To provide insight into mortality patterns associated with job-specific exposures, we examined rates of cause-specific mortality compared with the general U.S. population.
These estimated CO levels were converted into yearly estimates of job-specific exposures to REC using the job-specific REC exposures estimated using the 1998 2001 data and the assumed linear relationship between CO and REC.
We included all eight job-specific exposure variables in regression models to adjust lung cancer risk for different jobs held throughout a worker's career.
Measurement error that is nondifferential and of the Berkson type (Armstrong 1998; as in occupational studies where the mean job-specific exposure is assigned to all workers in that job) with constant error variance across exposure levels has been shown in RR models to result in a downward bias on the exposure response relationships in RR models (Armstrong 1990).
Lifetime occupational history included each occupational period by year, line of business, job title and specific exposures (solvents, radioactive substances, radiation, asbestos, dusts).
In this industry, the association between job and specific exposure-related duties has remained stable over time, and the dates of diesel and other equipment use are known (Garshick et al. 2002).
Some associations were also found with times spent in certain coke ovens jobs with specific exposure scenarios, but results were not consistent across the two cohorts and limitations in the exposure estimates were noted.
We did not ask direct questions about exposure, rather we sought information on jobs and tasks and assigned specific exposures using pre-defined rules (Peters et al, 2014).
Specifically, we used the structure of our exposure model along with historical input data on the model covariates to predict job-specific EC exposures for workers in the earlier study; we used the ratio of our model-based predictions to the measured values reported by Zaebst et al. (1991) to adjust for changes in work-related conditions over time.
Consequently, personal job-specific REC exposures for 1993 for Mine J were estimated using data from Mine B. Mine B was selected "because of the similarity of geographic location, the type of mining [both were potash mines], the amount of HP present, and the air flow rates in the two facilities" Stewart et al. (2010).
We grouped occupational titles instead of D-ISCO codes because D-ISCO codes are based on skills required to fulfil tasks and duties of the jobs and thus may not reflect specific exposures.
