Managing and Analyzing Pesticide Use Data for Pest Management, Environmental Monitoring, Public Health, and Public Policy Downloaded from pubs.acs.org by HONG KONG UNIV SCIENCE TECHLGY on 09/16/18. For personal use only.
Chapter 6
The Extensive Use of Pesticide Use Report (PUR) Data in Scholarly Scientific Research Michael L. Grieneisen and Minghua Zhang* Department of Land, Air & Water Resources, 1 Shields Ave., University of California, Davis, California 95616, United States *E-mail:
[email protected] The use of pesticides is effective for maintaining agricultural productivity, mitigating arthropod-vectored diseases and protecting structures from pest invasion and damage. However, intensive pesticide usage may have unintended impacts on human health (e.g., associations with cancer or Parkinson’s disease) and vital ecosystem services (e.g., air & water quality and pollinator health). Understanding and mitigating the risks in real-world scenarios requires detailed information on pesticide usage. California’s Pesticide Use Report (PUR) database is unique in the wealth of information it records on the millions of commercial pesticide applications in California annually. PUR data enable regulators, researchers and other stakeholders to examine fine-scale spatial and temporal patterns in pesticide usage and their potential negative effects on the environment and human health. Their investigations have generated over 500 scholarly articles in the scientific and medical literature. This chapter outlines the critical importance of PUR data to understanding the potential risks that agricultural and urban pesticide usage in California pose to human health and the environment to a degree that is not possible to achieve elsewhere in the world.
Introduction Pesticides are widely used to reduce pest damage to agricultural products and built structures and to mitigate populations of arthropod vectors of human health © 2018 American Chemical Society
concern. However, countless studies scattered throughout the published literature have examined the potential negative effects of pesticides (specifically pesticide active ingredients) on the quality of air, soil, and water natural resources, or on the health of exposed humans, model laboratory organisms or wildlife. The dozens of ACS Symposium Series volumes focused on such issues illustrate their importance. In particular, many volumes have been devoted to pesticide environmental fate, potential impacts on the environment or the health of humans and other organisms, or the mitigation of those impacts (Table 1). These are the major research topics in the published literature to which Pesticide Use Report (PUR) data have been applied. These volumes, illustrate the nature and extent of studies conducted to understand and mitigate the risks posed by intensive pesticide usage. In the broader published scientific literature, hundreds of studies on these topics have relied on pesticide usage data from California’s PUR database. This chapter provides a general overview of how PUR data have enabled numerous studies reported in the scholarly literature that have largely focused on the issues of pesticide environmental fate, changing pesticide usage patterns, pesticide-associated epidemiology, and risk assessments for pesticide exposure of human and wildlife populations.
Table 1. Thirty-six examples of ACS Symposium Series volumes, indicated by volume number and title, which focused on pesticide environmental fate or impacts on human health or the environment. (from: http://pubs.acs.org/series/symposium) 1249: Pesticide Dose: Effects on the Environment and Target and Nontarget Organisms 1168: Describing the Behavior & Effects of Pesticides in Urban and Agricultural Settings 1111: Pesticide Regulation and the Endangered Species Act 1075: Pesticide Mitigation Strategies for Surface Water Quality 1028: Turf Grass: Pesticide Exposure Assessment and Predictive Modeling Tools 1015: Pesticides in Household, Structural and Residential Pest Management 997: The Fate of Nutrients and Pesticides in the Urban Environment 991: Synthetic Pyrethroids: Occurrence and Behavior in Aquatic Environments 966: Rational Environmental Management of Agrochemicals: Risk Assessment, Monitoring, and Remedial Action 951: Assessing Exposures and Reducing Risks to People from the Use of Pesticides 947: Crop Protection Products for Organic Agriculture: Environmental, Health & Efficacy Assessment 899: Environmental Fate and Safety Management of Agrochemicals 853: Environmental Fate and Effects of Pesticides 813: Pesticide Environmental Fate: Bridging the Gap between Lab & Field Studies Continued on next page.
