Pneumoconiosis from Agricultural Dust Exposure among Young California Farmworkers

Abstract

BackgroundAgricultural workers are exposed to airborne pollutants, including organic and inorganic (mineral) dusts.ObjectivesLung 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.MethodsThe 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.ResultsProximal 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.ConclusionMineral 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.

Weathering and transport of chromium and nickel from serpentinite in the Coast Range ophiolite to the Sacramento Valley, California, USA

“…However, Dawson (2001) (Quantin et al, 2002) or could precipitate with sulfides under severely reducing conditions. Agricultural dust is a major issue in the Central Valley, which can cause health issues for agricultural workers and could lead to general air quality issues Singer, 1996,2000;Schenker et al, 2009). Exposure to the respirable fraction of mineral dusts can lead to lung disease (Schenker et al, 2009), and Ni in valley dust may be of particular concern.…”

Secondary pleuroparenchymal fibro-elastosis with airway-centered fibro-elastosis and con-strictive bronchiolitis associated with agriculture dust exposure

“…Similar to our case birefringent particles were observed in the pathological areas only. [7] Constrictive bronchiolitis without PPFE has been described in soldiers who had served in Iraq and Afghanistan [8] whereas PPFE without constrictive bronchiolitis was found in a patient following exposure to aluminosilicate dust. [9] These studies and case reports support the concept that occupational exposure can cause PPFE.…”

Expanding the Spectrum of Particle-and Fiber-Associated Interstitial Lung Diseases

“…Pulmonary fibrosis associated with agricultural work and farming is receiving increased attention since it may contribute to over 20% of all idiopathic cases [28]. This is now being defined clinically and the etiology has been suggested to result from inorganic components of soil dust [33][34][35]. Clerical work may protect against IPF [29].…”

“…Furthermore, technological advances of high resolution CT scan and semi-invasive methods of bronchoalveolar lavage, has shifted a focus from histological to the non-pathological mode of management and also in selection of representing groups for epidemiological studies [5]. Most of these diagnoses are determined without benefit of microscopic examination of lung tissue (in two UK surveys of patients with IPF, only 7.5% [33] and 12% [34], respectively, had an open lung biopsies), and, therefore, the issue of a pertinent exposure can sometimes not be introduced. Even when tissue is available, the conventional examination for the presence of particles and fibers uses light microscopy, which is insensitive and leads to misdiagnosis.…”