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The International Organization for Standardization defines Engineered Nanomaterials, or ENMS, as materials with external dimensions between 1 and 100nm, the nanoscale, or having an internal surface structure at these dimensions.[1] Nanoparticles can be both incidental and engineered. Incidental nanoparticles include particles from dust storms, volcanic eruptions, forest fires, and ocean water evaporation. Engineered nanoparticles (EMMs) are nanoparticles that are made for use in cosmetics or pharmaceuticals like ZnO and TiO2. They are also found from sources such as cigarette smoke and building demolition.[2] Engineered nanoparticles have become increasingly important for many applications in consumer and industrial products, which has resulted in an increased presence in the environment. This proliferation has instigated a growing body of research into the effects of nanoparticles in the environment.

Nanoparticle Sources

Products containing nanoparticles such as cosmetics, coatings, paints, and catalytic additives can release nanoparticles into the environment in different ways. There are three main ways that nanoparticles enter the environment. The first is emission during the production of raw materials such as mining and refining operations. The second is emission during use, like cosmetics or sunblock getting washed into the environment. The third is emission after disposal of nanoparticle products or use during waste treatment, like nanoparticles in sewage and wastewater streams.[3]

The first emission scenario, causing 2% of emissions, results from the production of materials. Studies of a precious metals refinery found that the mining and refining of metals releases a significant amount of nanoparticles into the air. Further analysis showed concentration levels of silver nanoparticles far higher than OSHA standards in the air despite operational ventilation.[4] Wind speed can also cause nanoparticles generated in mining or related activities to spread further and have increased penetration power. A high wind speed can cause aerosolized particles to penetrate enclosures at a much higher rate than particles not exposed to wind.[5]

Construction also generates nanoparticles during the manufacture and use of materials. The release of nanoscale materials can occur during the evacuation of waste from cleanout operations, losses during spray drying, filter residuals, and emissions from filters.[6] Pump sprays and propellants on average can emit 1.1 x 10^8 and 8.6 x 10^9 particles/g.[7]

A significant amount of nanoparticles are also released during the handling of dry powders, even when contained in fume hoods. Particles on construction sites can have prolonged exposure to the atmosphere and thus are more likely to enter the environment. Nanoparticles in concrete construction and recycling introduce a new hazard during the demolition process, which can pose even higher environmental exposure risks. Concrete modified with nanoparticles is almost impossible to separate from conventional concrete, so the release may be uncontrollable if demolished using conventional means. Even normal abrasion and deterioration of buildings can release nanoparticles into the environment on a long-term basis.[6] Normal weathering can release 10 to 10^5 mg/m^2 fragments containing nanomaterials.[7]

Another emission scenario is release during use. Sunscreens can release a significant amount of TiO2 nanoparticles into surface waters. Testing of the Old Danube Lake indicated that there were significant concentrations of nanoparticles from cosmetics in the water. Conservative estimates calculate that there were approximately 27.2 micrograms/L of TiO2, if TiO2 was distributed throughout the entire 3.5*10^6 M^3 volume of the lake.[8]

Although TiO2 is generally considered as weakly soluble, these nanoparticles undergo weathering and transformation under conditions in acidic soils with high proportions of organic and inorganic acids. There are observable differences in particle morphology between manufactured and natural TIO2 nanoparticles, though differences may attenuate over time due to weathering. However, these processes are likely to take decades.[9]

Copper and zinc oxide nanoparticles that get into water can additionally act as chemosensitizers in sea urchin embryos.[10] It is predicted that exposure through sunscreen is probably the most important route for animals in aquatic systems to get exposure to harmful metal particles.[11] ZnOs from sunblock and other applications like paints, optoelectronics, and pharmaceuticals are entering the environment at an increasing rate. Their effects can be genotoxic, mutagenic, and cytotoxic.[12]

Nanoparticles can be transported through different mediums depending on their type. Emissions patterns have found that TiO2 NPs accumulate in sludge-treated soils. This means that the dominating emission pathway is through wastewater. ZnO generally collects in natural and urban soil as well as landfills. Silver nanoparticles from production and mining operations generally enter landfills and wastewater. Comparing different reservoirs by how readily Nanoparticles pollute them, ~63-91% of NPs accumulate in landfills, 8-28% in soils, aquatic environments receive ~7%, and air around 1.5%.[3]

