No abstract

Cellulose nanomaterials (CNs) are emerging advanced materials with many unique properties and growing commercial significance. A life-cycle risk assessment and environmental health and safety roadmap identified potential risks from inhalation of powdered CNs in the workplace as a key gap in our understanding of safety and recommended addressing this data gap to advance the safe and successful commercialization of these materials. Here, we (i) summarize the currently available published literature for its contribution to our current understanding of CN inhalation hazard and (ii) evaluate the quality of the studies for risk assessment purposes using published study evaluation tools for nanomaterials to assess the weight of evidence provided. Our analysis found that the quality of the available studies is generally inadequate for risk assessment purposes but is improving over time. There have been some advances in knowledge about the effects of short-term inhalation exposures of CN. The most recent in vivo studies suggest that short-term exposure to CNs results in transient inflammation, similarly to other poorly soluble, low toxicity dusts such as conventional cellulose, but is markedly different from fibers with known toxicity such as certain types of multiwalled carbon nanotubes or asbestos. However, several data gaps remain, and there is still a lack of understanding of the effects from long-term, low-dose exposures that represent realistic workplace conditions, essential for a quantitative assessment of potential health risk. Therefore, taking precautions when handling dry forms of CNs to avoid dust inhalation exposure is warranted.

The National Institutes of Health (NIH) K18 award mechanism provides funded opportunities for established investigators to gain knowledge in fields outside of their primary disciplines, but outcomes associated with these awards have not been evaluated to date. NIH’s Basic Behavioral and Social Sciences Opportunity Network (OppNet) is one of the few initiatives that has used this award mechanism. We explored how the unique features of K18 awards affect the ability of recipients to obtain follow-on NIH research funding. We compared outcomes (ability to obtain follow-on funding and interval between receipt of the primary award and receipt of the first follow-on award) associated with OppNet K18 awards to findings from evaluations of other NIH career development (K) awards, which usually target early-career investigators. We hypothesized that K18 award recipients might be (1) more successful than are other K award recipients in obtaining follow-on NIH research funding due to their career experience or (2) less successful due to the competing demands of other projects. By analyzing follow-on NIH research awards and interview data, we found that OppNet K18 award recipients were at least as successful as were other K award recipients in obtaining follow-on funding and may have been more successful by certain measures. K18 awards produce their outcomes with a lower investment per investigator than do other K awards, suggesting continued or enhanced use of the mechanism.