In this human health dimension, quantified indicators often include probability of infection, probability of illness, or DALYs, all of which can be calculated from one another with certain assumptions. Additionally, there have been methods developed to calculate monetized indicators based on the contribution of pollutants to mortality and the value of a statistical life (VSL; e.g., human health damage from freight transportation 150 ). However, this approach has not been widely adopted in the development of environmental technologies due to its shortcomings and controversies (e.g., how VSL is estimated). To quantify human health indicators, QRA can be performed following the steps of hazard identification, exposure assessment, dose response, risk characterization, and risk management. More specifically, to assess local human health risk due to pathogens, QSD inputs and process algorithms can be used to simulate pathogen concentrations, after which quantitative microbial risk assessment (QMRA) 155 can be performed to quantify the human health risk. QMRA can be performed with generic (e.g., using generic pathogen concentrations in feces for evaluating water and sanitation systems 156 ) or site-specific data (e.g., and Example 2 in Table ). Additionally, there are examples where QMRA is hybridized with LCA to characterize trade-offs between human health risk and environmental impacts. Similarly, when health risk related to chemicals (e.g., contaminants of emerging concern) is the focus, quantitative chemical risk assessment (QCRA) 165 can be applied. To facilitate the risk assessment, quantitative structure models (e.g., quantitative structure-activity relationship, QSAR; 166 quantitative structure property relationship, QSPR 167 ) can be used to predictively model the properties (e.g., toxicity, albeit with significant uncertainty 168 ) of interest, and certain semiquantitative techniques (e.g., CHEM21 guide 169 as applied in ) can be used as a screening strategy to exclude technologies that have significant safety concerns.