RESUMEN
Approximately 1800 workers in pipe manufacturing plants in the United States may have been exposed to beta-napthlyamnine between 1970 and 1996. Once the chemical was detected, the contaminated additive in the resin was identified and discontinued. A bladder cancer-screening program was initiated in 1999. An annual two-stage screening program was developed to test for microscopic hematuria (stage one) and cytology (stage two), with a urology referral of positive or suspicious cytology. This paper presents the program methodology, cohort enumeration, recruitment, and enrollment strategies, and screening protocol. Enrollment data from the first 3 years are presented. Annual screening of a cohort of current and former employees is feasible. Original personnel records are often incomplete, making cohort identification important. Personal contact and follow-up are key elements of successful recruitment and retention.