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Published on: March 20, 2018
Is benzene exposure from gasoline carcinogenic?
Ijaz S Jamall1, Calvin C Willhite
1Risk-Based Decisions, Inc., 2033 Howe Avenue, Suite 240, Sacramento, CA 95825, USA. ijamall@riskbaseddecisions.com
Journal of Environmental Monitoring : JEM
|February 5, 2008
Summary
Benzene may not be a reliable indicator for gasoline cleanup levels. Current evidence suggests threshold mechanisms for leukemia, questioning the scientific basis for benzene-based risk assessments in contaminated sites.
Area of Science:
- Environmental Toxicology
- Occupational Health
- Risk Assessment
Background:
- Benzene is often used as a surrogate to determine health risks from gasoline-contaminated sites.
- Leaking underground storage tanks pose environmental challenges for soil and groundwater remediation.
Purpose of the Study:
- To critically evaluate the scientific validity of using benzene as a surrogate for health risk assessments of gasoline-impacted sites.
- To examine the dose-response relationships and toxicological mechanisms of benzene-induced leukemia.
Main Methods:
- Review of epidemiological studies on occupational benzene exposure and acute myelogenous leukemia (AML).
- Analysis of molecular toxicology and pharmacokinetic data for benzene.
- Evaluation of toxicological and epidemiological literature on chronic unleaded gasoline exposure.
Main Results:
- Epidemiological data suggest sigmoid dose-response relationships for benzene and AML.
- Evidence indicates threshold mechanisms for benzene-induced leukemia.
- Required benzene exposure levels for carcinogenic response exceed typical environmental exposures at contaminated sites.
Conclusions:
- Using benzene's theoretical cancer risks to set cleanup levels for gasoline is not scientifically defensible.
- Existing risk assessment models may overestimate health risks at gasoline-contaminated properties.
- Re-evaluation of cleanup standards for gasoline-impacted soil and groundwater is warranted.
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