Pesticides on Tobacco: Federal Activities to Assess Risks and Monitor Residues
Published: 2003-03-26T00:00:00

Fast Facts:

Highlights:
section_title: Why GAO Did This Study
paragraphs: Pesticides play a significant role in increasing production of tobacco, food, and other crops by reducing the number of crop-destroying pests. However, if used improperly, pesticides can have significant adverse health effects. GAO was asked to (1) identify the pesticides commonly used on tobacco crops and the potential health risks associated with them, (2) determine how the Environmental Protection Agency (EPA) assesses and mitigates health risks associated with pesticides used on tobacco, and (3) assess the extent to which federal agencies regulate and test for pesticide residues on tobacco.
section_title: What GAO Found
paragraphs: In the 1990s, domestic growers commonly used 37 pesticides approved for use on tobacco by EPA. Most of these pesticides were also used on food crops. When used in ways that deviate from conditions set by EPA, many of these pesticides can cause moderate to severe respiratory and neurological damage--and may result in death. Moreover, animal studies suggest that some of these pesticides may cause birth defects or cancer. Under its pesticide registration program, EPA evaluates toxicity and other data to assess health risks to workers and the public from exposure to pesticides--and risks to smokers from exposure to residues in smoke. These assessments have identified a range of risks that required such mitigation as limiting where and how the pesticide may be used, prohibiting use in certain states, and requiring workers to wear respirators and chemical-resistant clothing. On the other hand, EPA has concluded that low levels of residues in tobacco smoke do not pose short-term health concerns requiring mitigation. EPA does not assess intermediate or long-term risks to smokers because of the severity of health effects linked to use of tobacco products themselves. While EPA regulates the specific pesticides that may be used on tobacco and other crops and specifies how the pesticides may be used, it does not otherwise regulate residues of pesticides approved for use on tobacco. The U.S. Department of Agriculture (USDA), however, is required by the Dairy and Tobacco Adjustment Act to test imported and domestic tobacco for residues of pesticides not approved by EPA for use on tobacco that federal officials believe are used in other countries. By helping ensure that other countries do not use highly toxic pesticides that U.S. tobacco growers may not use, federal regulation of pesticide residues on tobacco addresses trade equity as well as health and environmental issues. However, USDA has not reevaluated the list of pesticides for which it tests since 1989, even though EPA has cancelled tobacco use for over 30 pesticides since then.

section_title: Letter
paragraphs: As you know, pesticides are used regularly on food and nonfood crops,  such as tobacco, to control a range of unwanted animal, plant, and  microbial pests. Trace amounts of pesticides, called residues, remain on  tobacco and other crops after treatment. Typically, the residue levels on  tobacco decline as the leaves are harvested, dried, and further processed  into consumer products, and still further when the tobacco is burned.  However, varying residue levels may remain. As a result, human exposure  to pesticide residues on tobacco may occur when residues remaining in  cigarette smoke are inhaled. While much is known about the significant  health risks of using tobacco products, limited information exists on the  extent to which the use of pesticides on tobacco may increase the  considerable health risks associated with tobacco use itself.
By controlling pests that reduce crop yields, pesticides can provide more  abundant supplies of fruits, vegetables, and other crops. Nonetheless,  pesticides are generally designed to be toxic to living organisms and thus  can have significant adverse health effects if used improperly. The  Environmental Protection Agency (EPA) determines whether and under  what conditions pesticides can be used in the United States without posing  an unreasonable risk to human health or the environment. Pesticides that  meet EPA’s requirements are granted licenses or “registrations,” which  permit their distribution, sale, and use according to specific directions and  requirements identified on the labels. In addition, the U.S. Department of  Agriculture (USDA) and the Food and Drug Administration (FDA) monitor  crops for certain pesticide residues.
In response to your request for information on how the federal  government addresses the public health implications of pesticides on  tobacco, this report describes (1) the pesticides commonly used on  tobacco and the potential health risks associated with them; (2) how EPA  assesses and mitigates health risks associated with pesticides used on  tobacco; and (3) how, and the extent to which, federal agencies regulate  and monitor pesticide residues on tobacco. Several pesticide use surveys  conducted or sponsored by the federal government provide information on  the types and amounts of pesticides commonly used on tobacco and other  crops in the 1990s. These data, available through 1998, estimate average  annual agricultural use of pesticides, excluding such uses as pest control  in greenhouses. To determine how EPA assesses and mitigates health risks  associated with pesticides used on tobacco, we reviewed, among other  things, studies and documentation related to 13 pesticides commonly used  on tobacco that EPA evaluated under its reregistration program between  1994 and 2002. For more details on our scope and methodology, see  appendix I.
subsections: section_title: Background
paragraphs: Tobacco is a high-value, pesticide-intensive crop. That is, tobacco is the  nation’s ninth highest valued crop, and in terms of the amount of pesticide  applied per acre, tobacco ranks sixth—behind potatoes, tomatoes, citrus,  grapes, and apples. In the United States, tobacco is grown in 16 states, 2 of  which—Kentucky and North Carolina—produce about two-thirds of all  domestic tobacco. Further, it is grown in over 100 countries. Until  recently, the United States was the world’s leading exporter of  unmanufactured tobacco; however, in 2001, it ranked third, behind Brazil  and Zimbabwe. The tobacco industry in the United States both exports  tobacco to Japan and Western Europe—principally Germany, the  Netherlands, Denmark, the United Kingdom, Belgium, Italy, and Spain— and imports tobacco in increasing amounts from countries such as Brazil,  Argentina, Malawi, and Thailand. Furthermore, the United States is the  second largest producer of cigarettes in the world, following China. More  than 90 percent of the tobacco grown in the United States is used to  manufacture cigarettes, as is most tobacco produced in the world. The  remainder is used for chewing tobacco, snuff, cigars, and pipe tobacco.  Tobacco types are often defined by such characteristics as how the  tobacco is cured (flue-, air-, or sun-cured), as well as the color, size, and  thickness of the leaves. Different types of tobacco are used in the various  tobacco products. The tobacco component of cigarettes made in the  United States usually consists of flue-cured and burley tobacco blended  with imported oriental tobacco and small amounts of specialty tobaccos  grown in Maryland and Pennsylvania.
Although pesticides play a significant role in increasing production of  tobacco, food, and other crops by reducing the number of crop-destroying  pests, exposure to pesticides can harm humans. The potential for harm is  related to both the amount of a substance a person is exposed to—the  dose—and the toxicity of the chemical. For example, small doses of  aspirin can be beneficial to people, but at very high doses, this common  medicine can be deadly. Furthermore, in some individuals, even at very  low doses, aspirin may be lethal. The age and health status of an individual  can also affect the potential for harm. Children may be more susceptible to  harm because, for example, they eat more food, drink more water, and  breathe more air than adults per pound of body weight, resulting in greater  exposure. Generally, assessments of dose and response involve  considering the dose levels at which adverse effects are observed in test  animals and using these dose levels to calculate an equivalent dose in  humans.
In many cases, exposure to pesticides is through residues that remain on  crops following use of the pesticides. The amount of pesticide residue that  remains reflects, among other things, the amount of pesticide applied, the  time lapsed since application, and the speed with which the pesticide  dissipates in the environment. Residue levels remaining on crops are also  affected by where the pesticides are applied, such as in the soil or on the  plant, and when they are used in the life cycle of the plant, such as when  the plant is a seedling or shortly before the plant is harvested. Typically,  residues on tobacco decline as the plant moves from field to finished  consumer product.
The primary federal requirements pertaining to the registration, sale, and  use of pesticides are in the Federal Insecticide, Fungicide, and  Rodenticide Act (FIFRA) and the Federal Food, Drug, and Cosmetic Act  (FFDCA), both as amended by the Food Quality Protection Act (FQPA).  Pesticides must generally be registered with EPA in order to be sold or  distributed. EPA will register a pesticide if it determines, among other  things, that the pesticide will not generally cause unreasonable adverse  effects on human health or the environment when used in accordance with  conditions specified on the label. Throughout this report we will focus on  EPA’s analysis of potentially harmful effects to human health, rather than  the environment.
