Regulating Pesticides (1980) / Chapter Skim
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7. Application to Chlorobenzilate
7. Application to Chlorobenzilate
Pages 154-238
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From page 154... ...
Because oPP has previously completed benefit and risk assessments for chlorobenzilate, including a comparison of benefits and risks associated with various regulatory options (U.S.
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From page 155... ...
Ethion and dicofol are two important alternatives to chlorobenzilate for control of rust mites on citrus fruits (U.S.
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From page 156... ...
Ethion may therefore persist as a surface residue allowing dermal exposure if reentry occurs before photochemical destruction or hydrolysis. Dicofol similarly shows low vapor loss, indicating ready adsorption.
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From page 157... ...
The largest doses are received by citrus spray applicators and citrus fruit pickers. Much lower doses are received by people who eat foods that contain residues of the pesticide.
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From page 159... ...
159 o ~ ~ o _ ~ ~o~ ~o o o _ ~_ oo o - .
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From page 160... ...
Since the data in Table 7.3 were obtained under conditions similar to those associated with the application of chlorobenzilate (i.e., similar type of crop, spray apparatus, and spray concentration) , oPP assumed that they provide a reasonable basis for estimating exposure of spray applicators to chlorobenzilate (Severe 19781.
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From page 161... ...
OPP estimated the daily dose of chlorobenzilate received by spray applicators based on the above data and assumptions. For dermal exposures without protective clothing or respirators, oPP considered 12 400 mg/day to be a reasonable estimate.
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From page 163... ...
Thus, the total incremental lifetime exposure of spray applicators to chlorobenzilate under assumed present conditions, i.e., no protective clothing, becomes: Probable case = 27 mg/dlay x 40 days/year x 10 years = 10,800 lag. Maximum-plausible case = 41 mg/day x 40 days/year x 10 years = 16,400 ma.
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From page 164... ...
In fact, when calculating risk to citrus spray applicators associated with the regulatory option that requires protective clothing and respirators, the Committee assumes only 50 percent compliance as the probable case and 20 percent in the maximum-plausible exposure case. These assumptions are based on the difficulty of enforcement and the Committee's direct experience with citrus growers and researchers in Texas, which indicated a disbelief that chlorobenzilate is hazardous.
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From page 165... ...
. However, chlorobenzilate residues on citrus fruit and foliage may be a primary source of contact (i.e., dermal)
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From page 166... ...
Chlorobenzilate residues are assumed to be ingested by Floridians via the meat and meat by-products of Florida beef and lamb, and via milk from the cattle. The procedure recommended and used by the Committee to estimate probable exposure involves using an observed residue accumulation ratio to estimate chlorobenzilate residue levels in beef, lamb, and milk, instead of analytical sensitivity levels.
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From page 167... ...
, the Committee estimates that the steady-state residue of chlorobenzilate in animal fat from using treated citrus pulp in livestock feed is the accumulation ratio (0.04) x the concentration of chlorobenzilate in the diet (2.0 ppm in pulp x 16 lb of pulp .
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From page 168... ...
To determine incremental lifetime doses for the Florida population, the daily doses are multiplied by the assumed duration of exposure, discounting past exposures. Using the assumption that chlorobenzilate will remain on the market for an additional 10 years if rereg~stered (see Chapter 4)
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From page 169... ...
oPP's maximum-plausible estimates of chlorobenzilate ingestion by Floridians via milk were derived from limited data based on analytical sensitivity indicating that cattle consumption of treated feed may result in chlorobenzilate residues in milk from 0.0024 to 0.04 ppm (U.S.
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From page 170... ...
; however, the maximumplausible estimates assume an analytical sensitivity of 0.1 ppm, whereas the probable case uses the sensitivity of new analytical methods, 0.01 ppm. Justification for the use of analytical detection limits comes from a review of actual residue data.
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From page 171... ...
These workers found residues in pulp to be less than 0.1 ppm, using gas chromatography with a detection limit of 0.1 ppm. oPP therefore assumed that 0.1 ppm was a reasonable upper limit of actual chlorobenzilate residue levels that would pass undetected in edible portions of citrus (Severe 1978~.
