Policy implications of the use of a process to describe the uncertainty in quantitative risk assessment

This research evaluates the utility of increasing sophistication of the risk assessment process through investigation of a U.S. Food and Drug Administration (FDA) regulation directed at reducing children's lead ingestion from ceramicware. The research evaluated: (1) If all risk components are identified and if variability and uncertainty associated with risk assessment data are specified and accounted for mathematically, will the resulting estimation of risk change? (2) Will the policy options based on the risk estimates change?; Lead ingestion from ceramicware was conceptualized as the product of the amount of a specific food ingested, the amount of lead leached into that food, and the frequency of use of ceramicware when ingesting that food. Two methods were used to calculate exposure and risk: point estimates (current FDA method) and distributional analysis using Monte Carlo simulation (an alternative method which includes a quantitative estimate of variability and uncertainty). The estimates of lead ingestion using the point estimate method for users (two year old children) ranged from 3.9 to 117 {dollar}mu{dollar}g lead/day from exposure to lead leaching from mugs into food assuming a 90th percentile ingestion rate. The distributional analysis of users resulted in 90th percentile values ranging from 1.5 to 56 {dollar}mu{dollar}g lead/day.; Risk to the population of two year olds was calculated by incorporating frequency of use data. The limited survey data available indicated very few children drank from ceramicware. The inclusion of use data resulted in near zero risk to the assessed population. The distributional analysis emphasized the role of coffee in increasing lead exposure from ceramicware suggesting that the FDA should examine the risk to adults drinking coffee from ceramicware, particularly pregnant women (due to concern of potential exposure to the fetus).; This study illustrates the importance of an iterative process of risk assessment in which target populations are identified, risk components are stated and quantified, and variability and uncertainty are recognized and incorporated, if possible. Even if FDA decides to regulate based on a "reasonable worst-case" scenario, the use of ceramicware remains very small. Perhaps alternatives to regulation are appropriate to decrease use of products in specific situations.