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Table 1. (Continued). Thirty-six examples of ACS Symposium Series volumes, indicated by volume number and title, which focused on pesticide environmental fate or impacts on human health or the environment. 771: Pesticides and Wildlife 751: Agrochemical Fate and Movement: Perspective and Scale of Study 743: Fate and Management of Turfgrass Chemicals 734: Pesticides: Managing Risks and Optimizing Benefits 724: International Pesticide Registration Requirements: The Road to Harmonization 699: The Lysimeter Concept: Environmental Behavior of Pesticides 683: Triazine Herbicides: Risk Assessment 652: Fumigants: Environmental Fate, Exposure, and Analysis 645: Molecular Genetics and Evolution of Pesticide Resistance 643: Biomarkers for Agrochemicals & Toxic Substances: Appl. & Risk Assessments 630: Herbicide Metabolites in Surface Water and Groundwater 542: Biomarkers of Human Exposure to Pesticides 524: Pest Control with Enhanced Environmental Safety 522: Pesticides in Urban Environments: Fate and Significance 459: Pesticide Transformation Products: Fate and Significance in the Environment 421: Managing Resistance to Agrochemicals: Fundamental Research to Practical Strategies 414: Carcinogenicity and Pesticides: Principles, Issues, and Relationships 382: Biological Monitoring for Pesticide Exposure: Measurement & Risk Reduction 336: Pesticides: Minimizing the Risks 273: Dermal Exposure Related to Pesticide Use: Discussion of Risk Assessment 182: Pesticide Residues and Exposure 99: Pesticide and Xenobiotic Metabolism in Aquatic Organisms
Traditionally, research studies on the impacts of pesticide usage on human and environmental health have relied on relatively short-term, small-scale experimental systems. However, the true effects of pesticide usage occur in continuous (i.e., long-term), large-scale real-world scenarios--such a as large, contiguous expanse of agricultural fields or residential settings, or an entire watershed where the confluence of non-point source runoff from thousands of acres of agricultural fields are concentrated in a single receiving body of water. Therefore, understanding and mitigating the effects of pesticide use in the real world requires pesticide usage information with high spatial and temporal resolution, and represents both long-term and large-scale usage. 117
Some sources of pesticide usage data have been derived from either selective surveys or pesticide sales data, but such sources lack the level of quantitative, spatial and temporal detail that is necessary to accurately and comprehensively assess usage. One example is the Estimated Annual Agricultural Pesticide Use system of the US Geological Service (https://water.usgs.gov/nawqa/pnsp/usage/ maps/county-level/), which only provides crude “high” and “low” estimated usage data for individual active ingredients (AI) at the county spatial level and annual temporal level. California’s PUR database (http://www.cdpr.ca.gov/docs/pur/purmain.htm) is the most comprehensive source of large-scale pesticide usage data at fine spatial (down to 1.6x1.6 km) and temporal (down to sub-daily) scales. PUR records an unparalleled wealth of data on the millions of commercial pesticide applications in California every year. As discussed in greater detail in other chapters in this volume, data records in the PUR include detailed information for individual pesticide applications regarding the product, active ingredient, amount used, time and place of the application, application method, and context (i.e., what the product was applied to, and whether a specific agricultural crop or a specific non-agricultural use such as “Structural pest control”). Recognizing the unique opportunity that the PUR presents in terms of the scope and richness of data, regulators, researchers, and other stakeholders have conducted extensive analyses of PUR data in order to understand the various economic, environmental, epidemiological and regulatory aspects of pesticide usage in California. In addition, PUR data have been instrumental in answering fundamental questions about the environmental fate and various risks posed by pesticide usage (e.g., (1–3), and many others). This chapter provides an overview of over 500 scientific and medical research studies using PUR data that have been reported in the published scholarly literature. It is beyond the scope of this chapter to delve into the nuances of the scientific results of individual studies; rather this chapter will showcase the types of questions that researchers have answered through the analysis of California’s unique repository of PUR data.
PUR as a Key Component of Pesticide Use Research Infrastructure Several features of the PUR database are critical for its utility in research on pesticide usage, and the potential impacts of that usage (Table 2). The features of the PUR data and PUR database listed in Table 2 are discussed in detail in other chapters in this book. Because the PUR is uniquely comprehensive in the data recorded for individual commercial pesticide applications, some fundamental research questions on the potential negative consequences of pesticide usage can only be studied in California systems. Consequently, many authors outside of the state have chosen study sites in California primarily to take advantage of the availability of the PUR data (e.g., (4, 5)).
