BENZENE EXPOSURE IN THE PETROLEUM DISTRIBUTION INDUSTRY ASSOCIATED WITH LEUKEMIA IN THE UNITED-KINGDOM - OVERVIEW OF THE METHODOLOGY OF A CASE-CONTROL STUDY

This paper describes basic principles underlying the methodology for o btaining quantitative estimates of benzene exposure in the petroleum m arketing and distribution industry. Work histories for 91 cases of leu kemia and 364 matched controls (4 per case) identified for a cohort of oil distribution workers up to the end of 1992 were obtained, primari ly from personnel records. information on the distribution sites, more than 90% of which were closed at the time of data collection, was obt ained from site visits and archive material. Industrial hygiene measur ements measured under known conditions were assembled for different ta sks. These were adjusted for conditions where measured data were not a vailable using variables known to influence exposure, such as temperat ure, technology, percentage of benzene in fuel handled, products handl ed, number of loads, and job activity. A quantitative estimate of derm al contact and peak exposure was also made.