Reply to Lombi et al.: Clear effects of manufactured nanomaterials to soybean

Lombi et al. (1) have two concerns with our study (2): (i) nano-ZnO may not reach soils in “neat” form as it does in other Zn forms, which are already regulated; and (ii) the nano-CeO2 concentrations we used are much larger than predicted from exposure modeling. They assert that we should have studied different materials, at different concentrations, as determined by “proper assessment of the pathways.” This point does not change the importance of what we researched and reported: If these manufactured nanomaterials (MNMs) occur in soil at the concentrations studied, then the reported outcomes are possible. Indeed, our findings, which elucidate the key processes involved, will be essential for interpretation of future exposure assessments.