U. S. Food and Drug Administration
Center for Food Safety and Applied Nutrition
Pesticide Residue Monitoring Database Users' Manual
March, 1999

U.S. FOOD AND DRUG ADMINISTRATION
PESTICIDE MONITORING DATABASES
FOR FISCAL YEARS 1996 AND 1997

USER'S MANUAL

LIST OF CONTENTS

Introduction

Database Structure and Content

Search Program and Report Formats

Installation

Structure and Content of Raw Individual Sample Data File

NOTE of change: This 1999 revision of the User's Manual replaces previous appendices for country and pesticide names with links to separate lists; either of these can be saved as a file by the user.

For further convenience, a single downloadable file is available for the user who intends to create a relational database with linked tables. The executable file decompresses to six files, one a ReadMe explaining the others; the other five files contain, respectively, additional information about: (1) names of countries, (2) pesticide names (including those that appear as part of "total" aggregates), (3) product codes, (4) analytical method extraction codes, and (5) analytical method determinative codes.

INTRODUCTION

This user's manual provides information you will need about the U.S. Food and Drug Administration (FDA) monitoring program for pesticide residues in food, the structure and content of the Pesticide Monitoring Database, and the search and report generation procedures offered in this package. PLEASE READ THE MANUAL BEFORE USING THE DATABASE!

Regulatory Responsibility for Pesticides

The FDA shares responsibility with two other federal agencies for the regulation of pesticides. The Environmental Protection Agency (EPA) registers (i.e., approves) the use of pesticides based on evidence that their use will not cause an unreasonable risk to health or the environment. EPA is also responsible for establishing tolerances if use of a pesticide may lead to residues in food. (A tolerance is the maximum amount of a residue that is permitted in or on a food.) With the exception of meat, poultry, and certain egg products, for which the Food Safety and Inspection Service (FSIS) of the U.S. Department of Agriculture (USDA) is responsible, FDA is charged with enforcing tolerances in imported foods and in domestically produced foods shipped in interstate commerce. FDA also acquires incidence/level data on particular commodity/pesticide combinations and carries out its market basket survey, the Total Diet Study. USDA's Agricultural Marketing Service (AMS), through contracts with participating states, conducts a residue testing program directed primarily at raw agricultural products. FSIS and AMS pesticide residue data are reported independently by those agencies.

FDA Pesticide Monitoring Program

The FDA pesticide monitoring program is comprised of three components: 1) regulatory monitoring; 2) incidence/level monitoring; and 3) the Total Diet Study. THE DATABASE PRESENTED HERE COVERS ONLY THE REGULATORY MONITORING COMPONENT. However, a brief description of the other two components is provided, and further information on them is available in the FDA annual reports, available from FDA's website.

Regulatory Monitoring

The regulatory monitoring component is directed toward enforcing tolerances in imported foods and in domestically produced foods shipped in interstate commerce. Under regulatory monitoring, FDA samples individual lots of domestically produced and imported foods and analyzes them for pesticide residues. Domestic shipments are collected as close as possible to the point of production in the distribution system; import samples are collected at the point of entry into U.S. commerce. Emphasis is on the raw agricultural product, which is analyzed as the unwashed, whole (unpeeled), raw commodity. Processed foods also are included.

Domestic and import food samples collected for analysis are classified as either "surveillance" or "compliance." Most samples collected by FDA are the surveillance type; that is, there is no prior knowledge or evidence that a specific food shipment contains illegal pesticide residues. Compliance samples are collected as follow-up to the finding of an illegal residue or when there is other evidence of a pesticide problem. Compliance samples include follow-up samples from the same shipment as a violative surveillance sample, follow-up samples from additional product from the same grower or shipper, and audit samples from shipments presented for entry into the United States with a certificate of analysis (i.e., shipments subject to detention without physical examination).