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From page 173... ...
Calculations for chlorobenzilate ingestion via nuts are based on analytical detection limits and, for the probable case, a 10 percent residue frequency: Probable case (almonds) = 0.59 g/day x 6.8 (% crop treated)
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From page 174... ...
x 0.1 ppm residue = 0.0003 ,ug/day. The sum total of daily doses of chlorobenzilate received by the general U.S.
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From page 175... ...
This bias, however, should be kept in mind in interpreting the following analysis. ESTIMATION OF RISK UNDER VARIOUS REGULATORY OPTIONS By risk we mean the combined eject of the number of people exposed to pathogenic compounds, the levels of dosage received by those people, and the pathological activity of the compounds.
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From page 176... ...
This step is taken in the last subsection before the economic evaluation of benefits is undertaken. Lifetime Doses of Chlorobenzilate Both the length of exposure to chlorobenzilate and the intensity will vary with the various regulatory options.
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From page 177... ...
The resulting estimates of exposure to chlorobenzilate under the five options are presented in Table 7.6. The first column displays the daily doses, in millimoles per kilogram of body weight, that the Committee estimates to be most probable for members of three population groups under each of the five options.
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From page 178... ...
178 ~D C~ ao ~o U
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From page 179... ...
179 o o o o _ _ t_ _ X X X X cr .
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From page 180... ...
. In addition, some have argued that the failure to treat for rust mites could lead to significant losses in yield per acre (see Luttner 1977b)
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From page 181... ...
Their derivation is sketched below. Estimates of total lifetime incremental exposure to dicofol for the various regulatory options are then presented in Table 7.8.
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From page 182... ...
182 E 0, i_ o ~ .a Cat .d D ~ _ v, | D ~C, o 8 o o ·C~ o .~ A o Cd .e LL an D o US 8 ~ o ~ Pi o ~ U
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From page 183... ...
183 o ~_ o (5 ~ _o o _o oo o ..
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From page 186... ...
The range of assumed residues will diner, however. For the Florida population, dicofol residue levels in meat and meat by-products from Florida beef and lamb and milk from the cattle are calculated using the accumulation ratio procedure recommended for chlorobenzilate.
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From page 187... ...
are based on the assumed residue levels of chlorobenzilate in citrus and noncitrus products multiplied by a factor of 5. This factor is rationalized as was done previously when estimating dicofol residues in citrus pulp, i.e., the greater application rate of dicofol (2.4 x ~ times the greater persistence of dicofol residues (2-3 x)
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From page 188... ...
Translating Dicofol Lifetime Exposures into Chlorobenzilate Exposure Equivalents As noted earlier, to present the most useful information to a decision maker about the pesticide exposure for each affected population attendant to the various regulatory options, it is necessary not only to estimate exposure outcomes for the pesticide in question-in this case chlorobenzilate but also to incorporate exposure to alternatives into the estimate. This is accomplished here by translating the lifetime exposure from dicofol (Table 7.8)
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From page 189... ...
Application to Chlorobenzilate Reference Compounds The implications of lifetime exposures expressed in millimoles per kilogram of body weight are hard to perceive. To gain an appreciation of the ejects on public health of using chlorobenzilate it is, therefore, virtually essential to compare its carcinogenic potency and anticipated dose levels with those of other pesticides that have been considered extensively and have been subjected to regulatory decisions.
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From page 190... ...
. Most of this chlorobenzilate, approximately 920,000 lb, was applied to control the citrus rust mite on Florida and Texas oranges and grapefruit and the citrus bud mite on Arizona and California lemons.
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From page 191... ...
.....i ~I:;. :;:;:; -- : :-:-.-:-:-.-:-:;::;:-.;:-:-:;:;:-:-:-' Dicofol Chlorobenzilate FIGURE 7.1 CAN'T used in Chapter 7 calculations (see section on "Estimation of Risk Under Various Regulatory Options" in this chapter)
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From page 192... ...
Allen and Stamper (1979) examined the frequency distribution of citrus rust mite damage on citrus fruit and concluded that the effect of russetting was not serious until 50-75 percent of the surface was russetted.
