RESUMO
Agricultural workers are at risk for developing many respiratory tract disorders. Crop production disorders include chronic bronchitis, asthma, organic dust toxicity syndrome, chemical poisoning, farmer lung, and silo-filler disease. Livestock production disorders include toxic manure poisoning (dung lung) and several zoonoses. Radiographic manifestations can be classified into three patterns: (a) normal findings, characteristic of chronic bronchitis, asthma, or organic dust toxicity syndrome; (b) acute diffuse interstitial or alveolar pattern, characteristic of farmer lung, silo-filler disease, dung lung, and chemical poisoning; and (c) chronic interstitial pattern in the upper lobes (farmer lung) or lower lobes (silo-filler disease, paraquat poisoning). Differential diagnosis is aided by knowledge that most of these disorders have a seasonal presentation. Zoonoses generally exhibit focal areas of consolidation in the lung: The type of splenic calcification, presence of mediastinal or hilar adenopathy, and development of bronchiectasis are additional findings useful in differentiating these rare infections.