In 1988 FIFRA was amended to require that EPA review pesticides initially  registered prior to November 1984—when less toxicity data were  available—to consider their health effects and to determine whether and  how they might continue to be registered. These reviews are designed to  ensure that older pesticides meet contemporary health and safety  standards and that their risks are mitigated. Essentially, manufacturers of  the older pesticides must provide EPA with substantially the same  toxicity, chemistry, and other data as are now required to register a new  pesticide. EPA reviews of the older pesticides are called reregistrations.  Most of the pesticides used on tobacco during the 1990s were initially  approved before 1984 and therefore are subject to reregistration.
In addition, the FQPA amendments to FIFRA passed in 1996 require EPA  to reevaluate the amounts of pesticide residues allowed on or in food— known as tolerances. EPA must ensure that there is a reasonable certainty  that no harm will result from all pesticide exposures from food and  nonfood uses for which there is reliable information. In doing so, unless  another safety factor is determined to be appropriate, EPA is required to  apply an additional 10-fold safety factor in setting tolerances to ensure the  safety of foods for children. EPA is also required to ensure that there is  reasonable certainty that no harm will result to children specifically from  “aggregate” exposure to a single pesticide—that is, from all sources, such  as lawn treatments, household uses, drinking water, and food. EPA must  also consider available information concerning the cumulative effects on  children of pesticides that act in a similar harmful way (known as a  common mechanism of toxicity). To accomplish this requirement, EPA  has recently developed a method to evaluate the cumulative exposure of  one class of highly toxic pesticides—the organophosphates—from  residues in food and drinking water and from residential uses.
EPA uses risk assessment—the systematic, scientific description of  potential adverse effects from exposure to hazardous substances—to  evaluate the potential health impacts of a pesticide on humans and  determine what measures are needed to mitigate identified risks. The  product of a risk assessment is an identification of the various health risks,  along with quantitative and/or qualitative statements regarding the  probability that an exposed population will be harmed and to what degree.  For example, EPA qualitatively classifies pesticides and other toxic  substances according to their potential to cause cancer using descriptors  such as “likely” or “suggestive evidence but not sufficient to assess human  carcinogenic potential.” In addition, for many carcinogens, EPA develops a  quantitative dose/response health risk assessment that estimates the  health risks at varying exposures. For health effects other than cancer,  EPA may calculate what it terms a “reference dose” or, in the case of  exposure by inhalation, a “reference concentration,” which represents a  daily level of exposure that is unlikely to result in harm over a lifetime.  Alternatively, EPA may calculate a “margin of exposure,” which is a ratio  that shows how far the actual (or estimated) human exposure to a  substance is from levels that are harmful. In essence, evaluating and  managing the risk of exposure to a pesticide involves determining the  maximum safe level of exposure to the pesticide and assessing whether  expected actual exposure is below this maximum level. If expected actual  exposure levels exceed the maximum safe amount, EPA must determine  the best ways to reduce exposure.
section_title: Pesticides Commonly Used on Tobacco Have Potential Short- and Long-Term Adverse Health Effects
paragraphs: According to federally sponsored surveys, during the 1990s tobacco  producers in the United States commonly used 37 of the pesticides  approved by EPA for such use. As shown in table 1, most of the pesticides  used on tobacco were insecticides and herbicides, which control insect  and plant pests; others were fungicides, which combat fungal diseases, or  plant growth regulators; and a few had more than one use.
Most of these pesticides were also widely used on food crops. The actual  number and amount of pesticides used on tobacco or other crops in any  given year vary depending on factors such as the weather and the specific  pests that become problematic. For example, the incidence of many plant  diseases is closely correlated to the amount of rainfall, resulting in greater  use of fungicides in years with high rainfall. In addition, pesticide use  tends to change over time as pests develop resistance to the pesticides and  as use on tobacco is approved for new pesticides and cancelled for older  pesticides. As table 2 shows, 10 pesticides identified in the 1997 survey as  commonly used on tobacco were not identified in the earlier survey. Two  of these pesticides, dimethomorph and mancozeb, began to be used in  response to the appearance of a disease resistant to metalaxyl, which  declined in usage during the 1990s. In addition, during the years included  in the 1997 survey, tobacco use for 5 of the 7 pesticides no longer reported  as being used—diazinon, diphenamid, isopropalin, methidathion, and  trichlorfon—was being cancelled. In some cases, pesticide cancellations  resulted in the increased use of other pesticides. For example, by 1997  clomazone had replaced diphenamid and isopropalin as the pesticide of  choice for controlling unwanted weeds, and imidacloprid was most  commonly used to control insect pests, leading to reduced use of  acephate, aldicarb, chlorpyrifos, ethoprop, and carbofuran. Manufacturers  may initiate cancellation of some or all uses of a pesticide, often for  economic reasons, or EPA may cancel uses when the agency determines  that one or more uses pose unreasonable risks to human health or the  environment. For example, as required under the Clean Air Act, EPA has  been phasing out the use of methyl bromide on tobacco and a wide range  of other crops because it depletes the earth’s protective layer of ozone.  Methyl bromide use on tobacco decreased from about 5.4 million pounds  in 1992 to about 0.7 million pounds in 1997 because of EPA’s efforts and  changes in how tobacco producers raise seedlings. Specifically, producers  have begun to grow tobacco seedlings in greenhouses, where methyl  bromide is not generally used.
EPA determines the amounts and conditions under which a pesticide may  be used so that it will not pose unreasonable risks to workers or the  general population. Failure to comply with the conditions set by EPA  could result in a range of harmful effects. For example, 17 of the 37  pesticides commonly used on tobacco in the 1990s belong to three  chemical classes that, at high doses, are known to cause adverse human  health effects up to and including death (see table 3).
Although they do not all produce their toxic effects in the same way,  pesticides in these three classes—organochlorines, organophosphates,  and carbamates—act on the nervous system to prevent the normal flow of  nerve impulses to muscles that control both voluntary movement, such as  walking, and involuntary movement, such as breathing and heart beat.  Pesticides in all three classes are absorbed to varying degrees through  inhalation, ingestion, and skin contact. Exposure to amounts of these  pesticides that exceed levels set by EPA could result in immediate and life- threatening effects, such as respiratory failure, or conditions that do not  appear immediately, such as cancer. While EPA has concluded that most  of these 17 pesticides do not cause birth defects, the agency has also  concluded that 5 of them and a by-product of another may cause cancer.
Since the 1970s, EPA has severely restricted its approvals of  organochlorine pesticides, which include DDT, aldrin, and chlordane,  because of their potential to harm humans and the environment.  Organochlorine pesticides persist in the environment—some have  remained in soil for over 50 years—and accumulate in body tissue,  particularly fat. Organochlorine pesticides are associated with a range of  adverse health effects, including cancer and damage to the neurological  and reproductive systems. The one organochlorine pesticide still approved  for use on tobacco, endosulfan, is highly toxic when ingested or inhaled  and slightly toxic through contact with the skin. While EPA has  determined that it is unlikely to cause cancer as other members of this  class do, endosulfan, like all organochlorine pesticides, primarily affects  the nervous system. EPA has requested additional data from the  manufacturer to address its concerns that exposure to endosulfan could  harm the nervous system of developing fetuses. Organophosphate and  carbamate pesticides have largely replaced the organochlorine pesticides  in the United States.
