A mortality, morbidity, and hematology study of petrochemical employees potentially exposed to 1,3-butadiene monomer

This three-part study is an update of a previous report that examined the m ortality, morbidity, and hematological data of employees from a petrochemic al facility in Texas who had potential exposure to 1,3-butadiene monomer. T he first part describes the updated cause-specific mortality of 614 workers . Vital status for each cohort member was ascertained through 1998, a 9-yea r extension of the previous study. The second part is an examination of the morbidity experience of cohort members who were still working during 1992- 1998, including 289 of the 614 mortality cohort members. The third part is an evaluation of the hematological results from routine health surveillance and/or medical examinations. Approximately 430 of the 614 employees who ha d complete blood count (CBC) data as of December 1999 were included in the hematological evaluations. The most recent examination containing CBC data was used and compared with similar data for over 2600 other employees from this facility. Overall mortality during the follow-up period, 1948-1998. wa s significantly lower than for the local comparison population (standardize d mortality ratio (SMR) of 0.55 with a 95% confidence interval (CI) of 0.42 -0.70). Mortality for all cancer was also significantly lower (SMR, 0.57; 9 5% CI, 0.32-0.92). Mortality for all lymphohematopoietic cancer was about t he same as the comparison population (SMR, 1.06; 95% CI, 0.22-3.11). None o f the cause-specific morbidity was in excess compared with an internal comp arison group. There were no differences in the distribution or mean values of heamatological variables (e.g. white blood cells, red blood cells, hemog lobin, platelets, mean corpuscular volume) between the butadiene cohort and the comparison group, or between a subgroup of workers in jobs with the hi ghest potential for butadiene exposure (i.e. shipping) and the rest of the butadiene cohort. The findings of this study suggest that the butadiene exp osure at this facility in the last 20 years does not pose a health hazard t o employees. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.