RESUMO
In Guyana, a large number of patients have been diagnosed as having a diffuse pulmonary fibrosis of unknown aetiology, characterized by typical radiological appearances, dyspnoea, cough, weight loss, and eventually pulmonary heart disease. Investigation of 56 patients showed that all had smoked a tobaco known as 'blackfat' or 'black tobacco'. In a community survey 20.4 per cent of the population aged 55 years and over smoked this tobbaco. 19.6 per cent of the blackfat smokers but no non-blackfat smokers showed definite radiological evidence of pulmonary fibrosis. Smokers with, but not those without fibrosis, had severe airway obstruction. Immunological studies made it unlikely that an extrinsic allergic aveolitis had caused the radiological changes. Three post-mortem open-lung specimens were obtained and in each case the histology showed a diffuse interstitial fibrosis and vasculitis associated with large deposits of lipid surrounded by black amorphous material. Blackfat is a tobacco leaf to which mineral oil and vaseline is added for flavouring and as humectants. The presence of oil in the tobacco, and the post-mortem findings of oil in the lungs, indicate that the diffuse pulmonary fibrosis can be more accurately described as a lipoid pneumonia caused by the inhalation of mineral oils when blackfat is smoked. The potential health hazards of many tobacco additives, particularly oils, employed by the tobacco industry should be recognized. A similar type of disease as that found in Guyana may be present in other parts of the world where blackfat, or related tobacco, are smoked.(Summary)
