Investigation of spatial and seasonal variation of VOCs at the Ysleta del Sur Pueblo American Indian nation

Abstract

The Ysleta del Sur Pueblo Environmental Management Office utilized passive air samplers to collect baseline data that can be used in the characterization of Tribal community exposures to ambient air toxics. These passive devices were deployed at ten separate sites. Five of these sites are representative of a housing subdivision (Old Reservation) that is located within the city limits of El Paso, TX, which is characterized as urban/suburban. The remaining five sites are situated in another housing subdivision (New Reservation) that is approximately 8 km southeast, in the city of Socorro, TX, in a rural area surrounded by agricultural fields. The project consisted of two distinct study phases, with each phase corresponding to different weather seasons. The first phase occurred from June through August (warm season), and the second phase occurred from November through February (cool season). During each study phase, passive samplers were deployed for 72 h on five separate occasions, mostly at 18-day intervals. Also, conventional 24-h canister monitoring was conducted at one of the monitoring sites in the Old Reservation for a period of 1 year with data collection occurring once every 6 days. Measurements from the two methods occurring during overlapping monitoring periods were found to be comparable, as were the estimates of precision for each method. Monitoring results indicated significant differences in concentrations of most volatile organic chemicals between reservations and between seasons, with automotive emissions the likely major determinant of levels of the majority of the quantifiable compounds.