The Food Quality Protection Act exploded on the pesticide regulatory process in August of 1996 with nary an objector's whimper. Finally the dust has settled, and analyses of the impact have been blooming like weeds following nearly a year of mind-numbing acceptance. And like thistles on a lawn, the picture is not pretty. Activists have been mobilizing on both sides of the pesticide divide. The first salvo came in February with the Environmental Working Group report about overexposure of kids to organophosphate (OP) insecticides. More quietly, but ever hopeful for a grass roots protest, the American Crop Protection Association has been circulating an informational packet intended to educate growers, commodity organizations, and congressional members about potentially adverse impacts on farming if FQPA is implemented according to current EPA proposals. Ironically, the ACPA supported the FQPA because it rescinded the Delaney Amendment, long a thorn in its side. Of course, law making is usually a compromise, and growers will reap the harvest of a regulatory process that now establishes health concerns rather than production as the chief arbiter of pesticide regulation.
Pesticide Police Powers
It's time for me to add fertilizer to the field, with another analysis of the potential for the FQPA to affect pesticide availability. EPA has two methods for controlling pesticide use and availability. The agency can refuse to grant a registration or suspend one if health risks are deemed greater than negligible. Negligible has no scientific, objective definition, but lawyers and policy makers like to think of it as no greater than a one in a million chance of adverse impact in the population. Another way to express this is to consider exposure to a carcinogenic substance. Negligible risk would be incurred if no more than one person out of a million contracted cancer as a result of exposure to the regulated substance.
The EPA may also restrict pesticides by lowering the residue tolerances. Tolerances are not safety standards, but they are set by considering potential exposure relative to the Reference Dose (RfD). For a chronic health hazard (for example, cancer), the RfD is the level of exposure to a specific pesticide that a person could receive every day over a 70-year period without experiencing appreciable risk. For an acute exposure risk, (for example worker poisoning or effects on a fetus), the RfD represents exposure in one day without significant risk.
FQPA Is A New Weapon in the Pesticide Wars
Prior to the FQPA, EPA could decide about registration eligibility and tolerance setting by considering a pesticide's potential benefits to production of food or protection of public health. FQPA allows no such consideration for pesticides that are noncarcinogenic (now called threshold pesticides) and very restricted considerations of benefits for carcinogenic pesticides (now called nonthreshold pesticides).
Under the FQPA, EPA must reassess tolerances for all pesticide residues in raw and processed foods. While the reregistration process where tolerances are reassessed has always been a part of modern law, EPA will prioritize reassessments to pesticides presenting risk concerns based on existing data. The FQPA now tells EPA what risk aspects need consideration:
While minor crops represent a minor proportion of total pesticide use compared to the vast acreage of major crops like corn, soybeans, wheat, and cotton, they represent a major source of dietary exposure to residues. Minor crops are more likely to have insecticide and fungicide residues because of a combination of pest complexes, consumer disdain for blemished produce, and the need to treat closer to the time of harvest. Fruits and vegetables rely heavily on OP insecticides for pest control. These have been targeted for cumulative exposure assessments because they all affect the nervous system by inhibiting the enzyme acetylcholinesterase. Because EPA has declared dietary exposure as representing 80% of the daily exposure to residues, pesticide use on minor crops will be the most influential factor governing new exposure assessments under FQPA.
Minor crops will also suffer under FQPA exposure assessments when pesticide use includes the few products that have both significant residential and agricultural uses. Because residential exposure of children is more important under the aggregate exposure assessment guidelines, tolerances may need to be lowered so that the sum of all exposure risks does not exceed the RfD.
