Adverse respiratory health effects in the agricultural industry have been linked to particulate endotoxin exposure. However, whether the endotoxin concentration is significantly correlated to the size of the particle remains an open question. To date, limited research has been conducted to assess particulate endotoxin exposures in the agricultural industry in general or the equine industry in particular. A task-based exposure assessment was conducted to characterize the endotoxin levels of inhalable and respirable particles on four Kentucky farms during the summer season. We conducted personal sampling of respirable and inhalable particles (n = 75) across all four farms and particulate endotoxin (n = 58) on two of them. Simultaneously, we collected real-time area samples across all four farms by task - horse care, filing hooves, cleaning stalls, cleaning barns, cleaning dry lots, and cleaning trucks. The endotoxin concentration of inhalable particles (geometric mean: 50.2-1,024 EU/m3) was ~50 times higher than that of respirable particles (geometric mean: 1.72-19.0 EU/m3). Horse care generated the lowest endotoxin concentrations for both particle sizes, while cleaning tasks tended to produce higher concentrations. There was no significant correlation between the endotoxin and particle concentrations for each size fraction based on tasks by farm (R2 = 0.069 for inhalable; 0.214 for respirable). The equine workers in this study were exposed to higher endotoxin concentrations than workers in other industries, such as the swine industry. Providing exposure control guidelines and recommendations to the equine industry is necessary to reduce long-term endotoxin exposure and to prevent adverse respiratory symptoms.

中文翻译：

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肯塔基州马场的可吸入和可吸入颗粒物及内毒素暴露。

农业行业对呼吸系统健康的不良影响与微粒内毒素的暴露有关。然而，内毒素浓度是否与颗粒大小显着相关仍是一个悬而未决的问题。迄今为止，已经进行了有限的研究来评估一般农业产业或特别是马产业中颗粒状内毒素的暴露。进行了基于任务的接触评估，以表征夏季夏季在肯塔基州的四个农场中可吸入和可吸入颗粒物的内毒素水平。我们对所有四个农场的可吸入和可吸入颗粒物（n = 75）进行了个人采样，并在其中两个农场进行了颗粒内毒素（n = 58）的采样。同时，我们按任务收集了所有四个农场的实时区域样本-马匹护理，锉蹄，清洁摊位，清洁谷仓，清洁干地和清洁卡车。可吸入颗粒的内毒素浓度（几何平均值：50.2-1024 EU / m3）比可吸入颗粒的内毒素浓度（几何平均值：1.72-19.0 EU / m3）高约50倍。在两种粒径下，马匹护理产生的内毒素浓度最低，而清洁任务往往产生更高的浓度。根据养殖场的任务，每个尺寸分数的内毒素和颗粒物浓度之间无显着相关性（可吸入性R2 = 0.069；可呼吸性R2 = 0.214）。与其他行业（例如养猪业）相比，本研究中的马工人受到的内毒素浓度更高。