The largest concentration of elements are Ca , S, Mg, Fe These elements are present in high amounts in the crust , and is mainly found in PM10 . However, these elements can also be considered as markers of traffic related to ressuspension dust of the roads. Schauer et al (2006) reported the enrichment of the road dust with elements derived for wear parts such as Fe and exhaust emission such as S, Ca , Mg.
Faggi et al (2011) found element mean concentration in the same order of magnitude in areas with heavy traffic streets and avenues.
The fuel composition differs in each country and studies shown that the Brazilian fuel emission diesel used in Brazil is mainly by Ca, Mg, Fe and Al (Loyola et al , 2009) compound. The knowledge of the average concentration of elements Ca, Mg, Fe suggests that despite a small fleet of diesel vehicles they are potential emission sources.
The mean concentration of elements in the same street have shown a significant difference (p < 0.05) indicating ...view middle of the document...
Quadrants 3, 7, 10, 11 have higher concentrations of Zn used as a lubricant additive derived from wear and vehicle parts, especially the brakes. These areas have the common characteristic of constant heavy traffic, heavy vehicles and large congestion on their streets. Thus it can be stated that this high concentration of Zn is related to wear parts.
According to PCA results we found 5 groups: group 1 (Al, Fe, Mn, Cu, Zn), group 2 (Ca, Sr), group 3 (Cl, Na), group 4 (K, P) and group 5 (Mg, S).
Group 1 explains 27.107 of the variance. The vehicular traffic is the main emission source of these element which are primarily related to ressuspension of dust ( Al , Fe , Cu ) and wear of vehicle parts ( Cu and Zn ) . Group 5 is explained by 9.83% of the variance and its source is connected by vehicular exhaust emissions fuel combustion , use of additives and lubricating oil) . Groups 2, 3, and 4 are explained by similar biogeochemical characteristics between elements.
The analysis of the different classifications of traffic streets showed that there is a hierarchy of elements emission. The street considered expressed have higher emissions and local minor emission.
The dispersion maps pollutant concentrations allows the identification of regions of the city with the highest traffic volume and analysis of each elements allows the separation of the most affected by heavy vehicles and light vehicles areas .
The analysis of the distribution maps of concentration allows you to individually test each element. The highest concentrations of Al are found in areas with higher density of heavy vehicles nearby express streets.
The Cu and Zn have high concentrations mainly in expressway which is predominantly used by trucks . The distribution of the concentration of Fe is located in areas that have a high flux density vehicular both lightweight as well as heavier vehicles Mn.
The dispersion of the S element is related to bus lanes indicating that the main source of vehicular emission of sulfur element is the bus fleet and fuel.
The dispersion of air pollution and the type of traffic flow could be identifying with the biomonitoring techniques. These techniques allow creating a micro scale distribution of pollutants giving us a more accurate data to be used in epidemiological studies