Regulating Pesticides in Food The Delaney Paradox (1987) / Chapter Skim
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3. Estimates of Dietary Oncogenic Risks
3. Estimates of Dietary Oncogenic Risks
Pages 45-99
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From page 45... ...
All risk estimates in this report are limited to oncogenic risks from residues of currently registered pesticides in or on food. The study focuses on the potential impact of the Delaney Clause on agricultural innovation and the public's dietary oncogenic risk.
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From page 46... ...
A more detailed analysis of the benefits associated with oncogenic pesticides used on eight selected crops is presented in the next chapter. To appreciate the potential impact of the Delaney Clause, one should note the percentage of all pesticide use that is accounted for by oncogenic herbicides, insecticides, and fungicides.
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From page 47... ...
Specifically, data indicating oncogenicity for the herbicides atrazine and 2,4-D were received by the EPA after the committee's analysis. These pesticides are included here and in Table 3-1 to indicate the potential impact of the Delaney Clause.
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From page 48... ...
These oncogenic fungicides represent from 70 million to 75 million of the 80 million pounds of all fungicides applied annually in the United States.3 Pesticide Use Data Pesticide use patterns in U.S. agriculture and thus pesticide residues in food are changeable.
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From page 49... ...
For example, depending on how the agency establishes average expected residue levels in food, the calculation of exposure to pesticide residues in a given foodstuff can yield risk estimates that vary by orders of magnitude. Assumptions of how and when to aggregate risks from a pesticide used on a variety of crops will also influence risk estimates.
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From page 50... ...
In certain cases, the committee used the data in new analyses to understand the theoretical impact of different regulatory standards and methods of calculating risks and benefits. Although estimated oncogenic risks generally are presented in a quantitative fashion, a wide margin of uncertainty surrounds nearly all of the numbers.
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From page 51... ...
Table 3-4 illustrates that the committee derived its risk estimates from a roughly equivalent percentage of currently used oncogenic insecticides, fungicides, and herbicides. The portion of oncogenic active ingredients analyzed ranges from 63 percent for insecticides to 79 percent for
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From page 52... ...
Chlorobenzilate 1956 Insecticide/ 1,500,000 Citrus acaricide Chlorothalonilb 1961 Fungicide 6,000,000 Fruits, peanuts, (Bravo) vegetables Copper arsenate 1971 Insecticide NA Vegetable crops Cypermethrinb 1984 Insecticide 600,000 Cotton (Ammo, Cymbush)
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From page 53... ...
P., 1986, A National Pesticide Usage Data Base, Resources for the Future, Washington, D.C., photocopy; and unpublished data from the EPA for the years 1981 through 1985, excluding 1983, for crops affected by PIK. bThese are compounds for which risk estimates were performed.
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From page 54... ...
in estimating oncogenic potential. Therefore, the estimated oncogenic risks for certain pesticides may appear overstated.
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From page 55... ...
67. In Tables 3-9 and 3-17 through 3-19, risk estimates are presented with the EPA's classification of the qualitative weight of the evidence.
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From page 56... ...
However, this information was used primarily in the crop-level analyses in Chapters 4 and 5. Estimating Dietary Exposure to Pesticide Residues The average consumer is exposed to pesticide residues, although in minute quantities, in nearly every food, including meat, dairy products, fruits, vegetables, sugar, coffee, oils, dried goods, and most processed foods.
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From page 57... ...
. Estimates of dietary exposure to pesticide residues are based on food consumption estimates.
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From page 58... ...
This conversion was necessary to make TAS milk consumption, otherwise expressed as milk solids, compatible with the Food Factor consumption figures for whole milk. The committee's risk estimates for milk and dairy products do not use this conversion factor.
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From page 59... ...
METHOD FOR ESTIMATING EXPOSURE TO RESIDUES The EPA traditonally has estimated dietary exposure conservatively by incorporating worst-case assumptions. Pesticide residues are assumed to be present in foods at the published tolerance level.
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From page 60... ...
Fourteen oncogenic fungicides account for 73 percent of the TMRC, 19 insecticides for 24 percent, and 17 herbicides for 3 percent. To estimate current oncogenic risk, the committee considered several ways to develop more realistic calculations of current dietary exposure.
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From page 61... ...
The distinction is the key to assessing the regulatory impact of the Delaney Clause. Most pesticides registered on food crops before 1978 lack tolerances and data for residues in processed foods, even though the EPA suspects that such residues are often present at concentrated levels.
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From page 62... ...
Consequently, pesticide residues that may be consumed in 12 out of 13 processed foods are incorporated in TAS-based exposure and risk assessments only through the assumption that residues in processed foods will equal section 408 raw food tolerance levels. A list of all oncogenic pesticides with section 409 food or feed additive tolerances is presented in Table 3-7.
