8259585 Using job exposure matrices to estimate an individual’s exposure for compensation?

<h3>Introduction</h3> Job exposure matrices are being used to assign (quantitative levels of) exposure to individuals based on their job history. In human observational studies a group-based approach in which every individual with a similar job will be assigned similar exposure will not bias the exposure-response association but will result in loss of precision. However, since job exposure matrices do not consider between-worker differences in average exposure some workers’ cumulative exposures will be underestimated. This may affect their chances for compensation when a minimal (cumulative) exposure threshold is applied. <h3>Material and Methods</h3> We analysed more than 80.000 repeated exposure measurements from a variety of industries and consequently combined variance components of location and worker (within a location within a job) to estimate the bandwidth of individual average exposures in a job. This allowed estimation of an upper average exposure for workers within a job (across locations/companies). <h3>Results</h3> The bandwidth factor appeared to be larger for exposures to particulates than for gases. It was also larger for biological agents. For exposure to particulate matter the bandwidth factor varied slightly between industries (84BWfactor 1-4) with a median of 2.5. <h3>Conclusion</h3> By applying a default upper (one standard deviation) bandwidth factor to an average exposure estimate resulting from a job-exposure matrix, the Dutch occupational disease compensation scheme has chosen for an approach that recognizes between-worker differences in exposure. This approach in addition to considering uncertainty in exposure-response associations addresses another important factor of uncertainty in ascertaining occupational disease based on the ‘presumably plausible’ principle.