RESUMO
Cigarette smoking has a supplementary effect in producing ventilatory functional deficit in cotton dust exposed workers. Exaggerated airway reactivity produced by autocoid [histamine] was also reported in smokers in experimental studies. Here, acute changes in FEV1 and PEFR over a shift and chronic changes as observed by the percentage of predicted FEV1 and PEFR values and blood histamine levels were compared in control and exposed [nonbyssinotics and byssinotics] workers according to smoking habits. Higher airway reactivity associated with elevated histamine levels was found in exposed workers and even higher in smokers than nonsmokers. Similar observations were also demonstrated with regard to chronic changes. The data shows that smoking has a cumulative effect over histamine induced fail in FEV1 and PEFR in cotton dust ex