Public health implications of the variability in the interpretation of 'B' readings for pleural changes.

During 1985 in Minnesota, an initial reading of 566 radiographs found 30% of them to be positive for pleural changes. However, only 4% were considered positive by at least two out of three readers from National Institute for Occupational Safety and Health panel reading the radiographs under blind conditions. The implications of this variability in radiographic readings for public health decisions was illustrated in Minnesota, where selective overreading of radiographs of female subjects created an illusion of a generalized environmental problem rather than an occupational exposure. One solution to this dilemma is establishment of criteria to minimize false-positive pleural findings. The study also supports the need for more careful consideration of other disease processes in the interpretation of "B" readings.