Bronchoalveolar lavage using flexible fibreoptic bronchoscope was carried out in 50 patients
1-2½ yr after exposure to the ‘toxic gas’ at Bhopal. Thirty six patients in the analysis were
categorised into 3 groups (viz., mild, moderate and severe), depending upon the severity of
exposure. There was an increase in cellularity in the lower respiratory tract (alveolitis) of
the severely exposed patients (in both smokers and non-smokers), compared to normals
(P< 0.05). The increase in cellularity in severely exposed non-smokers was due to abnormal
accumulation of macrophages (P<0.01), and in severely exposed smokers, to macrophages
(P<0.01) and neutrophils (P<0.05). Mild and moderately exposed patients did not show
significant change in cellularity in lower respiratory tract, compared to normal individuals
(P>0.2). There was a trend towards increasing cellularity, as the severity increased
(P < 0.0001) and higher numbers of total cells were seen in severely exposed smokers, suggesting
that smoking is a risk factor. It appears, therefore, that subjects severely exposed to
the toxic gas at Bhopal may have a subclinical alveolitis characterised by accumulation
and possibly activation of macrophages in the lower respiratory tract. Smokers, who
were exposed to the gas had in addition, accumulation of neutrophils
