Wednesday, November 4, 2009: 10:40 AM
Longhorn (Camino Real Hotel)
Particle less than 10 microns (PM10) in the atmosphere are potentially responsible of several health effects (Furusjö et al., 2007). The main source of PM10 in urban areas is the traffic of vehicles, especially when they drive through unpaved roads (
UR) causing that some particles of the ground suspend, facilitating its transport through wind. Until year 2002, there was approximately 1,820 km of UR in Juárez City, which represents more of 50% of the total (IMIP, 2002), however, there is a lack of studies for the speciation of the dust that rises from UR of the city. The objective was to measure the concentration of Lead and Cadmium in PM10 captured from paved roads (PR) and UR. Sampling followed the procedure of the compendium of methods for the determination of inorganic compounds in ambient air from EPA. Heavy metal extraction followed the USA federal regulations code IO-2.3. The heavy metal concentration was measured by ICP-MS. The PM10 concentration was higher in the UR and above the maximum contaminant level (MCL) established in the NOM-025-SSA1-1993. The heavy metal concentrations showed not significant differences between the PR and UR. The lead concentration was not over the MCL established by the Mexican regulations (NOM-026-SSA1-1993). However, the EPA proposed limit of 0.15 µg/m3 was exceeded in a great number of samples. Cadmium concentrations were under the MCL established by OSHA. Meteorological parameters such as: humidity, temperature, wind speed and atmospheric pressure are relevant for PM10 and heavy metal concentrations.