Wear particles from automotive friction brake pads of various sizes, morphology, and chemical composition are significant contributors towards particulate matter. Knowledge concerning the potential adverse effects following inhalation exposure to brake wear debris is limited. Our aim was, therefore, to generate brake wear particles released from commercial low-metallic and non-asbestos organic automotive brake pads used in mid-size passenger cars by a full-scale brake dynamometer with an environmental chamber simulating urban driving and to deduce their potential hazard in vitro. The collected fractions were analysed using scanning electron microscopy via energy-dispersive X-ray spectroscopy (SEM-EDS) and Raman microspectroscopy. The biological impact of the samples was investigated using a human 3D multicellular model consisting of human epithelial cells (A549) and human primary immune cells (macrophages and dendritic cells) mimicking the human epithelial tissue barrier. The viability, morphology, oxidative stress, and (pro-)inflammatory response of the cells were assessed following 24 h exposure to ~ 12, ~ 24, and ~ 48 µg/cm2 of non-airborne samples and to ~ 3.7 µg/cm2 of different brake wear size fractions (2-4, 1-2, and 0.25-1 µm) applying a pseudo-air-liquid interface approach. Brake wear debris with low-metallic formula does not induce any adverse biological effects to the in vitro lung multicellular model. Brake wear particles from non-asbestos organic formulated pads, however, induced increased (pro-)inflammatory mediator release from the same in vitro system. The latter finding can be attributed to the different particle compositions, specifically the presence of anatase.

BioNanomaterials Group Adolphe Merkle Institute University of Fribourg Chemin des Verdiers 4 1700 Fribourg Switzerland

Chemistry Department University of Fribourg Fribourg Switzerland

In Vitro Toxicology Group Swansea University Medical School Swansea Wales UK

Laboratory for Materials Biology Interactions Empa Swiss Federal Laboratories for Materials Science and Technology St Gallen Switzerland

Nanotechnology Centre VŠB Technical University of Ostrava Ostrava Czech Republic

Zobrazit více v PubMed

Amato F, Pandolfi M, Escrig A, et al. Quantifying road dust resuspension in urban environment by multilinear engine: a comparison with PMF2. Atmos Environ. 2009;43(17):2770. doi: 10.1016/j.atmosenv.2009.02.039. DOI

Balakrishna S, Lomnicki S, McAvey KM, Cole RB, Dellinger B, Cormier SA. Environmentally persistent free radicals amplify ultrafine particle mediated cellular oxidative stress and cytotoxicity. Part Fibre Toxicol. 2009;6(11):1. PubMed PMC

Blank F, Rothen-Rutishauser BM, Schurch S, Gehr P. An optimized in vitro model of the respiratory tract wall to study particle cell interactions. J Aerosol Med. 2006;19:392. doi: 10.1089/jam.2006.19.392. PubMed DOI

Blank F, Rothen-Rutishauser B, Gehr P. Dendritic cells and macrophages form a transepithelial network against foreign particulate antigens. Am J Resp Cell Mol. 2007;36(6):669. doi: 10.1165/rcmb.2006-0234OC. PubMed DOI

Blau PJ, Meyer Iii HM. Characteristics of wear particles produced during friction tests of conventional and unconventional disc brake materials. Wear. 2003;255:7–12. doi: 10.1016/S0043-1648(03)00111-X. DOI

Choi HC, Jung YM, Kim SB. Size effects in the Raman spectra of TiO2 nanoparticles. Vib Spectrosc. 2005;37(1):33. doi: 10.1016/j.vibspec.2004.05.006. DOI

Clift MJD, Fytianos K, Vanhecke D, Hočevar S, Petri-Fink A, Rothen-Rutishauser B. A novel technique to determine the cell type specific response within an in vitro co-culture model via multi-colour flow cytometry. Sci Rep UK. 2017;7(1):434. doi: 10.1038/s41598-017-00369-4. PubMed DOI PMC

Endes C, Schmidt O, Kinnear C, et al. An in vitro testing strategy towards mimicking the inhalation of high aspect ratio nanoparticles. Part Fibre Toxicol. 2014;11(1):40. doi: 10.1186/s12989-014-0040-x. PubMed DOI PMC

Filip P, Kovarik L, Wright M (1997) Automotive brake lining characterization. In: Proceedings of the 15th annual SAE Brake Colloquium P-319 10.4271/973024

