Risk assessment single chemical, aggregate

The MOE approach is often used to determine the acceptability of acute risks for single chemicals and MOEs of >100 or >10 are usually considered acceptable when derived from toxicological data from animal and human studies, respectively. The US-EPA favors this concept for performing aggregate and cumulative risk assessments (Whalan and Pettigrew 1997). 

Human health risk assessments with chemicals and other agents (biological, physical) typically follow a paradigm that involves four steps - hazard identification, dose-response assessment, exposure assessment, and risk characterization. The process was recommended by the US National Research Council in the 1980s, and is usually applied to a single agent and exposures associated with one or more routes (oral, dermal, inhalation). This has been more recently referred to as aggregate exposure and risk assessment. 

III. SINGLE-CHEMICAL, AGGREGATE RISK ASSESSMENTS FOR OPs AND A -METHYL CMs... 

Until recently, most risk assessments focused on a single pesticide, considered each route separately, and evaluated each separately. Aggregate assessments consider a single pesticide but combine multiple routes and multiple sources of exposure. Cumulative assessments combine exposure assessments for chemicals that share a common mechanism of toxicity. 

This chapter describes and illustrates probabilistic approaches to aggregate and cumulative assessments of exposure, dose and risk. Aggregate assessments account for multiple sources (e.g. food, water, residence and occupation) and multiple routes (ingestion, dermal and inhalation) of exposure for a single pesticide. Cumulative assessments combine exposures for chemicals that share a... 

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