2109.14,20 Page 1 of 8 FSH 2109.14 - PESTICIDE-USE MANAGEMENT AND COORDINATION HANDBOOK WO AMENDMENT 2109.14-94-1 EFFECTIVE 12/06/94 CHAPTER 20 - RISK ANALYSIS All human activities carry some degree of risk. Many risks are known with a relatively high degree of accuracy, because data have been collected on their historical occurrence (for example, smoking, drinking, and flying in airplanes). The risks associated with other activities, including voluntary and involuntary exposure to chemicals such as pesticides, cannot be readily assessed and quantified. A process called risk analysis has been developed to help answer these questions. In this chapter, risk analysis is considered to include all activities associated with the process of estimating and evaluating the doses of a pesticide with which people and various other components of the environment are likely to come into contact as a result of particular pesticide applications. Risk can be defined as the probability that injury, disease, death or environmental damage may result under a specific set of circumstances. It may be expressed in quantitative or qualitative terms. The following risk analysis guidelines are for use by pesticide specialists, pesticide project coordinators, and researchers. This direction is especially important to technical writers of environmental impact statements and other documents prepared in compliance with the National Environmental Policy Act (NEPA). Follow the additional direction on NEPA in FSM 1950 and FSH 1909.15. 21 - COMPONENTS OF RISK ANALYSES. Risk analysis can be subdivided into three procedural steps: Hazard analysis, exposure analysis, and risk characterization. 21.1 - Hazard Analysis. Use hazard analysis to identify the toxic properties of pesticides proposed for use. In conducting a hazard analysis, make a thorough review of available toxicological information, including acute, subchronic, chronic, teratogenic, reproductive, carcinogenic, and mutagenic toxicity and any human epidemiology evidence. Compile the information into a form that adequately describes the toxicological characteristics of the pesticide under review. Place emphasis on defining the characteristics of the active ingredient. Give attention to the toxicological characteristics of "inert" ingredients, such as carriers, stickers, spreaders, and other compounds that facilitate the use of the active ingredient. Their potential to cause adverse impacts should also be evaluated in the hazard analysis. Hazard analysis should: 1. Identify the kinds of health effects observed in laboratory studies on animals and at what levels of exposure. 2. Identify any health effects observed in humans. 3. Determine the median lethal dose (LD50 or LC50) for acute effects. 4. Determine the lowest no-observed-effect levels (NOEL's) for general chronic toxic effects and reproductive effects. 5. Determine the potential to cause cancer or mutations. 6. Identify data gaps. 21.11 - Sources of Toxicity Information. Consult a wide range of literature to establish the toxicity of a particular pesticide. Conduct literature searches or use Forest Service-developed Background Statements. In addition, much of these data on pesticide toxicity have been generated to comply with the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), as amended, and they are available from the Environmental Protection Agency (EPA). EPA uses these data to compile summary tables called "tox one-liners." Other toxicological information is available from EPA as Chemical Fact Sheets, Science Chapters, and Registration and Reregistration Standards. These information materials are available on request from EPA by asking for them by the common name of the active ingredient(s). EPA also maintains an on-line database of chemical-specific risk information for use in risk analyses. The database is called Integrated Risk Information System (IRIS). Its most significant information includes reference doses (which replace acceptable daily intake (ADI) levels) and slope factors (which replace potency factors). Access to IRIS information is through the EPA IRIS Coordinator, (202) 382-5949. 21.12 - Hazard Analysis for Other Organisms. In addition to hazard analysis for determining potential effects on humans, toxicity information for other organisms is also important. At a minimum, the following components of the environment should be considered: 1. Pollinators. Pesticide applications may affect domestic and wild bees and other pollinators. If there is potential for direct application to pollinators or residual effects during foraging and pollination, then consider data on acute toxicity to pollinators (primarily honeybees). Pesticide labels provide a good indication of the need to further evaluate adverse effects on native pollinators and domestic honeybees. 2. Other Insects. Insects, such as beneficial parasites and predators, and non-target species could be adversely affected by pesticides proposed for use. Check the literature to determine if there have been reports of adverse impacts. 3. Aquatic Organisms. Aquatic invertebrates, fish, and plants could be adversely impacted by pesticides proposed for use. Review toxicity studies on the impacts of pesticides on these components of the environment. In most cases, the only studies available are acute toxicity studies that describe the LD50 or LC50 for particular pesticides or specific kinds of organisms. Use the 96-hour period of exposure for LC50 values when available. 4. Mammals. In assessing the hazards of pesticide use to non-target wild mammals, consider appropriate human toxicity studies, wild animal LD50 studies, and simulated and actual field testing. However, in most cases, laboratory rat acute oral LD50 studies are used to extrapolate to other mammals. Use data on rabbits, goats, cows, or other mammals if they are available. 5. Birds. Consider birds in risk analyses. Review toxicity studies that determine potential adverse impacts of proposed pesticide uses. These include: Avian acute oral LD50, avian dietary LC50, avian reproductive studies, and avian cholinesterase tests. Birds frequently used in these tests are upland gamebirds and waterfowl. 