Cumulative damage models of additional exposures and host factors.

Cumulative damage models represent a mathematically accurate conceptualized approach for the consideration of various problems of descriptive and analytical epidemiology. This study demonstrates the application of these models to situations where additional exposures, e.g., occupational exposures or smoking, overlay an always existing background exposure. Moreover, a way to incorporate host responses into the model is outlined, which is straightforward within this new approach, but has not been achieved by existing models to date. Based on empirical data, it is shown that some effects, which arise from additional exposures, can be understood as a kind of host response. This result contrasts with interpretations given by existing models and promises to open interesting discussion regarding which biological processes can be observed by epidemiological data.