Field testing passive air samplers for current use pesticides in a tropical environment
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| Autores: | , , , |
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| Formato: | artículo |
| Fecha de Publicación: | 2008 |
| Descripción: | Air was sampled for one year in the central valley of Costa Rica using an active high-volume sampler as well as passive samplers (PAS) based on polyurethane foam (PUF) disks and XAD-resin filled mesh cylinders. Extracts were analyzed for pesticides that are either banned or currently used in Costa Rican agriculture. Sampling rates for PUF-based passive air samplers, determined from the loss of depuration compounds spiked on the disks prior to deployment, averaged 5.9 +- 0.9 m3 · d-1 and were higher during the windier dry seasonthan duringthe rainy season. Sampling ratesforthe XADbased passive sampler were determined from the slopes of linear relationships that were observed between the amount of pesticide sequestered in the resin and the length of deployment, which varied from 4 months to 1 year. Those sampling rates increased with decreasing molecular size of a pesticide, and their average of 2.1 +- 1.5 m3 · d-1 is higher than rates previously reported for temperate and polar sampling sites. Eventhoughthetrends ofthe sampling rate with molecular size and temperature are consistent with the hypothesis that molecular diffusion controls uptake in passive samplers, the trends are much more pronounced than a direct proportionality between sampling rate and molecular diffusivity would suggest. Air concentrations derived by the three sampling methods are within a factor of 2 of each other, suggesting that properly calibrated PAS can be effective tools for monitoring levels of pesticides in the tropical atmosphere. In particular, HiVol samplers, PUF-disk samplers, and XADbased passive samplers are suitable for obtaining information on air concentration variability on the time scale of days, seasons and years, respectively. This study represents the first calibration study for the uptake of current use pesticides by passive air samplers. |
| País: | Repositorio UNA |
| Institución: | Universidad Nacional de Costa Rica |
| Repositorio: | Repositorio UNA |
| Lenguaje: | Inglés |
| OAI Identifier: | oai:null:11056/23392 |
| Acceso en línea: | http://hdl.handle.net/11056/23392 https://doi.org/10.1021/es8008425 |
| Palabra clave: | AGRICULTURA AIRE COSTA RICA MUESTREO PLAGUICIDAS AGRICULTURE AIR SAMPLING PESTICIDES |