Exposure Toxicity

Knowledge of the effects of industrial nanoparticles (NPs) released into the environment remains limited. Effects vary widely over aquatic and terrestrial environments as well as types of organisms.[13] The characteristics of the nanoparticle itself plays a wide variety of roles including size, charge, composition, surface chemistry, etc.[14] Nanoparticles released into the environment can potentially interact with pre-existing contaminants, leading to cascading biological effects that are currently poorly understood.[15]

Several scientific studies have indicated that nanoparticles can cause a series of adverse physiological and cellular effects on plants including root length inhibition, biomass reduction, altered transpiration rate, developmental delay, chlorophyll synthesis disruption, cell membrane damage, and chromosomal aberration.[16] Though genetic damage induced by metal nanoparticles in plants has been documented, the mechanism of that damage, its severity, and whether the damage is reversible remain active areas of study.[17] Studies of CeO2 nanoparticles were shown to greatly diminish nitrogen fixation in the root nodules of soybean plants, leading to stunted growth. Positive charges on nanoparticles were shown to destroy the membrane lipid bilayers in animal cells and interfere with overall cellular structure. For animals, it has been shown that nanoparticles can provoke inflammation, oxidative stress, and modification of mitochondrial distribution. These effects were dose-dependent and varied by nanoparticle type.[14]

Present research indicates that biomagnification of nanoparticles through trophic levels is highly dependent upon the type of nanoparticles and biota in question. While some instances of bioaccumulation of nanoparticles exist, there is no general consensus.[14][18]

Difficulties in Measurement

There is no clear consensus on potential human and ecological impacts stemming from exposure to ENMs.[19] As a result, developing reliable methods for testing ENM toxicity assessment has been a high priority for commercial usage. However, ENMs are found in a variety of conditions making a universal testing method non-viable. Currently, both in-vitro and in-vivo assessments are used, where the effects of NPs on events such as apoptosis, or conditions like cell viability, are observed.[20]

In measuring ENMs, addressing and accounting for uncertainties such as impurities and biological variability is crucial. In the case of ENMs, some concerns include changes that occur during testing such as agglomeration and interaction with substances in the testing media, as well as how ENMS disperse in the environment.[19] For example, one investigation into how the presence of fullerenes impacted largemouth bass in 2004[21] concluded that fullerenes were responsible for neurological damage done to the fish, whereas subsequent studies revealed this was actually a result of byproducts resulting from the dispersal of fullerenes into tetrahydrofuran (THF) and minimal toxicity was observed when water was used in its place.[22] Fortunately, greater thoroughness in the process of testing could help to resolve these issues. One method that has proven useful in avoiding artifacts is the thorough characterization of ENMS in the laboratory conducting the testing rather than just relying on the information provided by manufacturers.[23]

In addition to problems that can arise due to testing, there is contention on how to ensure testing is done for environmentally relevant conditions, partly due to the difficulty of detecting and quantifying ENMs in complex environmental matrices.[24] Currently, straightforward analytical methods are not available for the detection of NPs in the environment, although computer modeling is thought to be a potential pathway moving forward.[25] A push to focus on the development of internationally agreed upon unbiased toxicological models holds promise to provide greater consensus within the field as well as enable more accurate determinations of ENMs in the environment.[26]

Regulation and Organizations

Current Policy

The regulation of nanomaterials is present in the U.S. and many other countries globally. Current policy is directed mainly at manufacturing exposure of NPs in the environment.

International / Intergovernmental Organizations

Organization for Economic Co-operation and Development (OECD) - Working Party on Nanomaterials (WPN)

The WPN works on a multitude of projects with the purpose of mitigating potential threats and hazards associated with nanoparticles. The WPN has conducted research on methods for testing, improvements on field assessments, exposure relief, and efforts to educate individuals and organizations on environmental sustainability with respect to NPs.[27]

International Organization for Standardization (ISO) - ISO/TC 229

ISO/TC 229 focuses on standardizing manufacturing, nomenclature/terminology, instrumentation, testing and assessment methodology, and safety, health, and environmental practices.[28]

North America

In terms of the United States, the FDA and OSHA focus on regulations that prevent toxic harm to people from NPs, whereas the EPA takes on environmental policies to inhibit harmful effects nanomaterials may pose on the planet.

