DeMeyer C L, Whitehead L W, Jacobson A P, Brown D G
Med Phys. 1986 Sep-Oct;13(5):748-50. doi: 10.1118/1.595841.
The shielding-block fabrication areas of three hospitals were surveyed to assess inhalation exposure to lead (Pb), cadmium (Cd), bismuth (Bi), and tin (Sn) fumes, as well as styrene and methyl chloride vapors. Area and personal breathing zone samples were collected for various steps in the block fabrication process. Only 3 of 16 air samples for metals resulted in detectable levels of Pb and/or Cd. The levels were well below the Occupational Safety and Health Administration (OSHA) Permissible Exposure Limits, excluding a sample which contained a visible metal fragment. Bi and Sn were not detected in any samples. Methyl chloride and styrene vapors were not detected in any air samples during foam cutting procedures. Total particulates (TP) were measurable in 11 of 17 air samples (ranging from 0.01 to 2.1 mg/m3). TP values were below the OSHA federal standard for nuisance particulates, which is 15 mg/m3. The data suggest that the materials and procedures sampled do not present an inhalation hazard to employees who construct shielding blocks. Precautions should, however, be exercised to prevent exposure under extreme procedural conditions such as soldering or overheating of alloy, and by other means such as ingestion. Care should also be taken during cleanup or housekeeping to prevent re-entrainment into the work atmosphere of mechanically generated metal particles or materials condensed within melting pots (which may be high in metal content).
对三家医院的屏蔽块制造区域进行了调查，以评估铅（Pb）、镉（Cd）、铋（Bi）和锡（Sn）烟雾以及苯乙烯和氯甲烷蒸气的吸入暴露情况。在屏蔽块制造过程的各个步骤中采集了区域和个人呼吸带样本。16份金属空气样本中只有3份检测到了可检测水平的Pb和/或Cd。这些水平远低于职业安全与健康管理局（OSHA）的允许暴露限值，但包含可见金属碎片的样本除外。在任何样本中均未检测到Bi和Sn。在泡沫切割过程中，任何空气样本中均未检测到氯甲烷和苯乙烯蒸气。17份空气样本中有11份可测量到总颗粒物（TP）（范围为0.01至2.1毫克/立方米）。TP值低于OSHA关于 nuisance 颗粒物的联邦标准，即15毫克/立方米。数据表明，所采样的材料和程序不会对制造屏蔽块的员工造成吸入危害。然而，在极端程序条件下（如焊接或合金过热）以及通过其他方式（如摄入），应采取预防措施以防止暴露。在清理或清洁过程中也应小心，以防止机械产生的金属颗粒或在熔炉内冷凝的材料（可能金属含量很高）重新混入工作环境中。
