Notice of Special Interest (NOSI): Understanding Exposure and Health Effects of Micro and/or Nanoplastics
Notice Number:

Key Dates

Release Date:

October 3, 2022

First Available Due Date:
February 05, 2023
Expiration Date:
November 17, 2027

Related Announcements

PA-20-185 - Research Project Grant (Parent R01 Clinical Trial Not Allowed)

PA-20-195 - NIH Exploratory/Developmental Research Grant Program (Parent R21 Clinical Trial Not Allowed)

PA-20-196 - NIH Exploratory/Developmental Research Grant Program (Parent R21 Basic Experimental Studies with Humans Required)

Issued by

National Institute of Environmental Health Sciences (NIEHS)


The purpose of this Notice of Special Interest (NOSI) is to inform potential applicants that the National Institute of Environmental Health Sciences (NIEHS), has special interest in applications that investigate exposure to, and health effects of, microplastics (MPs) and nanoplastics (NPs).


Production and usage of plastic has substantially increased all over the world. Plastic is utilized in various everyday use products including food packaging, consumer products, personal care products, paints, electronics and medical products, devices, & diagnostics. Although plastic provides significant benefit on several fronts, plastic waste is well-recognized as a major global environmental and health concern. Every year, it is estimated that 19 23 million metric tons of plastic waste enter waterways and 90% of this ends up in oceans through rivers. Plastic debris in aquatic environments degrade over time and auxiliary environmental conditions such as UV exposure, ambient and water temperature, agitation, pressure, and microbial digestion contribute to such degradation of bulk plastics into secondary microplastics (MPs) with size in the range of 5mm up to 100nm or nanoplastics (NPs) that are less than 100nm in size. Additionally, primary plastic particles in micro or nano size ranges are also generated for various applications and they get released into the environment as well. From various routes, primary/secondary MPs or NPs have been increasing in prevalence globally in the environment. The environmental MPs or NPs are recognized to have diverse properties, in terms of composition, shape, and size, and potential for containing proprietary additives.

Humans are exposed to MPs or NPs through oral, inhalation, and dermal routes, with major sources being drinking water, foods, air, clothing, and soil. Evidence suggests that exposure to MP or NP particles could lead to secondary exposure to hazardous chemicals that are adsorbed to them either from original processing or through environmental transportation and degradation. For example, metals, chemicals, pesticides, polychlorinated biphenyl (PCBs), Polyaromatic Hydrocarbons (PAHs), Persistent Organic Pollutants (POPs) and waterborne pathogens and Harmful Algal Blooms (HAB) toxins may bind to MPs or NPs.

In 2020, the Standing Committee on the Use of Emerging Science for Environmental Health Decisions of the National Academies of Sciences, Engineering, and Medicine (NASEM) held a workshop to explore Emerging technologies to advance research and improve decisions on the environmental health effects of microplastics . At this NIEHS sponsored workshop,, it was recognized that there is now sufficient evidence that humans are ingesting or breathing in MPs. It was concluded that there are significant and critical knowledge gaps about the risks and impacts of MPs on human health. The workshop further highlighted the need for future studies with controlled and focused approaches, application of advanced technologies, and incorporation of a cross-disciplinary approach. A need for studies incorporating the less understood NPs was highly emphasized as well.

More recent evidence demonstrates the presence of MPs in various human tissues including lung, blood, and placenta as well as in human breastmilk; however, the consequential biological and adverse effects are not well understood. Recognizing the emerging concerns associated with exposure to MPs or NPs from diverse routes of exposure, NIEHS seeks to promote research to understand potential health impacts of MPs and NPs. Due to the complexity associated with physical and chemical properties, NIEHS strongly recommends studies aimed at understanding biological effects to include MPs/NPs with defined physical and chemical properties.