Toxic Substances Control Act (TSCA)

The EPA is tackling regulations through two approaches under the TSCA: information gathering rule on new to old NMs and required premanufacturing notification for novice NMs. The gathering rule requires companies that produce or import NMs to provide the EPA with chemical properties, production/use amounts, manufacturing methods, and any found health, safety, and environmental impact for any nanomaterials being used. The premanufacturing notifications gives the EPA better governance over nanomaterial exposure, health testing, manufacturing/process and worker safety, and release amount which can allow the agency to take control of a NM if it poses concerning risk.[29]

National Nanotechnology Initiative (NNI)

This R&D initiative involves 20 departments and independent agencies that focus on nanotechnology innovation and regulation in the United States. Projects and activities of NNI span from R&D to policy on environment and safety regulations of NMs.[30]

Nano Environmental Health and Safety (NIEHS)

NIEHS built itself from the complications that came with conducting research and assessment on nanomaterials. NIEHS realized the rapid adoption of NMs in products from a large variety of industries, and since then the organization supports research focused on understanding the underlying threats NMs may pose on the environment and people.[31]

Canada-U.S. Regulatory Cooperation Council (RCC) Nanotechnology Initiative

This joint action plan was constructed in order for the U.S. and Canada to protect and improve safety and environmental impacts of NMs without hindering growth and investment in NMs for both countries. The RCC oversees both countries and has maintained regulations, worked to create new regulations with the goal of alignment, secure transparency, and ensure that new and beneficial opportunities in the nanotechnology sector were shared with both countries.[32]


Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) and Classification, Labeling, and Packaging (CLP)

Nanomaterials are defined consistently in both legislations in order to promote harmony in industry use. In January, 2020 REACH listed explicit requirements for businesses that import or manufacture NMs in Annex I, III, VI, VII-XI, and XII. Reporting of chemical characteristics/properties, safety assessments, and downstream user obligations of NMs are all required for reporting to the ECHA.[33]

Biocidal Products Regulation (BPR)

The BPR has different regulation and reporting requirements than what is stated in REACH and CLP. Data and risk assessments are required for substance approval, specific labeling requirements are needed, and reporting on the substance which includes current use and potential risks must be done every 5 years.[34]


Asia Nano Forum (ANF)

This network organization focuses on ensuring responsible manufacturing of nanomaterials that are environmentally, economically, and population safe. ANF supports joint projects with a focus on supporting safe development in emerging economies and technical research. Overall, the organization helps promote homogenous regulation and policy on NMs in Asia.[35]

National Nanotechnology Standardization Technical Committee (NSTC)

Standards and regulation policies are reviewed by the NSTC. The technical committee SAC/TC279 focuses on normalizing terminology, methodology, assessment methods, and material use in the field. The committee develops specific test protocols and technical standards for companies manufacturing NMs. In addition to this, the NSTC is constantly adding to their nano-material toxicology database in order to better standards and regulation.[36]

Future Policy

There are supporters and opponents of increased regulation on nanomaterials. Supporters of regulation want NPs to be seen as a class and/or have precautionary policy in place against them. Opponents believe that over-regulation could lead to harmful effects on the economy and customer and industrial freedom. There are currently multiple policies up for consideration for the purpose of changing nanomaterial regulation.[37]


