Kato Nobuyuki, Mastui Yasuto, Takaoka Masaki, Yoneda Minoru
Department of Environmental Engineering, Graduate School of Engineering, Kyoto University.
Agency for Health, Safety and Environment, Kyoto University.
J Occup Health. 2017 Nov 25;59(6):572-580. doi: 10.1539/joh.17-0008-FS. Epub 2017 Oct 7.
Nanoparticles (NPs), including hazardous substances, are generated in crematoriums due to the high temperatures during the combustion process. NPs are reported to greatly impact animals' health by reaching the alveoli and being carried to the entire body through the blood stream. However, studies in crematoriums have yet to assess workers' exposure to the generated NPs. The purpose of this study is to assess workers' exposure to NPs released in crematoriums.
Field surveys were conducted in three crematoriums with an emphasis on cremation, bone rearrangement and cleaning processes. The NP concentrations and size distributions were analyzed. The deposition of NPs in each respiratory region during each working process was calculated based on the measured data using the Human Respiratory Tract Model.
The mean particle number concentration was maximized momentarily during the bone rearrangement process. The concentration at the time a crematory's door was opened was 500,000 particle/cm. NPs aggregated to micro-sized particles within a few minutes, dust generated by the bone rearrangement, or both. As a result of model calculation, the mean ratios (alveolar per the other regions by a crematory) were approximately 3.0 (bronchus and bronchioles regions: except for the first survey in crematorium A which had the obstruction of measurement) and 4.3 (extrathoracic airways). The ratios were similar for all crematoriums.
These results can be used for health risk assessments in crematoriums. In addition, these results should be applicable to estimate the inhalation unit risk of each respiratory organ such as lungs and nose.
由于燃烧过程中的高温，火葬场会产生包括有害物质在内的纳米颗粒（NPs）。据报道，纳米颗粒会进入肺泡并通过血流输送到全身，从而对动物健康产生重大影响。然而，针对火葬场工作人员接触所产生的纳米颗粒的研究尚未开展。本研究的目的是评估火葬场工作人员接触纳米颗粒的情况。
在三个火葬场进行了实地调查，重点关注火化、骨骼整理和清洁过程。分析了纳米颗粒的浓度和粒径分布。使用人体呼吸道模型，根据测量数据计算每个工作过程中纳米颗粒在每个呼吸区域的沉积情况。
在骨骼整理过程中，平均颗粒数浓度瞬间达到最大值。火葬炉门打开时的浓度为500,000颗粒/立方厘米。纳米颗粒在几分钟内聚集成微米级颗粒、骨骼整理产生的灰尘，或两者皆有。模型计算结果显示，平均比例（每个火葬场肺泡与其他区域的比例）约为3.0（支气管和细支气管区域：火葬场A的第一次调查因测量受阻除外）和4.3（胸外气道）。所有火葬场的比例相似。
这些结果可用于火葬场的健康风险评估。此外，这些结果应适用于估计每个呼吸器官（如肺和鼻）的吸入单位风险。
