APPLICATION OF CATEGORICAL REGRESSION TO MANGANESE RISK ASSESSMENT

The Mn-CatReg analysis, is a quantitative component in the Human Health Risk Assessment (HHRA) of inorganic manganese compounds, and seeks to explore innovative statistical and toxicological approaches to describe the occurrence of health events attributed to excess or deficient Mn following oral and/or inhalation exposure. The Mn-CatReg analysis takes selected information from published peer reviewed literature on Mn and its inorganic compounds dating back 70 years and synthesizes it into a database containing the necessary information to support mathematical modeling of exposure-response relationships.

The Mn-CatReg database includes information on species, route and duration of exposure, sex, age, and study design (excess or deficiency). Studies examining oral and inhalation exposure are treated as two independent data sets since it is hypothesized that the distribution of Mn in vivo differs between excess and deficiency, as well as by route of exposure. The Mn-CatReg analysis seeks to establish the relationship between various levels of oral exposure (excess and deficiency) and inhalation exposure (excess) and the corresponding health effects these exposure levels exert on the general population. The primary focus of the research was to explore the potential of categorical regression to identify the intake levels that minimize the chance of adverse health effects from deficiency or excess exposures. The second object of this research was to identify the health consequences over a continuum of occupational exposures.