Basinas Ioannis, Sigsgaard Torben, Erlandsen Mogens, Andersen Nils T, Takai Hisamitsu, Heederik Dick, Omland Øyvind, Kromhout Hans, Schlünssen Vivi
1.Department of Public Health, Section for Environment, Occupation and Health, Danish Ramazzini Center, Aarhus University, Bartholins Allé 2, bg 1260, 8000 Aarhus C, Denmark
1.Department of Public Health, Section for Environment, Occupation and Health, Danish Ramazzini Center, Aarhus University, Bartholins Allé 2, bg 1260, 8000 Aarhus C, Denmark.
Ann Occup Hyg. 2014 Jul;58(6):707-23. doi: 10.1093/annhyg/meu024. Epub 2014 Apr 18.
Studies on determinants of dairy farmers' exposure to dust and endotoxin have been sparse and so far none has addressed the combined effect of tasks and farm characteristics.
To study whether and how work tasks and specific stable characteristics influence the level of dairy farmers' personal exposure to inhalable dust and endotoxin.
We applied an observational design involving full-shift repeated personal measurements of inhalable dust and endotoxin exposure among 77 subjects (owners and farm workers) from 26 dairy farms. Performed tasks were self-registered in activity diaries, and information on stable characteristics was collected through personal interviews and walk-through surveys. Associations between exposure, tasks, and stable characteristics were examined in linear mixed-effect models with individual and farm treated as random effects. Separate as well as combined models for tasks and stable characteristics were elaborated.
The 124 personal samples collected had a geometric mean level (geometric standard deviation) of 360 EU m(-3) (3.8) for endotoxin exposure and of 1.0mg m(-3) (2.7) for dust exposure. Identified factors that increased endotoxin exposure included a lower outdoor temperature and use of slope-based or back-flushed slurry systems along with milking, distribution of bedding, and handling of feed and seeds in barns. For dust, exposure was higher when fully automatic (robotic) milking was used and during re-penning of animals, handling of feed and seeds, handling of silos and when distributing bedding. Dust exposure increased also as a result of use of rail feed dispensers in a model without fully automatic milking.
The current exposure to dust and in particular endotoxin among Danish dairy farmers demand effective strategies to reduce their exposure. The present findings suggest that future interventions should focus on feeding and manure handling systems. Use of respirators during handling of feed and distribution of bedding should be advised until adequate risk management measures have been established. The expected increased use of fully automatic milking in the future might increase dust exposure of dairy farmers.
关于奶农接触粉尘和内毒素的决定因素的研究一直很少，到目前为止，还没有研究涉及工作任务和农场特征的综合影响。
研究工作任务和特定牛舍特征是否以及如何影响奶农个人吸入性粉尘和内毒素的接触水平。
我们采用了一种观察性设计，对来自26个奶牛场的77名受试者（场主和农场工人）进行了全时段可吸入粉尘和内毒素接触的重复个人测量。执行的任务在活动日记中自行记录，通过个人访谈和巡查收集有关牛舍特征的信息。在以个体和农场为随机效应的线性混合效应模型中检验接触、任务和牛舍特征之间的关联。分别构建了任务和牛舍特征的单独模型以及联合模型。
收集的124个个人样本中，内毒素接触的几何平均水平（几何标准差）为360 EU m(-3)（3.8），粉尘接触为1.0mg m(-3)（2.7）。确定的增加内毒素接触的因素包括较低的室外温度、在挤奶、铺垫料分配以及在牛舍中处理饲料和种子时使用基于坡度或反冲洗的粪便处理系统。对于粉尘，使用全自动（机器人）挤奶时以及在动物重新圈养、处理饲料和种子、处理筒仓以及铺垫料分配期间接触更高。在没有全自动挤奶的模型中，使用轨道式饲料分配器也会导致粉尘接触增加。
丹麦奶农目前接触粉尘尤其是内毒素的情况需要有效的策略来降低其接触水平。目前的研究结果表明，未来的干预措施应侧重于饲料和粪便处理系统。在建立适当的风险管理措施之前，建议在处理饲料和铺垫料分配时使用呼吸器。未来预期全自动挤奶的使用增加可能会增加奶农的粉尘接触。
