Off-target pyrethroid transport from urban and suburban landscapes is not well understood, especially when compared to the off-target transport in agricultural production systems. Various combinations of pervious surfaces (lawns, flower beds, shrubbery) and impervious surfaces (concrete, asphalt, house siding) surfaces, lawn irrigation, and rainfall contribute to some of the variability. Different methods of product applications to those surfaces (general broadcast, target spraying, and applications to both horizontal and vertical surfaces) compound the complexity in these environments. In outdoor settings, additional variables control the washoff of pyrethroids, including the timing and number of applications, meteorological conditions (including rainfall, temperatures, and evapotranspiration), irrigation amounts and methods, product formulations, and mass remaining as a function of time. A full-scale experimental site was constructed in California and applications were conducted matching historic and newly-revised label recommendations for pyrethroids. Initial results indicate a time-based, three-phase process with washoff occurring, changing, and gradually slowing over time. Also, natural and simulated rainfall events accounted for the majority of mass loss from the study site when compared to mass loss under lawn irrigation and its associated urban drool. Additional results will be presented, including a multivariate analysis of pyrethroid washoff from various surfaces to determine critical factors influencing the process-based mass loss of pyrethroids under California suburban conditions.

Determining critical factors controlling off-site transport of pyrethroids in the urban environment

246th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.