6. Endangered Species. Although most endangered species fit into the preceding biological classifications, additional toxicity studies may need to be reviewed to ensure endangered species protection. Such evaluations would be on a case-by-case basis to help ensure protection of populations of species already reduced to levels where their survival is questionable. To facilitate this process, consult with the U.S. Department of the Interior, Fish and Wildlife Service and ensure compliance with the Endangered Species Act. 21.2 - Exposure Analysis. The purpose of exposure analyses is to determine the various human, animal, and plant populations that could come into contact with a pesticide proposed for use. Exposure analysis should: 1. Identify people, animals and plants exposed. 2. Identify routes of exposure. 3. Estimate exposure using realistic exposure (sec. 21.25) and accident scenarios. 4. Calculate doses. 21.21 - Identification of Exposed People. People potentially at risk due to exposure to forestry-use pesticides fall into two groups: Workers and members of the general public. Workers include applicators, supervisors, and other personnel directly involved in pesticide application. The public includes forest visitors or nearby residents who could be exposed through pesticide drift or contact with treated vegetation; or by eating food items such as berries or mushrooms in or near the forest, eating game or fish containing pesticide residues, or drinking water that contains such residues. Identify appropriate categories in these two groups: 1. Workers. Identify appropriate categories of workers for the proposed pesticide application. Common categories of workers for exposure analysis should include those with the greatest potential for human exposure to pesticides in forestry operations. These categories include workers who are involved in: a. Mixing and loading pesticides into application equipment; b. Applying pesticides as ground equipment operators or aircraft pilots; and c. Supervising applications or serving as application observers, In some forestry pesticide-use situations other employees may have the potential for exposure to pesticide active ingredients. For example, in forest nursery operations weeders, tree handlers, seedling lifters, sorters, packers, and fumigation tarp handlers could be exposed. 2. Public. Identify appropriate categories for members of the general public who might be exposed as a result of pesticide applications in forestry. Although most exposure results from indirect rather than direct contact with a pesticide, calculations of the potential doses received by the public are important in any risk analysis. Consider the potential for members of the general public to come into contact with pesticides through: a. Incidental contact with foliage as a result of walking in treated areas; b. Inhalation of vapors or droplets that move offsite (drift); c. Ingestion of residues on forest products, such as berries, mushrooms, seeds, and nuts; d. Ingestion of game animals or fish containing pesticide residues; or e. Consumption of water containing pesticide residues. Also consider members of the public who may be particularly sensitive to certain pesticides. Included in this category are pregnant women, women of child-bearing age, children, senior citizens, or other persons who are known to be particularly sensitive or who have compromised immune systems. 21.22 - Potential Routes of Exposure. For individuals to be exposed to a pesticide there must be one or more points of entry. Use exposure analyses to evaluate the potential for humans to be exposed through three primary routes: inhalation, oral ingestion, and dermal absorption. Identify all appropriate routes of exposure. The amount of pesticide calculated to exist in a person's immediate environment is the exposure level. The amount of pesticide that actually gets into a human body (through inhalation, ingestion, or dermal absorption) is the dose. 21.23 - Exposure Scenarios. Calculate exposures and doses expected to be received on the basis of several scenarios. In most instances, routine operational conditions are likely to exist. Accidents and extreme case events can occur. In such cases, the exposure to pesticides can be increased, and these eventualities should be considered. Use routine scenarios that are likely to exist and accident scenarios that are likely to occur occasionally, such as the unintentional spraying of a worker. Use historical information to predict the probability of these kinds of events. Where data gaps have been identified, follow direction in 40 CFR 1502.22. 21.24 - Other Exposure Factors. 1. Other factors to consider at this time are: a. Any mitigation measures that can be taken to reduce the potential for exposure. For example, it may be appropriate to use only certain formulations, to use buffers, to wear protective clothing or a respirator, to wash with soap and water, or to make applications when exposure is unlikely to occur (when schools are not in session and when honeybees are not foraging). b. Duration of exposures may be acute (one-time), subchronic (more than one time, but for a relatively small fraction of a total lifetime), or chronic (repeated over a substantial fraction of a lifetime). c. Frequency of exposure may be continuous (daily) or intermittent (less than daily, but with no standard, quantitative definition). 2. It is also important with some chemicals and some situations to know the time in life when exposure takes place or could take place. With teratogenic agents, for example, it is essential to know if exposure will take place when there are pregnant women present who might be at risk. 21.25 - Dose Estimation. Estimate doses for each category of worker and group of forest users (general public) identified under each exposure scenario. Calculate doses resulting from exposure on the basis of studies of workers in each category; for example, the results of nursery worker exposure studies funded by the National Agricultural Pesticide Impact Assessment Program. It is generally necessary to provide at least two different measures of estimated doses: The Maximum Daily Dose (MDD) and the Lifetime Average Daily Dose (LADD). The MDD is generally used for evaluations of substances that are not carcinogens. It is the maximum daily dose an individual is likely to receive on any day during the period of exposure. The LADD is generally used for carcinogens. It is equivalent to using a cumulative lifetime dose. The LADD is estimated by multiplying the average MDD by the fraction of the total lifetime that an individual is exposed (exposure days divided by days per lifetime). 