  1. ^ ISO (International Organization for Standardization). Nanotechnologies—Vocabulary—Part 1: Core Terms, TS 80004-1; Geneva, Switzerland, 2010.
  2. ^ Jeevanandam, Jaison; Barhoum, Ahmed; Chan, Yen S; Dufresne, Alain; Danquah, Michael K (3 April 2018). "Review on nanoparticles and nanostructured materials: history, sources, toxicity and regulations". Beilstein Journal of Nanotechnology. 9: 1050–1074. doi:10.3762/bjnano.9.98. PMC 5905289. PMID 29719757.
  3. ^ a b Bundschuh, Mirco; Filser, Juliane; Lüderwald, Simon; McKee, Moira S.; Metreveli, George; Schaumann, Gabriele E.; Schulz, Ralf; Wagner, Stephan (8 February 2018). "Nanoparticles in the environment: where do we come from, where do we go to?". Environmental Sciences Europe. 30 (1): 6. doi:10.1186/s12302-018-0132-6. PMC 5803285. PMID 29456907.
  4. ^ Miller, A.; Drake, P. L.; Hintz, P.; Habjan, M. (19 April 2010). "Characterizing Exposures to Airborne Metals and Nanoparticle Emissions in a Refinery". The Annals of Occupational Hygiene. 54 (5): 504–13. doi:10.1093/annhyg/meq032. PMID 20403942.
  5. ^ Hertbrink, William A.; Thimons, Edward (February 1, 1999). In-depth survey report : Control technology for environmental enclosures - the effect of wind speed upon aerosol penetration into an enclosure at Clean Air Filter, Defiance, Iowa (Report).
  6. ^ a b Mohajerani; Burnett; Smith; Kurmus; Milas; Arulrajah; Horpibulsuk; Abdul Kadir (20 September 2019). "Nanoparticles in Construction Materials and Other Applications, and Implications of Nanoparticle Use". Materials. 12 (19): 3052. Bibcode:2019Mate...12.3052M. doi:10.3390/ma12193052. PMC 6804222. PMID 31547011.
  7. ^ a b Koivisto, Antti Joonas; Jensen, Alexander Christian Østerskov; Kling, Kirsten Inga; Nørgaard, Asger; Brinch, Anna; Christensen, Frans; Jensen, Keld Alstrup (January 2017). "Quantitative material releases from products and articles containing manufactured nanomaterials: Towards a release library". NanoImpact. 5: 119–132. doi:10.1016/j.impact.2017.02.001.
  8. ^ Gondikas, Andreas P.; Kammer, Frank von der; Reed, Robert B.; Wagner, Stephan; Ranville, James F.; Hofmann, Thilo (30 April 2014). "Release of TiO2 Nanoparticles from Sunscreens into Surface Waters: A One-Year Survey at the Old Danube Recreational Lake". Environmental Science & Technology. 48 (10): 5415–5422. Bibcode:2014EnST...48.5415G. doi:10.1021/es405596y. PMID 24689731.
  9. ^ Pradas del Real, Ana Elena; Castillo-Michel, Hiram; Kaegi, Ralf; Larue, Camille; de Nolf, Wout; Reyes-Herrera, Juan; Tucoulou, Rémi; Findling, Nathaniel; Salas-Colera, Eduardo; Sarret, Géraldine (2018). "Searching for relevant criteria to distinguish natural vs. anthropogenic TiO2 nanoparticles in soils". Environmental Science: Nano. 5 (12): 2853–2863. doi:10.1039/c8en00386f.
  10. ^ Wu, Bing; Torres-Duarte, Cristina; Cole, Bryan J.; Cherr, Gary N. (16 April 2015). "Copper Oxide and Zinc Oxide Nanomaterials Act as Inhibitors of Multidrug Resistance Transport in Sea Urchin Embryos: Their Role as Chemosensitizers". Environmental Science & Technology. 49 (9): 5760–5770. Bibcode:2015EnST...49.5760W. doi:10.1021/acs.est.5b00345. PMID 25851746.
  11. ^ Welch, Craig (14 May 2015). "Do Sunscreens' Tiny Particles Harm Ocean Life in Big Ways?". National Geographic News.
