All health care professionals confront questions involving risk on a daily basis. In the area of toxicology, these questions take many forms. An anxious parent with questions about a child’s potentially toxic exposure, an urgent consultation for a critically ill patient in the emergency department or intensive care unit, a request to interpret a laboratory test, media requests for information about environmental public health issues, a response to a hazardous materials incident, and biopreparedness education all involve directed communication of information and recommendations. Toxicologists and Certified Specialists in Poison Information (CSPIs) must establish rapport and provide information, instructions, and when appropriate, reassurance, typically by telephone or in short face-to-face interactions. For CSPIs, attribution of a patient’s symptoms to one or more potential exposures is further complicated by the absence of visual clues usually available during a clinical evaluation. In addition, the true reason or concern for a call is often difficult to discern, given limited time and incomplete information transfer. Cultural issues also impact perception and communication. All of these situations require a knowledgeable, compassionate, and well-reasoned response to toxicologic concerns.
This chapter focuses on 2 particular components of this response: risk assessment and risk communication. The underlying principles apply equally to individual calls to poison control centers (PCCs), educational outreach to the public and medical professionals, occupational and environmental exposure evaluations, and supportive roles with other public health agencies in terrorism preparedness, environmental public health tracking programs, and research.
In the context of this text, risk assessment is the process of determining the likelihood of toxicity for an individual or group after a perceived exposure to some substance, generally referred to as a xenobiotic. It involves determining the nature and extent of the exposure (ie, xenobiotic, dose, duration, route) and its specific clinical effects, defining an exposure pathway, and assessing the likelihood of effects from a given situation. When available, a published body of knowledge should be applied to some components of risk characterization or assessment. An overview and a number of tools are available through the websites of the US Environmental Protection Agency (EPA) and the Agency for Toxic Substances and Disease Registry (ATSDR) of the Centers for Disease Control and Prevention (CDC).1,12 However, any given risk assessment is hampered by incomplete information. The exact xenobiotic or mixture, whether there was an actual exposure or just proximity to the xenobiotic (completion of an exposure pathway), the exact dose, and unpredictable features such as host factors (underlying medical conditions or genetic polymorphisms) that could modify the response to a potential exposure, are all potential contributors of uncertainty. Unfortunately, those conducting a risk assessment are affected by their own biases and assumptions in the interpretation of their results, as are the people to whom a risk assessment is communicated. The emotional response to being “poisoned” makes evaluation and attribution even more difficult.