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From page 63... ...
Although the TAS residue estimates may overestimate exposure to some residues in processed foods and underestimate exposure to others, TAS is the best available tool for estimating pesticide residues in the diet. The consumption data the TAS incorporates, together with published and presumed residue levels, provide a reliable characterization of the relative magnitude and distribution of dietary exposure to pesticides.
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From page 64... ...
's, il as well as a significant degree of uncertainty regarding their importance to human cancer risk estimates. For example, although the models used to develop Q*
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From page 65... ...
Such a risk estimate, if accurate, would mean that the odds that an average individual would contract cancer in a lifetime would rise from about 25 percent to 26 percent.~° Further, potential cancer risk is estimated by identifying a conservative upper bound on potential human risk. The estimated risks reported in this chapter, which incorporate many conservative assumptions regarding crops consumed and pesticide residues, are no greater than 1 x 10-3.
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From page 66... ...
; · Active ingredients; and · The date tolerances were granted. In addition, estimated risks were aggregated for combinations of these factors.
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From page 67... ...
DISTRIBUTION OF RISK BY TOLERANCE TYPE: SECTION 408 VERSUS SECTION 409 The distribution of estimated oncogenic risk by tolerance type (raw versus processed food) is important because the Delaney Clause applies only when residues concentrate in processed foods above the levels allowed in raw foods.
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From page 68... ...
NOTE: In this table and in those following, risk estimates are based on EPA data and methods using the TAS U.S. mean consumption estimates.
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From page 69... ...
The clause's potential impact could be larger, however, for the following reasons: · In most cases, revoking processed-food tolerances would mean revoking section 408 raw-food tolerances for the crop from which the processed foods are derived. The EPA denies raw-commodity tolerances for new oncogenic active ingredients if it determines that their residues will concentrate in processed foods, which would ban them under the Delaney Clause.
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From page 70... ...
Consequently, residues in them are not subject to the Delaney Clause. Yet, the clause could indirectly reduce the dietary risk associated with these foods if residues concentrate in processed feed such as soybeans and corn and tolerances for the feeds are revoked.
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From page 71... ...
b Fungicides 2.45 x 10-3/70.7 27/19 Herbicides 5.75 x 10-4/36.4 34/20 Insecticides 2.12 x 10-4/26.5 25/16 Total 3.23 x 10-3/55.4C 38/20a' NOTE: These risk estimates are derived using EPA data and methods described on pages 50 66 and in Appendix B This scenario assumes that tolerances for all processed foods and the parent raw commodities are revoked.
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From page 72... ...
For oncogenic pesticides, the Delaney Clause would
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From page 73... ...
Were additional feed additive and food tolerances required, estimated oncogenic risk from animal products would probably increase. Because animal products have no processed-food forms under current EPA regulations, the Delaney Clause has smaller current and potential impacts on animal products than on other foods.
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From page 74... ...
Estimated risk from fungicides is TABLE 3-16 Distribution of Estimated Oncogenic Risk by Pesticide Type Type of Pesticide Risk (number/%) Fungicides Herbicides Insecticides Total 3.46 x 10-3/59.2 1.58x10-3/27.1 8.00 x 10-4/13.7 5.84 x 10 3 /100 NOTE: These risk estimates are derived using EPA data and methods described on pages 50~6 and in Appendix B
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From page 75... ...
The committee found that roughly 20 percent of the current estimated total dietary oncogenic risk is associated with consumption of processed foods; fungicides account for three-fourths of this risk and nearly 60 percent of total oncogenic risk (see Table 3-101. This contribution is extraordinary.
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From page 76... ...
NOTE: These risk estimates are derived using EPA data and methods described on pages 5~66 and in Appendix B B2 indicates a probable human carcinogen.
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From page 77... ...
1 7.67 x 10-6 4.3 x 10-3 3.29 x 10-8 C NOTE: These risk estimates are derived using EPA data and methods described on pages 50-66 and in Appendix B B2 indicates a probable human carcinogen.
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From page 78... ...
TABLE 3-20 Fifteen Foods with the Greatest Estimated Oncogenic Risk Total Dietary Oncogenic Risk Estimates Food Number Percentage Tomatoes 8.75 x 10-4 14.9 Beef 6.49 x 10-4 1l.l Potatoes 5.21 x 10-4 8.9 Oranges 3.76 x 10-4 6.4 Lettuce 3.44 x 10-4 5.8 Apples 3.23 x 10-4 5.5 Peaches 3.23 x 10-4 5.5 Pork 2.67 x 10-4 4.5 Wheat 1.92 x 10-4 3.3 Soybeans 1.28 x 10-4 2.2 Beans 1.23 x 10-4 2.1 Carrots 1.22 x 10-4 2.1 Chicken 1.12 x 10-4 1.9 Corn (bran, grain) 1.09 x 10-4 1.9 Grapes 1.09 x 10-4 1.9 Total 78.0 NOTE: These worst-case risk estimates are derived using EPA data and methods described on pages 50-66 and in Appendix B
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From page 79... ...
