The cerebellum and hippocampus seem to be more susceptible than other brain structures to in vitro direct PM exposure assay and the oxidative stress pathway catalyzes the neurotoxic effect of PM exposure, as evidenced by high consumption of CAT and high levels of TBA-RS. Thus, PM direct exposure seems to activate toxic neurological effects.

The aim of this study was to evaluate the use of tree barks as a bioindicator of atmospheric pollution in areas of contrasting population densities and to associate the levels of elements found in this bioindicator with those obtained in fingernail samples collected from students living in the same study areas. Tree bark samples were collected from urban areas near highways in regions with high (Area A), intermediate (Area B), and low (Area C) population densities of Porto Alegre, Brazil, and evaluated for chemical elements concentration. Since these areas also differed in traffic density, NO was measured by passive sampling. For a comparative purpose, the elements were also determined in fingernail samples collected from students living in the same areas. Accumulated elements were determined by inductively coupled plasma mass spectrometry (ICP-MS) and principal component analysis (PCA) was used as a tool in exploratory data analysis to identify possible sources. We found that Ba, Cd, Co, Cu, Mg, Mn, Ni, Pb, Sb, Sr, V, and Zn were at higher concentrations in tree barks in Area A, while Cd, Co, Cu, Mg, Mn, Ni, and Sr were at higher levels in students' fingernails of Area A as well. Furthermore, concentrations of elements found in barks were associated with those identified in fingernails collected from students living in the same areas. PCA demonstrated that vehicular traffic explained 66.4 % of the variance in tree bark and 50.8 % of the variance in fingernails. NO levels were significantly different among the areas, what is consistent with their respective vehicular flow and population density. In conclusion, we found conformance of elements levels accumulated in barks and fingernails at three monitoring areas with different profiles. The amount of traffic-related elements accumulated appears to be associated with the degree of urbanization and vehicular flow. Overall, data suggests a relationship between fingernails and tree bark as bioindicators of exposure to metals from air pollution.

Air pollution is exacerbated near heavy traffic roads in cities. Air pollution concentration and composition vary by region and depend on urban-rural gradients. The aim of this study was to evaluate the distribution of air pollution in areas of varying population densities and to compare plant biomonitoring with an established biomarker of human exposure to traffic-related air pollution in children. The areas of study were selected near a major street in 3 different regions. Areas A, B and C represent high, intermediate and low population densities, respectively. Micronucleus assay, an established biomarker of human exposure, was performed in children from these areas. For a plant biomonitoring assay, the pollen abortion assay was performed on Bauhinia variegata in these areas. NO2 and O3 concentrations were determined by passive sampling. We report here that the pollen abortion frequency in Bauhinia variegata is correlated with NO2 concentration (P = 0.004) and is strongly associated with vehicular flow and population density in the studied areas. Micronuclei frequency in buccal cells of children was higher in the regions with more degree of urbanization (P < 0.001) following the same pattern of O3 concentrations (P = 0.030). In conclusion, our results demonstrate that high concentrations of air pollutants in Porto Alegre are related to both human and plant genotoxicity. Areas with different concentration of pollutants demonstrated to have an urbanization gradient dependent pattern which also reflected on genotoxic damage among these areas.

The extension of pollutant accumulation in plant leaves associated with its genotoxicity is a common approach to predict the quality of outdoor environments. However, this approach has not been used to evaluate the environmental quality of outdoor smoking areas. This study aims to evaluate the effects of environmental tobacco smoke (ETS) by assessing particulate matter 2.5 μm (PM) levels, the pollen abortion assay, and trace elements accumulated in plant leaves in an outdoor smoking area of a hospital. For this, PM was measured by active monitoring with a real time aerosol monitor for 10 days. Eugenia uniflora trees were used for pollen abortion and accumulated element assays. Accumulated elements were also assessed in Tradescantia pallida leaves. The median concentration of PM in the smoking area in all days of monitoring was 66 versus 34 μg/m in the control area (P < 0.001). In addition, the elements Al, Cd, Cu, Ni, Pb, Rb, Sb, Se, and V in Tradescantia pallida and Al, Ba, Cr, Cu, Fe, Mg, Pb, and Zn in Eugenia uniflora were in higher concentration in the smoking area when compared to control area. Smoking area also showed higher rate of aborted grains (26.1 ± 10.7 %) compared with control (17.6 ± 4.5 %) (P = 0.003). Under the study conditions, vegetal biomonitoring proved to be an effective tool for assessing ETS exposure in outdoor areas. Therefore, vegetal biomonitoring of ETS could be a complement to conventional analyses and also proved to be a cheap and easy-handling tool to assess the risk of ETS exposure in outdoor areas.

