Medical research by the National Coal Board

In 1952 the National Coal Board accepted an invitation by the National Joint Pneumoconiosis Committee to ” undertake a field research to determine how much and what kinds of dust cause pneumoconiosis and to establish what environmental conditions should be maintained if mine workers are not to be disabled by the dust that they breathe during the course of their work ” This research was to be a long-term survey over a period of at least 10 years at a representative sample of collieries. With these objects in mind the Pneumoconiosis Field Research was started by the Board and the project has since become known as the ” twenty-five pits scheme “.
The survey was carefully designed and planned based on the experience of previous scientific studies, particularly those carried out by the Pneumoconiosis Research Unit (PRU) of the Medical Research Council at Cardiff. Altogether 25 pits, originally 20, were chosen, 6 in South Wales, 5 in Scotland, 2 in Northumberland, 2 in Durham, 3 in Yorkshire and 1 each in Cumberland, North Wales, Lancashire, North Staffordshire, Warwickshire, Nottinghamshire and Kent. These pits were selected not on the basis of cases certified for Industrial Injury Benefits but on 4 factors, which were considered most likely to influence the problem. These were: (i) level of dustiness, (ii) rank of coal mined, (iii) presence of quartz in the strata associated with the coal seam, and (iv) ash content of coal seam in situ.
The scheme has 3 main components, medical, environmental and the correlation of these. The primary objects of the medical surveys are to determine the prevalence of pneumoconiosis and to study the occurrence and progress of the disease in the individual workmen and in colliery groups. The purpose is to radiograph on full-size film the population of the selected 25 collieries regularly every 4 years or so. Participation in the scheme is voluntary. In the first tour, completed in 1956, over 30, 000 men representing 94.8% of the total pit populations were examined. In reading the films, which are classified according to the ILO classification, great care is taken to maintain consistent standards and to minimize inter- and intra-observer errors.
Concurrent environmental studies are designed to establish as accurately as possible the environment of each man under observation. The thermal precipitator is the standard sampling instrument. Since the inception of the surveys each item of the investigations has been kept under periodical review and the teams are satisfied that the original plan was satisfactory and is operating efficiently. Concurrent studies by the PRU and others have focused attention on the possible value of certain anthropometric indices and respiratory function tests and these have now been incorporated in the second tour.
The prevalence of pneumoconiosis, it is recorded, varies from very little significant pneumoconiosis at some collieries (1% of category 2 or more) to a considerable amount at others (about 20% of category 2 or more). Beyond this no results have been released for general information but these are promised “in due course “.
117 persons, of whom 19 are medical, are employed full-time on the project. A. Meiklejohn.