摘要

BACKGROUND:Agricultural workers are exposed to airborne pollutants, including organic and inorganic (mineral) dusts.
OBJECTIVES:Lung autopsy specimens from consecutive coroner's cases of Hispanic males in Fresno County, California, (n = 112) were obtained to determine whether mineral dust exposure in agricultural work leads to pneumoconiosis.
METHODS:The left lung was fixed by inflation. We evaluated airway and parenchymal pathology using standardized diagnostic criteria and semiquantitative grading schemata, including the grading of small airways for fibrosis and birefringent mineral dust particles. We analyzed lung dust burden on a subset of 37 lungs following bleach digestion, using scanning electron microscopy (SEM), X-ray spectrometry (XRS) and image analysis, and by X-ray diffraction for crystalline silica (CSi). Farmworkers comprised 51.5% and nonfarmworkers 48.5% of the samples.
RESULTS:Proximal airways demonstrated little mineral dust accumulation, but membranous and respiratory bronchioles had wall thickening, remodeling, and inflammation associated with carbonaceous and mineral dust deposition. These changes were independently associated with agricultural work, cigarette smoking, and increased age. Mineral dust small airways disease, pneumoconiosis (macules and nodules), and pathologic changes consistent with chronic bronchitis, emphysema, and interstitial fibrosis predominated in farmworkers compared with nonfarmworkers. CSi, determined gravimetrically, and aluminum silicate particles, determined by SEM/XRS, were increased in the lungs of farmworkers compared with nonfarmworkers and were significantly (p < 0.05) associated with small airway disease and pneumoconiosis.
CONCLUSION:Mineral dust exposure is associated with increased small airway disease and pneumoconiosis among California farmworkers; however, the clinical significance and natural history of these changes remains to be determined.

译文

背景: 农业工人暴露在空气污染物中，包括有机和无机 (矿物) 粉尘。
目的: 从加利福尼亚州弗雷斯诺县 (n = 112) 连续验尸官的西班牙男性案例中获得肺部尸检标本，以确定农业工作中矿物粉尘暴露是否会导致尘肺病。
方法: 左肺采用充气固定。我们使用标准化诊断标准和半定量分级模式评估了气道和实质病理，包括小气道纤维化和双折射矿物粉尘颗粒的分级。我们使用扫描电子显微镜 (SEM) 、 x射线光谱仪 (XRS) 和图像分析，分析了漂白消化后 37 个肺子集的肺尘负荷, 并通过 x射线衍射获得结晶二氧化硅 (CSi)。农场工人占样本的 51.5%，非农场工人占 48.5%。
结果: 近端气道显示出少量矿物粉尘积累，但膜性和呼吸性细支气管有壁增厚、重塑和与含碳和矿物粉尘沉积相关的炎症。这些变化与农业工作、吸烟和年龄增长独立相关。矿尘小气道疾病、尘肺 (斑疹和结节) 和病理变化与慢性支气管炎、肺气肿和间质纤维化一致，与非农业工人相比，农业工人占主导地位。重力测定的 CSi 和 SEM/XRS 测定的硅酸铝颗粒在农场工人的肺部较非农场工人显著增加 (p & lt; 0.05) 与小气道疾病和尘肺病相关。
结论: 矿物粉尘暴露与加州农场工人小气道疾病和尘肺病的增加有关; 然而，这些变化的临床意义和自然历史仍有待确定。