21.3 - Risk Characterization. Once hazard and exposure analyses have been completed, characterize risk by comparing toxicity (hazard) information with dose estimates and determine their probabilities of occurrence. This process helps to estimate the likelihood and severity of impacts on humans and the environment under the specified conditions. 21.31 - Evaluation. Compare the estimated doses with the acute LD50 or LC50 values to characterize the risk of acute effects. When humans are involved, calculate a margin of safety (MOS) for each pesticide dose estimate for workers and members of the public by dividing the chronic and reproductive NOELs by the estimated dose. Use a safety factor of 10 when extrapolating from laboratory animals to humans; and use an additional factor of 10 to account for differential sensitivities within the human population. This 100-fold safety factor provides an estimate of "safe" exposure levels. The calculated MOS values are compared with this safety factor in characterizing chronic and reproductive effects. Characterize the potential for a pesticide to cause cancer or mutations as well. These risks are normally estimated on the basis of estimated average daily exposure over a 70-year lifetime. Risk characterization also involves a determination of cumulative risk, synergistic effects, and risk to sensitive individuals. During the conduct of risk characterization for all exposure scenarios it is appropriate to also evaluate cumulative and synergistic effects: 1. Cumulative exposure situations should be considered since certain persons may be subject to repeated or cumulative exposures over time. For example, avid hunters and fisherman who frequently use forest areas subject to treatment with pesticides may be at risk of greater exposure than other members of the public. Therefore, prepare realistic calculations of their potential to receive excessive doses based on: a. The number of times they hunt/fish each year, b. The amount of game/fish they consume, c. The berries/mushrooms they collect and consume, and d. The water they drink while on recreational outings. 2. Synergistic effects should also be addressed, especially if pesticides are proposed for uses that are known to exhibit this phenomenon. Share knowledge of these situations with the public and decisionmakers. 22 - DOCUMENTATION OF RISK ANALYSIS. Document the results of Forest Service risk analyses (hazard, exposure, and risk) in risk assessments. These can take two forms: 1. Separate stand-alone publications that have been prepared by in-service or external writers; or 2. An appendix to a decisionmaking document prepared in compliance with the implementing regulations of the National Environmental Policy Act (NEPA). If the risk analysis is incorporated as an appendix to an Environmental Impact Statement (EIS), it is usually called a risk assessment, and a summary of its content must be included in the body of the EIS text and the Record of Decision (ROD). Prepare the summary in as non- technical terms as possible so that the public can reasonably understand the risks being considered in connection with a proposed action. If possible, describe examples of risk in terms to which the decisionmaker and others can relate from everyday experiences. 23 - RISK MANAGEMENT. Upon completion of a risk analysis, a number of techniques can be used to determine the best course of action for preventing identified problems. These range from taking appropriate mitigation measures to reduce risk, to not taking the proposed action, thus avoiding potential risks. Nearly all human activities involve some risk. The degree of risk ranges widely, both in fact and perception. Many activities, even though they involve risk, are both voluntary and acceptable to most people. Activities that are perceived to be very risky and perhaps unacceptable to the public require careful analysis and proper communication. The first involves judgments of science as described in preceding sections on hazard and exposure analysis. The second involves sharing this information with decisionmakers and the public as described in section 24. 24 - RISK COMMUNICATION. Risk communication is any purposeful exchange of information about health or environmental risks between interested parties. More specifically, risk communication is the act of conveying or transmitting information between interested parties about levels of health or environmental risks; the significance or meaning of such risks; or decisions, actions, or policies aimed at managing or controlling such risks. Risk communication takes a variety of forms, ranging from precautionary statements on pesticide labels to interactions among government officials, industry representatives, the media, agency employees, and the public. Consider the following for sensitive risk communication: 1. Accept and involve the public as a legitimate partner; 2. Plan and carefully evaluate risk communication efforts; 3. Listen to the public's specific concerns; 4. Be honest, frank, and open; 5. Coordinate and collaborate with other credible sources; 6. Meet the needs of the media and; and 7. Speak clearly and with compassion. 25 - RISK TAKING. The process of risk analysis is the most systematic means available for organizing, analyzing, and presenting information on environmental agents and events (such as pesticide use). Use risk analyses to decide whether, and to what extent, controls on exposure are necessary to protect public health and the environment. The most serious potential danger associated with the use of risk analyses concerns the failure to recognize their limitations. Preparers of risk analyses must make explicit all assumptions used and the reasons for selecting alternatives. Managers and decisionmakers must also recognize the uncertainties associated with risk analyses and incorporate those considerations into their decisionmaking.