Garg BD, Cadle SH, Mulawa PA, Groblicki PJ. Brake wear particulate matter emissions. Environ Sci Technol. 2000;34(21):4463. doi: 10.1021/es001108h. PubMed DOI

Gasser M, Riediker M, Mueller L, et al. Toxic effects of brake wear particles on epithelial lung cells in vitro. Part Fibre Toxicol. 2009;6(1):30. doi: 10.1186/1743-8977-6-30. PubMed DOI PMC

Geiser M, Kreyling WG. Deposition and biokinetics of inhaled nanoparticles. Part Fibre Toxicol. 2010;7(1):2. doi: 10.1186/1743-8977-7-2. PubMed DOI PMC

Ghio AJ, Cohen MD. Disruption of iron homeostasis as a mechanism of biologic effect by ambient air pollution particles. Inhal Toxicol. 2005;17(13):709. doi: 10.1080/08958370500224482. PubMed DOI

Grigoratos T, Martini G. Brake wear particle emissions: a review. Environ Sci Pollut Res Int. 2015;22:2491. doi: 10.1007/s11356-014-3696-8. PubMed DOI PMC

Hagino H, Oyama M, Sasaki S. Laboratory testing of airborne brake wear particle emissions using a dynamometer system under urban city driving cycles. Atmos Environ. 2016;131:269. doi: 10.1016/j.atmosenv.2016.02.014. DOI

Harrison RM, Jones AM, Gietl J, Yin J, Green DC. Estimation of the contributions of brake dust, tire wear, and resuspension to nonexhaust traffic particles derived from atmospheric measurements. Environ Sci Technol. 2012;46(12):6523. doi: 10.1021/es300894r. PubMed DOI

Hildemann LM, Markowski GR, Cass GR. Chemical composition of emissions from urban sources of fine organic aerosol. Environ Sci Technol. 1991;25(4):744. doi: 10.1021/es00016a021. DOI

Karlsson HL, Nilsson L, Moller L. Subway particles are more genotoxic than street particles and induce oxidative stress in cultured human lung cells. Chem Res Toxicol. 2005;18:19. doi: 10.1021/tx049723c. PubMed DOI

Kazimirova A, Peikertova P, Barancokova M, et al. Automotive airborne brake wear debris nanoparticles and cytokinesis-block micronucleus assay in peripheral blood lymphocytes: a pilot study. Environ Res. 2016;148:443. doi: 10.1016/j.envres.2016.04.022. PubMed DOI

Kennedy FE, Balbahadur AC, Lashmore DS. The friction and wear of Cu-based silicon carbide particulate metaal matrix composites for brake applications. Wear. 1997;203:715. doi: 10.1016/S0043-1648(96)07451-0. DOI

Krenkel W, Heidenreich B, Renz R. C/C-SiC composites for advanced friction systems. Adv Eng Mater. 2002;4(7):427. doi: 10.1002/1527-2648(20020717)4:7<427::AID-ADEM427>3.0.CO;2-C. DOI

Kukutschová J, Roubíček V, Malachová K, et al. Wear mechanism in automotive brake materials, wear debris and its potential environmental impact. Wear. 2009;267:5–8. doi: 10.1016/j.wear.2009.01.034. DOI

Kukutschová J, Moravec P, Tomášek V, et al. On airborne nano/micro sized wear particles released from low-metallic automotive brakes. Environ Pollut. 2011;159:998. doi: 10.1016/j.envpol.2010.11.036. PubMed DOI

Kumar P, Pirjola L, Ketzel M, Harrison RM. Nanoparticle emissions from 11 non-vehicle exhaust sources—a review. Atmos Environ Health Perspect. 2013;67:252. doi: 10.1016/j.atmosenv.2012.11.011. DOI

Lawrence S, Sokhi R, Ravindra K, Mao H, Prain HD, Bull ID. Source apportionment of traffic emissions of particulate matter using tunnel measurements. Atmos Environ. 2013;77:548. doi: 10.1016/j.atmosenv.2013.03.040. DOI

Lehmann A, Brandenberger C, Blank F, Gehr P, Rothen-Rutishauser B. A 3D model of the human epithelial airway barrier. In: Yarmush ML, editor. Alternatives to animal testing. Norwood, Massachusetts: Artech House; 2010. pp. 239–260.

