Transport of Lawn-Applied 2,4-D from Turf to Home: Assessing the Relative211 Importance of Transport Mechanisms and Exposure Pathways

摘要

Methods have been developed to estimate children's residential exposures to211u001epesticide residues and applied in a small field study of indoor exposures 211u001eresulting from the intrusion of lawn-applied herbicide into the home. Transport 211u001eof 2,4-D from the residential lawn into the home was measured following both 211u001ehomeowner and commercial application of this herbicide. Sampling methods included 211u001eparticle size-selective indoor air sampling; wipe sampling of floors, sills, 211u001etables; the polyurethane foam (PUF) roller for dislodgeable carpet surface 211u001eresidues; and the HVS3 vacuum sampler for floor dust. Personal exposure samples 211u001eincluded hand wipes and morning void urine samples. Pesticide spray drift was 211u001efound to result in only a relatively minor increase in indoor pesticide levels. 211u001ePost-application air intrusion from closed house ventilation and the opening and 211u001eclosing of doors and windows increased indoor background levels 6-fold, while 211u001etrack-in by high activity children and pets, and wearing shoes indoors, 211u001eincreasing indoor levels by 37-fold. Indoor 2,4-D levels were found to increase 211u001econtinually over a one-week period, with the increase in indoor air levels 211u001ecorresponding to the increased floor dust levels, suggesting resuspension of 211u001ehouse dust by human activity. Similar estimates of non-dietary exposure are 211u001eobtained from models based on 100 mg dust by human activity. Similar estimates of 211u001enon-dietary exposure are obtained from models based on 100 mg dust ingestion and 211u001esurface contact simulated by the PUF roller.