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From page 193... ...
All of the above effects were attributed to increased water loss from scarred fruit. Irrigation of citrus groves with citrus rust mite infestation would alleviate some of the problems of water loss caused by severe russetting.
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From page 194... ...
194 o cn .
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From page 195... ...
However, for purposes of estimating this value, it is misleading to compare the yields and qualities of orchards treated with chlorobenzilate with those of orchards where no protective measures have been taken. Citrus rust and bud mites are perceived by most growers and citrus entomologists as major pests.
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From page 196... ...
stated that H thompsonii controls the citrus rust mites when mite populations reach high densities in July and August.
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From page 197... ...
pest control methods used on citrus; k denotes one of K spray mixtures containing chlorobenzilate (e.g., chlorobenzilate-sulfur) ; Aj and Ak denote acres treated per year by method j or k, respectively; Tj is the average number of treatments per year by method j, and Tk is defined similarly; MCj and MCk are material costs per acre-treatment; ACj and ACk are application costs per acretreatment; and lt denotes the change in the variable or expression that follows it that would be induced by cancelling the registration of chlorobenzilate for the specific use being analyzed.
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From page 198... ...
2. The J pest control methods that would be more widely used following a chlorobenzilate cancellation were identified in several ways.
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From page 199... ...
Specifically, for miticide treatments in Arizona, Florida, and Texas, it is assumed that I:j ~ Aj = Ilk Ak . The exception occurs in connection with California lemons: to account for the claim in the USDA-ATR that cancellation of chlorobenzilate would lead to an increase in the number of acres requiring treatment, oPP inferred that base acres treated would grow to 41,000 (after 5 years)
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From page 200... ...
The oPP estimates for the change in annual pest control costs that are likely to occur if chlorobenzilate is withdrawn are shown in Table 7.10. The total is $57.6 million.
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From page 201... ...
, and Texas citrus. Florida IPM Effects Currently, the most important Florida citrus pests are citrus rust mite, greasy-spot disease, and citrus snow scale.
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From page 202... ...
In fact, the Florida Citrus Spray and Dust Schedule 1977 (University of Florida 1977) recommends a summer application of ethion and oil, and expresses no concern that
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From page 203... ...
However, dicofol treatments can produce abnormally high populations of citrus snow scale (Brooks and Whitney 1977:431~. Consequently, the Florida Citrus Spray and Dust Schedule 1977 recommends that dicofol be combined with a scalicide for use in groves infested with citrus snow scale.
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From page 204... ...
. much of the lemon acreage in the citrus bud mite areas will receive one petroleum oil treatment a year for other pest control purposes." He further notes that "dependence upon petroleum oil sprays for the control of citrus bud mite would be expected to result in the mandatory use of one petroleum oil treatment each year in all bud-mite-infested properties and both a spring and a fall treatment in some localities or during some seasons." As a maximum-plausible case assumption, we accept oPP's assessment that all 41,000 acres would require one mandatory treatment with oil for bud-mite control and that 27,500 of those acres would require two treatments with oil (USDA 1977b)
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From page 205... ...
. This set of maximum-plausible case assumptions implies that loss of chlorobenzilate for bud-m~te control on California lemons would occasion increases in pest control costs equal to $870,000 ($910,000 for oil less the $40,000 currently spent on chlorobenzilate)
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From page 206... ...
206 Cal .~ Ct o .
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From page 207... ...
207 ~ So rid ~ ~ ~ I~ ° °° ~ ~ ° 1 1 _ ~ ~ ~ ~, , ~4 ~ oo I '')
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From page 208... ...
with any one of the chlorobenzilate mixes is taken from the Doane report. Table 7.13 presents information on base acres treated annually with chlorobenzilate, by state and type of citrus.
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From page 209... ...
in the Doane miticide report appear to be unreliable (Luttner 1977a:48~. Consequently, for chlorobenzilate and the major alternatives, we derive independent estimates of MC using information on product prices and application rates recommended in the state citrus guides.5 For the various spray mixtures and a few of the alternatives, we accept the MC estimates used by oPP.
