“…The majority of workers have reported disappointing results as a result of chest surveys (Heasman, 1961;Shanks & Kerley, 1962;Virtama, 1962;Posner, McDowell & Cross, 1963;Gilbertsen, 1966;Rubin, 1966). It has been proposed by all these workers that routine mass radiography surveys should be directed to men who are in selected high risk groups, over 45 years of age, who are urban dwellers and heavy cigarette smokers.…”