| |
| Web URL(s): | http://archive.lib.msu.edu/tic/rpr/1997/54612,%20U%20Mass, Clark.PDF
Last checked: 10/28/2013
Requires: PDF Reader |
|---|
| Publication Type:
| Report |
|---|
| Material Type: | Manuscript |
|---|
| Monographic Author(s): | Clark, J. M.; Roy, G. R.; Doherty, J. D.; Curtis, A.; Cooper, R. J. |
|---|
| Author Affiliation: | Clark, Roy, Doherty, and Curtis: Massachusetts Pesticide Analysis Laboratory, Department of Entomology, University of Massachusetts, Amherst, MA; and Cooper: Department of Crop Science, North Carolina State University, Raleigh, NC |
|---|
| Monograph Title: | Evaluation of Management Factors Affecting Volatile and Dislodgeable Foliar Residues of Turfgrass Pesticides: [1997 Annual Research Report], 1997. |
|---|
| Publishing Information: | Amherst, Massachusetts: University of Massachusetts |
|---|
| # of Pages: | 21 |
|---|
| Collation: | [21] pp. |
|---|
| Abstract/Contents: | "Volatilization can be a major route of pesticide loss following application to turfgrass. Consequently, a significant proportion of applied pesticides may be available for human exposure via volatile and dislodgeable residues. Volatile residues were determined from small circular turf plots with high volume air samplers using the Theoretical Profile Shape method and dislodgeable residues were concurrently determined by wiping treated turfgrass with water-dampened cheesecloth. Inhaled doses were estimated from the volatile residues and dermal doses were estimated using the dislodgeable residues. Inhalation and dermal hazards were the determined using the USEPA Hazard Quotient (HQ) method (Murphy et al., 1996ab). Our research to date has established that there are volatile and dislodgeable pesticide residues available for golfer exposure following application to turfgrass and that not all of these exposures can be deemed completely safe by the above criteria. Of the 13 pesticides examined, however, 10 were deemed safe in that their application never resulted in HQ greater than 1.0. Included in this "safe" group are the organophosphous [organophosphorous] insecticides, isofenphos, trichlorfon, chlorpyrifos; the carbamate insecticides, bendiocarb, carbaryl; the pyrethroid insecticide, cyfluthrin; and the fungicides, chlorthalonil, ipridione, propiconizole, thiophanate methyl. Application of ethoprop, isazafos and diazinon, nevertheless, did result in HQs greater than 1.0 and cannot be deemed as completely safe by the above criteria. These three pesticides are all organophosphorous insecticides that belong to the high vapor pressure group and have the lowest reference dose (i.e., highest toxicity rating) as established by the USEPA Office of Pesticide Programs. Ethoprop, isazafos and diazinon had inhalation HQs greater than 1.0 through day 3, the maximum inhalation HQs all occurred on day 1, and all were below 1.0 after day 3 following application (Table 1). Chlorpyrifos, which is in the high vapor pressure category, had a maximum inhalation HQ of 0.1 an day 2. This is due to the high reference dose of chlorpyrifos compare to the other organophosphorous insecticides. Similarly, ethoprop, isazafos and diazinon had dermal HQs greater than 1.0 on day 1 (15 min post application, Table 2). However, only ethoprop had a dermal HQ greater that [than] 1.0 through day 1 (8 hr post application). From these findings, we have determined that the critical vapor pressure below which no turfgrass pesticide will volatilize to the extent that it will result in an inhalation HQ greater than 1.0 to be between 3.3 x 10-6 mm Hg (i.e., isofenphos vapor pressure, Table 1) to 5.6 x 10-6 mm Hg (i.e., isazafos vapor pressure, Table 1). Similarly, we have determined the critical OPP reference dose above which no turfgrass pesticide will result in a dermal HQ greater than 1.0 to be between 0.0005 (i.e., see isofenphos, Table 2) to 0.0009 (i.e., see diazinon, Table 2). In order to mitigate the exposure potential of the organophosphorous insecticides that have high vapor pressures and inherent high toxicity, we have evaluated the practical use of spray tank adjuvants. Two adjuvants were examined as to their abilities to suppress volatile and dislodgeable residues: Aqua Gro-L, a non-ionic surfactant/penetrant; and Exhalt 800, an encapsulating spreader/sticker. Neither product resulted in significant and meaningful differences in the exposure potential of these problematic insecticides. Additionally, we determined the importance of thatch accumulation on the dissipation of volatile and dislodgeable foliar residues following the application of these problematic insecticides. Neither aeration nor dethatching of turfgrass plots resulted in significant and meaningful differences in the exposure potential of these organophoshorous [organophosphorous] insecticides. In summary, the large majority of the turfgrass pesticides evaluated in this study were deemed safe using the USEPA Hazard Quotient method. Pesticides that were not deemed completely safe by these criteria were organophosphorous insecticides with high vapor pressures and inherent high toxicity. Because effective organophosphorous and carbamate insecticide alternatives are available that do not share these problematic features, the use of ethoprop, isazafos and diazinon on turfgrass should be minimized and applied only when a delayed reentry period is practical. Additionally, we have shown that some organophosphate insecticides that possess high toxicity and volatility may result in exposure situations that cannot be deemed completely safe as judged by the USEPA Hazard Quotient Determination. This assessment, however must be viewed in terms of the assumptions that were used in making these estimations. In all instances, Maximum pesticide concentrations were used for the entire four hour exposure period, maximum rates for pesticide applications were used, and dermal transfer coefficients and dermal permeability factors were taken from non-turfgrass situations that are likely to exceed those that would take place on a golf course. Because of this, we view such estimates as worst case scenarios. In order to more accurately predict the health implications of pesticide exposure to golfers, a relevant dosimetry evaluation of golfers, playing golf on a golf course, needs to be carried out. With more accurate exposure estimates, it is our belief that the exposure levels reported here will be found to be in excess of the true exposure to pesticides on a golf course." |
|---|
| Language: | English |
|---|
| References: | 8 |
|---|
| See Also: | See also related summary article "Evaluation of management factors affecting volatile loss and dislodgeable foliar residues" 1997 Turfgrass and Environmental Research Summary[USGA], p. 60-63, R=54612. R=54612 |
|---|
| Note: | Also appears as pp. 693-714 in the USGA Turfgrass Research Committee Reporting Binders for 1997.
"USGA - Green Section Research"
"Annual Report: (5/1/97 - 12/5/97)"
Tables |
|---|
| ASA/CSSA/SSSA Citation (Crop Science-Like - may be incomplete):
No defined citation format for TGIF #: 231760 |
| Fastlink to access this record outside TGIF: https://tic.msu.edu/tgif/flink?recno=231760 |
| If there are problems with this record, send us feedback about record 231760. |
| Choices for finding the above item: |
|---|
| Web URL(s):
http://archive.lib.msu.edu/tic/rpr/1997/54612,%20U%20Mass, Clark.PDF
Last checked: 10/28/2013
Requires: PDF Reader |
| Find from within TIC:
Digitally in TIC by record number. |
| Request through your local library's inter-library loan service (bring or send a copy of this TGIF record) |