To analyze the large numbers of samples whose pesticide treatment history is usually unknown, analytical methods capable of simultaneously determining a number of pesticides are used. These multiresidue methods (MRMs) can determine about half of the approximately 400 pesticides with EPA tolerances, as well as many others that have no tolerances. The most commonly used MRMs can also detect many metabolites, impurities, and alteration products of pesticides with and without tolerances.

Single residue methods (SRMs) or selective MRMs may be used to determine pesticides not covered by an MRM. An SRM usually determines one pesticide; a selective MRM measures a relatively small number of chemically related pesticides. These types of methods are usually more resource-intensive per residue, and they may require at least as much time to perform as an MRM. They are much less cost efficient than MRMs.

The lower limit of residue measurement in FDA's determination of a specific pesticide is usually well below tolerance levels, which generally range from 0.1 to 50 parts per million (ppm). Residues present at 0.01 ppm and above are usually measurable; however, for individual pesticides, this limit may range from 0.005 to 1 ppm. In this database, the term "trace" is used to indicate residues detected, but at levels below the limit of quantitation.

Incidence/Level Monitoring

A complementary approach to regulatory monitoring, incidence/level monitoring has been used to increase FDA's knowledge about particular pesticide/commodity combinations by analyzing certain foods to determine the presence and levels of selected pesticides. In 1995, a survey of triazines was started and in 1997 the survey was completed.

Statistically based monitoring surveys, focusing on domestic and imported foods were initiated in 1992 and the results have been published. These statistically based surveys were initiated to determine whether FDA data acquired under regulatory monitoring are statistically representative of the overall residue situation for a particular pesticide, commodity, or place of origin. In FDA's surveillance sampling for pesticide residues, sampling bias may be incurred by weighting sampling toward such factors as commodity or place of origin with a past history of violations or large volume of production or import shipments. In addition, the total number of samples of a given commodity analyzed for a particular pesticide each year may not be sufficient to draw specific conclusions about the residue situation for the whole volume of that commodity in commerce. Therefore, the objective of these statistically based surveys is to determine whether violation rates, frequency of occurrence of residues, and residue levels obtained from such a sampling regimen differ from those obtained through FDA's traditional surveillance approach.

Total Diet Study

The Total Diet Study is designed to estimate dietary intakes of pesticide residues by various age/sex groups from infants to senior citizens. FDA personnel purchase foods from supermarkets or grocery stores four times per year, once from each of four geographical regions of the country. Each collection contains 261 food items (234 items prior to 1992) that have been selected on the basis of information obtained through nationwide dietary surveys. The 261 foods are representative of over 3500 different foods in the national surveys; for example, apple pie represents all fruit pies and fruit pastries. Each of the four collections is a composite of like foods purchased in three cities in that region. The foods are prepared table-ready and then analyzed for pesticide residues (as well as radionuclides, industrial chemicals, toxic elements, trace and macro elements, vitamin B₆, and folic acid). The levels of pesticides found are used in conjunction with food consumption data to estimate the dietary intakes of the pesticide residues.

DATABASE STRUCTURE AND CONTENT

The database presented here pertains only to the regulatory monitoring component of the FDA pesticide programs for Fiscal Years 1996 and 1997. Under regulatory monitoring in 1996, 10,374 samples were analyzed; of these, 5062 were domestic samples and 5312 were imports. In 1997, 9843 samples (4501 domestic and 5342 imports) were analyzed.

Each year's database consists of three parts. A large, detailed data file presents FDA regulatory monitoring coverage and findings by country/sample flag/food product/pesticide combination. (Sample flag is the "surveillance" vs "compliance" classification described earlier.) Two smaller summary files are also available; they provide, respectively, an overview by country/sample flag/food product combination (without regard to pesticide) and by country/sample flag/pesticide combination (without regard to product). The smaller summary files can be used to conveniently obtain general information without the need to use the much larger detailed file.

The following notes apply to all data files.

--  Data files are in dBase (.dbf) format. A search program and report formats written in dBase III+ are provided as part of this package to enable users to perform simple searches and generate reports. The search program is described below.

