Development of a job-exposure matrix for exposure to total and fine particulate matter in the aluminum industry

Increasing evidence indicates that exposure to particulate matter (PM) at environmental concentrations increases the risk of cardiovascular disease, particularly PM with an aerodynamic diameter of less than 2.5mm (PM2.5). Despite this, the health impacts of higher occupational exposures to PM2.5 have rarely been evaluated, primarily due to the absence of information on PM2.5 exposures in the workplace. To address this gap, we developed a job-exposure matrix (JEM) to estimate exposure to two size fractions of PM in the aluminum industry. Using 8,385 personal total PM (TPM) samples collected from 11 facilities between 1980 and 2011, we calculated exposures for distinct exposure groups (DEGs) in the JEM. Additionally, for eight facilities, simultaneous personal monitoring of PM2.5 and TPM was conducted from 2010 to 2011 to ascertain the proportion of TPM that is composed of PM2.5. The results indicated that mean TPM concentrations were substantially higher in smelters (3.86 mg/m3) than in fabrication units (0.76 mg/m3), with mean PM2.5 concentrations reflecting a similar pattern. Overall, occupational exposures in this study generally exceeded environmental PM2.5 concentrations by an order of magnitude.