Exposure to diesel exhaust increases the risk of lung cancer, studies show, but it isn’t clear how much exhaust is dangerous. Miners come in contact with some of the highest levels of diesel exhaust, so the National Cancer Institute studied their exposure levels and risk of lung cancer. Westat helped create and carry out the study, including completing the design of the questionnaire, locating and interviewing former miners or their relatives, and preparing the data for analysis.
- Westat designed the study questionnaire, which was given using a computer-assisted telephone interviewing (CATI) system. Interviewers followed a script that the system can change based on the respondents’ answers and on information already known about the participant. CATI provided instant reports on the data collected.
- We developed training manuals and conducted interviewer training sessions.
- We also conducted in-depth telephone research and other tracing methods to locate the former miners or their surviving relatives, whom we then interviewed.
- We recruited former miners from selected mines to participate in a series of focus groups about their jobs, their use of diesel-powered equipment, and practices of the mining operations.
- We confirmed lung cancer diagnoses by reviewing the miners’ pathology reports.
- Our published results showed a strong and consistent relationship between how much diesel exhaust miners were exposed to and their risk of dying of lung cancer.
- We controlled for smoking and other factors that increase the risk of developing lung cancer.
- We had a very good response rate of between 94% and 98%, which added considerable validity to the survey results.
- The study results will help public health experts better understand the risks of diesel exhaust, including the risks to city dwellers and the 1.4 million Americans who are exposed to diesel exhaust.