Measurements and receptor modeling of volatile organic compounds in south-eastern Mexico City, 2000–2007
1Instituto Nacional de Ecología, Mexico City, Mexico
2Institute for Chemical and Bioengineering, ETH Zurich, Switzerland
3Seminar for Statistics, ETH Zurich, Switzerland
4Instituto Politécnico Nacional, Mexico City, Mexico
5Ehime University, Matsuyama, Japan
Abstract. Ambient samples of volatile organic compounds (VOCs) were measured between 2000 and 2007 in south-eastern Mexico City, quantifying 13 species (ethane, propane, propylene, butane, acetylene, pentane, hexane, heptane, benzene, octane, toluene, nonane, o-xylene). These time series were analyzed for long-term trends, using linear regression models. A main finding was that the concentrations for several of the quantified VOC species were decreasing during this period. A receptor model was applied to identify possible VOC sources, as well as temporal patterns in their respective activities. Domestic use of liquefied petroleum gas and vehicle exhaust are suggested to be the principal emission sources, contributing together between 70% and 80% to total VOC. Both diurnal and seasonal patterns, as well as a weekend effect were recognized in the modelled source activities. Furthermore, vehicle exhaust emissions showed a decreasing trend over time, with a reduction of about 8% per year.