While they break down quickly in the environment and do not accumulate  in body tissues, organophosphate pesticides are much more acutely toxic  to humans and animals than the persistent organochlorine pesticides they  have largely replaced. The primary cause of death from organophosphate  poisoning is respiratory failure, although cardiovascular symptoms, such  as decreased heart rate that progresses to cardiac arrest, usually occur as  well. In humans, additional symptoms from exposure to organophosphate  pesticides, which can develop during use or within minutes to hours after  exposure, include headache, nausea, dizziness, sweating, muscle  twitching, anxiety, and depression. Exposure by inhalation causes the  most rapid appearance of toxic symptoms. As a result, to minimize the  potential for harmful exposure of workers, EPA requires those who mix,  use, or apply the pesticides to have special training, use respirators, and  wear chemical-resistant clothing. Regarding the potential to cause cancer,  EPA has determined that 4 of the 10 organophosphate pesticides used on  tobacco—acephate, ethoprop, methidathion, and trichlorfon—may cause  cancer. In addition, EPA has concluded that 7 of the 8 organophosphate  pesticides it evaluated for their potential to cause birth defects would not  cause them but that the eighth—chlorpyrifos—may do so at very high  levels that may also harm the pregnant female.
Carbamates, which also affect the central nervous system, produce  symptoms similar to those of organophosphate pesticides, although the  effects of carbamate poisoning tend to be of shorter duration and  somewhat easier to treat. The primary cause of death from carbamate  poisoning is respiratory failure. Of the six carbamate pesticides used on  tobacco, EPA has determined that one and a by-product always associated  with another may cause cancer; two are unlikely to cause cancer; data are  insufficient to determine the cancer-causing potential of one; and one will  be evaluated in fiscal year 2003. EPA has evaluated four of the carbamates  for their potential to cause birth defects: three do not and only minimal  evidence exists for the potential of the fourth to cause birth defects. EPA  has requested, but not yet received, data from the manufacturer on the  potential of one of the two remaining carbamate pesticides to produce  birth defects, and the agency will evaluate the health effects of the other in  fiscal year 2003.
The potential acute adverse health effects from the remaining 20  pesticides used on tobacco—representing 12 different chemical classes— range from mild to severe. For example, EPA found no known health  effects on mammals from exposure to Bacillus thuringiensis as it is  currently manufactured. Similarly, EPA has found that both maleic  hydrazide, a plant growth regulator and herbicide, and metalaxyl, a  fungicide, have low acute toxicity, and neither is thought to cause cancer  or birth defects. However, EPA has found that serious adverse health  effects could occur with high exposures to insecticides, such as  chloropicrin, 1,3-dichloropropene (1,3-D), and methyl bromide, which are  applied as fumigants and can be severely irritating to the eyes, skin, and  lungs. EPA has also found that poisoning from exposure to methyl  bromide may result in persistent neurological impairment.
In general, because most of the pesticides used on tobacco are widely  used on food and other crops, as well as in residential and other settings,  the exposure resulting from residues on tobacco represents a small  portion of total exposure to these pesticides. Specifically, 1997 survey data  estimate that about 27 million pounds of the 37 pesticides were used on  tobacco, while the estimated use of these pesticides nationally on all crops  was 175 million pounds. Therefore, most of the exposure to these  pesticides stems from their use on other crops and in other products, such  as household insecticides. However, for some pesticides—dimethomorph,  fenamiphos, flumetralin, maleic hydrazide, mefenoxam, and  sulfentrazone—more than 50 percent of their use in 1994 through 1998 was  on tobacco. Further, more than 80 percent of maleic hydrazide used and  100 percent of flumetralin and sulfentrazone used were applied to tobacco.  Appendix II provides information on the amounts of the 37 pesticides used  on (1) tobacco and (2) domestic crops, as estimated in the 1992 and 1997  surveys.
section_title: EPA Concludes that Health Risks of Pesticide Residues on Tobacco Are Minimal but Requires Mitigation for Risks from Other Exposures
paragraphs: To determine whether the use of individual pesticides can reasonably be  expected not to harm human health, EPA conducts health risk  assessments under its pesticide registration program. These risk  assessments are based on EPA’s evaluations of the results of numerous  scientific studies and tests that the agency requires pesticide  manufacturers to carry out. EPA also assesses the health risks to smokers  from exposure to pesticides used on tobacco by analyzing data on their  toxicity and the residue levels that remain on tobacco and in tobacco  smoke. Because pesticides are used extensively on crops, including  tobacco, and in home pesticide products, the risk assessments focus on  exposures of (1) workers who handle the pesticides and (2) the general  public, which is exposed to pesticides via residues on food or in drinking  water or from pesticide products used in and around the home and in  public places. EPA’s health risk assessments often identify risks to  workers that must be mitigated before EPA will approve the pesticide. The  assessments also identify risks to the general population that may also  require special limitations on how or where the pesticides may be used.  EPA has generally concluded that the low levels of residues measured in  tobacco smoke do not pose health concerns that require mitigation. While  EPA officials were generally able to provide us with copies of the studies  and evaluations we requested during our review, documentation of the  agency’s evaluation of the validity and reliability of the residue studies was  inconsistently available.
subsections: section_title: EPA Assesses Health Risks of Varied Exposures to Pesticides
paragraphs: Under its pesticide registration program, EPA routinely assesses the health  risks of exposure to pesticides from residues in drinking water and food  and from pesticide use in the home, in public places, and at work. The  Health Effects Division of the Office of Pesticide Programs in EPA  develops its health risk assessments on the basis of a substantial body of  data, including toxicity, residue chemistry, and other data provided by  pesticide manufacturers, as well as other relevant information, such as  human and animal studies from the general scientific literature and  poisoning incident databases. The risk assessments focus on the potential  cancer and noncancer health risks associated with short-term (acute),  intermediate-, and long-term (chronic) exposures to pesticides from the  primary exposure routes—oral, inhalation, and contact with skin (dermal).  Noncancer health risks that EPA assesses include risk of birth defects,  reproductive impairments, damage to genetic material, and interference  with the body’s endocrine system. EPA’s health risk assessments are  subject to numerous reviews by a variety of committees, including the  agency’s Hazard Identification Science Assessment Review Committee,  Cancer Science Assessment Review Committee, and Reproductive and  Developmental Toxicity Science Assessment Review Committee. The  health risk assessments provide critical information to the pesticide  registration divisions on the human health component of risk management  decisions—such as whether to approve pesticides for use; what amounts  may be used; and what special restrictions, if any, may be needed.
To evaluate the levels of pesticides to which cigarette smokers might be  exposed from residues on tobacco, EPA reviews plant metabolism and  residue studies provided by manufacturers that identify the residues of  pesticides, and any harmful by-products they may produce, that remain  on the crop after it has been treated. The plant metabolism studies reveal  how plants process a pesticide once it is applied and the relative amounts  of the pesticide and its by-products that remain after treatment—the total  toxic residue (TTR). The residue studies, called field trials, quantify the  levels of pesticide and by-product residues that remain on plants grown  under actual agricultural conditions that approximate the expected “real  life” environment. Such field trial data, which are required for all  pesticides that will be used on food, may not always be required for  pesticides used on tobacco because EPA uses a “tiered” approach to  evaluate residues on tobacco. That is, for tobacco, the agency requires  additional residue data after the metabolism study only if it has shown that  the combined residue levels of the pesticide itself and any harmful   by-products exceed 0.1 parts per million (ppm)—the agency’s “threshold  of concern” for residues on tobacco. Thus, as figure 1 shows, EPA  generally requires plant metabolism studies for green tobacco and may  require data from field trials for both green and cured (aged) tobacco,  depending upon the amount of residues that are identified. In addition,  EPA may require pyrolysis studies that measure the residues in smoke  when tobacco treated with a pesticide is burned. Finally, EPA may require  additional residue studies to estimate potential exposure, even if the  residues are below 0.1 ppm, if it has concerns about the toxicity of a  pesticide.
The tiered approach to analyzing residues on tobacco reflects the fact that,  typically, pesticide residues on tobacco decline over time, as the tobacco  is stored, cured, manufactured into cigarettes, and burned during  smoking. EPA uses the tiered approach for tobacco, in part, because the  agency has concluded that the potential for harm to human health from  pesticide residues on tobacco at or below the 0.1-ppm level is extremely  low and unlikely to result in a risk of concern to smokers.