--  Throughout the database, surveillance samples and compliance samples are addressed separately because of the significant fundamental difference in the nature of the samples. The user is advised to be cognizant of this issue in using the data, particularly the data for compliance samples.

--  Because of the broad analytical coverage afforded by the multiresidue methods commonly used in FDA monitoring, a large number of pesticides typically are covered in analysis of a given country/food product combination. The listing in the database of coverage of a particular pesticide for a given country/food product combination should not be considered as indicating the existence of an EPA tolerance or known or anticipated usage of that pesticide on that product but rather as an indication of the capability of the analytical methods used.

--  Wherever possible, pesticide information in the database is expressed as a total of related residues (parent, metabolites, etc.). Examples are "DDT (TOTAL)" and "CHLORDANE (TOTAL)." However, in cases where the analytical behavior of related residue components differs significantly and therefore the analytical coverage of them would differ, the residue components are expressed separately.

--  The term "adverse" denotes a residue that: 1) exceeded a tolerance; or 2) had no tolerance for the food product involved and the residue level appeared to be of regulatory significance.

--  Data elements that provide "percent" information express the percent values in the form in which they best fit in a three-position field; examples of percent values are "3.7" and "26".

Summary File by Country/Sample Flag/Food Product Combination

For 1996, the summary file by country/sample flag/food product combination has 1,817 records (PROD1996.DBF); the 1997 file (PROD1997.DBF) has 1,725 records. There is one record for each combination of country/sample flag/food product. The records have the following structure.

Summary File by Country/Sample Flag/Pesticide Combination

For 1996, the summary file by country/sample flag/pesticide combination has 34,720 records (CHEM1996.DBF); the 1997 file (CHEM1997.DBF) has 32,028 records. There is one record for each combination of country/sample flag/pesticide. The records have the following structure.

Detailed File by Country/Sample Flag/Food Product/Pesticide Combination

For 1996, the detailed file by country/sample flag/food product/pesticide combination has 336,662 records (DATA1996.DBF); the 1997 combined file (DATA1997.DBF) has 320,519 records. There is one record for each combination of country/sample flag/food product/pesticide. The records have the following structure.

The data elements pertaining to residue concentration (MEAN, MINIMUM, MEDIAN, NINETITH, and MAXIMUM) are based on the number of samples covered and are expressed in parts per million. Trace findings and samples in which no residue was detected were treated as zero in calculation of the MEAN. In the MINIMUM, MEDIAN, NINETITH, and MAXIMUM data elements, "T" represents a trace finding and "0" represents "none detected." The vast majority of the detailed data records indicate that no residues were found (i.e., RESFND=0) for that country/sample flag/food product/pesticide combination.

SEARCH PROGRAM AND REPORT FORMATS

A search program and report formats written in dBase III+ are provided as part of this package to enable users to perform simple searches and generate reports. The search program and report formats will only work in dBase III+ and will give error messages if used in any other version of dBase. The search program contains procedures to search each of the three data files. The user selects the file to search from a menu and then fills in prompts on the screen to specify selection criteria by country, food product, and/or pesticide, depending on the data file chosen. After the search has executed and the number of records selected is shown, the user selects a report format from a menu. Each report format displays all of the data elements contained in the records selected; the difference among the formats is in the sort sequence of country, food product, and pesticide. All of the report formats require setting of the printer to use a nonproportional font of 16.6 characters per inch. (If you use a font with fewer characters per inch, the report output will be truncated.) In most cases, the column headings in the report formats are the same as the field names listed in the description of the file structure; in some cases, the column heading is a condensed form of the field name because of space limitations in the report.

For users who wish to examine the FDA pesticide monitoring data on an individual sample basis, the raw data for individual samples are provided as an ASCII text file. The search program and report formats do not apply to this file; to use this file, the user must develop his/her own search and report programs. The structure of the raw individual sample data is considerably more complex than that of the other files and requires greater familiarization and caution by the user to use the file properly. Structure and content of the file of individual sample data is described below.

