Abstract

A study has been made in working coal-miners of the repeatability of ventilatory tests, anthropometric measurements, and the answers to a questionnaire on respiratory symptoms.

On the first visit especially, there was evidence of a continuous increase in both forced expiratory volume (F.E.V.) and forced vital capacity (F.V.C.) from the first to sixth expirations at the same visit but it was minimal after the first expiration. No difference between the beginning and end of a shift was found. The effect on the F.E.V. and F.V.C. readings of the day of the week and time of day at which the examination was made was negligible. The observations recorded in Scotland were 15% higher than those obtained in South Wales.

Between the beginning and end of shift there was a small reduction in weight and in standing and sitting height measurements.

The repeatability of the answers to the questionnaire was good. No consistent difference was found between doctor and clerk observers.