Straumfors Anne, Heldal Kari Kulvik, Wouters Inge M, Eduard Wijnand
1.Department of Chemical and Biological Work Environment, National Institute of Occupational Health, PO Box 8149 Dep, Oslo N-0033, Norway
1.Department of Chemical and Biological Work Environment, National Institute of Occupational Health, PO Box 8149 Dep, Oslo N-0033, Norway.
Ann Occup Hyg. 2015 Jul;59(6):724-36. doi: 10.1093/annhyg/mev012. Epub 2015 Mar 5.
The grain and compound feed industry entails inevitable risks of exposure to grain dust and its microbial content. The objective of this study was therefore to investigate task-dependent exposure differences in order to create knowledge basis for awareness and exposure reducing measures in the Norwegian grain and compound feed industry.
A total of 166 samples of airborne dust were collected by full-shift personal sampling during work in 20 grain elevators and compound feed mills during one autumn season and two winter seasons. The personal exposure to grain dust, endotoxins, β-1→3-glucans, bacteria, and fungal spores was quantified and used as individual outcomes in mixed models with worker nested in company as random effect and different departments and tasks as fixed effects.
The exposure levels were highest in grain elevator departments. Exposure to endotoxins was particularly high. Tasks that represented the highest and lowest exposures varied depending on the bioaerosol component. The most important determinants for elevated dust exposure were cleaning and process controlling. Cleaning increased the dust exposure level by a factor of 2.44 of the reference, from 0.65 to 1.58mg m(-3), whereas process controlling increased the dust exposure level by a factor of 2.97, from 0.65 to 1.93mg m(-3). Process controlling was associated with significantly less grain dust exposure in compound feed mills and the combined grain elevators and compound feed mills, than in grain elevators. The exposure was reduced by a factor of 0.18 and 0.22, from 1.93 to 0.34mg m(-3) and to 0.42mg m(-3), respectively, compared with the grain elevators. Inspection/maintenance, cleaning, and grain rotation and emptying were determinants of higher exposure to both endotoxin and β-1→3-glucans. Seed winnowing was in addition a strong determinant for endotoxin, whereas mixing of animal feed implied higher β-1→3-glucan exposure. Cleaning was the only task that contributed significantly to higher exposure to bacteria and fungal spores.
Cleaning in all companies and process controlling in grain elevators were the strongest determinants for overall exposure, whereas seed winnowing was a particular strong determinant of endotoxin exposure. Exposure reduction by technical intervention or personal protective equipment should therefore be considered at work places with identified high exposure tasks.
谷物和复合饲料行业不可避免地存在接触谷物粉尘及其微生物成分的风险。因此，本研究的目的是调查与任务相关的接触差异，以便为挪威谷物和复合饲料行业的认知及减少接触措施建立知识基础。
在一个秋季和两个冬季期间，在20个谷物升降机和复合饲料厂工作时，通过全时段个人采样共收集了166份空气传播粉尘样本。对个人接触谷物粉尘、内毒素、β-1,3-葡聚糖、细菌和真菌孢子的情况进行了量化，并将其用作混合模型中的个体结果，其中工人嵌套在公司中作为随机效应，不同部门和任务作为固定效应。
谷物升降机部门的接触水平最高。内毒素接触尤其高。代表最高和最低接触的任务因生物气溶胶成分而异。粉尘接触增加的最重要决定因素是清洁和过程控制。清洁使粉尘接触水平比参考值提高了2.44倍，从0.65毫克/立方米增至1.58毫克/立方米，而过程控制使粉尘接触水平提高了2.97倍，从0.65毫克/立方米增至1.93毫克/立方米。与谷物升降机相比，过程控制在复合饲料厂以及谷物升降机和复合饲料厂联合企业中与显著更低的谷物粉尘接触相关。接触水平分别降低了0.18倍和0.22倍，从1.93毫克/立方米降至0.34毫克/立方米和0.42毫克/立方米。检查/维护、清洁以及谷物周转和清空是内毒素和β-1,3-葡聚糖接触增加的决定因素。此外，种子风选是内毒素的一个重要决定因素，而动物饲料混合意味着更高的β-1,3-葡聚糖接触。清洁是导致细菌和真菌孢子接触增加的唯一显著任务。
所有公司的清洁以及谷物升降机中的过程控制是总体接触的最强决定因素，而种子风选是内毒素接触的一个特别重要决定因素。因此，在确定存在高接触任务的工作场所，应考虑通过技术干预或个人防护设备来减少接触。
