periods. Lastly, there was no correlation between the mineral type of asbestos found in the air and the type found in samples of bulk material.
对计划进行石棉清除的71所学校的总共473个空气样本（328个室内静态样本、51个个人样本和94个室外样本）采用透射电子显微镜技术进行了分析。考虑了六项空气中石棉浓度的测量指标：（1）每立方厘米的石棉结构总数；（2）每立方厘米的温石棉结构数；（3）每立方厘米的闪石结构数；（4）每立方厘米长度至少0.5微米且宽度至少为长度五倍的结构数；（5）每立方厘米长度至少5微米的结构数；（6）每立方厘米长度至少5微米且宽度至少0.2微米的结构数。室内空气样本中温石棉结构的平均浓度为0.017个结构/立方厘米；闪石结构的平均浓度为0.0015个结构/立方厘米。所发现结构的95%为温石棉。所有结构的平均浓度在室内显著高于室外（P小于0.001）。室内长度超过5微米的结构的平均浓度为0.00023个结构/立方厘米。以下因素均与空气中的石棉浓度无显著相关性：存在的含石棉材料（ACM）类型、ACM的状况、学生接触ACM的难易程度、ACM是否被覆盖、气流或采样期间是否注意到清扫情况。此外，不同类型的学校（高中、初中或小学）或不同时期建造的学校，其空气中的石棉浓度无显著差异。最后，空气中发现的石棉矿物类型与散装材料样本中发现的类型之间没有相关性。