According to EPA officials in the Health Effects Division, since August  1999, EPA’s policy for assessing the health risks from using pesticides on  tobacco has been to evaluate the risks of short-term exposure to residues  on tobacco and to quantify the estimated health risks using a consistent  method and set of assumptions. This policy is applied to all newly  registered pesticides, as well as to currently registered pesticides as they  are periodically reviewed to ensure they meet current human health and  environmental safety standards in accordance with the requirements of  the 1988 amendments to FIFRA. EPA officials attribute the more  structured approach to advances in the science of risk assessment and the  1996 enactment of FQPA, which has spurred the agency to more  systematically quantify the exposure to pesticide residues in food and  drinking water and from residential uses.
EPA selected the margin of exposure method to quantify the health risks  associated with exposure to pesticide residues in smoke. As discussed  earlier, a margin of exposure shows how far the actual (or estimated)  human exposure to a substance is from levels that have been shown to  cause no harm in animal studies. To estimate exposure, EPA typically uses  (1) the residue levels identified in tobacco field trials or pyrolysis studies  and (2) standard assumptions for key variables that affect exposure.  Specifically, EPA assumes that people smoke 15 cigarettes a day and that  they weigh about 150 pounds, if male, and 130 pounds, if female.  Moreover, EPA assumes 100 percent of the pesticide residue on the  tobacco is inhaled and absorbed. In practice, some residues will be  trapped in cigarette butts, and the amount of smoke inhaled varies widely  among people. EPA officials said the assumptions are conservative—that  is, they are protective of public health—because they tend to overstate,  rather than understate, the extent to which smokers are exposed to the  potentially toxic effects of the pesticides.
Also according to EPA officials, the agency does not include exposure to  the residues in tobacco smoke in its aggregate health risk assessments of  individual pesticides, which are required by FQPA, because the added  exposure from residues in smoke is minimal. In addition, EPA has chosen  not to assess the risk of either intermediate- or long-term exposure to  pesticide residues in smoke because of the severity and quantity of health  effects associated with the use of tobacco products themselves.  Specifically, exposure to tobacco products—particularly cigarettes—is the  single major preventable cause of cancer and heart and lung disease in the  United States.
Finally, although experts and public health officials are concerned about  the potential for harm, particularly to children, from exposure to  pesticides, little is known directly about the chronic effects of pesticide  use in general in the United States—for example, in agriculture and in  schools. Moreover, studies linking adverse human health effects to  exposure to pesticide residues on tobacco are rare, according to public  health officials and experts we spoke to. And while a number of federally  sponsored studies of the effects of exposure to pesticides are underway, it  will be years, if not decades, before conclusive results are known. Officials  and experts we spoke with about possible harm from pesticide residues on  tobacco generally agreed that such residues could incrementally add to  the risk, and some also believed the known harm from using tobacco  products dwarfs any potential effect from exposure to pesticide residues  in the smoke.
section_title: EPA Concludes That Risks Associated with Pesticide Use Can Be Significant, but Those Associated with Pesticide Residues on Tobacco Appear to Be Minimal
paragraphs: EPA’s health risk assessments have identified a number of potential  adverse health effects associated with the pesticides used on tobacco and  other crops that, in some cases, have led the agency to impose special  limitations on the uses of these pesticides. The risks that required  mitigation stemmed from (1) potential exposure of workers who apply  pesticides or harvest crops and (2) potential exposure of the general  population to pesticide residues in food or drinking water or from  pesticides used in the home or in public. None of the risks requiring  mitigation were associated with exposure to residues on tobacco or in  tobacco smoke.
subsections: section_title: Some of EPA’s Risk Assessments Result in Special Mitigation Measures
paragraphs: Our review of studies and other documentation related to EPA’s  completed reregistration reviews of 13 of the 37 pesticides commonly used  on tobacco identified the health risks associated with them and the related  mitigation measures the agency required. The following cases illustrate  some of the health risks that have required mitigation.
EPA has classified 1,3-D, a widely used fumigant that controls soil-borne  pests and diseases, as a probable carcinogen—that is, evidence from  human and animal studies suggests that 1,3-D, once ingested or inhaled, is  likely to cause cancer. In its risk assessment, EPA determined that 1,3-D  could make its way to groundwater and pose a risk of cancer for residents  who obtained their drinking water from wells near treated fields. To  mitigate the potential cancer risks and as a condition for reregistration,  EPA required that wells used for drinking water be located 100 or more  feet from treated fields and prohibited the use of 1,3-D altogether in 11  states with porous soil. In addition, vapors from 1,3-D—which is injected  as a liquid into soil, where it quickly evaporates—can move into the air.  Consequently, EPA also required (1) a 300-foot buffer between occupied  buildings and fields treated with the pesticide and (2) workers who apply  the pesticide to wear respirators and protective clothing, among other  things. Further, because of 1,3-D’s volatility and potential to harm humans,  EPA classified it as a “restricted use” pesticide, which means it can only be  applied by, or under the supervision of, individuals trained to handle  particularly toxic or harmful pesticides. Currently, 1,3-D is registered for  use on soils in which all food and feed crops may be planted. Moreover,  according to the 1997 survey, an estimated 13 million pounds of 1,3-D were  applied to tobacco annually during the survey period—almost twice the  amount of chloropicrin, the second most commonly used pesticide on  tobacco. Despite the health risks posed by injecting 1,3-D into soil, EPA  identified no risks associated with residues on tobacco leaves or in  tobacco smoke because 1,3-D metabolizes to nontoxic by-products and is  subsequently absorbed by the plant.
Similarly, EPA determined that residues on tobacco of chlorpyrifos— another pesticide frequently used on tobacco and food crops and one of  the most widely used organophosphate insecticides in the United States— were below the agency’s threshold of concern. But the agency determined  that chlorpyrifos presented potential health risks unrelated to its use on  tobacco that required strict mitigation measures. Specifically, the agency  identified health risks to children from exposure to chlorpyrifos. Before  2000, chlorpyrifos was one of the insecticides used most often in  residential and commercial settings—for example, on carpets and in  schools, daycare centers, hotels, and restaurants—and on food crops. EPA  identified significant risks to children from these many uses and required  stringent measures to address them. Between 1997 and 2000, EPA  cancelled nearly all indoor and outdoor residential uses and prohibited the  use of chlorpyrifos in schools and public parks. In addition, manufacturers  agreed to eliminate the use of chlorpyrifos on tomatoes and restrict its use  on apples. EPA also identified concerns for some workers who mix, load,  and apply chlorpyrifos in agricultural and other nonresidential settings. As  a result, EPA required that workers wear a respirator and a double layer of  clothing, including chemical-resistant gloves, shoes, and headgear.  Workers must also use water-soluble packages to mix powdered forms of  chlorpyrifos and remain in an enclosed cockpit when aerially spraying a  field. EPA also set a time interval between applications of the pesticide  and when workers can reenter treated areas, ranging from 24 hours for  most crops to 5 days for others. EPA did not, however, identify risks  associated with chlorpyrifos used on tobacco because residue levels on  green tobacco were below 0.1 ppm.
