Svedberg Urban, Samuelsson Jerker, Melin Staffan
Department of Occupational and Environmental Medicine, Sundsvall Hospital, Sundsvall, Sweden.
Ann Occup Hyg. 2008 Jun;52(4):259-66. doi: 10.1093/annhyg/men013. Epub 2008 Apr 7.
Five ocean vessels were investigated for the characterization and quantification of gaseous compounds emitted during ocean transportation of wood pellets in closed cargo hatches from Canada to Sweden. The study was initiated after a fatal accident with several injured during discharge in Sweden. The objective with the investigation was to better understand the off-gassing and issues related to workers' exposure. Air sampling was done during transport and immediately before discharge in the undisturbed headspace air above the wood pellets and in the staircase adjacent to each hatch. The samples were analyzed with Fourier transform infrared spectroscopy and direct reading instruments. The following compounds and ranges were detected in samples from the five ships: carbon monoxide (CO) 1460-14650 ppm, carbon dioxide (CO2) 2960-21570 ppm, methane 79.9-956 ppm, butane equivalents 63-842 ppm, ethylene 2-21.2 ppm, propylene 5.3-36 ppm, ethane 0-25 ppm and aldehydes 2.3-35 ppm. The oxygen levels were between 0.8 and 16.9%. The concentrations in the staircases were almost as high as in the cargo hatches, indicating a fairly free passage of air between the two spaces. A potentially dangerous atmosphere was reached within a week from loading. The conclusions are that ocean transportation of wood pellets in confined spaces may produce an oxygen deficient atmosphere and lethal levels of CO which may leak into adjacent access spaces. The dangerous combination of extremely high levels of CO and reduced oxygen produces a fast-acting toxic combination. Measurement of CO in combination with oxygen is essential prior to entry in spaces having air communication with cargo hatches of wood pellets. Forced ventilation of staircases prior to entry is necessary. Redesign, locking and labeling of access doors and the establishment of rigorous entry procedures and training of onboard crew as well as personnel boarding ocean vessels are also important.
对五艘远洋船舶进行了调查，以确定和量化从加拿大运往瑞典的封闭货舱中木屑颗粒海洋运输过程中排放的气态化合物。这项研究是在瑞典卸货期间发生致命事故并造成数人受伤后启动的。调查的目的是更好地了解废气排放以及与工人接触相关的问题。在运输过程中以及即将卸货前，在木屑颗粒上方未受干扰的顶部空间空气以及每个舱口相邻的楼梯间进行了空气采样。样品用傅里叶变换红外光谱仪和直读仪器进行了分析。在五艘船舶的样品中检测到了以下化合物及其浓度范围：一氧化碳（CO）1460 - 14650 ppm、二氧化碳（CO₂）2960 - 21570 ppm、甲烷79.9 - 956 ppm、丁烷当量63 - 842 ppm、乙烯2 - 21.2 ppm、丙烯5.3 - 36 ppm、乙烷0 - 25 ppm以及醛类2.3 - 35 ppm。氧气含量在0.8%至16.9%之间。楼梯间的浓度几乎与货舱内一样高，这表明两个空间之间的空气流通相当顺畅。装货后一周内就达到了潜在危险的大气环境。结论是，在密闭空间内进行木屑颗粒的海洋运输可能会产生缺氧大气环境以及可能泄漏到相邻通道空间的致命浓度的一氧化碳。极高浓度的一氧化碳与氧气减少的危险组合会产生一种速效毒性组合。在进入与木屑颗粒货舱有空气连通的空间之前，结合氧气测量一氧化碳至关重要。进入前对楼梯间进行强制通风是必要的。重新设计、锁定和标记通道门，制定严格的进入程序，对船上船员以及登上海洋船舶的人员进行培训也很重要。