INSTALLATION

The search program and report formats are written in dBase III+. The data files are in dBase (.dbf) format. The installation instructions for the database assume that dBase III+ or higher has been installed on your computer. Usage of a 486 or higher computer is recommended for practical processing speed. The search program, report formats, and data files occupy a total of approximately 60 megabytes.

Instructions

The following files are necessary for complete installation of the database:

1996 database: FDA1996.EXE, PROD1996.EXE, CHEM1996.EXE, US1996.EXE, IMVE1996.EXE, IMOT1996.EXE, IMFR1996.EXE, SMPL1996.EXE, and METH1996.EXE

1997 database: FDA1997.EXE, PROD1997.EXE, CHEM1997.EXE, US1997.EXE, IMVE1997.EXE, IMOT1997.EXE, IMFR1997.EXE, SMPL1997.EXE, and METH1997.EXE

Note: the following directions use "199X" to refer to the files and commands for either 1996 or 1997.

To install a database, move one complete set of these files to the dBase directory. At the DOS prompt change to the dBase directory and type:

•    FDA199X

The file will decompress and be loaded into the dBase directory. Repeat the operation for each of the EXE files listed above.

[If an earlier version of the Pesticide Monitoring Database is contained in the same dBase directory, the report format (*.FRM) files (loaded by executing FDA199X.EXE) are already present and need not be overwritten.]

When complete, enter at the DOS prompt:

•    rename US199X.DBF DATA199X.DBF

Invoke dBase III+ by entering dbase at the DOS prompt. Then enter the following dBase commands in succession at the dot prompt:

•    use DATA199X.DBF; loads United States data into the database
•    append from IMFR199X.DBF; adds imported fruit data
•    erase IMFR199X.DBF
•    append from IMVE199X.DBF; adds imported vegetable data
•    erase IMVE199X.DBF
•    append from IMOT199X.DBF; adds other imported commodities data
•    erase IMOT199X.DBF

The APPEND operations each take several minutes to complete; a new dot prompt will appear when the APPENDing is concluded.

The installation process may take 30 minutes or more to complete, depending on the clock speed of the computer and other factors.

NOTE: If you have interest in only part of the data, you may combine (append from) only those files (as above) and rename that file to DATA199X.dbf.

To run the search program, set your printer to a nonproportional font of 16.6 characters per inch. Then enter the following at the dot prompt:

• do FDA199X

Then follow the instructions on the screen. (Follow the instructions carefully. For example, when filling in your search criteria for country, food product, and/or pesticide, use the ENTER key to move to the next box; DO NOT use the arrow key because you will generate incorrect output.) A search of the detailed database may take 10 minutes or more.

Explanation

The files are all provided as compressed executable files which automatically decompress when you load them. The file content for the two groups of files (1996 and 1997) is as follows.

The search program references a single file named DATA1996.DBF (or DATA1997.DBF) for the detailed data. Therefore, the installation instructions include creation of this file from the four detailed files loaded.

In addition to the summary files listed above, the following text files are available; these may be used to create databases with appropriate software.