EPA also identified a range of potential harmful effects from other  exposures to the other pesticides we reviewed. For 11 pesticides,  including 1,3-D and chlorpyrifos, EPA identified a range of concerns,  largely for exposures of workers—particularly those engaged in spraying  the pesticides—that required at least some mitigation. Most often the  mitigation measures included the use of enclosed mixing systems and  tractor cabs, additional protective respirators and clothing, reductions in  the rate and frequency of application, and increases in the time between  application and reentry to the treated areas. In some cases, such as for  acephate, disulfoton, and ethoprop—all of which are organophosphate  pesticides—certain uses were cancelled, including use on golf courses and  lawns and indoor and outdoor residential uses. Three of these 11  pesticides—disulfoton, endosulfan, and ethoprop—also raised concerns  about dietary or drinking water exposure for which EPA required such  mitigation as canceling use on some foods, reducing the rate and  frequency of application on others, and requiring buffer zones between  treated fields and water bodies. EPA placed a number of additional  restrictions on the use of endosulfan, a highly toxic and persistent  organochlorine pesticide, including restricting use on cotton and tobacco  to certain states; eliminating or reducing aerial spray applications on crops  such as strawberries, nuts, and tobacco; and requiring buffer zones  between treated areas and bodies of water. In addition, EPA required that  all products containing endosulfan be labeled as restricted use pesticides,  which can only be used by, or under the supervision of, specially trained  applicators. EPA also noted that it may require further restrictions on  acephate once the agency completes its assessment of the cumulative  exposure to organophosphate pesticides because this organophosphate  pesticide degrades in plants to another organophosphate pesticide. EPA  found that 2 of the 13 pesticides we reviewed presented no concerns that  needed changes in existing conditions on how to use and apply the  pesticides.
The pesticides we reviewed, including ones no longer approved for use in  the United States, are used in many other tobacco-producing countries,  according to experts. Researchers and advocacy groups have raised  concerns about adverse health effects on tobacco workers in other  countries from exposure to pesticides, citing such factors as the absence  of cautionary labels on some pesticides and the limited use of protective  clothing by agricultural workers. For example, researchers found elevated  rates of depression and suicide rates that were twice the national average  among tobacco producers in Brazil, a leading tobacco exporter. And  although many factors, such as poverty and stress, may play a role in  suicide, one group of researchers noted tobacco producers in Brazil  routinely used organophosphate pesticides, which have been shown to  cause depression. Moreover, these researchers reported that suicides are  more likely to occur during planting and harvesting seasons, when  organophosphate pesticides are used intensively. To some extent, such  harmful exposure may occur because pesticide regulations in other  countries may be less stringent than those in the United States or because  other countries’ enforcement of regulations may be more limited,  according to advocacy groups.
Regarding pesticide residues on domestic tobacco, overall, EPA officials  did not find associated health risks that required mitigation. Further, the  data we reviewed on 13 pesticides were consistent with statements from  EPA officials that the residues on tobacco were below the agency’s  identified level of concern in 11 cases. EPA did not evaluate the remaining  2 pesticides—diazinon and pendimethalin—for use on tobacco. In the case  of diazinon, evaluating residue data was not relevant because the pesticide  was no longer approved for use on tobacco at the time EPA conducted its  evaluation. In the case of pendimethalin, at the time we conducted this  work, EPA had not yet reviewed the relevant data received from the  manufacturer. EPA approved the reregistration for this pesticide, but its  use on tobacco is subject to the agency’s evaluation of this data.
Of the 11 pesticides that EPA evaluated for use on tobacco, 3 left residues  on green or cured tobacco that were less than 0.1 ppm—and one left no  residues at all. Specifically, the maximum residues of ethoprop on green  tobacco were 0.01 ppm, the residues of chlorpyrifos were 0.09 ppm, the  residues of pebulate on both green and cured tobacco were less than   0.02 ppm, and the plant metabolism study for 1,3-D showed no residues  remaining on the plant. Manufacturers provided pyrolysis studies in two of  the four cases in which the residue levels on green tobacco were 0.1 ppm  or less. The pyrolysis study for ethoprop identified residues in the smoke  that were below the agency’s level of concern. The pyrolysis study for a  by-product of chlorpyrifos that was initially of concern to the agency  identified the by-product in the smoke. However, EPA subsequently  concluded that the by-product, which accounted for more than 10 percent  of the residue in the smoke, was not of toxicological concern because,  unlike its parent compound, it does not act toxically on the nervous  system.
Of the seven pesticides that progressed through EPA’s tiered risk  assessment approach because residues on cured tobacco were greater  than 0.1 ppm, pyrolysis studies were conducted on five. No residues were  found in the smoke of four of these five pesticides; the residues of the fifth  were not of sufficient magnitude to require further study or evaluation.  One of the remaining two pesticides with residue levels greater than   0.1 ppm was evaluated using a study of the health effects on rats exposed  to residues in smoke, and one was approved subject to EPA’s review of  requested additional residue data, including a pyrolysis study, to confirm  EPA’s assessment that residues on tobacco do not pose a risk to human  health.
The reregistration decisions for 7 of the 13 pesticides we reviewed were  issued after EPA implemented guidance in 1999 requiring quantification of  the risks of short-term exposure to pesticide residues in tobacco smoke.  However, none of the human health risk assessments or other  documentation we reviewed contained this information—that is, the  margin of exposure estimate—because the health risk assessments  supporting these decisions were completed before the policy was  implemented. For pesticides with many uses and much data, several years  may elapse between the initial scientific assessment of the tobacco use  and the issuance of the reregistration decision.
Not including the 13 pesticides mentioned above, we reviewed five  additional health risk assessments EPA prepared after it developed the  policy requiring the quantification of the risks of short-term exposure to  pesticide residues in tobacco smoke that did include estimates of margin  of exposure. EPA generally does not have concerns about adverse health  effects when a margin of exposure is greater than 100—that is, when the  pesticide causes no adverse effects at levels 100 or more times greater  than the expected actual exposure to the pesticide. Consequently, a  margin of exposure greater than 100 is considered to reflect risk that is  below EPA’s level of concern. As table 4 shows, EPA’s recent health risk  assessments of five pesticides approved for use on tobacco—four of which  were newly registered and one reregistered—generally indicated that the  margins of exposure were substantially greater than 100. Although one  margin of exposure was below 100, EPA officials told us that because they  used very conservative assumptions to estimate exposure, resulting in an  extreme overstatement of actual exposure, EPA was not concerned about  the potential for adverse health effects. For these five pesticides, EPA  concluded that no mitigation related to the use on tobacco was required.  Overall, EPA officials said that potential risks from exposure to residues  on tobacco had never been high enough to require mitigation.
EPA requires that pesticide manufacturers provide most of the studies it  considers in assessing the health risks of pesticides, and the agency’s  evaluations of these studies are critical to the assessment process. EPA  officials were generally able to provide us with copies of the studies and  evaluations we requested, but documentation of the agency’s evaluation of  the quality of the residue studies and other data upon which it relied to  evaluate the potential for adverse health effects was inconsistent.  Specifically, for eight of the pesticides, EPA officials were unable to  provide their evaluations of the validity and reliability of residue data used  in their assessments of potential health risks. In addition, for chlorpyrifos,  EPA officials were unable to provide the residue studies and agency  evaluations of them from the early 1980s. As a result, we examined  subsequent EPA evaluations that referred to the results of these early  studies and the agency’s conclusion that the residues were below the level  of concern. According to EPA officials, they were unable to locate the  documents, in part, because not all records from this time have yet been  converted to electronic format, and the paper copies could not be located  among the substantial backlog of paper documents. EPA officials noted  that each pesticide registration could consist of 100 or more studies from  pesticide manufacturers, each of which requires one or more agency  evaluations. The officials reported that, as resources permit, contract and  agency staff are converting documents to electronic format to make them  more readily available for review.
section_title: Federal Regulation of Pesticide Residues on Tobacco Is Limited
paragraphs: While EPA is required to regulate residues of pesticides approved for use  on human food and animal feed crops, no such requirement applies to  pesticides approved for use on tobacco. However, primarily as a matter of  trade equity, USDA does (1) regulate residues of selected pesticides that  are prohibited in the United States but that may be used on imported  tobacco and (2) test certain types of imported and domestic tobacco to  ensure they do not exceed residue limits. USDA has not reevaluated the  pesticides it regulates since 1989, although changes in the pesticides used  on tobacco have occurred since then. Through its testing programs, USDA  has found that a small fraction of imported and domestic tobacco exceeds  the residue limits.
subsections: section_title: Federal Regulation Focuses on Pesticides Not Approved for Use on Tobacco
paragraphs: As discussed previously, EPA regulates pesticides in the United States by  granting registrations, which permit the distribution, sale, and use of the  pesticides according to directions identified on the label. EPA also  regulates the residues of pesticides that are approved for use on human  food and animal feed crops by setting tolerances—maximum  concentrations of residues that may remain on crops. FDA and USDA test  food and feed crops to ensure that residue levels do not exceed the  tolerances EPA has set. Because tobacco is not used as food or feed,  however, EPA does not set tolerances for residues of pesticides approved  for use on tobacco, and FDA and USDA do not test tobacco for maximum  concentrations of residues of approved pesticides. Consequently, residues  of pesticides approved for use on tobacco in the United States are not  federally regulated.
