Dust in the Housing of Laying Hens: A case study

ABSTRACT As dust particles in laying poultry houses can have negative effects on health and on the environment, this study aimed to measure and compare dust concentrations in egg production sheds. The experiment was carried out in three sheds: Californian shed (G1), conventional closed shed with artificial ventilation (G2) and conventional closed shed without artificial ventilation (G3), and the birds housed were in the 22nd week of housing, in Cuité, Paraíba, Brazil. The dust particles were collected by a gravimetric pump, attached to the workers’ clothes, at the height of the respiratory zone, being removed at the end of the working day. Using the evaluation methodologies (total or breathable dust) according to NIOSH (1998), weighing was performed with sample concentration calculation, then the particle size was measured by microscopy according to the methodology described by Feret (Santos, 2001), with diameter of function obtained using an optical microscope, and particles classified by size (inhalable <100 µm, thoracic <25 µm and breathable <10 µm). Considering the limit of concentration x exposure time of 3.0 mg/m3, according to ACGIH (2013), the sheds had the following values: G1-0.98 mg/m3, G2-1.45 mg/m3 and G3-1.13 mg/m3. In the classification of particles by size, the highest frequencies were 83% thoracic, 13% inhalable, and 4% breathable. With the results presented, the implementation of the Respiratory Protection Program - PPR is suggested.

摘要 由于家禽产蛋舍内的粉尘颗粒会对畜禽健康与周边环境造成负面影响，本研究旨在测定并对比不同产蛋鸡舍内的粉尘浓度水平。本实验共设置三类鸡舍：加州式鸡舍（G1）、配备人工通风系统的传统密闭鸡舍（G2）以及无人工通风的传统密闭鸡舍（G3），受试家禽处于入舍饲养第22周，实验场地位于巴西帕拉伊巴州奎特市（Cuité）。粉尘颗粒采用重量法粉尘采样泵（gravimetric pump）进行采集，将采样泵固定于作业人员衣物的呼吸带高度位置，于每个工作日结束时回收样本。参照美国国家职业安全与健康研究所（National Institute for Occupational Safety and Health, NIOSH）1998年发布的评价方法（总粉尘或呼吸性粉尘），对采集样本进行称重并计算粉尘浓度；随后依据Feret（Santos, 2001）所述的方法，通过显微镜开展粒径测定：利用光学显微镜获取粒径函数直径，并按粒径对颗粒进行分级分类：可吸入粉尘（粒径＜100 µm）、胸外粉尘（粒径＜25 µm）与呼吸性粉尘（粒径＜10 µm）。参照美国政府工业卫生学家会议（American Conference of Governmental Industrial Hygienists, ACGIH）2013年制定的3.0 mg/m³浓度-暴露时间限值标准，三类鸡舍的粉尘浓度分别为：G1组0.98 mg/m³，G2组1.45 mg/m³，G3组1.13 mg/m³。在按粒径对颗粒进行分类后，占比最高的为胸外粉尘（83%），其次为可吸入粉尘（13%），呼吸性粉尘占比最低（4%）。基于本研究结果，建议推行呼吸防护计划（Respiratory Protection Program, PPR）。