Methodology

How To Use the Pesticide Database

The Center’s online pesticides data search allows anyone to determine what kinds of reactions the pesticides and chemicals they use at home and at work have caused across the country. Searches can be made by product name or chemical name and one or all of the following: city, state, or type of exposure. The search function does not allow for a search by both product name and chemical name, as many products have multiple chemicals and therefore the results would include multiple instances of the same incident.

For the best results, begin with broad searches using only one or two criteria and then narrow the analysis with additional criteria. The searches by chemical and product name will find some records that are not spelled exactly the way the search was entered. For example, a search for the chemical pyrethrin will also return those records with the spelling pyrethrins or pyrethrin. But some records may contain misspelled words. Experimenting with different spellings may find those records.

Searching by city is possible, but about 33 percent of records do not include the name of the city. This is because people exposed to pesticides do not always provide the name of the city.

The Pesticide Incident Data System

The analysis for this project was conducted using the Environmental Protection Agency’s Pesticide Incident Data System. The data system aggregates information concerning more than 90,000 specific pesticide exposures from 1992 through 2007 and was obtained through a Freedom of Information Act request. The vast majority of the pesticide incident information is provided by pesticide manufacturers. These companies, however, are only required by law to report to the EPA the incidents they learn of, such as through media reports, a call to a company hotline, or legal action.

This means the Pesticide Incident Data System is not a comprehensive list of every pesticide exposure that occurred in the United States or even every exposure that resulted in a trip to a medical facility. As some companies make more of an effort to learn about incidents than others and most exposures go unreported, according to pesticide data experts, definitively stating that a specific product causes more incidents than all others is problematic. For the most part the data also do not capture information concerning long-term health consequences, as attributing chronic effects to specific pesticide exposures is difficult. The vast majority of incidents in the system involve immediate health reactions to pesticide exposure.

The incident reports that are relayed to the EPA are not verified and often do not come from medical experts, but from members of the public who have been exposed to a pesticide or have a friend or family member who has been exposed to a pesticide. Incidents may not be reported correctly. In 98 percent of all cases, the EPA described the certainty that the reported pesticide caused the described symptoms as unknown.

This is not to say the data are without value. The EPA uses the system to observe broad trends and to identify dangerous spikes in incidents for specific products and chemicals. And while the EPA plans to overhaul the system in the next year to make it more efficient, agency analysis of exposure data has prompted product recalls, chemical use restrictions, and chemical and product phase outs.

The analysis only included those records that were new incidents and not updates of previously recorded incidents. This was to avoid counting the same incident more than once. The updated records were not reconciled with the new incidents because the EPA’s system only links the updated and new records via paper forms. The EPA plans to rectify this problem by making electronic copies of the paper forms after reviewing the data system this year. Less than 5 percent of incident records are updated records.

How We Did It

Using EPA pesticide regulatory information, chemical identification numbers, and the National Pesticide Information Retrieval System, the Center identified chemicals belonging to the pyrethrin and pyrethroid families. Organophosphates were identified in the same manner. Then those major, moderate, and fatal human exposures recorded in the EPA pesticide incident database that included pyrethrins or pyrethroids were selected on a year-by-year basis for the last 10 years.

The Center selected only data for the last 10 years, despite the fact that the system was created in 1992, because exposures are labeled more clearly beginning in 1998. Starting in 1998, the EPA required chemical companies to identify exposures as fatal, major, moderate, or minor.

Only those incidents that took place in the United States were included in the analysis, as this project focuses on domestic pesticide exposures. Pesticide manufacturers are required to report foreign incidents, but only about 2,500 reported pesticide exposures of more than 90,000 total occurred outside the United States over the last 15 years.

The analysis only included those incidents classified as adverse or unknown. Incidents recorded as non-adverse reactions, product defect, or not effective were not included in the analysis, as this investigation was concerned with adverse reactions.

To confirm the analysis of EPA data that found an increase of human exposures to pyrethrins and pyrethroids over the last 10 years, the Center studied data provided by the American Association of Poison Control Centers. This data also demonstrated that the number of pyrethrin and pyrethroid exposures increased since the residential-use restrictions for organophosphates went into effect.

The Center interviewed dozens of toxicologists, epidemiologists, physicians, and pesticide data specialists as part of this investigation. These specialists helped interpret the data analysis and present a broader picture of the effects of pesticides and EPA policies.