Further, the ranking of estimated risk from fungicides varies from crop to crop. When estimated risks from individual foods are ranked, 15 crops and animal products contribute nearly 80 percent of all estimated dietary oncogenic risk from pesticide residues (see Figure 3-3 and Table 3-20~.
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From page 80... ...
1.59 x 10-4 1.11 X 10-4 1.10 x 10-4 9.95 X 10-5 5.19 x 10-5 5.17 x 10-5 5.02 x 10-5 3.50 x 10-5 2.80 x 10-5 1.82 x 10-5 2.5 1.9 1.9 1.7 0.9 0.9 0.9 0.6 0.5 0.3 12.1 TABLE 3-23 Estimated Oncogenic Risk from Fungicides in Major Foods Estimated Risk Crop Number Percentage Tomatoes 8.23 x 10-4 14.1 Oranges 3.72 x 10-4 6.3 Apples 3.18 x 10-4 5.4 Peaches 2.86 x 10-4 4.9 Lettuce 1.81 x 10-4 0.1 Potatoes 1.29 x 10-4 2.2 Beans 1.17 x 10-4 2.0 Grapes 1.08 x 10-4 1.8 Wheat 6.65 x 10-5 1.1 Celery 6.04 x 10-5 1.l Percentage of total risk from herbicides, 42.0 insecticides, and fungicides NOTE: These worst-case risk estimates are derived using EPA data and methods described on pages 50-66 and in Appendix B They assume residues are at the tolerance level, although actual residues may be different.
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From page 81... ...
The results are presented below. If one assumes that all acres are treated, that residues on raw tomatoes are at the current tolerance level, and that these residues in processed tomato products undergo a 10-fold concentration, then total estimated oncogenic risk from all fungicide residues in tomatoes would increase more than 300 percent above the committee's risk estimates, which assume no concentration of residues in processed foocis.
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From page 82... ...
Revoking all tolerances for linuron would reduce the committee's total estimate of dietary oncogenic risk by about 30 percent. By contrast, estimated risk from tomatoes is primarily from fungicide residues.
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From page 83... ...
(Many of these tolerances were established in the absence of oncogenicity data or information indicating residue concentration.) Conversely, the agency has enforced the Delaney Clause strictly to refuse section 408 and section 409 tolerances on all crops when section 409 tolerances are needed for new oncogenic active ingredients registered since 1978.
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From page 84... ...
Lauren Oryzalin Glyphosate Linuron Oxadiazon Alachlor Terbutryn Glyphosate 5.34 x 10-4 2.12 x 10-6 1.94 x 10-6 5.92 x 10-7 7.23 x 10-l° 3.87 x 10-4 2.01 x 10-6 1.39 x 10-8 2.16 x 10-4 8.54 x 10-7 7.82 x 10-7 2.27 x 10-7 1.68 x 10-1° Potatoes 5.64 x 10-7 2.72 x 10-9 2.0 x 10Pork o o o o o 5.34 x 10-4 2.12 x 10-6 1.94 x 10-6 5.92 x 10-7 7.23 x 10-1° 3.88 x 10-4 2.01 x 10-6 1.40 x 10-8 2.16 x 10-4 8.54 x 10-7 7.82 x 10-7 2.27x 10-7 1.68 x 10-1° 99 0.4 0.4 Negligible Negligible 99 0.5 Negligible 99 Negligible Negligible Negligible Negligible NOTE: These risk estimates are derived using EPA data and methods described on pages 50-66 and in Appendix B TABLE 3-26 Foods with the Greatest Estimated Oncogenic Risk from Insecticides Estimated Risk Risk from Active Processed Insecticides Ingredient Raw Food Food Risk on Crop (Jo)
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From page 85... ...
Tolerances for one insecticide, permethrin, granted after 1978 account for slightly more than half of all insecticide risk and less than 5 percent of total estimated dietary oncogenic risk. As shown in Figure 3-4, more than 90 percent of all estimated dietary oncogenic risk is associated with tolerances granted before 1978.
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From page 86... ...
About one-fifth of all estimated dietary oncogenic risk is associated with residues of pesticides in processed food; nearly 80 percent of this risk is derived from tolerances granted before 1978. EPA Application of the Delaney Clause to New Active Ingredients From 1975 through 1981 the EPA issued a series of standards and requirements for data to support pesticide registrations.
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From page 87... ...
In the late 1970s, pesticide oncogenicity and residue concentration data became available for newly registered pesticides. The EPA began exploring the regulatory ramifications of the Delaney Clause in the granting of tolerances for new active ingredients.