Throwing a Bone to Minor Crops
The FQPA does have provisions that on the surface seem to take into account problems of minor crops and pesticide registrations. EPA's Implementation Plan for the FQPA recognizes that minor crop registrations produce smaller revenues for pesticide registrants than do major uses. Understandably, registrants may be reluctant to support and maintain registrations and associated tolerances for minor crops. EPA states "minor crops are very important to a healthy diet," and "minor uses are worth preserving because they are of major significance in agricultural production and public health protection." The FQPA provides the following incentives for supporting minor uses and developing new ones:
While FQPA intentions are good, EPA cannot make economic decisions for pesticide manufacturers. Marketplace realities, rather than well-meaning incentives, will likely be the final word on minor crop registrations. The situation is particularly worrisome for pesticides having substantial uses in major crops, minor crops, and residences. If push comes to shove, how can chlorpyrifos use on about 334,000 acres of apples compete with use on about 6.8 million acres of corn, when most dietary exposure would come from apples?
Test Driving FQPA
Perhaps the best way to illustrate potential FQPA impacts on pesticide use and availability in minor crops is to determine which pesticides pose greater than desired risks as defined by the new law. Apples make a good test track because they are major players among minor crops, they represent a significant proportion of dietary exposure to children (fresh apples, applesauce, apple juice), and they rely heavily on the OP insecticides subject to aggregate and cumulative exposure assessment . I've assigned the pesticides registered for use on apples to one of three categories of FQPA concerns - OP or carbamate (CB) insecticide, carcinogen (C), and endocrine disruptor (ECD). For each major category of pesticide use (i.e., insecticide, fungicide, herbicide, and plant growth regulator), I've listed in descending order the percentage of planted acres treated with a registered active ingredient and the reason for FQPA targeting (Tables 1-4). To further the perspective of the relative importance of the targeted and nontargeted chemicals, I've also calculated percentages of total apple pesticides used and the percentage used by use category.
|Active Ingredient||% of Planted Acres 2||% of Total Pesticides Applied||% of Total Insecticides Applied||FQPA Priority |
1 Amounts used based on the USGS database developed
for the Pesticide National Synthesis Project
(http://watr.wr.usgs.gov/pnsp/crop/), which was updated July, 1997
2 Total apple acreage planted was 497,903 (Gianessi,
L. P, 1997, National Center for Food
Agricultural Policy, Wash., DC.)
3 FQPA risk prioritization: OP= organophosphate;
CB = carbamate; C = carcinogen
(based on EPA revised list,1997); ECD = endocrine disruptor (based on Keith, L. 1998)
Insecticides account for 65% and fungicides 9% of all pesticide usage on apples (Table 1 and 2). The FQPA will most closely scrutinize insecticides. Of the 24 insecticides covered in the U.S. Geological Survey pesticide usage database, 17 are targeted. Six chemicals are targeted because they are endocrine disruptors in addition to being an OP, CB, or C. Carbaryl, listed separately in Table 4 because of its extensive use as a blossom thinner rather than as an apple insecticide, is marked as a CB, C, and ECD. Of the 22 fungicides and 13 herbicides listed (Table 2 and 3), 12 are listed as carcinogens. Five of these are also tagged as endocrine disruptors.
|Active Ingredient||% of Planted Acres||% of Total Pesticides Applied||% of Total Fungicides Applied||FQPA Priority Concerns|
|Active Ingredient||% of Planted Acres||% of Total Pesticides Applied||% of Total Herbicides Applied||FQPA Priority Concerns|
|Active Ingredient||% of Planted Acres||% of Total Pesticides Applied||% of Total Plant Growth Regulators Applied||FQPA Priority Concerns|
|Active Ingredient||Formulations||Active Ingredient||Formulations|
|azadirachtin||Azatin,Neemazad, Trilogy||Ampelomyces quisqualis||AQ-10|
|Bacillus thuriengiensis (B.t.)||Biobit, Cutlass, Foray, Dipel||calcium polysulfide||Lime Sulfur|
|Beauveria bassiana||Botanigard, Mycotrol||copper hydroxide||Kocide, Blue Shield, Nu Cop|
|codling moth sex pheromone||Isomate-C||copper metallic||Cooke Kop-R-Spray|
|delta endotoxin (B.t.)||MVP Bioinsecticide||copper sulfate||Basic Copper|
|garlic oil/powder||Envirepel, Guardian, Y-Guard||sulfur||Ben-Sul, Cavalry, Flotox, Shield-Brite, Thiolux|
|oil/petroleum distillates||Clean Crop, Stylet, Sunspray||Herbicides|
