You are here:
The Use of Biomonitoring Data in Exposure and Human Health Risk Assessment: BENZENE CASE STUDY.
Citation:
Arnold, S., J. Angerer, P. Boogaard, M. Hughes, R. O'Lone, S. Robison, AND A. Schnatter. The Use of Biomonitoring Data in Exposure and Human Health Risk Assessment: BENZENE CASE STUDY. CRITICAL REVIEWS IN TOXICOLOGY. CRC Press LLC, Boca Raton, FL, 43(2):119-153, (2013).
Impact/Purpose:
Benezene biomarker levels for non-smokers are generally consistent with ambient air monitoring results. Smoker's exposure to benzene is generally 2-5 times higher. More research to assess where biomarkers of benzene exposure can predict early, key events is needed.
Description:
HESI Biomonitoring Technical Committee A framework of "Common Criteria" (i.e., a series of questions) has been developed to inform the use and evaluation of biomonitoring data in the context of human exposure and risk assessment (Albertini et al., 2006). The data-rich chemical benzene was selected for use in a case study to assess whether refinement of the Common Criteria framework was necessary, and to gain additional perspective on approaches for integrating biomonitoring data into a risk-based context. The available data for benzene satisfied most of the Common Criteria and allowed for a risk-based evaluation of the benzene biomonitoring data. Key data gaps were identified such as the mode of action of benzene and the correlation of specific biomarkers of exposure to health effects, but there is still strong evidence that supports a causal relationship between exposure to benzene and toxic effects. In general, biomarker central tendency concentrations for non-smokers are at or below the predicted blood or urine concentration of benzene that would correspond to exposure at the USEPA reference concentration (30 ug/m3), but greater than blood or urine concentration relating to the air concentration at the 10'5 excess cancer risk (2.8 ug/m3), assuming a stochastic genotoxic mechanism. Smokers clearly have higher levels of benzene exposure, and biomarker levels of benzene for non-smokers are generally consistent with ambient air monitoring results. More research to assess whether biomarkers of benzene exposure can help predict early, key toxicological events is needed. However, since many of benzene's metabolites, which are hypothesized to be involved in its mode of action have non-benzene sources such as the diet, interpretation of these data will be difficult at current exposure levels.