Quantitative risk assessment utilizes a variety of human and animal studies, invariably significant animal data supplemented with limited human studies. The use of these human studies, however, can be problematic in committees heavily weighted to expertise in animal studies. This presentation covers specific examples of the misuse of cross sectional human studies in the EPA's Acute Exposure Guideline Level Committee. This Committee recommends once in a lifetime exposures to acutely toxic chemicals for five time periods; 10 and 30 minutes, and 1, 4 and 8 hours. These are set for three health endpoints: mild symptoms, serious injury and death. The current problems in the use of human studies in the AEGL process are; use of secondary sources rather than primary sources (methanol, hydrogen cyanide); primary sources where symptoms are reported by investigators or lack of reporting to investigators rather than a more scientific examination (acrylic acid, propylene oxide); pharmacokinetic human studies have been relied on that have no mention of symptom examination (methanol); and lastly, the association between a range of exposures and either symptoms or lack of symptoms is often attributed erroneously to the single highest measurement in the range (propylene glycol dinitrate, hydrogen cyanide). The primary solution to these problems is the inclusion in risk assessment committees of all relevant expertises. This should be from initial planning committees, the drafting of standard operating procedures and each chemical specific technical support document, the composition of the committee that recommends levels and all review committees.
Learning Objectives: Particiapnts will be able to recognize 3 ways that human studies can be misused.
Keywords: Risk Assessment, Environmental Health Hazards
Presenting author's disclosure statement:
Organization/institution whose products or services will be discussed: None
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.