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From page 210... ...
. set of assumptions selected, we estimate the increase in pest control costs following loss of chlorobenzilate to be somewhere between $2.4 million and $9.2 million (the range represents a 90 percent confidence interval; see Appendix F)
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From page 211... ...
As suggested in Chapter 5, conventional benefit-cost analysis defines the benefit of continued Chlorobenzilate use as the sum of (1) the value of productive resources saved due to its use and (2)
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From page 213... ...
213 o 6~ o o _ so He o o _ ~ o o He 69 ._ ~ Ho fig o o cr o To o 6~ o 6~ o 69 lo o 69 o 6~ 1 ~ ~ ~ 8 ~ ·= =~]
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From page 214... ...
As a result of the obvious uncertainty about the actual magnitude of the price elasticities of demand for the various types of citrus and citrus products, the subsequent analysis evaluates (with two exceptions) the efficiency and distributional implications of chlorobenzilate use under the alternative assumptions that the price elasticities of demand equal either 0.7 or -2.5.
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From page 215... ...
Note that our estimates are substantially lower than oPP's; virtually the entire difference arises from our differing appraisals of the eject of disallowing chlorobenzilate on the cost of IPM. The estimates in these tables that correspond to the zero-elasticity-ofsupply case are identical to the estimated maximum-plausible increases in pest control costs following a loss of chlorobenzilate.
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From page 216... ...
. If shortrun citrus supply is responsive to changes in price and variable production costs, then disallowing chlorobenzilate would lead to slightly higher prices (around 1 - cents per box in most cases)
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From page 217... ...
. These changes have the eject of transferring some of the increased pest control costs from users of chlorobenzilate to consumers.
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From page 218... ...
and the reduction in risk that can be anticipated from a number of regulatory options. As mentioned in the risk section of this chapter, five options are being considered.
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From page 219... ...
Under Maximum-Plausible-Case Assumptions: Florida Lemons OPP Estimate: -$432,000 Committee Estimates Alternative Demand Conditions Alternative Supply Conditions E&= - ~Es=0 Es=O.S Users -$95,000 -$94,000 Nonusers O O Consumers O O Net effect -$95,000 -$94,000 Note: En is demand elasticity; ES is supply elasticity.
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From page 220... ...
220 REGULATING PESTICIDES TABLE 7.22 Alternative Estimates of Forgone Benefits Under Maximum-Plausible-Case Assumptions: Florida and Texas Grapefruit OPP Estimate: -$9,081,000 Committee Estimates Alternative Demand Conditions Ed - -07 Users Nonusers Consumers Net effect Ed = -2.5 Users Nonusers Consumers Es =o -$1,942,000 o To -$ 1,942,000 -$1,942,000 o o Alternative Supply Conditions ES = 0 5 -$ 1,401,000 + 300,000 835,000 -$ 1,936,000 -$1,724,000 + 128,000 334,000 Net effect -$ 1,942,000 -$ 1,930,000 Note: Ed is demand elasticity; Es is supply elasticity. TABLE 7.23 Alternative Estimates of Forgone Benefits Under Maximum-Plausible-Case Assumptions: Texas Oranges OPP Estimate: -$230,000 Committee Estimates Alternative Demand Conditions Ed= _ ~ Users Nonusers Consumers Net effect Es =o -$ 160,000 o o -$ 160,000 Alternative Supply Conditions ES = 0 5 -$159,000 o o -$ 159,000 Note: Ed is demand elasticity; ES is supply elasticity.
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From page 221... ...
