became concerned about the adverse health effects of coal dust and the amount it was costing them to compensate miners working at the coalface. Pneumoconiosis proved to be a particular problem for miners in South Wales, accounting for almost 90% of the total cases for the whole of the UK in both 1939 and 1945, and with more than 25% of the South Wales mining labour force affected between 1959 and 1963. Women's roles Women in South Wales were often not economically active in the second half of the nineteenth century due to the Mines and Collieries Act 1842 which prohibited women from working underground. It has been suggested that this explains the lower marriage age and higher fertility of women in the coalfield. See also Coal mining History of coal mining 1926 United Kingdom general strike UK miners' strike (1984–85) Miners' institute List of British coalfields References External links Welsh Coal Mines - all the histories of all the pits BBC Wales feature on Coal in South Wales Coal mining in Wales Coal mining regions in Wales