The present work aims at evaluating the respiratory effects on workers chronically exposed to bagasse during the manufacture of particle-boards. Special emphasis is to be given to the fungal content of bagasse during storage and manufacture. The present work comprised 102 workers employed for durations ranging from 1 to 35 years in various departments of a particle-board company, located at Kom-Ombo in Upper Egypt. The workers were subjected to a questionnaire comprising full personal, present, past and family and occupational histories, full clinical examination, chest X-ray, ventilatory function tests, complete blood picture, full immunological assay (Ig, G, Ig A, Ig M, and Ig E), and sputum analysis for mycological examination. Personal total, respirable and non-respirable dust samples being collected from different workplace air proved to exceed the TLV. Bagasse culture in dust revealed Aspergillus fumigatus, Asp Flavus, Candida spp. and Penicillium and the number of colonies, being isolated, ranged 40,000-90,000 colonies forming units per gram dried weight. Respiratory symptoms affected more than 3/4 of the examined workers. Clinically, 32 workers (31%) had chronic obstructive pulmonary disease, while chronic hypersensitivity pneumonitis affected 13 workers (13%). By plain chest X-ray, 31 are interpreted as having bilateral diffuse reticulo-nodular infiltrates (interstitial pattern), six with other chest abnormalities (deformities, thickened pleura, etc.) and four showed increased cardiothoracic ratio. Spirometric study showed that 56 workers (54%) had reduced parameters. Obstructive ventilatory defects are present in about 28.5% of the studied workers (15.7% had major airways' obstruction and 12.8% had a pattern of small airways' dysfunction). Restrictive defects ranked second, affecting about 19.6% of the workers, while combined defect affected about 6% of the studied group. Although the presence of mycological cultures are not related to the majority of the clinical data, they are proved to be related to the duration of employment (exposure), small airways' functional parameters, and all the studied immunoglobulins and interleukins. This is considered a very strong proof of the cause-effect relation of the respiratory diseases affecting the present series of workers.
