Estimation of Lead Exposure Prevalence in Korean Population through Combining Multiple Experts' Judgment based on Objective Data Sources.

Objective: Estimating carcinogen exposure prevalence is important for preventing occupational cancers. To develop the Korean version of CARcinogen EXposure (CAREX), a carcinogen surveillance system used in many countries, we estimated lead exposure prevalence in the Korean working population.

Methods: We used three Korean nationwide data sources to obtain objective database-derived prevalences of lead exposure across industries: airborne lead measurement data from the work environment measurement database (WEMD), blood lead measurement data from the special health examination database (SHED), and lead exposure prevalence computed using data from the work environment condition survey (WECS), which is a nationwide occupational exposure survey. We also asked a panel of 52 experts with ≥20 years of experience in industrial hygiene practice for their judgment about lead exposure prevalence across industries after they reviewed the database-derived prevalences computed from the three exposure databases. We developed and compared various estimation methods for combining the experts' judgments. The 2010 census was used as the reference population to estimate the number of lead-exposed workers in 228 industries by multiplying the exposure prevalence by the number of workers in each industry.

Results: The database-derived prevalences of lead exposure in the 228 industries were calculated using data collected between 2009 and 2011 from the WEMD and SHED and from the 2009 WECS. From the various estimation methods assessed, the median values of experts' responses were selected as our estimates of lead exposure prevalence in each industry. As a result, it was estimated that 129,250 Korean workers were exposed to lead in 2010.

Conclusions: Based on objective databases, we developed a method for estimating exposure prevalence for the CAREX system by combining experts' judgments. This work may offer an unbiased approach to the development process that accounts for the uncertainty in exposure.