• Chapter

Experimental skeletal dysmorphology: risk assessment issues


Tyl, R., Marr, M., & Myers, C. (2004). Experimental skeletal dysmorphology: risk assessment issues. In E. J. Massaro, & J. M. Rogers (Eds.), The Skeleton: Biochemical, Genetic, and Molecular Interactions in Development and Homeostasis (pp. 385-414). Totowa, NJ: Humana Press.


The two components of formal risk assessment are hazard identification and risk assessment. Hazard can be defined as the intrinsic capacity of an agent to do harm. Risk can be defined as the assessment of whether an agent will produce adverse outcomes to the species of interest under relevant exposure conditions. The critical aspect of risk is relevant exposure, by a relevant route, at relevant doses or concentrations, during sensitive life stages (i.e., timing of exposure), and for appropriate durations. Laboratory animal studies are critical for the risk component. The doses for the animal studies at which effects are observed or not observed are then compared with the exposures from all sources (e.g., feed, water, air) as measured, calculated, or modeled of the species of interest, to calculate a margin of exposure (MOE). The larger the MOE, the less concern. The species of interest is usually, but not always, humans (e.g., increasing attention to environmental risk assessments).