The mortality experience of a cohort of 1165 white male rubber workers with at least 1 part per million (ppm) per day of cumulative exposure to benzene (71432) was reexamined. At the manufacturing facilities where they were employed, natural rubber was dissolved in benzene and spread on a conveyor. The benzene was evaporated and recovered and the resultant thin film was stripped from the conveyor, rolled, and milled according to specifications. For the most part, employee 8 hour time weighted average exposures to airborne benzene were within the limits of the standard in effect at any given time during the history of operation of these facilities from 1939 to 1976. Neither the mortality from all causes of death combined nor the mortality from all malignant neoplasms combined was above the expected rate. However, there was a statistically significant increase in deaths from all lymphatic and hematopoietic neoplasms (standardized mortality ratio, 227), due primarily to increased death from leukemia and from multiple myeloma. A marked progressive increase in leukemia mortality was noted with increasing cumulative exposure to benzene. There was no apparent pattern in these deaths with regard to latency, which ranged from under 5 to over 30 years. Standardized mortality ratios for multiple myeloma did not increase with increasing exposure. Case control analysis confirmed the relationship of benzene exposure and leukemia. The authors conclude that an exponential decrease in the risk of death from leukemia could be achieved by lowering occupational exposure to benzene. A worker occupationally exposed to benzene at the average exposure level of 10ppm for 40 years would have an increased risk of death from leukemia of 154.5. If the average exposure were lowered to 1ppm, that excess risk would decrease to 1.7, and at 0.1ppm, the risk would reach background levels.
We take your privacy seriously. You can review and change the way we collect information below.
These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. They help us to know which pages are the most and least popular and see how visitors move around the site. All information these cookies collect is aggregated and therefore anonymous. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance.
Cookies used to make website functionality more relevant to you. These cookies perform functions like remembering presentation options or choices and, in some cases, delivery of web content that based on self-identified area of interests.
Cookies used to track the effectiveness of CDC public health campaigns through clickthrough data.
Cookies used to enable you to share pages and content that you find interesting on CDC.gov through third party social networking and other websites. These cookies may also be used for advertising purposes by these third parties.