  12. ^ Beegam, Asfina; Prasad, Parvathy; Jose, Jiya; Oliveira, Miguel; Costa, Fernando G.; Soares, Amadeu M. V. M.; Gonçalves, Paula P.; Trindade, Tito; Kalarikkal, Nandakumar; Thomas, Sabu; Pereira, Maria de Lourdes (2016). "Environmental Fate of Zinc Oxide Nanoparticles: Risks and Benefits". In Larramendy, Marcelo; Soloneski, Sonia (eds.). Toxicology: New Aspects to This Scientific Conundrum. pp. 81–112. ISBN 978-953-51-2716-1.
  13. ^ Nadres, Enrico Tapire; Fan, Jingjing; Rodrigues, Debora Frigi (2016), Gonçalves, Gil; Marques, Paula; Vila, Mercedes (eds.), "Toxicity and Environmental Applications of Graphene-Based Nanomaterials", Graphene-based Materials in Health and Environment: New Paradigms, Carbon Nanostructures, Cham: Springer International Publishing, pp. 323–356, doi:10.1007/978-3-319-45639-3_11, ISBN 978-3-319-45639-3, retrieved 2021-09-08
  14. ^ a b c Exbrayat, Jean-Marie; Moudilou, Elara N.; Lapied, Emmanuel (2015). "Harmful Effects of Nanoparticles on Animals". Journal of Nanotechnology. 2015: 1–10. doi:10.1155/2015/861092.
  15. ^ Deng, Rui; Lin, Daohui; Zhu, Lizhong; Majumdar, Sanghamitra; White, Jason C.; Gardea-Torresdey, Jorge L.; Xing, Baoshan (31 July 2017). "Nanoparticle interactions with co-existing contaminants: joint toxicity, bioaccumulation and risk". Nanotoxicology. 11 (5): 591–612. doi:10.1080/17435390.2017.1343404. PMID 28627273. S2CID 10243283.
  16. ^ Ma, Chuanxin; White, Jason C.; Dhankher, Om Parkash; Xing, Baoshan (4 June 2015). "Metal-Based Nanotoxicity and Detoxification Pathways in Higher Plants". Environmental Science & Technology. 49 (12): 7109–7122. Bibcode:2015EnST...49.7109M. doi:10.1021/acs.est.5b00685. PMID 25974388.
  17. ^ López-Moreno, Martha L.; de la Rosa, Guadalupe; Hernández-Viezcas, José Á.; Castillo-Michel, Hiram; Botez, Cristian E.; Peralta-Videa, José R.; Gardea-Torresdey, Jorge L. (October 2010). "Evidence of the Differential Biotransformation and Genotoxicity of ZnO and CeO2 Nanoparticles on Soybean (Glycine max) Plants". Environmental Science & Technology. 44 (19): 7315–7320. Bibcode:2010EnST...44.7315L. doi:10.1021/es903891g. PMC 2944920. PMID 20384348.
  18. ^ Zhao, Xingchen; Yu, Miao; Xu, Dan; Liu, Aifeng; Hou, Xingwang; Hao, Fang; Long, Yanmin; Zhou, Qunfang; Jiang, Guibin (17 April 2017). "Distribution, Bioaccumulation, Trophic Transfer, and Influences of CeO2 Nanoparticles in a Constructed Aquatic Food Web". Environmental Science & Technology. 51 (9): 5205–5214. Bibcode:2017EnST...51.5205Z. doi:10.1021/acs.est.6b05875. PMID 28383254.
  19. ^ a b Petersen, Elijah J.; Henry, Theodore B.; Zhao, Jian; MacCuspie, Robert I.; Kirschling, Teresa L.; Dobrovolskaia, Marina A.; Hackley, Vincent; Xing, Baoshan; White, Jason C. (27 March 2014). "Identification and Avoidance of Potential Artifacts and Misinterpretations in Nanomaterial Ecotoxicity Measurements". Environmental Science & Technology. 48 (8): 4226–4246. Bibcode:2014EnST...48.4226P. doi:10.1021/es4052999. PMC 3993845. PMID 24617739.
  20. ^ Kumar, Vinay; Sharma, Neha; Maitra, S. S. (25 November 2017). "In vitro and in vivo toxicity assessment of nanoparticles". International Nano Letters. 7 (4): 243–256. Bibcode:2017INL.....7..221K. doi:10.1007/s40089-017-0221-3.
  21. ^ Oberdörster, Eva (July 2004). "Manufactured Nanomaterials (Fullerenes, C60) Induce Oxidative Stress in the Brain of Juvenile Largemouth Bass". Environmental Health Perspectives. 112 (10): 1058–1062. doi:10.1289/ehp.7021. PMC 1247377. PMID 15238277.
