The following letter was sent to the National Nanoscale Science Engineering and Technology (NSET) Subcommittee of the National Science and Technology Council of the White House Office of Science and Technology Policy (OSTP) on June 16, 2023.
The Institute for Agriculture and Trade Policy (IATP)1 appreciates this opportunity to contribute to the RFI and is grateful for the comment deadline extension that allows us to do so. IATP last wrote to OSTP about NNI EHS research strategy in November 2020, in the context of our response to a RFI about NNI’s Strategic Plan.2 We advocated for the inclusion of research on ethical, legal and societal implications (ELSI) of nanotechnology in the EHS strategy. IATP is pleased to see that this RFI includes a question concerning the integration of ELSI research into EHS strategy. Since 2020, IATP has analyzed research towards the commercialization of nanotechnology enabled pesticide products (“nanopesticides”) and protection of workers manufacturing and applying those products.3 This letter will reference some of that research and ELSI related issues to protecting workers, particularly from underserved populations, from inhalation and dermal exposure to nanopesticides.
This letter responds to three of the RFI questions:
2. What research gaps remain in addressing the six NNI EHS core research areas listed in question 1? We address the core research areas of 2) Human Exposure Assessment; (5) Risk Assessment and Risk Management Methods.
Human Exposure Assessment: Two scientists involved in the development of engineered nanomaterial coated RNA interferon (i.e., double stranded RNA) pesticide products wrote in 2020 that “At present, there seems to be an absence of published data concerning the potential biological impact of inhalation of RNA molecules.”4 Nevertheless, they conclude, “the plausibility of systemic dsRNA exposure from agricultural applications at levels capable of initiating RNAi machinery saturation is highly questionable.”5 They also advise the use of “appropriate personal protective equipment (PPE),” but to our knowledge, there is no such PPE for nano-enabled pesticide products. Because most of the scientists’ safety assessment concerns oral exposure to dsRNA, IATP believes on there is an urgent need for studies on inhalation exposure to dsRNA, particularly the chronic exposure of farmworkers spraying these nano-encapsulated dsRNA pesticide products.
The commercial use of this new generation of pesticide products could be imminent, hence our characterization of the research needs as “urgent.” On March 7, one product developer, GreenLight Bioscience, Inc., announced that it was “actively preparing for commercial launch prior to end of 2023 of our leading dsRNA solution, Calantha™, subject to regulatory approval.”6 Although the Environmental Protection Agency (EPA) has yet to issue an experiment use permit for field trials of this and other dsRNA-based products, EPA scientists have participated in a large literature and patent review of dsRNA pesticide products.7 The review of more than 500 research articles and 36,000 patents “identified 569 Type 1 [anti-microbial nano-metals and metal oxides] and 1,094 Type 2 [nano-encapsulation of current Active Ingredients] nanopesticides.”
EPA publicized this review and heralded the potential of dsRNA as a tool for sustainable agriculture.8 The nanomaterial coating serves both to protect the dsRNA from destruction by ultra-violet light and to dosing the dsRNA in response to an environmental signal. If the nano-coated pesticide particle bioaccumulates in the lower part of the lungs, it would be important to understand whether that exposure would result in immunosuppressive effects. A related research question would be if the composition of a nanomaterial coating would increase possible immunosuppressive impacts. We return in our response to the ESLI question to the problem of PPE for farmworkers and others with chronic inhalation exposure risk.
Risk Assessment and Risk Management Methods
According to our notes from one of the panelists at the May 31-June 1 “Refreshing the NNI’s Environment Health and Safety Research Strategy” meeting,9 most risk assessment studies of Manufactured Nanomaterials (MNs) still do not use well-characterized MNs from a standardized “library,” such as that of the Organization for Economic Cooperation and Development (OECD). Therefore, the results of such risk assessments, however well conducted, cannot be compared for regulatory use in making risk management decisions. A NNI EHS research strategy should prioritize surveying the reasons that researchers are not using well-characterized MNs in their risk assessments. The results of the survey could be used to propose some research funding rules that would commit applicants to using and reporting the use of well-characterized MNs or scientifically relevant comparators in their risk assessments.
A great deal of work has been done to categorize MNs for regulatory purposes, e.g., to ensure that toxicological studies are valid and scientifically accepted.10 Given the proliferation of new MNs, including nano-bio compounds, it must not be easy for researchers who are designing an experiment to risk assess a new MN by finding in a library of well-characterized MNs a relevant MN comparable to the one/s subject to the risk assessment, even with the aid of nano-informatic data bases. However, the alternative to experimental design without reference to well characterized MNs and their relevant comparators (if they exist), is a proliferation of risk assessments that are much less relevant to the scientific information needs of regulators.
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