Gail Amos TPSA Session 6A 2010/23/February Savanna, Georgia USA. Buffer Zones No Spray Zones

Transcription

1 Gail Amos TPSA Session 6A 2010/23/February Savanna, Georgia USA Buffer Zones No Spray Zones

2 EPA s No Spray Zone A no spray zone is an area in which direct application of the pesticide is prohibited; This area is specified in distance between the closest point of direct pesticide application and the nearest boundary of a site to be protected, unless otherwise specified on a product label.

3 Farming at the Edge

4 Where does the stuff go? What is the homeowner s likely exposure? Should a homeowner be concerned? June

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6 June 2003 Developer established buffer March 2005

7 03/11/05 (A.M.) Dormant Spraying (oil+) 03/11/05 (P.M.)

8 Hard, Cold Reality All sprays drift All chemicals are toxic at some dose Thus, the best we can do is minimize drift to a potential exposure level that is estimated to have a reasonable certainty of no harm

9 Drift Continues to Be the Top Cause of Bad PR, Lawsuits, and Regulatory Concern

10 Tri City Herald 11/30/02

11 WSDA PIRT Analysis 2000 (Pesticide Incident Reporting & Tracking) Complaints Associated with Cases Miscellaneous (12%) Animal Incidents (2%) Water Contamination (3%) Bee Kills (3%) PCO/WDO Inspections (5%) Drift (27%) Direct (8%) Licensing (10%) Human Exposure (20%) Misuse (12%) N=199 Complaints

12 WA Department of Health PIRT Analysis 2000 (Pesticide Incident Reporting & Tracking) Exposure Sources Associated with Cases Residues (11%) (treated surface) Unknown Source (4%) Contact (18%) (spill, leaking equipment) Drift (52%) Spray (15%) N=114 Cases

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14 Wind 3-8 MPH Pesticide Application Record

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19 How Do Pesticides Move to Water? In drier climates, spray drift is likely a major source of pesticide residues in water In wetter climates, runoff is likely to be the source of pesticide residues in water However, minimizing off target movement from spray drift into riparian zones will mitigate runoff concentrations Must avoid direct entry into water Thus, minimizing spray drift makes sense for any climatic region

20 Achieving a Reasonable Certainty of No Harm Minimize the amount of drift by employing BMPs (Best Management Practices) Minimize transport out of targeted area Maintain efficacy Need to understand the mechanics of drift, the factors affecting drift, and how we can manage those factors

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23 Mustang MAX BUFFER ZONES Vegetative Buffer Zones Construct and maintain a minimum 10-foot-wide vegetative filter strip of grass or other permanent vegetation between the field edge and down gradient aquatic habitat (such as, but not limited to, lakes; reservoirs; rivers; permanent streams; marshes or natural ponds; estuaries; and commercial fish ponds.)

24 Mustang MAX Only apply products containing zeta-cypermethrin onto fields where a maintained vegetative buffer strip of at least 10 feet exists between the field and down gradient aquatic habitat. For guidance, refer to the following publication for information On constructing and maintaining effective buffers: Conservation Buffers to Reduce Pesticide Losses, Natural Resources Conservation Services, USDA, NRCS Fort Worth, Texas. 21pp.

25 Mustang MAX Buffer Zone for Ground Application (groundboom, overhead chemigation, or airblast)- Do not apply within 25 feet of aquatic habitats (such as, but not limited to, lakes, reservoirs, rivers, permanent streams, marshes, natural ponds, estuaries, and commercial fish ponds.) Buffer Zone for ULV Aerial Application- Do not apply within 450 feet of aquatic habitats, (such as, but not limited to, lakes, reservoirs, rivers, permanent streams, marshes, natural ponds, estuaries, and commercial fish ponds.)

26 Mustang MAX Buffer Zone for Non-ULV Aerial Application- Do not apply within 150 feet of aquatic habitats, (such as, but not limited to, lakes, reservoirs, rivers, permanent streams, marshes, natural ponds, estuaries, and commercial fish ponds.)

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28 30 Vegetation buffer strip No spray zone: Ground 100 Air 300 Airblast direct spray above trees turn off outward pointing nozzles at row ends and outer rows

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31 The Pesticide Label Prime Mechanism of Controlling Pesticide Use

32 Low humidity high temp

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34 Turn off at row ends

35 Is it the sprayer or the operator?

36 Application Control on Amended Guthion Label For airblast applications, turn off outward pointing nozzles at row ends and when spraying the outer two rows

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40 Airblast Proptec Evidence for Sprayer Backwash When Nozzles Off on One Side Guthion (mg/m 2 ) Inside Orchard n l l n n l l n nn l l 1 n l l l nnnn l l Outside Orchard Airblast n Spray A l Spray B n nl nl nl l ln ln nl Inside Orchard l l l 0.1 l n nnn 0.01 lnn l n n l l n n l l l n Outside Orchard n l nl nl Proptec n Spray A l l n Spray B l n l n l n Downwind Distance (ft) from Tree Row One

41 Old style sprayer air dam has merit to eliminate backwash Backwash Air dam slide over manifold Air intake Turning off nozzles on one side of manifold will not eliminate spray

42 Manifold Shields: An Easy Solution to An Avoidable Problem

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44 No Spray Buffer Zones A Solution for Minimizing Impact of Drift Downwind distance between the outer edge of the last swath and the point beyond which exposure to a nontarget receptor is reasonably certain to pose no harm May be required on the pesticide product label Can be estimated using relevant toxicological endpoints Can be estimated so that Regulatory water quality standards are not likely to be violated Acceptable daily intakes (ADIs) or reference doses (RfDs) are not likely to be reached

45 Toxicological Criteria Of all the herbicides likely to be used in turf management, 2,4 D is probably considered the most hazardous Set a no spray zone to protect against 2,4 D and you ll protect against all others 2,4 D acute Reference Dose (RfD) is mg/kg/day The acute RfD is the safe dose ( reasonable certainty of no harm ) following exposure during a 24 hour period A human body dose <0.025 mg/kg/day is 1000 times less than the dose observed to cause no effects of in toxicological studies Thus, any spray drift should be below the RfD

46 Conclusions All sprays drift Minimize drift with BMPs Goal: Exposure potential meets the test of reasonable certainty of no harm or residues do not exceed State water quality standards No spray buffer zones are one of many BMPs Size of the buffer zone can be tailored to the nontarget (human or ecological) and the specific pesticide Labels or lawsuit decision may dictate the size!

47 Conclusions Other Options Nozzle, pressure, boom height, alternative sprayers/nozzles, drift control agents, shields, optimal weather Vegetation wind breaks hide activities & filter sprays Be aware that solid hedge rows can increase deposition on the leeward side Choose reduced risk pesticides Tend to have higher NOAECs & LC50s Will significantly reduce buffer zone size May eliminate need for no spray buffer

48 Establishing Buffer Zones Compile toxicological data Endpoints for Aquatic Nontarget Organisms NOAEC dose at which no adverse effect is observed on development and reproduction Endpoints for Sensitive Plant Species EC25 application rate equivalent that affects plant vigor by 25% compared to control Adjust with safety factor Endpoints for Humans RfD EPA s Reference Dose (exposure dose with reasonable certainty of no harm; applies at least a 100X safety factor to the NOAEL

49 Establishing Buffer Zones Information Sources Registration Eligibility Decision Documents EPA Acquire Database Information is now linked to Pesticide Action Network Database!! State regulatory agencies (Agriculture, Environment/Ecology) GOOGLE it!!!