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The
Environmental Occurrence, Fate, and Ecotoxicity of Selective Serotonin Reuptake
Inhibitors (SSRIs) in Aquatic Environments. For each drug laboratory
environmental fate and ecotoxicity measurements are conducted in a manner
similar to those tests required for pesticide registration following EPA
protocols wherever possible. Organisms tested will include water fleas,
mosquito fish and frogs. Additionally the occurrence of each drug is measured
in raw and treated wastewater, and receiving water at sub-ppb levels. This
approach will allow exposure and risk assessments for these chemicals to
be directly benchmarked with pesticides.
Pesticide runoff from simulated fairways. Pesticides are sprayed at label rates to bermuda grass turf plots set on a 5% slope to estimate relative loads transported offsite by simulated rainfall events. Chemicals measured include imidacloprid, quinclorac, oxadiazon, MSMA and prodiamine. Movement of Pesticide and Pesticide Degradation Products Through Golf Course Greens. Golf course greens are intensively managed with pesticides and are designed for good drainage. Most are tile drained into ponds, streams or storm drains, thus green leachate very often becomes surface water. Monitoring of drainage water from greens at a metro Atlanta country club has shown major use pesticides are rarely detected however degradation products are frequently found at significant concentrations. Subsequent research indicates that the degradation products that do leave the green via leachate are rapidly degraded by sunlight in surface water. Development of computer model scenarios for turf grass to predict off-site chemical movement into aquatic ecosystems. In collaboration with the pesticide industry, USEPA/OPP and USDA scientists, laboratory degradation experiments and field experiments are being conducted on cooperating golf courses to calibrate turfgrass scenarios using PRZM3 for off-site pesticide movement and EXAMS to estimate fate in receiving water. The goal of this project is to generate turfgrass scenarios that will be used by EPA to conduct tier 2 exposure assessments for turf pesticides. Impact of Lawncare Practices on Aquatic EcoSystems in Suburban Watersheds. Temporal and event based monitoring of stormwater runoff from high and low income residential neighborhoods to measure the relative loads of pesticides contributed to a watershed. Water samples and are collected using autosamplers and stormwater flow rate is measured at time intervals over the course of storm events. Grab samples of water and sediment are also collected from receiving waters. Turf pesticides and degradation products are monitored in water and sediment. Laboratory degradation of pesticides is being measured in water and sediment. Assessment of biological effects to aquatic invertebrates, insects, and leaf-litter degrading fungi assessed in streams and in laboratory experiments. Development of Irradiated-Water-Sediment systems to better simulate
pesticide degradation in shallow water aquatic environments.
Sunlight in aquatic systems strongly influences pesticide fate via abiotic
mechanisms (e.g. photodegradation) and biotic mechanisms (e.g. metabolism
by algae and phototropic bacteria). Systems similar to those used in aerobic-aquatic
metabolism and water-sediment studies have been developed to better assess
pesticide fate in aquatic systems in a laboratory setting. Such laboratory
experiments should allow better estimations for aquatic risk assessment. |
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