Risk Assessment and Management of Chemical Contaminants in a Global Food Supply

Chemicals in food may be broadly grouped into two categories; additives that are added deliberately, and contaminants which are not.  The latter category includes chemicals that occur naturally in food and the environment.  Both additives and contaminants in food are often regulated by setting levels that limit the amount of a chemical that may be present in food.  However, because the presence and levels of additives can be more easily controlled than contaminants in food, establishing a limit is generally more effective for controlling dietary exposures from the former than the latter.  For that reason, alternative management options must often be considered for contaminants in food.  These options include placing limits on industry introduction of a chemical into the environment or a raw agricultural product prior to food production, establishing codes of agricultural practice, and consumer advisories to limit consumption of a particular food.  Since regulation of contaminants requires more effort than simply not adding them, executing any of these options may have other consequences, including increased effort, increased costs of food production, or loss of nutritional benefits.  The safety-factor based approaches that have been the primary means of evaluating toxicological data over the last fifty years are predicated on the notion that limits may be set without regard to other considerations.  Alternative approaches that separate the scientific evaluation from policy formulation (i.e., the risk assessment/risk management “Redbook” decision paradigm) are more easily utilized with alternative management options.  It has been recognized for many years that two key components of the Redbook paradigm are: 1) a dose-response model that will provide quantitative estimates of health outcomes at relevant levels of exposure, and 2) formal representation of the uncertainty associated with the risk estimates.  Yet, for reasons that are both scientific and political, decision paradigm shifts do not always occur smoothly.  First, changing paradigms may change the role of the scientific community in the decision-making process.  Additionally, a formal risk assessment approach often replaces a decision process that is relatively simple with one that may be quite complex.  Nonetheless, even though it has been used sporadically, there are examples of Redbook in the federal government that have successfully resulted in policy formulation, demonstrating that when needed, risk assessment and risk management can indeed be thought of as separate processes.