Research Objectives

This Notice of Special Interest seeks to support research to gain comprehensive understanding of the physiochemical characterization, exposure, and related human health effects of MPs and NPs. Specific topics of research interest include, but are not limited to the following:

Exposure Assessment

  • Development of screening methods to rapidly detect and quantify MPs or NPs in air, food, drinking water, and other media such as biological fluids or tissues and assess exposure levels. These may include adopting many of the instruments or technologies developed to study engineered nanomaterials (ENMs) for the purpose of studying NPs and MPs.
  • Development and application of analytical methods or technologies to directly characterize or assess the MPs or NPs with a focus on analyzing the size, shape, type, surface property and chemical composition of MPs or NPs. These may include evaluation of the prevalence, types and concentration of classes of chemicals or natural toxins adsorbed to NPs and MPs. These methods should be developed in the context of assessing environmental exposure of MPs or NPs.
  • Standardization of approaches for methods of sample collection, processing from complex mixtures for real-world sample analysis, and physiochemical characterization of MPs or NPs for environmental exposure assessment.
  • Development and application of reference standards, quality controls, application of fluorescently labeled MPs or NPs and validated test methods for the selection, identification and quantitation of MPs or NPs in diverse milieu such as food, drinking water, air, and other media including biological fluids.
  • Development and validation of sensor/monitoring technologies or tools that can be applied to detect personal exposure levels of MPs or NPs

Health Effects

  • Application of In vitro & Air Liquid Interface (ALI) models and micro-physiological systems for characterizing the biological or toxicological effects of well characterized MPs or NPs.
  • Evaluation of acute and/or sub-chronic toxicity or risk assessment in diverse species/strains using well characterized MPs or NPs with studies focused on the relevant biological or toxic effects. These studies may focus on oxidative stress, inflammation, reproductive toxicology, respiratory effects, gut microbiome, or other systemic effects
  • Utilization of alternative model systems (e.g. Zebra fish, C. elegans) for developmental, acute, subchronic and/or chronic toxicity studies of well characterized and diverse MPs or NPs or mixtures of different types, size, shapes, and aged MP particles.
  • Characterization of biodistribution, bioaccumulation, absorption, biotransformation, biological interaction, and excretion of well characterized and environmentally relevant MPs or NPs.

It is highly recommended that the proposed biological, risk assessment, adverse effects and/or health effects studies are well controlled, special emphasis is placed on the characterization of the MPs or NPs species for the size, shape and type, and consideration is given to environmentally relevant concentrations and most important characteristics of the MPs or NPs. Where possible, standardized approaches should be used, and physically relevant assays should be applied. Cross-disciplinary approaches involving diverse team expertise are ideal and necessary to accomplish these research objectives, thus it is highly recommended that the applications include team of investigators with multidisciplinary expertise.

Application and Submission Information

This notice applies to due dates on or after Februray 5, 2023 and subsequent receipt dates through November 16, 2027.

Submit applications for this initiative using one of the following funding opportunity announcements (FOAs) or any reissues of these announcement through the expiration date of this notice.

PA-20-185 - Research Project Grant (Parent R01 Clinical Trial Not Allowed)

PA-20-195 - NIH Exploratory/Developmental Research Grant Program (Parent R21 Clinical Trial Not Allowed)

PA-20-196 - NIH Exploratory/Developmental Research Grant Program (Parent R21 Basic Experimental Studies with Humans Required)

All instructions in the SF424 (R&R) Application Guide and the funding opportunity announcement used for submission must be followed, with the following additions:

  • For funding consideration, applicants must include NOT-ES-23-002 (without quotation marks) in the Agency Routing Identifier field (box 4B) of the SF424 R&R form. Applications without this information in box 4B will not be considered for this initiative.

Applications nonresponsive to terms of this NOSI will not be considered for the NOSI initiative.


Please direct all inquiries to the Scientific/Research, Peer Review, and Financial/Grants Management contacts in Section VII of the listed funding opportunity announcements.

Scientific/Research Contact(s)

Lingamanaidu V. Ravichandran, Ph.D

National Institute of Environmental Health Sciences (NIEHS)

Telephone: 984-287-3309