Application to Chlorobenzilate TABLE 7.24 Alternative Estimates of Forgone Benefits Under Maximum-Plausible-Case Assumptions: All Citrus OPP Estimate: -$57,629,000 Committee Estimates Alternative Demand Conditions Alternative Supply Conditions Ed= -0.7Or- ~Es=0 Es=0.5 Users-$9,200,000 -$6,869,000 Nonusers0 + 1,397,000 Consumers0 - 3,696,000 Net effect-$9,200,000 -$9,168,000 Ed= -2.5Or- ~ Users-$9,200,000 -$8,310,000 Nonusers0 + 465,000 Consumers0 - 1,308,000 Net effect-$9,200,000 -$9,153,000 Note: Ed is demand elasticity; ES is supply elasticity. TABLE 7.25 Farm Size Distribution: California and Florida Oranges 221 Size Category 0.1 -24.9 25-49.9 Acres Acres 50-99.9 100 or Acres More Acres Percentage of total state orange production attributable to each category California 15.4 16.7 21.2 46.7 Florida 6.7 7.1 9.0 77.2 Average annual sales per farm California $12,000 $40,500 $82,200 $305,200 Florida - $ 7,600 $20,700 $43,300 $336,000 Source: All estimates based on data from U.S.
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From page 222... ...
Thus, the Committee has chosen not to treat this potential option separately from the option that would cancel the uses of chlorobenzilate in all states. The PD 3 also lists as a regulatory option the prohibition of chlorobenzilate-treated citrus pulp as cattle feed (oPP's Option G)
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From page 223... ...
As one moves across Table 7.26 from Option A to Option E, the costs, or value of forgone benefits, increase. The probable lifetime doses decrease for all population groups, or at least do not increase, as one moves from continuing registration to increasingly stringent regulations.
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From page 224... ...
224 ·4= e~ oo o .~ .> (4o U, o o U
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From page 225... ...
225 1 0 1 _ o x ^ ~ o o ~ o o 1 1 o o _ ~ X X _ o ~4 ~ o o 1 1 o o _ _ X X oo _ ~ o o 1 1 o o _ _ X X oo _ .
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From page 226... ...
FIGURE 7.2 Equivalent probable lifetime doses for the Florida and U.S. populations and ranges of discounted costs under five options for regulating chlorobenzilate; heptachlor comparison shown (see text for discussion)
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From page 227... ...
FIGURE 7.3 Equivalent probable lifetime doses for citrus ground applicators (700) and ranges of discounted costs under five options for regulating chlorobenzilate; Heptachlor comparison shown (see text for discussion)
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From page 228... ...
FIGURE 7.4 Equivalent maximum-plausible lifetime doses for the Florida and U.S. populations and ranges of discounted costs under five options for regulating chloroben~late; heptachlor comparison shown (see text for discussion)
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From page 229... ...
FIGURE 7.5 Equivalent maximum-plausible lifetime doses for citrus ground applicators (700) and ranges of discounted costs under five options for regulating Chlorobenzilate Heptachlor comparison shown (see text for discussion)
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From page 230... ...
. On the other hand, if we turn to Figure 7.3, it can be seen that citrus ground applicators are expected to receive nearly 4 times the mean chlorobenzilate equivalent of heptachlor cutoff for the general U.S.
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From page 231... ...
Citrus ground applicators, on the other hand, may plausibly be exposed to doses greater than the mean chlorobenzilate equivalent of heptachlor under any of the options (Figure 7.5~. The excess is smallest under Option E, which requires immediate cancellation of chlorobenzilate use on citrus.
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From page 232... ...
Therefore, the Preliminary Benefit Analysis of Chlorobenzilate (Luttner 1977a) was an EPA product to which the USDA reacted by producing a USDA assessment team report (USDA 1977b)
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From page 233... ...
(1979) The effects of citrus rust mite damage on citrus fruit growth.
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From page 234... ...
Chlorobenzilate Residues in Sheep and Cattle Tissues. Report submitted by Geigy Research Analytical Department to Office of Pesticide Programs, U.S.
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From page 235... ...
(1976) Chlorobenzilate Residues in Selected Citrus Products in the Washington Metropolitan Area, Fall 1966.
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From page 236... ...
Chlorobenzilate: Position Document 4. Special Pesticide Review Division, Office of Pesticide Programs, U.S.
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From page 237... ...
Wasserloslichkeit van insektiziden chlorierten kohlenwasserstoffen und polychlorierten biphenylen im hinblick auf eine gewasserbelastung mit diesen stoffen. Zeitschrift fuer Wasser und Abwasser Forschung 7: 169-175.
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