Developing a characterization factor framework for microbial contamination

Abstract

Life Cycle Impact Assessment (LCIA) can be used as a method to assess environmental impact of pathogen contamination in several stages. This paper attempts to determine the characterization factor (CF) for microbial contamination from livestock emission in surface water on a global scale. CF was defined as the change in Disability Adjusted Life Years (dDALY in yr) due to a marginal change in emission of a pathogen (dOocyst/day). This CF consists of intake fraction, effect factor and damage factor. The average intake fraction per river basin specific is 0.003, meaning that 0.3% of the emitted oocysts is emitted by the human population via drinking water and swimming. The effect factor value has a range from 0.0022-0736 case/oocyst, with the average 0.29 case/oocyst. The final characterization factor has a range between 0 to 1.2 x 10-5 DALY/oocyst in a river basin scale. In this study, CFs was determined for pathogen contamination for the first time. It was shown how these can be derived for Cryptosporidium and other pathogen with similar cause-impact pathways.