Instead, federal regulation of pesticide residues on tobacco focuses  exclusively on pesticides not approved for use on tobacco. The Dairy and  Tobacco Adjustment Act of 1983, as amended, requires USDA to   (1) establish maximum allowable concentrations for residues of selected  pesticides that are not approved for use on tobacco in the United States  but that are likely used on tobacco in some other countries and (2) test  imported and domestic flue-cured and burley tobacco to ensure the  residue levels do not exceed the maximum levels allowed. In selecting  which pesticide residues to regulate, USDA is to consider pesticides  whose use on tobacco has been cancelled, suspended, revoked, or  otherwise prohibited under FIFRA. The regulation helps ensure that  domestic tobacco producers are not placed at an unfair disadvantage in  the market because they are not allowed to use certain pesticides that may  be used in other countries; it also helps protect the public from exposure  to the residues of highly toxic pesticides not approved for use on tobacco  in the United States.
While the focus of U.S. regulation of pesticide residues on tobacco is on  those pesticides not approved for use on tobacco, some other countries  have set limits on residues of pesticides that are used on tobacco. Further,  as in the United States, some countries limit the concentration of residues  as measured on tobacco leaf. However, at least one country—Germany— limits the pesticide residues as measured in cigarettes and other tobacco  products. Appendix III provides information on the limits established by  Germany, Italy, and Spain.
section_title: USDA Has Not Reevaluated the Pesticides it Regulates Since 1989
paragraphs: USDA has implemented the Dairy and Tobacco Adjustment Act, in part, by  setting 15 residue limits (maximum allowable concentrations) covering 20  pesticides currently not approved for use on tobacco in the United States  that the agency believed were used in other countries. Most of the  pesticides USDA regulates, such as DDT and toxaphene, are  organochlorine pesticides. As discussed earlier, organochlorine pesticides  persist in the environment and accumulate in the bodies of humans and  animals, and many are highly toxic—a number of them have been banned  for these reasons. Eleven of the 15 residue limits apply to individual  pesticides and 4 apply to 2 or more pesticides in combination. For  example, aldrin and dieldrin are summed because dieldrin is the primary  degradation product of aldrin. Table 5 lists the residue limits included in  USDA’s testing program, with the 12 organochlorine pesticides  highlighted. As indicated in the table, methoxychlor is the only  organochlorine pesticide included in USDA’s testing program that is  currently approved for other uses in the United States, such as on food  crops.
USDA’s Agricultural Marketing Service (AMS) initially established  maximum allowable concentrations of pesticides in August 1986 after  determining the countries from which the United States imports tobacco,  the pesticides that might reasonably be expected to be used on tobacco in  those countries, and the pesticides not approved for use in the United  States. In 1989, AMS revised the number of pesticides to its current total of  20 residues.
Although in 1986 USDA stated its intent to periodically reevaluate the  pesticides it regulates, the department has not done so since 1989.  According to officials at USDA, reevaluating the regulated pesticide  residues has not been a priority of the department. However, since USDA  selected the pesticides it would test in 1989, tobacco uses have been  cancelled for more than 30 pesticides that had been approved for use on  tobacco. For example, by 2000, EPA had cancelled all tobacco uses of  lindane—a highly persistent, organochlorine pesticide that may cause  cancer and harm the environment. USDA does not currently regulate  pesticide residues of lindane because it was still approved for tobacco  when USDA last reevaluated the regulated pesticides. Other pesticides,  such as trichlorfon and diazinon, are also candidates for regulation—that  is, pesticides no longer approved for use on tobacco in the United States  but likely to be used in some other countries. As appendix III shows, some  countries that set limits for pesticides used on tobacco have established  them for trichlorfon and diazinon—one of the leading causes of acute  insecticide poisoning for humans. However, because USDA has not  revised the regulated pesticide residues it tests for, the department’s  testing program may not include some pesticides with characteristics  similar to those of pesticides currently included in the testing program and  that may still be used in other countries. Tobacco and pesticide experts  with whom we spoke agreed that periodic reevaluations of the regulated  pesticides would be appropriate. Furthermore, two of these experts—a  toxicologist who has measured residues on tobacco for many years and a  former government official who now represents tobacco producers—told  us that many of the pesticides USDA currently regulates, particularly the  organochlorine pesticides, warrant continued inclusion in the testing  program because they are persistent in the environment, accumulate in the  body, and continue to be used on crops overseas.
section_title: USDA Tests Imported and Domestic Tobacco for Regulated Pesticides
paragraphs: Also as required by the Dairy and Tobacco Adjustment Act, USDA tests  certain imported and domestic tobacco to ensure that residues do not  exceed the maximum allowable concentrations the agency established.  USDA is required to test samples of two types of tobacco—flue-cured and  burley—that are commonly imported from other countries and also  produced in the United States to determine whether they conform to the  pesticide residue limits. These two types of tobacco are the major  components of cigarettes, and imports of them have continued to increase  over time. For example, USDA reported that imports of flue-cured tobacco  represented about 12 percent of the flue-cured tobacco used in the United  States in 1980 and about 36 percent in 2001. USDA is not required to test  other types of imported tobacco, such as oriental tobacco, which is added  to cigarettes for purposes of flavor and aroma but which is not grown in  the United States.
Tobacco is imported into the United States in large, sealed shipping  containers that hold approximately 40,000 pounds of tobacco in 90 to 96  boxes weighing about 440 pounds each. In 1986, AMS began testing  imported flue-cured and burley tobacco, which represented about   60 percent of the tobacco imported into the United States in 2001. Random  samples of imported flue-cured and burley tobacco are tested for residues  of the 20 regulated pesticides. AMS inspectors use a computer program to  randomly select one box of tobacco from each shipping container. The  domestic testing program began in 1989 and is administered by the USDA  Farm Service Agency (FSA) under a cooperative agreement with AMS.  Similar to the AMS program for tobacco imports, FSA tests randomly  selected samples of domestic flue-cured and burley tobacco for the 20  regulated pesticides not approved for use in the United States. FSA tests  the portion of domestically grown flue-cured and burley tobacco that  becomes loan stock (surplus tobacco) under USDA’s tobacco price  support program. The proportion of domestic tobacco that becomes loan  stock varies each year, depending on tobacco quality and demand from  manufacturers, and has declined in recent years. Additional information  about the domestic loan stock program is provided in appendix IV.
For 1999 through 2001, USDA’s testing programs found less than 1 percent  of domestically produced or imported flue-cured and burley tobacco with  residue levels above the allowable levels. According to agency officials,  those results are consistent with results obtained since testing began in  1986. More specifically, for 1999 through 2001, the FSA domestic testing  program found a small fraction of a percentage of domestically produced  tobacco in excess of the limits. FSA found 4 samples of flue-cured tobacco  and 24 samples of burley tobacco—representing more than 12,000 pounds  of tobacco—that exceeded the maximum allowable concentrations of 2 of  the regulated pesticides—methoxychlor and permethrin. AMS found  residues of DDT/TDE/DDE, cypermethrin, and ethylene dibromide in  excess of the limits on less than 1 percent of the imported tobacco  entering the United States during this time.
