Environment - Overview - EHS - Text

Not much is known about exposure of humans to nanomaterials in the environment sector. CNT was identified for use in water filtration systems and nanosensors implemented to monitor environmental parameters. Other nanomaterials (e.g. Ni, Pt, Au, Si, InP, GaN) are used in nanosensors, evaluated as part of the ICT sector (see NanoData Landscape Compilation: ICT), and are therefore not further discussed here. Nano-remediation was identified as an important environmental application.

Various nanomaterials, such as nanoparticles, tubes, wires, fibres, function as adsorbents and catalysts and their composites with polymers are used for remediation as in the detection and removal of gases (e.g. SO2, CO, NOx), chemical contaminants (e.g. arsenic, iron, manganese, nitrate, heavy metals), organic pollutants (aliphatic and aromatic hydrocarbons) and biological substances, such as viruses, bacteria, parasites and antibiotics [1]. Examples of nanomaterials applied are cobalt manganese oxide nanoparticles, synthesised in situ in pressurised reactors for the supercritical water oxidation process to clean waste water of organics; zero-valent iron in permeable reactive barriers and silver, iron, gold, iron oxides and titanium oxide in polymeric membranes to remove metals and other contaminants from wastewater; nanofibres (silica, dendrimers, CNTs) in nanofibre media and membranes used for filtration; nano-zeolites and dendrimers functionalised with inorganic nanoparticles, used as sorbents to remove heavy metals from wastewater [2]. Another nanomaterial used in remediation, is nano-calcium peroxide, which is applied in in situ chemical oxidation (ISCO) of contaminated ground water, sediment or soil in order to destroy the contaminants by converting them to innocuous compounds [3].

The basis for the evaluation was “Stoffenmanager Nano” application [4,5] a risk-banding tool developed for employers and employ­ees to prioritise health risks occurring as a result of respiratory exposure to nanoparticles for a broad range of worker scenarios.

The respiratory route is the main route of exposure for many occupational scenarios, while the oral route of exposure is considered minor and sufficiently covered, from a safety point of view, by good hygiene practices established in production facilities as prescribed through general welfare provisions in national health and safety legislation in EU countries [6]. In view of the nature of the products in this sector, oral exposure of consumers is also considered to be minor.

The dermal route may be the main route of exposure for some substances or exposure situations, and cause local effects on the skin or systemic effects after absorption into the body [7]. However, nanoparticles as such are very unlikely to penetrate the skin [8] and consequently nano-specific systemic toxicity via the dermal route is improbable. Therefore, when evaluating risks from nanotechnology for the respiratory route, the most important aspects of occupational and consumer safety are covered.

Carbon nanotubes, dendrimers, graphene and graphene oxide have a high risk priority, indicating the need to apply exposure control methods or to assess the risks more precisely. All other materials have an intermediate priority, except calcium peroxide and titanium dioxide in the in-use phase, for which they have a low priority.

[1] Khin, M.M., Nair, A.S., Babu, V.J., Murugan, R., Ramakrishna, S., 2012. A review on nanomaterials for environmental remediation. Energy Environ. Sci. 5, 8075. doi:10.1039/c2ee21818f

[2] Ibid

[3] Khodaveisi, J., Banejad, H., Afkhami, A., Olyaie, E., Lashgari, S., Dashti, R., 2011. Synthesis of calcium peroxide nanoparticles as an innovative reagent for in situ chemical oxidation. J. Hazard. Mater. 192, 1437–40. doi:10.1016/j.jhazmat.2011.06.060

[4] Marquart, H., Heussen, H., Le Feber, M., Noy, D., Tielemans, E., Schinkel, J., West, J., Van Der Schaaf, D., 2008. 'Stoffenmanager', a web-based control banding tool using an exposure process model. Ann. Occup. Hyg. 52, 429-441.

[5] Van Duuren-Stuurman, B., Vink, S., Verbist, K.J.M., Heussen, H.G.A., Brouwer, D., Kroese, D.E.D., Van Niftrik, M.F.J., Tielemans, E., Fransman, W., 2012. Stoffenmanager Nano version 1.0: a web-based tool for risk prioritization of airborne manufactured nano objects. Ann. Occup. Hyg. 56, 525-541.

[6] ECHA, 2012. Chapter R.14: Occupational exposure estimation in: Anonymous Guidance on Information Requirements and Chemical Safety Assessment., Version: 2.1 ed. European Chemicals Agency, Helsinki, Finland.

[7] Ibid

[8] Watkinson, A.C., Bunge, A.L., Hadgraft, J., Lane, M.E., 2013. Nanoparticles do not penetrate human skin - A theoretical perspective. Pharm. Res. 30, 1943-1946

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