Lemen RA. Asbestos in brakes: exposure and risk of disease. Am J Ind Med. 2004;45(3):229. doi: 10.1002/ajim.10334. PubMed DOI

Lenz AG, Karg E, Lentner B, et al. A dose-controlled system for airliquid interface cell exposure and application to zinc oxide nanoparticles. Part Fibre Toxicol. 2009;6:1743–8977. doi: 10.1186/1743-8977-6-32. PubMed DOI PMC

Loret T, Peyret E, Dubreuil M, et al. Airliquid interface exposure to aerosols of poorly soluble nanomaterials induces different biological activation levels compared to exposure to suspensions. Part Fibre Toxicol. 2016;13(1):58. doi: 10.1186/s12989-016-0171-3. PubMed DOI PMC

Malachova K, Kukutschova J, Rybkova Z, et al. Toxicity and mutagenicity of low-metallic automotive brake pad materials. Ecotoxicol Environ Saf. 2016;131:37. doi: 10.1016/j.ecoenv.2016.05.003. PubMed DOI

Mathissen M, Scheer V, Vogt R, Benter T. Investigation on the potential generation of ultrafine particles from the tire–road interface. Atmos Environ. 2011;45:6172. doi: 10.1016/j.atmosenv.2011.08.032. DOI

Nichols JE, Niles JA, Vega SP, Argueta LB, Eastaway A, Cortiella J. Modeling the lung: design and development of tissue engineered macro- and micro-physiologic lung models for research use. Exp Biol Med (Maywood) 2014;239:1135. doi: 10.1177/1535370214536679. PubMed DOI

Oberdörster G, Oberdörster E, Oberdörster J. Nanotoxicology: an emerging discipline evolving from studies of ultrafine particles. Environ Health Perspect. 2005;113:823. doi: 10.1289/ehp.7339. PubMed DOI PMC

Österle W, Griepentrog M, Gross T, Urban I. Chemical and microstructural changes induced by friction and wear of brakes. Wear. 2001;251(1–12):1469. doi: 10.1016/S0043-1648(01)00785-2. DOI

Paur HR, Cassee FR, Teeguarden J, et al. In-vitro cell exposure studies for the assessment of nanoparticle toxicity in the lung—a dialog between aerosol science and biology. J Aerosol Sci. 2011;42(10):668. doi: 10.1016/j.jaerosci.2011.06.005. DOI

Peikertová P, Kukutschová J, Vávra I, et al. Water suspended nanosized particles released from nonairborne brake wear debris. Wear. 2013;306(1–2):89. doi: 10.1016/j.wear.2013.07.008. DOI

Peters A, Wichmann HE, Tuch T, Heinrich J, Heyder J. Respiratory effects are associated with the number of ultrafine particles. Am J Respir Crit Care Med. 1997;155:1376. doi: 10.1164/ajrccm.155.4.9105082. PubMed DOI

Pope CA, Burnett RT, Thun MJ, et al. Lung cancer, cardiopulmonary mortality, and long-term exposure to fine particulate air pollution. J Am Med Assoc. 2002;287:1132. doi: 10.1001/jama.287.9.1132. PubMed DOI PMC

Riediker M, Devlin RB, Griggs TR, et al. Cardiovascular effects in patrol officers are associated with fine particulate matter from brake wear and engine emissions. Part Fibre Toxicol. 2004;1(2):2. doi: 10.1186/1743-8977-1-2. PubMed DOI PMC

Rothen-Rutishauser BM, Kiama SG, Gehr P. A three-dimensional cellular model of the human respiratory tract to study the interaction with particles. Am J Respir Cell Mol Biol. 2005;32:281. doi: 10.1165/rcmb.2004-0187OC. PubMed DOI

Rothen-Rutishauser B, Blank F, Mühlfeld CGP. In vitro models of the human epithelial airway barrier to study the toxic potential of particulate matter. Exp Opin Drug Metab Toxicol. 2008;4:1075. doi: 10.1517/17425255.4.8.1075. PubMed DOI

Rothen-Rutishauser B, Mueller L, Blank F, Brandenberger C, Muehlfeld C, Gehr P. A newly developed in vitro model of the human epithelial airway barrier to study the toxic potential of nanoparticles. Altex. 2008;25:191. doi: 10.14573/altex.2008.3.191. PubMed DOI

