TP6 Degradates in the Environment
202 Oregon Ballroom
1:20 PM - 4:40 PM, Tuesday
() Pesticide Degradates: Monitoring and Occurrence.
Kolpin, D1, Battaglin, W2, Meyer, M3, Schnoebelen, D1, Kalkhoff, S1, 1 U.S. Geological Survey, Iowa City, IA2 U.S. Geological Survey, Denver, CO3 U.S. Geological Survey, Lawrence, KS
ABSTRACT- Research has documented that the transport of pesticide compounds to streams and groundwater is substantially underestimated if degradation products (degradates) of pesticides are not considered. Results from a study of 51 Midwestern US streams found that pesticide degradates were seven of the 10 most frequently detected pesticide compounds in late spring runoff (after application of pre-emergence herbicides), and nine of the 10 most frequently detected compounds in fall season runoff (during and after harvest). Seasonal degradate concentration patterns in streams mirrored that of their parent compounds, but degradate concentrations remained higher than the parent concentrations throughout the year. Results from a study of 86 municipal wells in Iowa found the frequency of detection increased from 17% when pesticide parent compounds were considered to 53% when both parents and degradates were considered. Degradates were 12 of the 15 most frequently detected compounds for this groundwater study. These findings show that degradates must be considered to fully assess the potential occurrence of pesticides in surface and groundwaters and their transport and fate in various compartments of the hydrologic system.
Key words: degradates, pesticides, streams, groundwater