Influence of Temperature, Relative Humidity, and Soil Properties on the Soil-Air Partitioning of Semivolatile Pesticides: Laboratory Measurements and Predictive Models
Document Type
Article
Journal/Book Title
Environmental Science and Technology
Publication Date
8-10-2015
Publisher
American Chemical Society
Volume
49
Issue
17
First Page
10431
Last Page
10439
Abstract
Soil–air partition coefficient (Ksoil-air) values are often employed to investigate the fate of organic contaminants in soils; however, these values have not been measured for many compounds of interest, including semivolatile current-use pesticides. Moreover, predictive equations for estimating Ksoil-air values for pesticides (other than the organochlorine pesticides) have not been robustly developed, due to a lack of measured data. In this work, a solid-phase fugacity meter was used to measure the Ksoil-air values of 22 semivolatile current- and historic-use pesticides and their degradation products. Ksoil-air values were determined for two soils (semiarid and volcanic) under a range of environmentally relevant temperature (10–30 °C) and relative humidity (30–100%) conditions, such that 943 Ksoil-air measurements were made. Measured values were used to derive a predictive equation for pesticide Ksoil-air values based on temperature, relative humidity, soil organic carbon content, and pesticide-specific octanol–air partition coefficients. Pesticide volatilization losses from soil, calculated with the newly derived Ksoil-air predictive equation and a previously described pesticide volatilization model, were compared to previous results and showed that the choice of Ksoil-air predictive equation mainly affected the more-volatile pesticides and that the way in which relative humidity was accounted for was the most critical difference.
Recommended Citation
Influence of temperature, relative humidity, and soil properties on the soil-air partitioning of semivolatile pesticides: Laboratory measurements and predictive models (2015). Davie-Martin, L., Hageman, K.J., Chin, Y.-P., Rougé, Fujita, Y. Environmental Science and Technology 49, 10431-10439.
