ABSTRACT
This chapter focuses on the general types of dose-response theories that can be used in risk assessment and risk management. It addresses the notion of observational limitations at small doses typically encountered in environmental or occupational settings. Choosing the right dose response has broad public health, political, social, and economic implications. Low-dose risk projections are not scientifically defensible because data are inadequate to select one theory to the exclusion of alternatives, and risks at low doses have large uncertainties that preclude utility in risk management decisions. The existence of a threshold provides a natural benchmark for the establishment of dose limits and risk-management goals. Using dose-response theories to calculate health effects of exposure to very small doses of carcinogens is so ingrained that real risks are no longer distinguishable from calculated, theoretical risks. The shape of the dose-response curve influences how risks are managed and communicated.
