ABSTRACT
Studies were conducted to determine the dislodgeability of two (2,4-D and dicamba) phenoxy and benzoic acid herbicides applied to turfgrass and to assess golfer risk of phenoxy herbicide exposure by dermal and incidental ingestion pathways.
Dislodgeability was determined using damp cotton fabric, damp leather, golf balls, golf club head, and damp cheesecloth after herbicide application to hybrid bermudagrass (Cynodon dactylon L. X C. transvaalensis), and to hybrid bermudagrass overseeded with rough bluegrass (Poa trivialis L.) followed by irrigation, and through a 24 h period after application. In addition, a comparison of two methods, damp cotton press vs. a damp cheesecloth wipe, for dislodging herbicides from turf surfaces was conducted. Several models encompassing golfer behavior and realistic golf course exposure scenarios were used in conjunction with field data to assess risk using the hazard quotient approach to assess potential effects.
The quantities of the herbicides dislodged were influenced by time. Dislodgeable residues of 2,4-D and dicamba did not decrease appreciably until 24h and after irrigation. No significant differences were noted between overseeded and non-overseeded bermudagrass. Little difference was observed for the two methods for dislodging residues from turfgrass surfaces.
The risk assessment models used indicated that golfer exposure to 2,4-D immediately following application may exceed acceptable daily intakes for chronic exposure (i.e. hazard quotients > 1.0) and will decrease with time after application. Dicamba never had an hazard quotient greater than 1.0.