If imported tobacco exceeds any of the limits, the importer is notified of  the violation and may choose to appeal the result or reexport the tobacco  to another country. When an importer appeals, AMS inspectors randomly  select three additional samples for testing, and the residue levels for the  four samples are averaged. If the average result is below the limits, the  tobacco is cleared for entry into the United States. However, if the average  exceeds the limits, the container of tobacco is denied entry and is typically  reexported. Under the Dairy and Tobacco Adjustment Act, domestically  produced flue-cured or burley tobacco not meeting the residue  requirements must be destroyed. According to USDA officials, because of  restrictions on the disposition of products contaminated by pesticides,  boxes of domestic tobacco are typically disposed of in an approved landfill  with a permit from EPA.
section_title: Conclusions
paragraphs: To ensure that pesticides can be used without posing an unreasonable risk  to human health, EPA conducts risk assessments of exposures to the  pesticides it evaluates for use in the United States, including exposure to  pesticide residues on tobacco. EPA’s decision to limit its quantitative  assessment of the risks associated with pesticides on tobacco to the  effects of short-term exposure, and not include the long-term exposure of  smokers, recognizes that the pesticides are used on a crop that itself poses  very significant health risks to humans through use in various consumer  products—primarily cigarettes. Overall, EPA’s health risk assessments  show that the pesticides used on tobacco and other crops are probably a  greater hazard for those who handle them than for those who inhale  tobacco smoke. Nonetheless, while the risks of some exposures, such as  acute poisoning, are clear, less is known with certainty about the effects of  long-term exposure to small amounts of pesticides, such as residues in  food and water, on tobacco, or in the environment.
While historically EPA has required pesticide manufacturers to provide  data on the residues remaining on tobacco, its assessments of the health  effects associated with exposure to the residues were not identified in risk  assessment documents and generally were not quantified. Mirroring the  improvements in risk assessment methods in recent years, EPA has  adopted a more formal and consistent approach to evaluating the health  risks associated with pesticides used on tobacco and has started to  document, in its risk assessment documents, its conclusions on the  potential for short-term risks from pesticide residues that may remain in  tobacco smoke. As a result, interested parties are better informed about  the potential risks, and EPA is appropriately more accountable for its  assessments.
When used as intended—most commonly in cigarettes—tobacco is  generally inhaled into the body. However, because it is not a food, tobacco  is regulated as a nonfood crop with regard to pesticide residues. That is,  no residue limits are established or monitored for pesticides approved for  use on tobacco, as is done for foods. While the regulation of pesticide  residues on tobacco is limited because it does not include pesticides  approved for use on this crop, USDA tests tobacco for residues of 20  pesticides not approved for domestic use on tobacco, primarily for  purposes of trade equity. Because many of the tested pesticides are known  to harm humans and the environment, the USDA testing program helps  minimize the public’s exposure to some highly toxic pesticides. The  universe of pesticides not approved for use on tobacco has grown since  USDA selected the pesticides it tests, but USDA has not reevaluated the  program’s coverage in 14 years. The USDA testing program would be  improved by assessing the current universe of pesticides not approved for  use on tobacco and determining whether an update to its program is  warranted.
section_title: Recommendation for Executive Action
paragraphs: To better protect the public from exposures to residues of pesticides not  approved for use on tobacco in the United States and ensure that domestic  tobacco producers are not placed at an unfair disadvantage relative to  producers in other countries, we recommend that the Secretary of the  Department of Agriculture direct the Administrators of the Agricultural  Marketing Service and the Farm Service Agency to periodically review and  update the pesticides for which they set residue limits and test imported  and domestic tobacco.
section_title: Agency Comments
paragraphs: We provided copies of our draft report to EPA and USDA for review and  comment. In commenting on the draft, EPA officials said we accurately  characterized the agency’s risk assessment process for pesticides used on  tobacco, and USDA officials agreed with our recommendation to  periodically review and update the pesticides for which the department  sets residue limits and tests tobacco. USDA officials said they plan to  annually review and update the testing program for tobacco.
We conducted our review from May 2002 through March 2003 in  accordance with generally accepted government auditing standards. Our  scope and methodology are discussed in appendix I.
As agreed with your office, unless you publicly announce the contents of  this report earlier, we plan no further distribution until 30 days from the  report date. At that time we will send copies of this report to the  Administrator, EPA; the Secretary of Agriculture; and other interested  parties. We will make copies available to others upon request. In addition,  the report will be available at no charge on GAO’s Web site at  http://www.gao.gov.
If you or your staff have any questions, please call me at (202) 512-3841.  Key contributors to this report are listed in appendix V.
section_title: Appendix I: Objectives, Scope, and Methodology
paragraphs: This report provides information on (1) the pesticides commonly used on  tobacco and the potential health risks associated with them; (2) how the  Environmental Protection Agency (EPA) assesses and mitigates health  risks associated with pesticides used on tobacco; and (3) how, and the  extent to which, EPA, U.S. Department of Agriculture (USDA), and other  federal agencies regulate and monitor pesticide residues on tobacco. In  addition, this report provides information on the regulatory residue limits  adopted by three countries that are significant importers of tobacco grown  in the United States.
To identify the chemicals commonly used on tobacco, we reviewed  pesticide-use databases developed by the National Center for Food and  Agricultural Policy (NCFAP), a nonprofit research organization, under a  cooperative agreement with USDA. These databases summarized national  use of 235 pesticides on 87 food and nonfood crops for the period 1990  though 1998. These databases, compiled from more than 130 federal and  state surveys and reports, include pesticide use on cropland in the  coterminous 48 states and do not include new pesticides approved by EPA  since 1997. We also reviewed data from national surveys conducted in the  1990s by the U.S. Geological Survey and USDA and from several tobacco- producing states—Kentucky, North Carolina, Tennessee, and Virginia. In  total, 53 pesticides were identified as being used on tobacco in one or  more of the surveys. Of these, 37 were identified in one or more of the  surveys that included national data, and we refer to this latter group as the  pesticides that were commonly used on tobacco in the United States  during the 1990s. To identify the adverse health effects associated with  these 37 pesticides, we collected and reviewed relevant human health risk  assessments prepared by EPA’s Office of Pesticide Programs. Where such  assessments were not available, we reviewed documents from academic  experts who maintain a database on pesticides and other toxic chemicals  for USDA, and other programs within EPA. In addition we interviewed,  and reviewed reports prepared or recommended by, experts on the human  health effects of exposure to pesticides and other toxins at the National  Cancer Institute, the National Institute of Environmental Health Sciences,  the National Center for Environmental Health, Johns Hopkins Bloomberg  School of Public Health, and the Institute for Cancer Prevention (formerly  the American Health Foundation).
To determine how EPA assesses and mitigates potential health risks from  pesticide residues on tobacco, we reviewed agency policies and  procedures on identifying the levels of pesticide residues on tobacco and  the related health risks, and we interviewed EPA officials in the Office of  Pesticide Programs who perform these tasks. In addition, we examined in  detail how EPA implemented its policies and procedures for 13 of the 37  pesticides commonly used on tobacco. That is, we reviewed pesticide  residue studies submitted to EPA and EPA’s evaluations of pesticide  residues and their potential health effects conducted as part of the  pesticide registration process under the Federal Insecticide, Fungicide,  and Rodenticide Act for 1,3-D, acephate, chlorpyrifos, diazinon, disulfoton,  endosulfan, ethoprop, ethephon, maleic hydrazide, metalaxyl,  methidathion, pebulate, and pendimethalin. We focused primarily on those  pesticides for which EPA had completed registrations between 1994 and  2002. We did not independently evaluate the validity or scientific merit of  the studies that EPA relied upon to reach its conclusions.
