Living close to livestock farms has been associated with increased symptoms in patients with chronic obstructive pulmonary disease (COPD). The causes of these effects are still poorly understood. This panel study attempts to assess the acute effects of livestock-related air pollution in patients with COPD living in an area with intensive livestock farming in the Netherlands. Between February 2015 and July 2016, 82 participants took spirometry measurements twice daily (morning and evening) during a 3-month period, resulting in 12,672 FEV1 and PEF records. Participants also kept a diary on respiratory symptoms as well as livestock-related odor annoyance. Daily average ammonia (NH3) (a proxy for livestock-related air pollution) and fine particulate matter (PM10) levels were collected from monitoring stations in the area. Lung function was analyzed as decrements of >10% and >20% from their median as well as absolute values. Self-reported odor annoyance was analyzed as a dichotomous variable. All analyses were done using generalized estimated equations. We adjusted for humidity, temperature, linear trend, and took multiple testing into account. We found an odds ratio of 1.14 95%CI [1.05; 1.25] for decrements >20% in morning FEV1 per interquartile range (12 µg/m3) increase in NH3 concentration (lag 2). Odor annoyance was negatively associated with evening PEF (-4.46 l/min 95%CI [-7.59; -1.33]). Sensitivity analyses showed a stronger effect in participants with worse baseline lung function. No associations with symptoms were found. Our results show acute effects of livestock-related air pollution on lung function in COPD patients living in close proximity to livestock farms.

中文翻译：

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一组COPD患者中与家畜有关的空气污染的急性呼吸作用。

在牲畜养殖场附近生活与慢性阻塞性肺疾病（COPD）患者的症状增加有关。这些影响的原因仍然知之甚少。这项小组研究试图评估居住在荷兰集约化畜牧业地区的COPD患者与家畜有关的空气污染的严重影响。在2015年2月至2016年7月之间，有82名参与者在三个月的时间内每天两次（上午和晚上）进行肺活量测定，得出12,672份FEV1和PEF记录。参加者还记录了呼吸道症状以及与牲畜相关的气味烦恼。从该地区的监测站收集了每日平均氨（NH3）（代表牲畜相关的空气污染）和细颗粒物（PM10）水平。肺功能分析是从其中位数和绝对值分别> 10％和> 20％的递减。自我报告的气味烦恼被分析为二分变量。所有分析均使用广义估计方程进行。我们针对湿度，温度，线性趋势进行了调整，并考虑了多项测试。我们发现优势比为1.14 95％CI [1.05; 1.25]表示，每隔四分位范围（12 µg / m3）的早晨FEV1的减少> 20％，则NH3浓度增加（滞后2）。气味烦恼与夜间PEF呈负相关（-4.46 l / min，95％CI [-7.59； -1.33]）。敏感性分析显示，对于基线肺功能较差的参与者，效果更佳。未发现与症状相关。