Environmental and Experimental Botany 72 (2011) 272–277 Contents lists available at ScienceDirect Environmental and Experimental Botany journal homepage: www.elsevier.com/locate/envexpbot Pollen abortion rates, nitrogen dioxide by passive diffusive tubes and bioaccumulation in tree barks are effective in the characterization of air pollution M.F.H. Carneiro a , F.Q. Ribeiro b , F.N. Fernandes-Filho b , D.J.A. Lobo b , F. Barbosa Jr. c , C.R. Rhoden a , T. Mauad b , P.H.N. Saldiva b , R. Carvalho-Oliveira b,∗ a Federal University of Health Sciences of Porto Alegre (UFCSPA). Porto Alegre, RS, Brazil b Experimental Air Pollution Laboratory, Department of Pathology, Sao Paulo University Medical School, Sao Paulo, Brazil c Department of Clinical Analysis, Toxicology and Bromatology, Faculty of Pharmaceutical Sciences of Ribeirao Preto, Sao Paulo University, Brazil article info Article history: Received 9 March 2011 Received in revised form 31 March 2011 Accepted 1 April 2011 Keywords: Air pollution Bioaccumulation in tree barks Bioassays using plants Nitrogen dioxide Passive monitoring Pollen abortion assay abstract This study aims to evaluate the feasibility of using simple techniques – pollen abortion rates, passive diffusive tubes (NO 2 ) and trace element accumulation in tree barks – when determining the area of influence of pollution emissions produced in a traffic corridor. Measurements were performed at 0, 60 and 120 meters from a major road with high vehicular traffic, taking advantage of a sharp gradient that exists between the road and a cemetery. NO 2 values and trace elements measured at 0 meters were significantly higher than those measured at more distant points. Al, S, Cl, V, Fe, Cu, and Zn exhibited a higher concentration in tree barks at the vicinity of the traffic corridor. The same pattern was observed for the pollen abortion rates measured at the three different sites. Our data suggests that simple techniques may be applied either to validate dispersion land-based models in an urban settings or, alternatively, to provide better spatial resolution to air pollution exposure when high-resolution pollution monitoring data are not available. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Epidemiological studies indicate that emissions from high traffic streets impose a significant health burden on those living in close proximity (Edwards et al., 1994; Wilkinson et al., 1999; Brauer et al., 2002; Lin et al., 2002; Lwebuga-Mukasa et al., 2004; Gauderman et al., 2004; Schwartz et al., 2005; Maynard et al., 2007; Kim et al., 2008; McEntee and Ogneva-Himmelberger, 2008; Brauer et al., 2008; Medina-Ramón et al., 2008; Morgenstern et al., 2008). In addition, the risk associated with traffic emissions exhibits a spatial gradient, as reported by Gauderman et al. (2004), who demonstrated in an 8-year longitudinal study that living within 500 m of highways caused deficits in attained lung function at 18 years of age. An important component of studies of the influence of traffic corridors on human health is the adequate exposure assessment. In previous studies, where the spatial variation in air quality is made by conventional network systems, the distance to a major road has been used as a proxy estimate for exposure. This can lead to error in the estimates as the monitoring networks often cover a large area that may not reflect small-area exposures (Jerrett et al., 2005). ∗ Corresponding author at: Department of Pathology, Medical School, Sao Paulo University, Av. Dr. Arnaldo, 455 – Room 1150, Zip code: 01246-903, Sao Paulo, SP, Brazil. Tel.: +55 11 30617254; fax: +55 11 30680072. E-mail address: regiani@usp.br (R. Carvalho-Oliveira). Measurement strategies that combine low costs and adequate pre- cision could improve the spatial resolution of the impact of traffic emissions close to major roads. Several plants have been used as bioassays to evaluate the tox- icity of environmental air pollutants (Batalha et al., 1999; Monarca et al., 1999; Guimaraes et al., 2000; Isidori et al., 2003; Sumita et al., 2003; Carvalho-Oliveira et al., 2005; Miˇ sík et al., 2007). One of the most promising methods for in situ monitoring using plants is the pollen abortion test. These assays are highly sensitive, as the target cells (microspores) are haploid, and they are able to detect lethal mutations that affect the development of pollen (Miˇ sík et al., 2006). In studies of air pollution in urban areas, the pollen abortion test was able to detect the effects of air pollution and show the differ- ences in genotoxicity of different pollutant sources (Uhríková and Miˇ cieta, 1995; Miˇ sík et al., 2006; Miˇ cieta and Murin, 2007; Miˇ sík et al., 2007). In studies that seek to determine the gradient of air pollution on a small scale, both physiological changes in plants and measure- ments of the accumulation of trace metals have been considered. In bioindication studies, botanical materials such as lichens, mosses, tree barks, tree leaves and pine needles have been used as bioaccu- mulators to assess the deposition and distribution of metals (Loppi et al., 1997; Carreras et al., 1998; Bargagli et al., 1999; Pacheco et al., 2001; Rosamilia et al., 2004; Rusu et al., 2006; Pacheco et al., 2008). Nitrogen dioxide (NO 2 ) concentrations in urban spaces show a strong correlation with traffic densities (Gilbert et al., 2005; da Silva 0098-8472/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.envexpbot.2011.04.001