Occupational exposures to beryllium and lead: Investigating worksite conditions, personal behaviors, and job stress

This dissertation examines the work environment in association with occupational exposures to beryllium and lead. The first paper examines the association between occupational exposure to beryllium and the risk of beryllium sensitization (BeS) among former workers of the Nevada Test Site (NTS) where beryllium parts were machined. The risk of developing BeS was characterized is relation to workers' previous employment and job tasks performed while working at the NTS. While those individuals sensitized to beryllium did not have decreased pulmonary function or increased chest abnormalities when compared to those not sensitized, they may have a greater risk of developing chronic beryllium disease (CBD). We identified certain job tasks and work locations at the NTS, such as the machine shops, associated with increased risk of developing BeS.;The second paper investigates the significant workplace predictors of blood lead levels (BLL) among bridge painters. In addition to respirator-adjusted air lead levels, we found that education, months working on bridge painting crews, personal hygiene, and worksite containment facilities were associated with BLL. Hand wipe lead levels were positively associated with higher BLL at the end of the monitoring period compared with the beginning, and those who reported having their respirator fit-tested had smaller increases in BLL during the two-week period, whereas those who smoked on the work-site had greater increases in BLL over time. With identification of significant predictors of BLL, individual and work-site changes can be made to minimize personal exposure to lead among bridge painters.;The third paper investigates the relationship between workers' perception of job stress and personal exposure to lead. The Karasek model was used to characterize perception of psychological and physical demand, decision latitude, social support, and job insecurity, and mediation analysis was used to investigate the pathways from these job stress characteristics and BLL. We hypothesized that workers' perception of high demand and low decision latitude were related to high-exposure job tasks resulting in elevated personal exposures to lead via inhalation and incidental ingestion. Additionally, high demand and low decision latitude were thought to be associated with personal behaviors that may increase exposures, such as smoking on-site.