Transferable Turf Residue (TTR) Methodology

Conducting exposure assessments for people reentering turf that has been treated with a pesticide requires an assessment of the amount of residue that can be transferred from the grass to the person. Several techniques have been proposed for assessing the amount of transferable turf residues (TTR). ORETF investigated five established turf sampling techniques for high sensitivity and low variability among and between individuals.

From these evaluations, the ORETF developed a single standardized technique for measuring product-specific TTRs that was followed by all member companies.  The technique, named the Modified California Roller technique, consists of pushing a 32-pound roller 10 times across a 6 square foot area of percale cloth that is securely fastened to the ground on top of treated turf.

The Modified California Roller methodology has been published (see below) and incorporated into the USEPA guidelines for exposure studies.

References:

Klonne D, Cowell J, Mueth M, Eberhart D, Rosenheck L, Ross J, Worgan J (2001) Comparative study of five transferable turf residue methods. Bull Envir Contam Toxicol, pp 771-779.

Rosenheck L, Cowell J, Mueth M, Eberhart D, Klonne D, Norman C, Ross J (2001) Determination of a standardized sampling technique for pesticide transferable turf residues. Bull Environ Contam Toxicol, pp 780-786.

Fuller R, Klonne D, Rosenheck L, Eberhart D, Worgan J, Ross J (2001) Modified California roller for measuring transferable residues on treated turfgrass. Bull Environ Contam Toxicol, pp 787-794.