Abstract
There is a paradox in that some types of nanoparticles (a generic term for particles less than ∼100 nm in diameter) are used in nanomedicine for imaging and therapy, whereas other types of nanoparticles produced by combustion are thought by many scientists to be responsible for the adverse health effects of air pollution. In addition, the nanotechnology industry is in the process of producing new nanoparticles whose hazard and potential for human exposure are not yet determined. Medicinal nanoparticles are being designed and tested on a case-by-case basis using testing procedures derived from biomaterials and drug safety and with due regard to risk–benefit. There are considerable differences in physical and chemical properties between medicinal nanoparticles and the industrial and combustion-derived nanoparticles studied by particle toxicologists, a recognized branch of toxicology that studies particles. Medical nanoparticles tend to be composed of materials that are similar to biological molecules and they are generally biodegradable. By contrast, combustion-derived nanoparticles are carbon-centered and contaminated with metals and organics, with a biopersistent core. To fully address the paradox that nanoparticles can be both beneficial and harmful, there is a need, over the next 10 years, to advance our understanding of the characteristics that determine acute and chronic toxicity, translocation, biodegradation and elimination of all types of nanoparticles likely to gain access to the human body.
Papers of special note have been highlighted as either of interest (•) or of considerable interest (••) to readers.
Bibliography
- 1 Donaldson K, Tran L, Jimenez L et al.: Combustion-derived nanoparticles: a review of their toxicology following inhalation exposure. Part Fibre Toxicol.2(1),10 (2005).Crossref, Medline, Google Scholar
- 2 Dennekamp M, Mehenni OH, Seaton A, Cherrie J: Exposure to ultrafine particles and PM2.5 in different micro-environments. Ann. Occup. Hyg.46(Suppl.),412–414 (2002).• Shows the ubiquitousness of nanoparticles in environmental air.Crossref, Google Scholar
- 3 Oberdorster G, Sharp Z, Elder AP, Gelein R, Kreyling W, Cox C: Translocation of inhaled ultrafine particles to the brain. Inhal. Toxicol.16,437–445 (2004).Crossref, Medline, CAS, Google Scholar
- 4 Nel A, Xia T, Madler L, Li N: Toxic potential of materials at the nanolevel. Science311(5761),622–627 (2006).Crossref, Medline, CAS, Google Scholar
- 5 Donaldson K, Jimenez LA, Rahman I et al.: Respiratory health effects of ambient air pollution particles: role of reactive species. In: Oxygen/Nitrogen Radicals: Lung Injury And Disease. Vallyathan V, Shi X, Castranova V (Eds). Marcel Dekker, NY, USA (2004).Google Scholar
- 6 Donaldson K, Stone V, Borm PJ et al.: Oxidative stress and calcium signaling in the adverse effects of environmental particles (PM10). Free Radic. Biol. Med.34(11),1369–1382 (2003).Crossref, Medline, CAS, Google Scholar
- 7 Donaldson K, Mills N, MacNee W, Robinson S, Newby DE: Role of inflammation in cardiopulmonary health effects of PM. Toxicol. Appl. Pharmacol.207(Suppl. 2),483–488 (2005).Crossref, Medline, Google Scholar
- 8 Sun Q, Wang A, Jin X et al.: Long-term air pollution exposure and acceleration of atherosclerosis and vascular inflammation in an animal model. JAMA294(23),3003–3010 (2005).Crossref, Medline, CAS, Google Scholar
- 9 Mills NL, Tornqvist H, Robinson SD et al.: Diesel exhaust inhalation causes vascular dysfunction and impaired endogenous fibrinolysis. Circulation112(25),3930–3936 (2005).Crossref, Medline, CAS, Google Scholar
- 10 Schwartz J: What are people dying of on high air-pollution days. Environ. Res.64,26–35 (1994).Crossref, Medline, CAS, Google Scholar
- 11 Suwa T, Hogg JC, Quinlan KB, Ohgami A, Vincent R, van Eeden SF: Particulate air pollution induces progression of atherosclerosis. J. Am. Coll. Cardiol.39(6),935–942 (2002).Crossref, Medline, CAS, Google Scholar
- 12 Wichmann HE, Peters A: Epidemiological evidence of the effects of ultrafine particle exposure. Phil. Trans. R. Soc. Lond. A358,2563–2565 (2000).Crossref, Google Scholar
- 13 Peters A, von KS, Heier M et al.: Exposure to traffic and the onset of myocardial infarction. N. Engl. J. Med.351(17),1721–1730 (2004).Crossref, Medline, CAS, Google Scholar
