Estimating occupational radiation doses when individual dosimetry information is not available: a job exposure matrix

A job exposure matrix (JEM) was developed for a population based case control study to assess the possible association between occupational radiation and non-Hodgkin's lymphoma.

Using published radiation monitoring data, we developed a radiation JEM composed of estimated annual dose distributions, categorized by time period, for a broad range of occupational and industrial groups.

When information is available to correctly assess an individual's exposure status, the annual dose distributions in the JEM can be used in conjunction with job histories to estimate the distribution of possible cumulative doses for individuals. The median of the cumulative dose distribution can then be used in standard epidemiologic analysis. In addition, methods can be applied that incorporate the uncertainty about each individual's true dose into risk estimates and associated confidence intervals.

The JEM can be useful in estimating occupational radiation exposures in other studies, particularly population based case control studies which include detailed occupational histories.