Donham K J, Reynolds S J, Whitten P, Merchant J A, Burmeister L, Popendorf W J
Department of Preventive Medicine and Environmental Health, College of Medicine, University of Iowa, Iowa City 52242, USA.
Am J Ind Med. 1995 Mar;27(3):405-18. doi: 10.1002/ajim.4700270309.
Human respiratory health hazards for people working in livestock confinement buildings have been recognized since 1974. However, before comprehensive control programs can be implemented, more knowledge is needed of specific hazardous substances present in the air of these buildings, and at what concentrations they are harmful. Therefore, a medical epidemiological and exposure-response study was conducted on 207 swine producers using intensive housing systems (108 farms). Dose-response relationships between pulmonary function and exposures are reported here. Positive correlations were seen between change in pulmonary function over a work period and exposure to total dust, respirable dust, ammonia, respirable endotoxin, and the interactions of age-of-producer and dust exposure and years-of-working-in-the-facility and dust exposure. Relationships between baseline pulmonary function and exposures were not strong and therefore, not pursued in this study. The correlations between exposure and response were stronger after 6 years of exposure. Multiple regression models were used to identify total dust and ammonia as the two primary environmental predictors of pulmonary function decrements over a work period. The regression models were then used to determine exposure concentrations related to pulmonary function decrements suggestive of a health hazard. Total dust concentrations > or = 2.8 mg/m3 were predictive of a work period decrement of > or = 10% in FEV1. Ammonia concentrations of > or = 7.5 ppm were predictive of a > or = 3% work period decrement in FEV1. These predictive concentrations were similar to a previous dose-response study, which suggested 2.5 mg/m3 of total dust and 7 ppm of NH3 were associated with significant work period decrements. Therefore, dust > or = 2.8 mg/m3 and ammonia > or = 7.5 ppm should be considered reasonable evidence for guidelines regarding hazardous exposure concentrations in this work environment.
自1974年以来，人们就已经认识到在牲畜圈舍建筑中工作对人类呼吸健康的危害。然而，在实施全面控制计划之前，需要更多地了解这些建筑空气中存在的特定有害物质，以及它们在何种浓度下有害。因此，对207名使用集约化养殖系统的养猪户（108个农场）进行了一项医学流行病学和暴露-反应研究。本文报告了肺功能与暴露之间的剂量-反应关系。在一个工作期间肺功能的变化与总粉尘、可吸入粉尘、氨、可吸入内毒素以及生产者年龄与粉尘暴露、在该设施工作年限与粉尘暴露之间的相互作用呈正相关。基线肺功能与暴露之间的关系并不强烈，因此本研究未对此进行探讨。暴露6年后，暴露与反应之间的相关性更强。使用多元回归模型确定总粉尘和氨是工作期间肺功能下降的两个主要环境预测因素。然后使用回归模型确定与提示健康危害的肺功能下降相关的暴露浓度。总粉尘浓度≥2.8毫克/立方米可预测第一秒用力呼气量（FEV1）在工作期间下降≥10%。氨浓度≥7.5 ppm可预测FEV1在工作期间下降≥3%。这些预测浓度与先前的剂量-反应研究相似，该研究表明2.5毫克/立方米的总粉尘和7 ppm的NH3与工作期间的显著下降有关。因此，总粉尘≥2.8毫克/立方米和氨≥7.5 ppm应被视为该工作环境中有害暴露浓度指南的合理依据。
