1969). Brit. J. industr. Med., 26,[231][232][233][234][235][236]. Respiratory effects of chlorine gas. Seven chemical workers who were accidentally exposed to chlorine gas in separate accidents were investigated. The usual symptoms were cough, dyspnoea, and chest pains, the symptoms starting within 10 minutes of exposure and lasting two to eight days. Chest radiographs showed congestion, consolidation, and nodules; lung oedema was also present in a severe case. These changes usually cleared within one week but in the severe case persisted for 10 weeks. Three patients had respiratory failure. Hypoxaemia was found in four patients and was quickly corrected by oxygen therapy in three of them, but in the severe case hypoxaemia persisted for four days despite continuous oxygen therapy. All the patients recovered completely.Half a million tons of chlorine are produced in this country every year; the bulk of this is manufactured locally. Despite this, serious accidents during manufacture or transportation are rare. Jones (1952) reported 820 cases of chlorine gassing from the local factories, but only seven cases were clinically severe and none of his patients died. In 1967 a man aged 49 died from lung oedema three hours after gassing, and this, as far as we know, is the only fatality in this region (Whitehead, personal communication). During the past year we have studied the natural history, chest radiograph, and arterial blood of process workers exposed to chlorine in our local factories.Clinical findings Table 1 shows the clinical findings on our seven patients, one of whom had chronic bronchitis (M.R.C. definition, 1965). Six men had mild or moderate illnesses which lasted two to eight days. The usual symptoms were conjunctivitis, cough, breathlessness, and chest pains. With one exception (patient no. 6) the onset of the symptoms followed within 10 minutes of exposure. The illness threatened the life of our first patient, and the natural history can best be described by referring to this case.Case history A 44-year-old process worker was exposed to a high concentration of gas when closing a valve which was allowing liquid chlorine to leak on to the floor. He quickly began to choke and developed severe dyspnoea, a persistent cough, and chest pain. His eyes were smarting.The patient was given oxygen and was transferred to the Intensive Care Unit 10 hours later. He was cyanosed, his breathing was rapid and shallow, and he was coughing up pink, frothy sputum. The conjunctivae were markedly injected and numerous coarse crepitations could be heard. On the second day the patient had a severe headache and pains in the limbs and chest which persisted for two days. He remained critically ill for 48 hours and then gradually improved. The axillary temperature was 100°F. (37-8'C.) on days 6 and 7, presumably due to respiratory infection; the patient was given tetracycline, 250 mg. 6-hourly for five days. The sputum was purulent on day 3 but contained no pathogens.For nine days the patient was given continuous oxygen. On days ...
