Nonagricultural pesticides encompass a wide range of products—including home and garden insecticides and fungicides, sterilants, insect repellents, and household cleaning agents—and the potential for exposure is significant. The effects of exposure on humans depend on the characteristics of the pesticide, dosage, duration of the exposure (usually through inhalation, skin contact, or ingestion), and physiological reaction of the person affected. Some people suffer no effects; others experience symptoms ranging from relatively mild headaches, skin rashes, eye irritation, and general flu-like symptoms to more serious chemical burns, paralysis, and even death. Chronic and delayed-onset illnesses such as cancer may only appear years after repeated exposure to small doses of a pesticide. Under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), EPA is responsible for ensuring that pesticides, when properly used, do not have any unreasonable adverse effects on the environment (any unreasonable risk to man or the environment, taking into account the economic, social, and environmental costs and benefits of the use of any pesticide). The act authorizes EPA to register pesticide products, specify the terms and conditions of their use before they are marketed, and remove unreasonably hazardous pesticides from the marketplace. Thus, registrations are basically licenses for specified uses of pesticide products. The act also requires that EPA reassess and reregister thousands of older pesticide products on the basis of current scientific standards. The process requires the pesticides’ registrants to complete studies of various health and environmental effects, which are then reviewed by EPA to determine whether the products can be reregistered and thus remain on the market. Section 6(a)(2) of FIFRA also requires that registrants of pesticides report to EPA any additional factual information that they may obtain about unreasonable adverse effects that their registered pesticides have on the environment. According to EPA, the additional information on adverse effects that the registrants must report includes toxicology studies, human epidemiological and exposure studies, and efficacy studies, as well as incidents of pesticide exposure. In addition, the act requires that EPA monitor, among other things, the extent to which humans, animals, and the environment are incidentally exposed to pesticides, trends over time, and the sources of contamination. According to EPA, the data on incidents of pesticide exposure often augment the extensive studies performed by registrants as part of reregistration. This review focused on the data on incidents of exposure reported to EPA. When EPA identifies risks during its review of data on incidents, the agency may initiate one or more actions. These actions include restricting pesticide uses by placing specific instructions for use on the product’s label (for example, requiring protective equipment), canceling specific uses of the pesticide, and/or canceling the pesticide’s registration, thus removing the pesticide from the marketplace. From 1978 through 1981, EPA coordinated and collected information on incidents of pesticide exposure through its Pesticide Incident Monitoring System. The system’s reports originated from registrants and from sources such as state and local agencies, poison control centers, health clinics, and hospitals that provide this information voluntarily. After this system was eliminated because of funding cuts, EPA continued to receive reports of incidents involving pesticides from registrants and from the voluntary sources. However, the agency did not have an automated system for monitoring data on such incidents until 1992, when it developed the Incident Data System to organize and track data originating from both pesticide registrants and the voluntary sources. This system stores data on incidents involving humans, domestic animals, wildlife (fish, birds, and mammals), and groundwater and surface water. Although most—about 87 percent, according to an Office of Pesticide Programs official—of the reports on incidents in EPA’s system come from registrants, EPA also receives supplementary data from voluntary sources. FIFRA does not require states or sources other than registrants to collect or submit data on exposures. However, some states have established mandatory reporting regulations specifically for pesticide-related illnesses. EPA currently receives data on incidents routinely from five of these states—either directly or indirectly. California and Washington voluntarily send annual summary reports to EPA directly, while the agency receives quarterly reports on incidents in New York, Oregon, and Texas from the National Institute of Occupational Safety and Health, which collects data from these states. According to an EPA health statistician, other states may report some data on incidents to EPA, but not routinely. Written reports on incidents are forwarded to a single location at EPA headquarters, where they are cataloged and screened to determine whether they warrant detailed attention and/or consideration in registration or reregistration reviews. Aggregate reports are periodically generated from the data entered into the computerized system to determine if patterns are emerging that could cause concern. However, EPA has a backlog of data to be entered into the Incident Data System, thus limiting the effective use of the data it receives. Although the agency currently has a number of people involved in collecting and analyzing data on pesticide