Hello,
I have been using USEtox in my research as a mean to assess potential toxicological impacts in agricultural soil from different sorts of materials which may be used as fertilizers. With regards to metals, usually the highest Impact Score comes from Zn and Fe, which I understand it have a toxic potential but also is a micronutrient that may benefit the vegetable growth depending on its concentration.
Would you have any recommendation on how to interpret the USEtox results for these case, particularly for substances that has a role as plant nutrients?
Thanks in advance and best regards.
Zinc and iron, among other metals, are essential metals for several ecological species as well as for humans. A large fraction of the human population is in fact deficient of, for example, zinc. Hence, the characterization factor for zinc is an overestimation of the potential impacts on human population-level health. For ecosystems, the current recommendation is to assume that ecosystems are adjusted to the current background levels of any metal, including essential metals. Hence, any additional emission is assumed to have a negative effect on ecosytems. This topic is further discussed in Fantke et al. 2018 (p. 2967).