  22. ^ Henry, Theodore B; Petersen, Elijah J; Compton, Robert N (August 2011). "Aqueous fullerene aggregates (nC60) generate minimal reactive oxygen species and are of low toxicity in fish: a revision of previous reports". Current Opinion in Biotechnology. 22 (4): 533–537. doi:10.1016/j.copbio.2011.05.511. PMID 21719272.
  23. ^ Park, Heaweon; Grassian, Vicki H. (March 2010). "Commercially manufactured engineered nanomaterials for environmental and health studies: Important insights provided by independent characterization". Environmental Toxicology and Chemistry. 29 (3): 715–721. doi:10.1002/etc.72. PMID 20821499. S2CID 5388886.
  24. ^ von der Kammer, Frank; Ferguson, P. Lee; Holden, Patricia A.; Masion, Armand; Rogers, Kim R.; Klaine, Stephen J.; Koelmans, Albert A.; Horne, Nina; Unrine, Jason M. (January 2012). "Analysis of engineered nanomaterials in complex matrices (environment and biota): General considerations and conceptual case studies". Environmental Toxicology and Chemistry. 31 (1): 32–49. doi:10.1002/etc.723. PMID 22021021. S2CID 40391637.
  25. ^ Bundschuh, Mirco; Filser, Juliane; Lüderwald, Simon; McKee, Moira S.; Metreveli, George; Schaumann, Gabriele E.; Schulz, Ralf; Wagner, Stephan (8 February 2018). "Nanoparticles in the environment: where do we come from, where do we go to?". Environmental Sciences Europe. 30 (1): 6. doi:10.1186/s12302-018-0132-6. PMC 5803285. PMID 29456907.
  26. ^ Bahadar, Haji; Maqbool, Faheem; Niaz, Kamal; Abdollahi, Mohammad (2016). "Toxicity of Nanoparticles and an Overview of Current Experimental Models". Iranian Biomedical Journal. 20 (1): 1–11. doi:10.7508/ibj.2016.01.001. PMC 4689276. PMID 26286636.
  27. ^ "Regulatory Frameworks for Nanotechnology in Foods and Medical Products" (PDF). OECD Science, Technology and Industry Policy Papers. 2013. doi:10.1787/5k47w4vsb4s4-en. ((cite journal)): Cite journal requires |journal= (help)
  28. ^ "About". ISO/TC 229 - Nanotechnologies.
  29. ^ Deng, Rui; Lin, Daohui; Zhu, Lizhong; Majumdar, Sanghamitra; White, Jason C.; Gardea-Torresdey, Jorge L.; Xing, Baoshan (31 July 2017). "Nanoparticle interactions with co-existing contaminants: joint toxicity, bioaccumulation and risk". Nanotoxicology. 11 (5): 591–612. doi:10.1080/17435390.2017.1343404. PMID 28627273. S2CID 10243283.
  30. ^ "What is the NNI?". United States National Nanotechnology Initiative.
  31. ^ "Nano Environmental Health and Safety (Nano EHS)". National Institute of Environmental Health Sciences.
  32. ^ "Joint Action Plan for the Canada-United States Regulatory Cooperation Council". 12 April 2016.
  33. ^ "Nanomaterials". ECHA.
  34. ^ "Nanomaterials under Biocidal Products Regulation". ECHA.
  35. ^ "Control of Nanoscale Materials under the Toxic Substances Control Act". US EPA. 27 March 2015.
  36. ^ Jarvis, Darryl Stuart; Richmond, Noah (24 October 2011). "Regulation and Governance of Nanotechnology in China: Regulatory Challenges and Effectiveness". European Journal of Law and Technology. 2 (3).
  37. ^ Resnik, David B. (1 April 2019). "How Should Engineered Nanomaterials Be Regulated for Public and Environmental Health?". AMA Journal of Ethics. 21 (4): 363–369. doi:10.1001/amajethics.2019.363. PMID 31012424.