Data sources
Tracking California's Agricultural Pesticide Mapping Tool uses 1991-2018 data from the California Department of Pesticide Regulation's (CDPR) Pesticide Use Reporting (PUR) program. Under this program, all agricultural pesticide use must be reported monthly to county agricultural commissioners, who in turn report the data to CDPR.
The Agricultural Pesticide Mapping Tool only displays agricultural pesticide applications, applications for which 'Acres_treated' is greater than 0, and applications for which 'Unit_treated' must equal A (acres) or S (square feet). Adjuvants are not displayed in the Pesticide Mapping Tool. 2,133 records that were missing an application date were excluded from the tool.
The PUR includes applications by licensed pest control operators for agricultural and nonagricultural applications. The primary exceptions to pesticide reporting are consumer home-and-garden, most industrial uses, and institutional uses. Customized data reports can be generated through CDPR's California Pesticide Information Portal (CalPIP).
Definition of Pesticide Categories
For the Agricultural Pesticide Mapping Tool, Tracking California selected and grouped pesticides into categories based on known health effects or regulatory status. Many pesticides may belong to more than one category. The selection criteria are described below. These pesticide categories were last updated June of 2019, and can be downloaded here.
Carcinogens
Carcinogens include: (1) active ingredients in the CDPR database that are "Known," "Probable," or "Likely" to be carcinogenic in humans, based on evaluations by the Health Effects Division of the United States Environmental Protection Agency (U.S. EPA) Office of Pesticide Programs (i.e.,U.S. EPA Category A, B1, or B2); and (2) chemicals "known to the State of California to cause cancer" under Proposition 65. There are differing weights of evidence for specific chemicals that summarize researchers" confidence that they, in fact, can cause cancer in humans. This list includes "Likely" or "Probable" carcinogens, for which the evidence is relatively strong for their cancer-causing potential.
Cholinesterase Inhibitors
Sources from U.S. EPA, CDPR, or the World Health Organization (WHO) provided the basis for inclusion in the cholinesterase inhibitor category.
Endocrine Disruptors
There is no conclusive list of endocrine disruptors, and classification as such will vary based on ongoing research. The tool incorporates pesticides classified as endocrine disruptors by staff scientists based on existing evidence from the U.S. EPA and the European Commission, and will be periodically updated. These updates may result in some chemicals being added, while others may be removed. The European Commission's Directorate-General for the Environment has established a list to prioritize further review of suspected endocrine disruptors, and more information is also available from the U.S. EPA.
Fumigants
Pesticides classified as fumigants include chemicals used in a gaseous form and identified by CDPR or U.S. EPA as volatile substances or substances which degrade to volatile active substances.
Neonicotinoids
These compounds share a common mode of action that affects the central nervous system of insects. The compounds included in this list of neonicotinoids are those which are currently under review by the U.S. EPA.
Reproductive and Developmental Toxicants
Reproductive and developmental toxicants were selected from CDPR's list of pesticide active ingredients that have been identified through Proposition 65 as chemicals known to the State of California to cause reproductive or developmental toxicity.
Toxic Air Contaminants
The chemicals classified as toxic air contaminants are chemicals in the CDPR database that are also listed as California Toxic Air Contaminants (TACs) or U.S. EPA Hazardous Air Pollutants (HAPs). Additional information on the designation of TACs and HAPs is available from the California Air Resources Board (CARB) and the U.S. EPA.
Limitations
According to CDPR's Summary of Pesticide Use Report Data - 2015,
"The pounds of pesticides used and the number of applications are not necessarily accurate indicators of pesticide risk. There are reduced-risk pesticides that require higher use rates or more applications than many conventional pesticides but have little environmental or human health risk due to their mode of action, toxicity, and selectivity to the targeted pest.
"In addition, it should be noted that the pounds of pesticides used and the number of applications are not necessarily accurate indicators of the extent of pesticide use or, conversely, the extent of use of reduced-risk pest management methods. For example, farmers may make a number of small-scale "spot" applications targeted at problem areas rather than one treatment of a large area. They may replace a more toxic pesticide used at one pound per acre with a less hazardous compound that must be applied at several pounds per acre. Either of these scenarios could increase the number of applications or amount used, respectively, without indicating an increased reliance on pesticides."
Frequently Asked Questions
What sort of data quality checks have been done to make sure the data matches up with CalPIP?
Before the pesticide use data is made public CDPR does its own quality checks including replacing clear outliers with median values. They also flag additional outliers in the raw data, but we do not remove these. Our quality assurance process includes removing records with missing application dates, chemical codes, site codes, or pounds of chemical used, and records where the acres treated is invalid (i.e. equal to 0 or missing). We also check to see if new sites or chemicals have been added to the database.
Where does the acres treated data come from?
Each application record includes the number of treated acres. These acres are summed by the year, site, and pesticide by county, township, and section geographies.
Are there any caveats to using the data?
Some of the PUR data provided by CDPR is censored in instances where the product information and chemical information is confidential (i.e. where adjuvant chemicals are used in the pesticide application). For example, the raw data can include the product number and product totals but not the chemical totals and, as a result, the chemicals used in these applications are not included in the application. Alternatively, CDPR may remove the product number from a dataset but report the total pounds of chemicals used. In these cases, there may be a small mismatch in total pounds between the raw PUR data versus what is displayed on the pesticide mapping tool.
The pesticide mapping tool displays pesticide use at the section level (1 x 1 mile), but when thinking about exposures it should not be assumed that pounds of pesticides used is evenly distributed across this area; it is concentrated to specific fields within the section.
Why did you decide to use a percentile binning for the maps instead of just using the values?
Range of pounds used, acres treated, and rate vary by the pesticide, category, and site selected so percentiles make it easier to see and color code the highs and lows on the map versus just using the values.
Suggested Citation
Please use the following citation when using mapping results in reports or other materials: Tracking California, Public Health Institute. Agricultural Pesticide Mapping Tool. Accessed from www.trackingcalifornia.org/data-and-tools/pesticide-mapping-tool [Month/Day/Year] .