The Composition of Precipitation in El Paso, Texas

The composition of precipitation reflects the transport of particles from varying air mass source regions as well as input from local environmental and anthropogenic activities. Air research in El Paso, TX, U.S.A/Ciudad Juarez, Chihuahua, Mexico has been traditionally limited to studies of local inputs of air pollution; no transition has been made to studying the scavenging, washout, and transport of pollutants by precipitation. The goal of this research project was to identify transported pollutants in precipitation, and determine if there were any health and ecological implications. The research investigated biological, chemical, and geological constituents in precipitation samples collected between September 2004 and October 2005. A variety of analysis techniques were used to determine composition of the precipitation. These techniques included bacterial and fungal plate counts, inductively coupled plasma/mass spectrometry, ion chromatography, transmission electron microscopy, scanning electron microscopy, and electron microprobe analysis. Samples were collected from an urban site in El Paso, Texas at the campus of the University of Texas at El Paso. Wet only samples were the target of the sample collection. Particulate matter \u3c10 microns was correlated with fungal growth while particulate matter \u3c 2.5 microns was correlated with bacterial growth in analyzed samples.. Microscopy methods revealed new techniques in particle characterization, evidence of anthropogenic influence, and a wide variety of particle compositions. The ionic chemistry results reflected elevated levels of ions as well as an overall alkalinity of rainwater samples. Elemental analysis of the inorganic fraction suggested elevated enrichment of Phosphorus in the study area and possible ratios for transport identification of southwestern dust storms