Ethylene Oxide Cancer Risk Assessment Based on Epidemiological Data: Application of Revised Regulatory Guidelines

Abstract

Ethylene oxide (EO) research has significantly increased since the 1980s, when regulatory risk assessments were last completed on the basis of the animal cancer chronic bioassays. In tandem with the new scientific understanding, there have been evolutionary changes in regulatory risk assessment guidelines, that encourage flexibility and greater use of scientific information. The results of an updated meta-analysis of the findings from 10 unique EO study cohorts from five countries, including nearly 33,000 workers, and over 800 cancers are presented, indicating that EO does not cause increased risk of cancers overall or of brain, stomach or pancreatic cancers. The findings for leukemia and non-Hodgkin's lymphoma (NHL) are inconclusive. Two studies with the requisite attributes of size, individual exposure estimates and follow up are the basis for dose-response modeling and added lifetime risk predictions under environmental and occupational exposure scenarios and a variety of plausible alternative assumptions. A point of departure analysis, with various margins of exposure, is also illustrated using human data. The two datasets produce remarkably similar leukemia added risk predictions, orders of magnitude lower than prior animal-based predictions under conservative, default assumptions, with risks on the order of 1 x 10(-6) or lower for exposures in the low ppb range. Inconsistent results for "lymphoid" tumors, a non-standard grouping using histologic information from death certificates, are discussed. This assessment demonstrates the applicability of the current risk assessment paradigm to epidemiological data.

Exposure to Ethylene Oxide in Hospitals: Biological Monitoring and Influence of Glutathione S-Transferase and Epoxide Hydrolase Polymorphisms

“…The use of this gas necessitates strict precautions as it is considered to be a human carcinogen capable of increasing the incidence of leukemia and/or lymphoma (1)(2)(3)(4)(5). Besides its carcinogenic properties, ethylene oxide is an irritant (6) and may induce abortion (7).…”

Mortality Study Update of Ethylene Oxide Workers in Chemical Manufacturing: A 15 Year Update

“…In a meta-analysis of the 10 cohort studies, including nearly 30,000 workers and over 800 expected cancer deaths the authors concluded that there was no clear evidence of increased cancer risk related to EO exposure. 5 However, the evidence for an association with leukemia and non-Hodgkin lymphoma (NHL) was deemed inconclusive. After this meta-analysis several cohort studies have been updated.…”

Correlação entre exposição ao óxido de etileno e câncer de próstata: doença ocupacional?

“…Os 22 , mas nenhum estudo até a presente data foi conclusivo [8][9][10][22][23][24] . O risco de desenvolvimento de doença neoplásica maligna associada à exposição ao OEt não pode, até a presente data, ser confirmado.…”