PROTECTING CROPS FROM PESTS IS AN IMPORTANT STRATEGY TO PROVIDE FOOD FOR A GROWING POPULATION. THE USE OF BIOTECHNOLOGY IN AGRICULTURE HAS ENABLED THE DEVELOPMENT OF NEW METHODS TO CONTROL PESTS. AN IMPORTANT RECENT ADVANCEMENT IN AGRICULTURAL BIOTECHNOLOGY HAS BEEN THE DEVELOPMENT OF BIOPESTICIDES THAT FUNCTION BY A CELLULAR PROCESS CALLED RNA INTERFERENCE (RNAI). RNAI-BASED CROP PROTECTION BIOTECHNOLOGY USES DOUBLE-STRANDED RNA (DSRNA) MOLECULES AS BIOPESTICIDES. THESE DSRNA BIOPESTICIDES CAN PREVENT PESTS FROM GROWING OR DEVELOPING AND POTENTIALLY CAUSE PEST MORTALITY. RNAI-BASED CROP PROTECTION MUST UNDERGO ECOLOGICAL RISK ASSESSMENT TO EVALUATE THE POTENTIAL RISKS ASSOCIATED WITH THE USE OF RNAI BIOTECHNOLOGY IN AGRICULTURE. ECOLOGICAL RISK ASSESSMENT IS CARRIED OUT BY EVALUATING (1) THE POTENTIAL HAZARDS POSED BY DSRNA BIOPESTICIDES (E.G., TO NON-TARGET ORGANISMS) AND (2) LIKELY EXPOSURE OF ORGANISMS TO DSRNA BIOPESTICIDES. ALTHOUGH EXPOSURE TO DSRNA BIOPESTICIDES WILL BE LARGELY DETERMINED BY DSRNA ENVIRONMENTAL FATE (I.E., HOW DSRNA MOLECULES MOVE THROUGH AND DEGRADE IN ENVIRONMENTAL SYSTEMS SUCH AS SOILS AND SURFACE WATERS), VERY LITTLE IS CURRENTLY KNOWN ABOUT THE ENVIRONMENTAL FATE OF DSRNA BIOPESTICIDES.THIS PROJECT WILL PROVIDE DATA ON THE ENVIRONMENTAL FATE OF DSRNA BIOPESTICIDES THAT IS NECESSARY FOR THE ECOLOGICAL RISK ASSESSMENT OF RNAI AGRICULTURAL BIOTECHNOLOGY. THE FIRST OBJECTIVE OF THE PROJECT IS TO DEVELOP METHODS TO ACCURATELY MEASURE CONCENTRATIONS OF DSRNA BIOPESTICIDES IN ENVIRONMENTAL SYSTEMS. THE ABILITY TO PERFORM THESE MEASUREMENTS IS REQUIRED TO PROVIDE INFORMATION ON THE AMOUNT OF DSRNA BIOPESTICIDES IN SOILS AND SURFACE WATERS AND TO INVESTIGATE DSRNA MOVEMENT AND DEGRADATION IN THESE SYSTEMS. THE SECOND OBJECTIVE OF THE PROJECT IS TO STUDY THE FUNDAMENTAL PROCESSES DETERMINING THE FATE OF DSRNA BIOPESTICIDES IN ENVIRONMENTAL SYSTEMS. IN PARTICULAR, WE WILL INVESTIGATE HOW THE BIOLOGICAL, PHYSICAL AND CHEMICAL CONDITIONS OF SOILS AND SURFACE WATERS AFFECT DSRNA BIOPESTICIDE MOVEMENT AND DEGRADATION. THIS INFORMATION CAN BE USED TO MODEL THE FATE OF DSRNA BIOPESTICIDES IN THE ENVIRONMENT AND WILL PROVIDE INFORMATION NECESSARY FOR THE ECOLOGICAL RISK ASSESSMENT OF RNAI AGRICULTURAL BIOTECHNOLOGY. IN DOING SO, THE PROJECT WILL CONTRIBUTE FOUNDATIONAL KNOWLEDGE TO THE SCIENTIFIC AND PUBLIC EVALUATION OF THE POTENTIAL BENEFITS AND RISKS ASSOCIATED WITHTHE USE OF EMERGING RNAI BIOTECHNOLOGY IN AGRICULTURE.