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Questions still exist regarding which indicator better estimates worker’s exposure to diesel particulate matter (DPM) and, especially for ultrafine particles (UFP), how exposure levels and the characteristics of the particles vary in workplaces with different exposure conditions. This study aimed to quantify and characterize DPM exposures in three workplaces with different exposure levels: an underground mine, a subway tunnel, and a truck repair workshop. The same sampling strategy was used and included measurements of the particle number concentration (PNC), mass concentration, size distribution, transmission electron microscopy (TEM), and the characterization of carbonaceous fractions. The highest geometric means (GMs) of PNC and elemental carbon (EC) were measured in the mine [134 000 (geometric standard deviation, GSD = 1.5) particles cm−3 and 125 (GSD = 2.1) µg m−3], followed by the tunnel [32 800 (GSD = 1.7) particles cm−3 and 24.7 (GSD = 2.4) µg m−3], and the truck workshop [22 700 (GSD = 1.3) particles cm−3 and 2.7 (GSD = 2.4) µg m−3]. This gradient of exposure was also observed for total carbon (TC) and particulate matter. The TC/EC ratio was 1.4 in the mine, 2.5 in the tunnel and 8.7 in the workshop, indicating important organic carbon interference in the non-mining workplaces. EC and PNC were strongly correlated in the tunnel (r = 0.85; P &lt; 0.01) and the workshop (r = 0.91; P &lt; 0.001), but a moderate correlation was observed in the mine (r = 0.57; P &lt; 0.05). Results from TEM showed individual carbon spheres between 10 and 56.5 nm organized in agglomerates, while results from the size distribution profiles showed bimodal distributions with a larger accumulation mode in the mine (93 nm) compared with the tunnel (39 nm) and the truck workshop (34 nm). In conclusion, the composition of the carbonaceous fraction varies according to the workplace, and can interfere with DPM estimation when TC is used as indicator. Also, the dominance of particles &lt;100 nm in all workplaces, the high levels of PNC measured and the good correlation with EC suggest that UFP exposures should receive more attention on occupational routine measurements and regulations.

Asthma is a multifactorial disease and its severity varies with the inflammatory status of the patient. It has been hypothesized that deficiency of trace elements has an important role in the etiology of asthma. The aim of the study was to evaluate the concentration of trace elements in nails of adolescents with different degrees of airway inflammation. We assessed the prevalence of active and severe asthma in adolescents (n = 106) through the ISAAC questionnaire. Subjects were allocated into two different groups according to the value of fraction exhaled nitric oxide (FeNO) measured. Also, nail specimens were collected in order to determine the concentration of accumulated trace elements (Cu, Zn, Mn, Se) by ICP-MS. It was performed Student's t test to evaluate statistical differences between inflammatory groups considering normally distributed data. On the other hand, when data presented non-normal distribution, Mann-Whitney U test was utilized. Spearman coefficients were calculated to investigate correlations between FeNO and mineral concentrations. Exhaled NO was increased in male subjects. We found association between active asthma and elevated exhaled NO. There was no significant difference in Cu (4.40 vs. 4.52), Zn (84.66 vs. 79.48), Mn (0.59 vs. 0.76), and Se (0.18 vs. 0.19) concentrations (μg/g) among distinct FeNO groups as well as was not observed correlation between exhaled NO levels and any element. Deficiency of trace elements in nails were not associated with increased FeNO.

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