Respiratory and cardiac function tests in relation to occupational lung diseases.

Tests of lung function have a number of important roles in occupational medicine but the results need to be of high technical quality if they are to be useful. On this account, as well as careful supervision and scrutany of results, only appropriate tests should be applied. The choice will vary with circumstances; it is likely to be made from a limited number of procedures including those recommended in Respiratory function tests in pneumoconioses (I.L.O., 1966). Tests of maximal and near maximal exercise are seldom indicated. Care should be taken over the selection of reference values and of mathematical treatments for the results.