Linnainmaa M, Kangas J, Kalliokoski P
Finnish Institute of Occupational Health, Kuopio, Finland.
Am Ind Hyg Assoc J. 1996 Feb;57(2):196-201. doi: 10.1080/15428119691015142.
This study evaluated the exposure of Finnish workers to airborne metals. It was conducted in 16 workplaces; 8 tool manufacturing companies (3 of which specialize in the maintenance of hard metal blades) and 8 blade repair shops in the mechanical wood-processing industry. The main emphasis of the study was on exposure in servicing (resharpening), especially involving wet-tip grinding processes. The results show that workers grinding hard metal blades may be exposed to high levels of airborne cobalt even when airborne total dust concentrations are low. The respirable proportion of the total dust was found to be high, and the total dust concentrations correlated well with the cobalt concentrations. Most of the airborne cobalt was water soluble (ionized), but there was also solid particles containing cobalt and other materials in the air of the workplaces. The mean concentration of cobalt in the grinding coolants was high, though it varied considerably. Concentrations of all the other metals measured in the air (tungsten, chromium, cadmium, silver, and nickel) and in the coolants (tungsten and chromium) were low. To reduce workers' exposure to cobalt, it is recommended that grinding machines should be enclosed and equipped with local exhausts. Use of coolants that dissolve less cobalt is also recommended, and the coolants should be changed more often. Brazing should be done in a well-ventilated place, and only cadmium-free materials should be used.
本研究评估了芬兰工人接触空气中金属的情况。研究在16个工作场所进行，其中包括8家工具制造公司（其中3家专门从事硬质合金刀片的维修）以及机械木材加工行业的8家刀片修理店。该研究的重点是维修（再打磨）过程中的接触情况，特别是涉及湿磨尖工艺的情况。结果表明，即使空气中总粉尘浓度较低，研磨硬质合金刀片的工人仍可能接触到高浓度的空气中钴。发现总粉尘的可吸入比例较高，且总粉尘浓度与钴浓度密切相关。空气中的大部分钴是水溶性的（离子化的），但工作场所空气中也存在含钴和其他物质的固体颗粒。研磨冷却液中的钴平均浓度较高，不过差异很大。在空气中测量的所有其他金属（钨、铬、镉、银和镍）以及冷却液中（钨和铬）的浓度都很低。为减少工人接触钴，建议将研磨机封闭并配备局部排气装置。还建议使用钴溶解度较低的冷却液，并且应更频繁地更换冷却液。钎焊应在通风良好的地方进行，并且只应使用无镉材料。