1. The data reflect FDA monitoring results as entered into a computerized reporting system by FDA's field offices and are unedited.
2. For each analysis performed on a given sample, the following is entered: 1) one record for each residue that was found in the analysis; or 2) one record which states that no residues were found. The data file does not contain a "none detected" record for each chemical that was covered in a given analysis but was not found. Therefore, to determine which pesticides were covered in a given analysis or in FDA pesticide monitoring as a whole, or to determine the extent of coverage of a given pesticide, the user must also refer to the accompanying file that lists the pesticides known to be covered for the analytical method codes reported in the raw individual sample data. ANALYTICAL COVERAGE CANNOT BE INTERPRETED SIMPLY BY EXAMINING THE RESIDUE CODES/NAMES REPORTED IN THE RAW DATA!
3. For most samples, more than one analysis is performed. Therefore, the file contains multiple records for most of the samples, even if no residues were found. The user must adjust for the multiple records per sample when processing the data to determine sample counts such as the number of samples analyzed, etc.
4. The analytical methods used for a given sample may overlap in coverage, i.e., a given pesticide may be covered by more than one of the methods used. The user must adjust for overlapping coverage when processing the data to determine the number of samples covered for a given pesticide.
5. More than one record may be entered for a given pesticide in a given sample. For example, there can be both an original analysis record and a check analysis record for a given pesticide in a given sample, and there can be records for a given pesticide for each subsample analyzed. The user must adjust for the multiple records per pesticide per sample when processing the data to determine the number of residues found and distribution of residue levels for a given pesticide. [In compilation of the other data files in this package, FDA used the following criteria to select one record per pesticide per sample from the raw data: sort by analysis type field using sequence of check, additional, original, identification; within analysis type, sort by descending adverse flag (adverse results would then precede non-adverse results); within adverse flag, sort by subsample field after converting all non-blank subsample codes to a "dummy" code of "SS" (records for sample composite, which has blank subsample code, would then precede records for individual subsamples, and conversion of all non-blank subsample codes to a common "dummy" code will allow subsample with highest residue amount to be selected preferentially over other subsample results); within subsample field, sort by descending residue amount (after conversion to parts per million); within residue amount field, sort by descending trace field; then select the first record in the sort sequence to use in tabulating monitoring coverage and findings.]
6. In most cases, the raw individual sample data are reported by individual residue component (e.g., endosulfan I, endosulfan II, endosulfan sulfate) rather than as a total of components related to a given parent pesticide. (The list of pesticide names indicates which names found in the raw data file are contained within a "total" entry in the summary files.) There are some samples for which results were reported both by individual component and as a total. For example, some samples have results reported for one analysis as "permethrin, cis" and "permethrin, trans" as well as a result from another analysis reported as "permethrin." The user must adjust for such situations when processing the data to determine the number of residues found and distribution of residue levels for a given pesticide.
7. The analytical methods routinely used in FDA pesticide monitoring also cover some industrial chemicals (e.g., polychlorinated biphenyls). Findings of the industrial chemicals are reported in the raw data file but were excluded in compilation of the other data files contained in this package.
8. As stated in item 2, the data file does not usually contain a "none detected" record for each pesticide that was covered in a given analysis but was not found. However, there is an exception in the case of analyses reported with extraction code 998 ("other methods used for determination of single components"), for which the analyzing laboratory will report the code of the pesticide that was covered in the analysis, even if it was not found. For analyses by methods other than "998", the analyzing laboratory may choose to enter the code for a given chemical that was covered but not found if they wish to highlight the result for some reason.

The following describes the structure of the raw data records. Each record is uniquely identified by its combination of year/analyzing district/sample number/PAC/LID/entry number, and the file is provided in sequence by this record key.

File of Pesticides Covered by the Analytical Methods Reported in the Raw Individual Sample Data

The following is the structure of the file that lists the pesticides covered by the analytical methods reported in the raw individual sample data. (A "method" is a given combination of extraction code and determination code.) This file lists the individual residue components covered. It reflects documented coverage based on recovery/response data received by FDA headquarters in Washington, D.C.; in some cases, residue findings may have been reported in the raw individual sample data for pesticide/method combinations for which FDA headquarters has not yet received recovery and/or response data to document the coverage. The file does not list the industrial chemicals covered by the methods.

District Code Definitions

Program/Assignment Code (PAC) Definitions

The following are code definitions for the general monitoring programs and special field assignments.

Sample Type Code Definitions

Laboratory Classification Definitions

If you have questions about the database that are not addressed in this manual, contact Mark Wirtz, mwirtz@cfsan.fda.gov

Hypertext updated by ear/cjm 2000-OCT-26