Risk assessment for metallic substances usually follows the generally accepted framework format for risk assessment for all toxic substances, which involves (1) exposure assessment, (2) hazard identification, (3) assessment of dose-response relationships, and (4) risk characterization. The importance of risk communication is also addressed. Risk assessment/risk communication is of particular relevance for metals and metalloids, because all living organisms are exposed to these elements, and metals such as lead, cadmium, and mercury and the metalloid arsenic have been responsible for many human poisonings and even deaths. It is, hence, imperative that readers of this handbook have a firm perspective on the exposure levels of metallic substances that produce adverse health effects and the various risk assessment approaches that have been used and are evolving to protect the health and well-being of living organisms. Biomonitoring approaches, identification of toxic metallic species for hazard identification, dose-effect relationships, construction of dose-response curves, and the development of benchmark doses for various metallic species are discussed in relation to protecting sensitive subpopulations, because not all individuals within a general population are at equal risk for toxicity. Risk characterization using modern biomarkers that are capable of detecting early cellular effects to low-dose exposures to metallic substances will play an increasingly important role in assessing risk from exposure to this class of toxic substances on an individual or mixture basis. The issue of metal/metalloid-induced carcinogenesis is of ever increasing importance, because many of the elements associated with this cellular outcome produce a number of early cellular effects, including formation of reactive oxygen species (ROS) and apoptosis. Finally, the issue of risk communication/risk management is of great importance, because these issues are critical to addressing the health concerns of exposed populations and the practical, ethical, and financial issues related to reducing hazardous exposures to metallic substances.
San Diego: Elsevier, 2007, 3. 281-301 p.