Physical characteristics and ventilatory function of 404 commercial divers working in the North Sea

Abstract

The physical characteristics and simple lung ventilatory indices (FVC, FEV1, FEV1/FVC) of 404 commercial divers employed by companies operating in the North Sea were analysed. These findings were correlated with the diving experience and maximum operating depth of each diver. All the divers were men of average height 176.9 cm, and weight 77.1 kg which is greater than average for active Western males, but only 6% were more than 120% of their predicted weight. The average duration of commercial diving was 7.1 years, 11% of divers having less than one year's experience. Sixty seven per cent had worked at a maximum depth of 200 ft (61 m) and only 6% had worked deeper than 500 ft (153 m). The mean forced vital capacity (FVC) was 120.4% of the predicted value which indicated that they could voluntarily move large amounts of gas in and out of their lungs. This was greatest in the divers who went deepest. The mean forced expired volume in one second (FEV1) was 117% of the predicted value showing that expiratory airflow capacity was also increased, but to a lesser extent than the FVC. The mean FEV1/FVC ratio was normal but in 16% of the divers it was less than 75% which might indicate early expiratory airflow obstruction. This finding was related to age, and not to undersea environmental factors. These results show that commercial divers form an experienced, physically fit group of men who have large lung capacities advantagenous to their occupation. Moving gas of increased density in and out of their lungs may well have hypertrophied the muscles of respiration.