Samet JM, Dominici F, Curriero FC, Coursac I, Zeger SL. Fine particulate air pollution and mortality in 20 US cities, 1987–1994. N Engl J Med. 2000;343:1742. doi: 10.1056/NEJM200012143432401. PubMed DOI

Sanders PG, Xu N, Dalka TM, Maricq M. Airborne brake wear debris: size distribution, composition, and comparison of dynamometer and vehicle tests. Environ Sci Technol. 2003;37:4060. doi: 10.1021/es034145s. PubMed DOI

Schaumann F, Borm PJA, Herbrich A, et al. Metal-rich ambient particles (particulate matter 2. 5) cause airway inflammation in healthy subjects. Am J Resp Crit Care. 2004;170(8):898. doi: 10.1164/rccm.200403-423OC. PubMed DOI

Scheibe HJ, Drescher D, Alers P. Raman characterization of amorphous carbon films. Fresen J Anal Chem. 1995;353(5):695. doi: 10.1007/BF00321352. DOI

Schulz H, Harder V, Ibald-Mulli A, et al. Cardiovascular effects of fine and ultrafine particles. J Aerosol Med. 2005;18:1. doi: 10.1089/jam.2005.18.1. PubMed DOI

Stone V, Miller MR, Clift MJD, et al. Nanomaterials versus ambient ultrafine particles: an opportunity to exchange toxicology knowledge. Environ Health Perspect. 2017;125(10):106002. doi: 10.1289/EHP424. PubMed DOI PMC

Sun Q, Hong X, Wold LE. Cardiovascular effects of ambient particulate air pollution exposure. Circulation. 2010;121(25):2755. doi: 10.1161/CIRCULATIONAHA.109.893461. PubMed DOI PMC

Tada Y, Yano N, Takahashi H, et al. Acute phase pulmonary responses to a single intratracheal spray instillation of magnetite (Fe3O4) nanoparticles in Fischer 344 Rats. J Toxicol Pathol. 2012;25(4):233. doi: 10.1293/tox.25.233. PubMed DOI PMC

Thorpe A, Harrison RM. Sources and properties of non-exhaust particulate matter from road traffic: a review. Sci Total Environ. 2008;400:270. doi: 10.1016/j.scitotenv.2008.06.007. PubMed DOI

Tjalve H, Henriksson J. Uptake of metals in the brain via olfactory pathways. Neurotoxicology. 1999;20:181. PubMed

Uexküll O, Skerfving S, Doyle R, Braungart M. Antimony in brake pads—a carcinogenic component? J Clean Prod. 2005;13:19. doi: 10.1016/j.jclepro.2003.10.008. DOI

van der Gon HACD, Hulskotte JHJ, Visschedijk AJH, Schaap M. A revised estimate of copper emissions from road transport in UNECE-Europe and its impact on predicted copper concentrations. Atmos Environ. 2007;41(38):8697. doi: 10.1016/j.atmosenv.2007.07.033. DOI

Wåhlin P, Berkowicz R, Palmgren F. Characterisation of traffic-generated particulate matter in Copenhagen. Atmos Environ. 2006;40(12):2151. doi: 10.1016/j.atmosenv.2005.11.049. DOI

Wang Y, Alsmeyer DC, McCreery RL. Raman spectroscopy of carbon materials: structural basis of observed spectra. Chem Mater. 1990;2:557. doi: 10.1021/cm00011a018. DOI

Westerlund KG, Johansson C. Emission of metals and particulate matter due to wear of brake linings in Stockholm. WIT Trans Ecol Environ. 2002;53:23.

Wiedensohler A, Stratmann F, Tegen I. Environmental particles particle-lung interactions. New York: CRC Press; 2000. pp. 67–88.

World Health Organisation WHO (2013) Health effects of particulate matter

Xiong S, George S, Yu H, et al. Size influences the cytotoxicity of poly (lactic-co-glycolic acid) (PLGA) and titanium dioxide (TiO2) nanoparticles. Arch Toxicol. 2013;87(6):1075. doi: 10.1007/s00204-012-0938-8. PubMed DOI PMC

Yazdi AS, Guarda G, Riteau N, et al. Nanoparticles activate the NLR pyrin domain containing 3 (Nlrp3) inflammasome and cause pulmonary inflammation through release of IL-1α and IL-1β. Proc Natl Acad Sci USA. 2010;107(45):19449. doi: 10.1073/pnas.1008155107. PubMed DOI PMC