Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

California’s Pesticide Use Reporting System(PUR)

Larry Wilhoit

August 29, 2011

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

1 Pesticide Use Data in Endangered Species Assessments

2 Description of the Pesticide Use Reporting (PUR) system

3 Data Quality

4 Uses and Misuses of the PUR

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

Endangered Species Assessments

In endangered species biological opinions, several unlikelyassumptions are made about pesticide use:

Pesticides are applied at maximum label rates

All agricultural areas were assumed to be treated

Treatments can occur at any time of the year

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

Pesticide Use Data

With actual data on pesticide use, we can make more realisticassumptions. The PUR has data on:

Actual maximum rates rather maximum rates frompesticide labels

Specific areas where pesticides are used

The dates pesticides are used

The methods of applications

Data exists for more than 20 years

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

History of the PUR

California first required limited reporting of pesticide use in1950.

The PUR database contains records starting in 1974.

Current full use reporting system started in 1990.

The PUR database contains about 2.5 million records foreach year since 1990.

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

What is Reported

All pesticide applications in California productionagriculture must be reported to the appropriate CountyAgricultural Commissioner’s office.

All pesticide applications made by commercial pest controlbusinesses must be reported.

The exceptions: pesticide applications made by home andgarden use or most institutional use are not reported.

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

Two Types of PUR Records

Production agricultural applications

Applications to agricultural fieldsCalifornia defines agriculture broadly, including forests,parks, rangelands, turfEach record in the PUR refers to one application

Monthly summary reports

All other uses by commercial applicators (post harvest,landscape, structural)Each record refers to total use of a pesticide during eachmonth on a site in a county by the applicator

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

Data Collected for Production Agricultural Records

Pesticide product used (its name and EPA registrationnumber)Amount of product used, in gallons, pounds, or other unitsCrop treatedArea of the crop plantedArea of the crop treatedDate of treatmentGeographic location of the treatment (to a square mile)Grower or operator identifierField identifierMethod of application (by air, ground, or other method)

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

Process from Grower to DPR Database

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

Importance of Error Screening

It is critical that the PUR be as accurate and complete aspossible.

Even a few errors can have large effects on an analysis.

The PUR is screened for about 40 kinds of errors.

Error rate is less than 0.5%.

Probably 80 to 90% of actual use is reported.

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

Common Errors in the PUR

Units of measures (ga, qt, oz)

Units treated (acres, square feet, cubic feet, pounds)

Amount applied

Product name or registration number

Duplicate records

Errors in DPR’s label database

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

Errors Affecting Rate of Use

Many of these errors affect rate of use (pounds applied perarea treated).

Indentifying rate errors is difficult because rates depend onthe pesticide, crop treated, and many other things.

An unusual reported rate is not necessarily an error—highor low rates are sometimes used.

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

Identifying Rate Outliers

Maximum label rates

Fixed limits for most AIs and high rate AIs and for eachkind of unit treated

Median of the log (rate * 50) of similar uses

Trimmed mean log rate + 8 * standard deviation

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

Visual Inspections of DistributionsGlyphosate

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

PUR vs Sales Data

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

Pounds of 2,4-D by Crop, County, Month, and Year

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

Map of Thiobencarb Use In Colusa Area by Section

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

Maximum Label Rates vs Actual RatesGlyphosate

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

Forecasting Pounds of ChlorothalonilWith 80% and 95% prediction intervals

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Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

Strengths of PUR

PUR data includes detailed records of each agriculturalapplication.

Data are obtained from a census not just samples.

Data are GIS friendly.

Data can be linked with many other databases on thechemical, environmental, and health properties ofpesticides.

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

Misuses of the PUR

Failing to check for errors in your dataset

Misunderstanding of some of the data: eg acre_treatedand acre_planted do not always mean acres

Confusing pesticide products with active ingredients

Comparing extent of use of different AIs using only poundsMethyl bromide is used at rates about 230 lbs/acre

Esfenvalerate is used at rates about 0.04 lbs/acre

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

Limitations of the PURMissing Information

Does not include most applications to animals and tonon-agricultural sites

No pest information

No date of planting or harvest

No information on person or business making agriculturalapplications

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

Conclusion

The PUR is a valuable source of high quality and detaileddata on pesticide use, especially in production agriculture.

Users of the data need to be aware of some of thelimitations in the data.

The PUR can be used to make more realistic and accurateassessments of the exposure of pesticides to endangeredspecies.

Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion

Any Questions?