Volatile and dislodgeable residues from pesticide-treated turfgrass were determined. Four pesticides (isazofos, MCPP, triadimefon, and trichlorfon) were applied separately at the manufacturer's recommended high rate to an established plot of "Penncross" creeping bentgrass. Trichlorfon was applied with and with out irrigation following the application. DDVP and CG-17193, the metabolites of trichlorfon and isazofos, respectively, were analyzed for as well. For each application, a 10 m radius plot was sprayed. The Theoretical Profile Shape (TPS) method was used to estimate source flux from a 10 m radius plot. For each sampling period, 120 mL of XAD-4 resin was placed into an air pump and ambient air sampled for 4 h at an average rate of 0.8 m$\sp3$ min$\sp{-1}.$ Dislodgeable residues were determined by wiping the treated turfgrass with a dampened piece of cheesecloth. All pesticides resulted in less than 13% of applied compound being lost as volatile residues. Both diphasic and diurnal patterns of volatilization were observed. Irrigating treated plots immediately after application greatly reduced initial volatile and dislodgeable residues. However, there was a significant increase in volatile and dislodgeable residues on Days 2 and 3 compared to those residues on Day 1 after irrigation. Irrigation enhanced the transformation of trichlorfon to DDVP, the more toxic compound. Measured volatile and dislodgeable residues were used to estimate human exposure. The air concentrations were compared to 8-h exposure limits (mg m$\sp{-3}$), rat "no-effect" levels (mg m$\sp{-3}$), and the acute toxic LC$\sb{50}$ values (mg m$\sp{-3}$). Dislodgeable residues (ug m$\sp{-2}$) were incorporated into two dermal exposure models. The estimated dermal exposure (mg 70 kg person$\sp{-1}$) was compared to dermal "no-effect" level values. Overall, golfer exposure to volatile and dislodgeable residues were deemed at safe levels in terms of acute toxicity. However, DDVP as a volatile residue, and isazofos as a dislodgeable residue may be of toxicological importance. The bonding of MCPP with Pb$\sp{+2}$ was characterized with UV absorbtion. No interaction was observed.
| Identifer | oai:union.ndltd.org:UMASS/oai:scholarworks.umass.edu:dissertations-8930 |
| Date | 01 January 1994 |
| Creators | Murphy, Kathleen Christine |
| Publisher | ScholarWorks@UMass Amherst |
| Source Sets | University of Massachusetts, Amherst |
| Language | English |
| Detected Language | English |
| Type | text |
| Source | Doctoral Dissertations Available from Proquest |
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