The known unknowns of nanomaterials: Describing and characterizing uncertainty within environmental, health and safety risks

Various stakeholders have acknowledged that uncertainty within determining the potential environmental, health and safety (EHS) risks of nanomaterials (NM) may inhibit nanotechnology from reaching its full potential. A thorough description of such uncertainties is an imperative first step towards closing knowledge gaps and prioritizing research strategies. Through a qualitative uncertainty analysis which systematically screened 31 reports and articles published by leading scientists and authorities on the potential risks of NM, we found that knowledge gaps pervade nearly all aspects of basic EHS knowledge, with a well recognized need for improved testing procedures and equipment, human and environmental effect and exposure assessments and full characterization of NM. We also estimate the current level of knowledge to be at an early state of development, and further empirical research will most likely reduce most knowledge gaps. According to this analysis, research should be prioritized towards the assessment and development of test procedures and equipment and full characterization of NM in order to most effectively reduce uncertainties in the short term.