To determine the extent to which EPA, USDA, and other federal agencies  regulate and monitor pesticide residues on tobacco, we met with  cognizant officials and reviewed authorizing legislation, regulations, and  documentation on how programs related to pesticide residues on tobacco  are implemented. In addition, we analyzed USDA data on tobacco  production, imports, and residue-testing results. We also interviewed  academic and tobacco industry experts and reviewed residue data  collected by North Carolina State University.
To provide information on other countries that have adopted regulatory  limits on pesticide residues, we reviewed articles by academic experts on  the international regulation of pesticides on tobacco. We provide  information on three major importers of U.S. tobacco—Germany, Italy,  and Spain—as examples of regulatory approaches in other countries,  focusing on the residue limits they set. We did not examine how, or the  extent to which, these countries monitor or enforce their pesticide residue  limits. We updated and clarified the information on the three countries’  residue limits provided in the articles with information from the  Cooperation Centre for Scientific Research Relative to Tobacco  (CORESTA), an international tobacco research organization, and officials  responsible for oversight of pesticides and tobacco in Germany and Spain.  To identify countries that import U.S. tobacco, we extracted data from the  United States International Trade Commission’s interactive tariff and trade  database on the countries that received U.S. flue-cured and burley tobacco  from 1996 through 2001.
We conducted our review from May 2002 through March 2003 in  accordance with generally accepted government auditing standards.
section_title: Appendix II: Pesticide Use on Tobacco and Other Crops
paragraphs: Most of the pesticides used on tobacco are widely used on food and other  crops. As shown in table 6, tobacco use of most pesticides represents a  small portion of the total use. However, for some pesticides— dimethomorph, fenamiphos, flumetralin, maleic hydrazide, mefenoxam,  and sulfentrazone—most of the use in 1994 through 1998 was on tobacco.
section_title: Appendix III: Germany, Italy, and Spain Have Adopted Regulatory Limits for Pesticide Residues on Tobacco
paragraphs: Several countries that are major importers of U.S. tobacco have adopted  regulations for specific pesticide residues on various forms of tobacco.  For example, Germany’s residue limits (maximum residue levels) apply to  finished products, such as cigarettes, whereas limits in Italy and Spain  generally apply to tobacco leaf. Although they have somewhat different  regulatory approaches to pesticides on tobacco, Germany, Italy, and Spain  differ from the United States in that they regulate residues of pesticides  approved for use on tobacco in addition to regulating some residues of  pesticides not approved for use on tobacco.
According to 2003 data from CORESTA—the Cooperation Centre for  Scientific Research Relative to Tobacco—Germany, Italy, and Spain have  residue limits on tobacco for 79, 100, and 58 pesticides, respectively. Of  the 37 pesticides commonly used on tobacco in the United States during  the 1990s, Germany has limits for 20, Italy for 24, and Spain for 21 (see  table 7). None of these countries have adopted limits for 7 of the pesticides  commonly used on U.S. tobacco during the 1990s.
In addition to residue limits for approved pesticides, Germany and Italy  collectively have residue limits on tobacco that apply to 15 of the 20  pesticides not approved for use in the United States that USDA monitors in  its tobacco testing programs. The 15 pesticides are aldrin, dieldrin,  chlordane, cypermethrin, DDT, DDE, endrin, ethylene dibromide,  formothion, heptachlor, heptachlor epoxide, hexachlorobenzene,  methoxychlor, permethrin, and TDE. Further, where no specific pesticide  limits are set for tobacco products in Germany, residues of pesticides not  approved for use on tobacco in Germany may be present in amounts that  are not likely to pose a risk to human health. In Italy and Spain, residues of  pesticides not approved for use on tobacco in those countries must not  exceed the limit of detection, generally between 0.01 ppm and 0.05 ppm.  We did not examine how, or the extent to which, these countries monitor  or enforce their pesticide residue limits.
From 1971 to 2000, researchers at the North Carolina State University  (NCSU) collected limited data on the residues of various pesticides on  some domestically grown tobacco. NCSU data for the 1990s included six  pesticides for which Germany, Italy, or Spain have residue limits. The  domestic tobacco tested by NCSU identified residue levels that were   (1) consistently below the lowest limit for endosulfan, flumetralin, and  metalaxyl; (2) generally above the limit for maleic hydrazide; and (3) more  varied for fenamiphos and the dithiocarbamates—a class of fungicides  that includes mancozeb. For example, in 1995 residue levels on flue-cured  tobacco were below the lowest limit for fenamiphos—0.02 ppm adopted  by Spain—but exceeded this limit in 1992 and 1994. Also, in 1991 and 1997  residue levels of dithiocarbamates were generally lower on burley tobacco  than limits in Germany and Italy—50 ppm and 10 ppm, respectively—but  exceeded Spain’s limit of 0.05 ppm.
section_title: Appendix IV: USDA Tests Domestic Tobacco in the Loan Stock Program
paragraphs: The USDA Farm Service Agency (FSA) tests the portion of domestically  grown flue-cured and burley tobacco that becomes loan stock (surplus  tobacco) under USDA’s tobacco price support program for the 20  regulated pesticides. To receive price supports, tobacco must be sold in  USDA-approved auction warehouses and inspected by USDA graders. At  the auction warehouse, each individual lot of tobacco is sold to the highest  bidder. If the highest bid is below the government’s loan (support) price,  or no bid is received, the stabilization cooperative makes loans to growers  whose tobacco does not bring the minimum price at auction with funds  borrowed from USDA’s Commodity Credit Corporation. The growers’  tobacco, which is consigned to the cooperative as loan stock, is pledged as  collateral to the credit corporation for the money borrowed. The  cooperative receives, processes, stores, and later sells the loan stock  tobacco when demand increases, with the proceeds used to repay the  credit corporation loan, plus interest. An alternative to traditional auction  marketing—growers contracting to sell their tobacco directly to  manufacturers—also reduces the amount of tobacco going to auction and  thus potentially to loan stock. For the most recently completed marketing  season—growing year 2001—20 percent of domestic tobacco was sold at  auction, and 2.4 percent became loan stock.
After auction, the tobacco is processed in distinct “runs” of approximately  100,000 pounds, when the tobacco is stemmed, redried, finely chopped,  and placed into boxes holding approximately 440 pounds. The tobacco  cooperative randomly selects one box from each run and draws a  one-pound sample of tobacco for pesticide testing at USDA’s laboratory. If  the sample exceeds any of the residue limits, the box of tobacco from  which it came is destroyed. The adjacent boxes, processed before and  after the original box, are also sampled. The testing continues with  adjacent boxes of tobacco until the samples are found to be below the  residue limits. Because the samples are drawn by the tobacco  cooperatives, FSA resamples 5 percent of the tested inventory (or 25  samples, whichever is less) for oversight purposes each year.
Historically a substantial portion of domestic tobacco was sold at auctions  in conjunction with the tobacco price support program, but in recent years  most domestic tobacco has been sold under contract directly to cigarette  manufacturers—approximately 80 percent in 2001. Officials from USDA  and tobacco associations told us the market has changed because  manufacturers asserted that auction markets were not providing quality  tobacco with the characteristics they required. The recent, dramatic shift  in the way tobacco is marketed—with a 60 to 80 percent reduction in the  amount of tobacco at auction—has decreased the amount of domestic  tobacco that potentially becomes loan stock and thus is tested. Although  the amount of domestically produced tobacco that becomes loan stock  has varied greatly, an average of 13 percent became loan stock over the  past decade. In 2001, only about 2 percent of domestically produced  tobacco has become loan stock, reducing the amount of domestic tobacco  subjected to pesticide testing. The officials with whom we spoke said that  this change is not likely to be reversed.
section_title: Appendix V: GAO Contacts and Staff Acknowledgments
subsections: section_title: GAO Contacts
section_title: Acknowledgments
paragraphs: In addition to those named above, Nancy Crothers, Laura Gatz, Terrance  Horner, Richard Johnson, Ilga Semeiks, Tina Smith, and Cheryl Williams  made key contributions to this report.