- 14 Kreuter J: Influence of the surface properties on nanoparticle-mediated transport of drugs to the brain. J. Nanosci. Nanotechnol.4(5),484–488 (2004).Crossref, Medline, CAS, Google Scholar
- 15 Radomski A, Jurasz P, Alonso-Escolano D et al.: Nanoparticle-induced platelet aggregation and vascular thrombosis. Br. J. Pharmacol.146(6),882–893 (2005).Crossref, Medline, CAS, Google Scholar
- 16 Laden F, Neas LM, Dockery DW, Schwartz J: Association of fine particulate matter from different sources with daily mortality in six U.S. cities. Environ. Health Perspect.108(10),941–947 (2000).Crossref, Medline, CAS, Google Scholar
- 17 Schwartz J: Daily deaths are associated with combustion particles rather than SO2 in Philadelphia. Occup. Environ. Med.57(10),692–697 (2000).Crossref, Medline, CAS, Google Scholar
- 18 Ibald-Mulli A, Wichmann HE, Kreyling W, Peters A: Epidemiological evidence on health effects of ultrafine particles. J. Aerosol. Med.15(2),189–201 (2002).Crossref, Medline, CAS, Google Scholar
- 19 Pope CA, III, Burnett RT, Thun MJ et al.: Lung cancer, cardiopulmonary mortality, and long-term exposure to fine particulate air pollution. JAMA287(9),1132–1141 (2002).Crossref, Medline, CAS, Google Scholar
- 20 Dockery DW, Luttmann-Gibson H, Rich DQ et al.: Association of air pollution with increased incidence of ventricular tachyarrhythmias recorded by implanted cardioverter defibrillators. Environ. Health Perspect.113(6),670–674 (2005).Crossref, Medline, CAS, Google Scholar
- 21 Seaton A, MacNee W, Donaldson K, Godden D: Particulate air-pollution and acute health-effects. Lancet345,176–178 (1995).Crossref, Medline, CAS, Google Scholar
- 22 Norris G, Larson T, Koenig J, Claiborn C, Sheppard L, Finn D: Asthma aggravation, combustion, and stagnant air. Thorax55(6),466–470 (2000).Crossref, Medline, CAS, Google Scholar
- 23 Brunekreef B, Janssen NH, deHartog J, Harssema H, Knape M, vanVliet P: Air pollution from truck traffic and lung function in children living near motorways. Epidemiology8,298–303 (1997).• Key summary of the health impacts of air pollution particles.Crossref, Medline, CAS, Google Scholar
- 24 Li XY, Gilmour PS, Donaldson K, MacNee W: Free radical activity and pro-inflammatory effects of particulate air pollution (PM10) in vivo and in vitro. Thorax51(12),1216–1222 (1996).Crossref, Medline, CAS, Google Scholar
- 25 Ghio AJ, Kim C, Devlin RB: Concentrated ambient air particles induce mild pulmonary inflammation in healthy human volunteers. Am. J. Respir. Crit. Care Med.162(3 Pt 1),981–988 (2000).Crossref, Medline, CAS, Google Scholar
- 26 Pope CA III, Hill RW, Villegas GM: Particulate air pollution and daily mortality on Utah’s Wasatch Front. Environ. Health Perspect.107(7),567–573 (1999).Crossref, Medline, CAS, Google Scholar
- 27 Dockery DW, Pope CA, Xu XP et al.: An association between air-pollution and mortality in 6 united-states cities. N. Engl. J. Med.329,1753–1759 (1993).Crossref, Medline, CAS, Google Scholar
- 28 Churg A, Brauer M, Carmen Avila-Casado M, Fortoul TI, Wright JL: Chronic exposure to high levels of particulate air pollution and small airway remodeling. Environ. Health Perspect.111(5),714–718 (2003).Crossref, Medline, CAS, Google Scholar
- 29 Kunzli N, Jerrett M, Mack WJ et al.: Ambient air pollution and atherosclerosis in Los Angeles. Environ. Health Perspect.113(2),201–206 (2005).Crossref, Medline, CAS, Google Scholar
- 30 Dailey LA, Jekel N, Fink L et al.: Investigation of the proinflammatory potential of biodegradable nanoparticle drug delivery systems in the lung. Toxicol. Appl. Pharmacol. DOI 10.1016/j.taap.2006.01.016 (2006) Epub ahead of print.Medline, Google Scholar
- 31 Oberdorster G, Maynard A, Donaldson K et al.: Principles for characterizing the potential human health effects from exposure to nanomaterials: elements of a screening strategy. Part Fibre Toxicol.2,8 (2005).•• Outlines the thinking of particle toxicologists on how to test nanoparticles.Crossref, Medline, Google Scholar
- 32 Oberdorster G, Oberdorster E, Oberdorster J: Nanotoxicology: an emerging discipline evolving from studies of ultrafine particles. Environ. Health Perspect.113(7),823–839 (2005).•• Overview of nanoparticle toxicology.Crossref, Medline, CAS, Google Scholar