|potassium oleate||Natural Guard||Plant Growth Regulators|
|Pseudomonas fluorescens||Mattch, Blightban||cytokinin||WFS Cascade|
|pyrethrins||Py-Rin||gibberellic acid||Accel, Promalin|
|rotenone||Natural Guard, Pyrelin||hydroxypropionic acid||Propel|
Ironically, apple growers use a lot of certified organic pesticides - 52% of total pounds used includes different types of oils and sulfur. The use in pounds of these two products is so great that it obscures the importance of the other compounds. For example, azinphos-methyl (Guthion) accounts for 3% of total pounds of apple pesticides, but it is applied to 86% of the acres. Such widespread use indicates that growers rely heavily on this product, largely for codling moth control, because alternatives are considered less effective. Loss of azinphos-methyl, chlorpyrifos, phosmet, and methyl parathion would have adverse impacts on growers not only because of heavy reliance. These chemicals are not necessarily substitutes for each other; each has a particular spectrum of pests that it controls best. Furthermore, with so many insecticides considered prioritized risks, few alternatives exist should the organophosphate registrations be dropped.
While sulfur dominates pounds of fungicides used, captan, labeled by EPA as a carcinogen, is used on more than 50% of the acreage. Mancozeb, listed as a carcinogen and believed to be an endocrine disruptor, is used on 42% of the acreage. Loss of these two compounds would mean even greater reliance on sulfur, myclobutanil, fenarimol, or others, but the spectrum of diseases controlled is not necessarily the same. Thus, for fungicides even more so than insecticides, one chemical does not automatically substitute for another. Furthermore, University of California researchers have ranked sulfur as the biggest health problem for workers, probably because of the ability of sulfur to cause dermal irritation.
Light at the End of the Tunnel?
If, in fact, the apple industry faces loss of its most important insecticides, the EPA Implementation Plan does promote new ideas for lowering the risk to maintain use. One suggestion is to limit uses to targeted applications only in conjunction with an integrated pest management (IPM) program. This idea is probably of little comfort, considering that most Washington apple growers already use some form of pest scouting and economic thresholds, the mainstays of IPM. Another possibility is limiting the number of applications that can be made within certain time intervals, either seasonally and annually. However, if the alternative products are less effective against the most serious pests, growers will suffer the effects of reduced marketing quality.
FQPA recognizes the importance of safer or "reduced-risk" pesticides, and EPA has supported expedited review of these pesticides so that they can quickly replace older, riskier chemicals. Of the 12 new conventional compounds EPA registered during 1997, only four were considered "reduced risk." None was labeled for apples. Biological pesticides derived from microorganisms or plant extracts would likely fall into the reduced risk category. Sixteen new active ingredients were registered during 1997, but only AVG, a plant growth regulator, was registered on apples.
Thus far, currently registered synthetic pesticides have not been judged as "reduced risk." However, any currently registered pesticide that is also certified for organic production, can be considered "reduced risk". Thus, a number of "reduced risk" pesticides are already labeled for apples (Table 5). Whether any of these will substitute for currently registered conventional products has to be assessed on a case-by-case basis. The big question is one of availability. Can enough pyrethrins, for example, be manufactured to address minor crop needs? Ironically, pyrethrins themselves have a minor problem. They work adequately under field conditions only when synergized with piperonyl butoxide (PBO). Athough essentially non-toxic to insects, PBO has been labeled a carcinogen by EPA.
Cross Your Fingers
Despite the above analysis, I cannot predict what will happen to the availability of FQPA "risky" pesticides once they go through the tolerance reassessment process. Perhaps nothing, or perhaps we won't use organophosphates any more. I am sure of one thing: American industry has always risen to the challenge of providing us with the tools we need. After all, isn't necessity the mother of invention? Perhaps. But in a global economy, where regulatory perspectives differ from those in the United States, mother demands a profit.
Return to title page April 1998 Agrichemical and Environmental News