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From page 88... ...
In these cases the Delaney Clause has been bypassed. (For further discussion, see Chapter 2 and the case studies in Appendix C.)
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From page 89... ...
Citrus, field crop herbi- 1.14 x 10-5 1,600,000 cide Thiophanate-methyl Fruit, vegetable fungicide No risk assess- 28,000 (Topsin M) ment per formed NOTE: These risk estimates are derived using EPA data and methods described on pages 50 66 and in Appendix B
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From page 90... ...
The agency also gave the committee a list of 10 active ingredients for which it suspects that manufacturer or registrant concern about the impact of the Delaney Clause significantly influenced the content of tolerance applications (see Table 3-311. In each case, the agency is aware of section 408 and section 409 tolerance petitions that a registrant withdrew or declined to file because of concerns about the Delaney Clause.
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From page 91... ...
The committee finds no convincing legal or scientific basis for the EPA, as it completes the special review and reregistration processes, to avoid applying the standards of section 409, including the Delaney Clause, to currently registered compounds. Prior-Sanctioned Pesticides The prior-sanction exception to the Food Additives Amendment of the FDC Act would arguably render the Delaney Clause inapplicable to any pesticide residue in processed foods approved before 1958.
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From page 92... ...
Fosetyl Al residues were determined to concentrate during the drying of hops, and it has demonstrated weak but positive oncogenic effects in animals. Therefore, the EPA cited the Delaney Clause in denying section 408 and section 409 tolerances for residues in or on hops.
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From page 93... ...
The key change was extension of the time between application and harvest, allowing residues to degrade below detection levels by harvest. With residues theoretically eliminated from the raw commodity, the issue of concentration in the processed foods was moot.
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From page 94... ...
In the absence of the Delaney Clause, therefore, the risk associated with thiodicarb tolerances would not have warranted agency review. D~cAMsA Dicamba is a broadleaf herbicide widely used in the production of soybeans, corn, and other row and field crops.
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From page 95... ...
BENOMYL Benomyl is the most widely used systemic fungicide in the world. It is important because its existing section 409 tolerances will probably be the first to force an EPA decision on retroactive application of the Delaney Clause.
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From page 96... ...
The impact of tolerance revocations for benomyl and other oncogenic active ingredients included in the committee's risk estimates is projected in the next section and discussed in further detail in Chapter 5. PROJECTING PAST ACTIONS INTO THE FUTURE Over the next five years, the EPA will receive new data on the oncogenicity of many agriculturally important chemicals through the data call-in, special review, and registration standards programs.
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From page 97... ...
Fourth, most fungi-~.~ - ~ ~^~ ^~ a -- -- or TABLE 3-33 Potential Short-Term Impact of the Delaney Clause on Selected Fungicides Fungicide Possible Market Date for Estimated Risk on Commodities Share Active Tolerance (% acre Ingredient Revocation Action Raw Processed Total treatments) Benomyl 1986 Rsa 3.42 x 10-5 7.91 x 10-5 1.13 x 10-4 15 EBDCs 35 Mancozeb 1987 RS 2.43 x 10-4 9.44 x 10-5 3.38 x 10-4 Maneb 1987 RS 3.90 x 10-4 5.22 x 10-5 4.42 x 10-4 Metiram 1987 RS 7.65 x 10-5 3.91 x 10-5 1.15 x 10-4 Zineb 1987 RS 4.71 x 10-4 2.45 x 10-4 7.17 x 10-4 Captafol 1987 sRb 4.34 x 10-4 1.59 x 10-4 5.94 x 10-4 5 Folpet 1987 RS 1.81 x 10-4 1.43 x 10-4 3.24 x 10-4 5 Captan 1988 SR 2.80 x 10-4 1.93 x 10-4 4.74 x 10-4 15 Chlorothalonil 1988 SR 1.89 x 10-4 4.82 x 10-5 2.37 x 10-4 10 NOTE: These risk estimates are derived using EPA data and methods described on pages 50-66 and in Appendix B
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From page 98... ...
Linuron (Lorox) 1986 1987 Rsa 7.14 x 10-6 6.28 x 10-7 7.77 x 10-6 RS RS RS SR <1 2.86 x 10-' No risk assessment conducted 2.86 x 10-7 <1 8 No risk assessment conducted 1.36 x 10-5 1.06 x 10-5 2.42 x 10-5 18 1.12 x 10-3 3.96 x 10-4 1.52 x 10-3 <1 NOTE: These risk estimates are derived using EPA data and methods described on pages 50-66 and in Appendix B
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From page 99... ...
1986. Report on the Status of the Chemicals in the Special Review Program, Registration Standards Program, and Data Call-In Program.
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