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Table 2. Selected features of PUR data which make it amenable for use in research studies. The meta-data fields apply to individual records, which represent either individual agricultural pesticide applications or aggregations of individual applications for non-agricultural uses. Meta-data fields specify key parameters of the applications What: Product commercial name, active ingredient (AI) chemical(s) and their percentages in the formulation. Identification by product name allows the user to incorporate other relevant product properties, such as volatility for air quality VOC considerations. When: Application timing provided at sub-daily scale for agricultural applications, aggregated to monthly time-scale for non-agricultural applications. This allows the user to place individual applications into contexts by season or other time-sensitive events, such as pollinator presence. Where: Spatial resolution to 1.6x1.6 km section for agricultural applications, aggregated to the county-level for non-agricultural applications. This allows the user to integrate usage data with a wide range of external spatial datasets, such as proximity to sensitive sites like public schools. How much: The amounts of product and active ingredient(s) (in pounds), and acres treated are given and can be used to derive application rate (lb/acre). Applied to what: The “site_code” field identifies the agricultural commodity treated or non-agricultural use (such as “Public health pest control” or “Rights-of-way”) of the application. PUR data are easily integrated with external datasets By identifying the AI(s) of the pesticide products used, PUR facilitates the integration of PUR data with external databases that cotain information specific to the AI, such as chemical or mode of action classes, physicochemical properties, or regulatory lists of AIs of interest (e.g., Proposition 65) Application timing can be integrated with weather data, pollination timing for specific crops (for consideration of potential bee toxicity), or timing of human exposure risk activities (e.g., public school attendance) Application spatial data can be integrated with various spatial datasets, such as the boundaries of municipal entities (e.g., counties or zip codes), environmental parameters (e.g., slope of land or soil properties), or proximity to sensitive sites (e.g., schools or endangered species habitat) PUR data may be obtained by anyone with Internet access, and downloaded by several routes CalPIP (calpip.cdpr.ca.gov) – command-line interface, queries limited to one year at a time Annual summaries of PUR data can be downloaded as Zip files (ftp://transfer.cdpr.ca.gov/pub/outgoing/pur_archives) Continued on next page.
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Table 2. (Continued). Selected features of PUR data which make it amenable for use in research studies. The meta-data fields apply to individual records, which represent either individual agricultural pesticide applications or aggregations of individual applications for non-agricultural uses. PUR data may be obtained by anyone with Internet access, and downloaded by several routes PURwebGIS (http://purwebgis.ucdavis.edu) – graphical user interface (GUI), supports multi-year queries, though query size is limited by the capacity of the user’s computer and Internet download speeds DPR Annual Reports– Each report includes hundreds of static summary tables by active ingredient (AI), selected AI classes, commodities/use types, etc. Many of the tables include trends over time.
Over 550 Studies Published through June 2017 Have Relied on PUR Data To Answer Scientific Questions We wanted to determine how extensively PUR data have been used in scholarly research, and therefore consulted two primary sources, Science Citation Index (SCI) and Google Scholar, to find published studies which cited PUR as a data source. Since PUR data may be accessed through various routes, article authors have used a variety of ways of referring to the database. SCI was queried for “citing articles” with various logical abbreviations for either the “Source title” field (such as “Pest* Use Rep*”) or the “Author” field (such as “CDPR” or “Dep* Pest* Reg*”). Online databases such as PUR are often cited in the Materials and Methods section of articles, rather than the References Cited section. Therefore, since Google Scholar indexes the full text of articles across a wide range of scholarly journals, it was queried using several logical text strings that would identify PUR or its primary web-access points (e.g., “Pesticide Use Report(s)” or “calpip.cdpr.ca.gov”). In all cases, the contexts of the PUR citations in the original articles were checked to verify that they did indeed refer to the California PUR database and incorporate pesticide usage data into the study. The resulting list of published studies, the PUR Bibliography (Jun 2017 edition posted at: http://agis.ucdavis.edu/publications/pur_citations/PURbiblio2017Edition.docx), includes a total of 553 articles and theses. The number of citations per year has increased from
