Malmberg P, Larsson K
National Institute of Occupational Health, Solna, Sweden.
Eur Respir J. 1993 Mar;6(3):400-4.
Six urban subjects, with little or no previous experience of farm-work, were exposed to dust while weighing swine for 2-5 h. Three subjects experienced toxic symptoms 4-5 h after the beginning of exposure. Bronchial responsiveness increased in all subjects within 6 h (more than three doubling steps difference in a methacholine test). One week later, airway responsiveness had partly normalized. The mean (interquartile range) cumulative dose of methacholine causing a 20% decrease in forced expiratory volume in one second (FEV1) was 3.1 (1.0-6.6) mg, before exposure, fell to 0.13 (0.01-0.76) mg 6 h after exposure (p < 0.02), and was 0.99 (0.42-1.5) mg one week later (n = 5, p < 0.05), Mean (SD) FEV1 decreased 5 (2)%. The concentration of total dust varied between 9 and 14 mg.m-3 and of endotoxin between 0.1 and 0.5 mu g.m-3. Thus inhalation of swine farm dust, caused a marked increase in bronchial responsiveness in non-sensitized subjects.
六名城市受试者此前几乎没有或完全没有从事过农场工作的经历，他们在称猪体重的2至5小时内接触了灰尘。三名受试者在接触开始后4至5小时出现中毒症状。所有受试者在6小时内支气管反应性均增加（乙酰甲胆碱试验中差异超过三个加倍步长）。一周后，气道反应性部分恢复正常。引起一秒用力呼气量（FEV1）下降20%的乙酰甲胆碱平均（四分位间距）累积剂量在接触前为3.1（1.0 - 6.6）mg，接触6小时后降至0.13（0.01 - 0.76）mg（p < 0.02），一周后为0.99（0.42 - 1.5）mg（n = 5，p < 0.05）。FEV1平均（标准差）下降了5（2）%。总灰尘浓度在9至14 mg.m-3之间，内毒素浓度在0.1至0.5 μg.m-3之间。因此，吸入猪场灰尘会使未致敏受试者的支气管反应性显著增加。
