A statistical study of coal-mining accidents.

Statistics of accidents in British coal-mines have been collected in one form or another since 1873 (Ministry of Power, 1957). From those early days there has been a steady decline in the numbers of fatalities but even now more than 300 men a year are killed in mining accidents. About a million and a half injuries, varying from the trivial to the fatal, are reported in a year and coal-miners, who form only about a twentieth of the insured male population of Great Britain, account for nearly half of all industrial injuries attracting benefit. Because of, on the one hand, the requirements of the Mines Inspectorate of the Ministry of Power, and, on the other, arrangements for compensation, casualties* in the industry are classified into the following four categories: (a) Fatal casualty. (b) Other "reportable" casualty: a report must be made to the Mines Inspectorate of any case of " serious personal injury" (such as a major fracture) and of every "dangerous occurrence '"t (c) Other compensable casualty: an injury which causes absence from work for more than three days and which is therefore compensable under the National Insurance (Industrial Injuries) Act. (d) Non-compensable casualty, i.e., any casualty not included in the three categories above. Although the great majority of casualties are in category (d), the compensable casualties, i.e., those in categories (a) and (c) together with most of those in (b), amount at present to over 200,000 a year. For the years 1945 to 1949 inclusive, certain information about these casualties was reported to the Ministry of Power where a card was punched for each casualty. It was natural to assume that this material, consisting of over 900,000 cards, would be a reasonable source of data for statistical research. The material (data A) was, therefore, borrowed by the National Coal Board and the work described below was carried out on it. Work was also done by the technical section of the Board's central Statistics Branch on more detailed and more up-todate material (data B) relating to 14 collieries onlyless than 2% of those in the Board. The third source of material (data C) was available in the shape of colliery accident rates and other colliery statistics. These data are described in detail below. Despite the vast amount of data available, the conclusions were mainly negative. This was largely because standards of recording and habits of reporting appeared to differ appreciably and because the background information necessary for detailed work was not available. There were, however, a number of positive findings which are discussed in this paper.