incidents, only a portion of each individual’s work time is spent dealing with incidents, and no one has been assigned full-time to data collection efforts such as entering data into the system. Since the system became operational in June 1992, EPA has received about 12,575 reports. While about 8,125 of the reports had been entered into the system as of April 1995, information on about 3,250 incidents had not yet been entered because of limited staff resources. Another estimated 1,200 reports, which the registrants say contain confidential information, will not be entered into the system until the agency determines the validity of these claims. According to EPA staff, data on incidents of exposure played a significant part in 19 instances in which the agency took measures to protect the public health between 1989 and 1994. For example, after analyzing data from emergency rooms, hospitals, and poison control centers, the agency determined that most uses of arsenical (arsenic-based) ant baits could no longer be used in homes because of the potential high risk to children. In another instance, EPA, after reviewing cases involving the deaths of two individuals who died when they entered structures treated with methyl bromide, required that the product’s label be revised to extend the period before people are allowed to reenter a treated area. In a third case, EPA determined that many reports of adverse reactions to pet care products likely resulted from misuse of the product or accidental exposure. Specifically, it appeared that some animals and humans had reacted adversely as a result of overdoses or repeated applications at too frequent intervals, or simultaneous applications of multiple pesticide products to pets and their environment. In several incidents, cats were injured by pet care products intended for dogs only. In this case, the aggregate number of incidents and other data in the Incident Data System on all pet care products led EPA to draft a proposed Pesticide Regulation Notice. EPA intends for the proposed notice to provide registrants of pesticide products with instructions on how a product’s label should be changed to reflect the proper intervals for repeated use of the product and to restrict the use of the product to animals for which it was specifically intended. At the time of our review, the proposed notice had not been finalized. (App. I lists other examples of actions that EPA has taken using data on incidents involving nonagricultural pesticides.) Although EPA has been able to take some actions using data on incidents of exposure, the data the agency receives may not always be sufficient and its ability to assess risk and take action based on such data may be limited. The reports on incidents that EPA receives from registrants, as well as some of the voluntary reports such as those received from states, often vary in detail and lack key information needed to assess risk. For example, the reports frequently lack information on what pesticide caused the incident, how the exposure occurred, and what symptoms the victim suffered. EPA believes this type of information is essential in assessing risks and thus determining whether the label on a product should be changed or its use restricted or cancelled. Also, EPA cannot be sure that the reports it receives from registrants and voluntary sources are representative of incidents of exposure occurring nationwide. In addition, according to experts involved in these issues, underreporting of such incidents is widespread because, among other things, health care professionals may not always be adequately trained to recognize pesticide poisoning. Although pesticide registrants are required to report to EPA any additional factual information on the unreasonable adverse effects of their registered pesticides, their incident reports vary in detail. Section 6(a)(2) of FIFRA, which requires the registrants to report to EPA, does not require specific information, and EPA does not require standardized formats. An official in EPA’s Office of Pesticide Programs said that registrants interpret FIFRA’s reporting requirements in a variety of ways. Also, some registrants report frequently, while others do not. In reviewing recent reports received by EPA, we found that some registrants do not always include important information such as whether the product was misused or how frequently the victim was exposed to a pesticide. For example, one registrant submitted several reports that identified the pesticide involved and described the symptoms suffered but did not mention whether the product was used according to the label’s instructions or whether the victim was exposed to the pesticide once or repeatedly. EPA believes some reports may lack important data simply because the data was unavailable to the registrants, while other reports may exclude data due to registrant interpretation of reporting requirements. The data that the states provide to EPA voluntarily also frequently lack important information, such as whether the product was misused, whether the victim was repeatedly exposed to the pesticide, what symptoms the victim suffered, how the exposure occurred, and—in some cases—what pesticide caused the incident. Information on laboratory tests, which would help confirm the exposure and health effects, is seldom present. In reviewing some of the data received by EPA, we found that although two states, in their 1994 quarterly reports, summarized the number of pesticide-related incidents, they did not provide detailed information about the exposures.