Shedding light on uncertainty by applying APROBA-Plus in the risk assessment of genotoxic carcinogens

Risk assessments of genotoxic carcinogens often rely on deterministic approaches with unknown conservatism. Full probabilistic risk assessments include the quantification of uncertainties and population variability, but are time- and data-intensive. The APROBA-Plus tool offers a (semi-)probabilistic alternative to quantify and visualize uncertainties in risk assessment. This paper evaluates the APROBA-Plus tool's applicability to the risk assessment of genotoxic carcinogens, by comparing deterministic and probabilistic approaches. The results show that APROBA-Plus effectively visualizes key uncertainties in risk assessments of genotoxic carcinogens. It can also compare exposure groups or separate components of mixtures. For the probabilistic approach, APROBA-Plus provides insight into the magnitude of uncertainty, the degree of conservativeness, the population coverage and possibilities for uncertainty reduction. Deterministic approaches are generally more conservative compared to the probabilistic approaches for the same substances, and do not provide these insights. In particular for genotoxic carcinogens, where uncertainty may be large, insight into these aspects may provide risk managers with more information, supporting decision taking on risk-reducing measures. Overall, APROBA-Plus can be the first tier in probabilistic risk assessment and will therefore facilitate the transition from deterministic to probabilistic risk assessment by providing a rapid, user-friendly means to incorporate uncertainty prior to more comprehensive analyses.