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Background: Beryllium is known to be toxic to the lungs, causing beryllium lung disease and associated with increased lung cancer risk. Airborne beryllium exposures have been monitored since the 1940s. This study describes methods used to measure airborne beryllium concentrations and how historical measurements from a beryllium manufacturing plant were used to estimate workers' exposures in a lung cancer case-control study., Methods: Airborne beryllium concentrations had been measured using all-glass impingers, high-volume air filters, and personal respirable and total dust samplers. To provide consistency in exposure estimates over time, measurements collected by the other monitoring methods were converted to approximate the most frequently used high-volume, time-weighted average measurements. Because industrial hygiene measurements were not collected in every year for all jobs throughout the duration of the case-control study, exposure estimates had to be extrapolated from the existing measurements over time and across jobs., Results: Over 7,000 historical measurements were available to estimate beryllium exposures of workers over time. Average exposures between jobs varied considerably and exposures for all jobs decreased dramatically between the 1940s and 1970s due to major plant production changes., Conclusions: Although error in the exposure metrics for the cases and controls likely occurred due to limitations of the exposure assessment data, the exposure estimates for each job over time provided a reasonable, objective mechanism for categorizing workers by the relative exposures they were likely to have encountered during their tenure. Published 2001 Wiley-Liss, Inc.

Background: Cohort mortality studies have found elevated lung cancer mortality among beryllium-exposed workers, but none evaluated the association between beryllium exposure level and lung cancer risk. A nested case-control study of lung cancer within a beryllium processing plant was conducted to investigate the relationship between level of beryllium exposure and lung cancer., Methods: Lung cancer cases were identified by mortality follow-up through 1992 of a cohort of male workers at a beryllium alloy production plant. Each of 142 lung cancer cases was age-race-matched to five controls. Calendar-time-specific beryllium exposure estimates were made for every job in the plant and were used to estimate workers' cumulative, average, and maximum exposures. The potential confounding effects of smoking were also evaluated., Results: Lung cancer cases had shorter tenures and lower lifetime cumulative beryllium exposures than controls, but higher average and maximum exposures. However, after applying a 10- and 20-year lag, exposure metrics were higher for cases. Odds ratios in analyses lagged 20 years were significantly elevated for those with higher exposure compared to the lowest exposure category. Significant positive trends were seen with the log of the exposure metrics. Smoking did not appear to confound exposure-response analyses., Conclusion: Increased lung cancer among workers with higher lagged beryllium exposures and lack of evidence for confounding by cigarette smoking, provide further evidence that beryllium is a human lung carcinogen. Published 2001 Wiley-Liss, Inc.

A study of random digit dialing as a method of control selection was conducted as part of a matched case-control study of risk factors for neuroblastoma. The study was conducted in 1981-1982 in the Greater Delaware Valley region. Participation involved parents submitting to a 2-4-hour telephone interview. Potential control telephone numbers were selected by substituting the last two digits of the case family's telephone number with randomly selected digits. Successive random telephone numbers were called until a family with a child matching the case by year of birth plus or minus three years and race who agreed to participate was identified. A total of 3,245 telephone numbers were dialed to select controls for 101 cases, an average of 32.1 telephone numbers per case. Among 1,908 residential households contacted, 25.5% refused to give information about household characteristics. Of households with known characteristics, 45% had children under 25 years of age and 14.9% had a child eligible for the study. Among 181 households invited to participate, 101 agreed. For 18.6% of all calls, residential respondents were randomly offered $10 as an inducement to participate. This inducement did not significantly influence participation rates among families invited to participate.