Open Forum:
In an attempt to promote open discussion of issues, The Agrichemical and Environmental
News encourages letters and articles with differing views. To include an article, contact:
Catherine Daniels, Food and Environmental Quality Laboratory, Washington State University, Tri-Cities campus, 2710 University Drive, Richland, WA 99352-1671. Phone: 509-372-7495. Fax: 509-372-7491.
E-mail:
cdaniels@tricity.wsu.edu.
Lugar, chairman of the Senate Agriculture Committee, said the Delaney Clause "diminishes global competitiveness of U.S. agriculture. Significant data indicate that the pesticides impacted by Delaney do not pose an unacceptable risk to public health."
The Delaney Clause, which sets a zero tolerance for carcinogens in the food supply, would be replaced by a "negligible risk" standard.
Lugar's bill would ease the regulatory burden on "minor-use" pesticides used on fruits and vegetables. Lugar has folded an earlier bill, The Minor Use Crop Protection Act, into the new bill.
The bill also directs the USDA and the FDA to place special emphasis on
protecting infants and children when assessing the safety of pesticides. This
change stems from recommendations by the National Academy of Sciences. Lugar's
bill is similar to legislation on food safety being considered now by the U.S.
House of Representatives.
Speakers at the workshop will include Lynn Goldman, EPA Assistant Administrator for Pesticides, Karl Stauber, USDA Undersecretary for Research, Education and Economics, and Richard Rominger, USDA Deputy Secretary.
The workshop, the premiere biopesticide event expected within the next
12 months, is scheduled for November 7 and 8 in Washington, D.C.
For more information, contact Christina Hartman, Biopesticide Manager,
IR-4 Project at 908-932-9575. Attendance is limited to 200. Anyone
interested in registration of biopesticides is urged to attend.
In other action, the agency exempted from tolerance cotton genetically
modified to express Bt toxins.
The first day will concentrate on how to obtain a Section 18 emergency exemption. As part of this session, Andrea Beard, from EPA's Emergency Response Section (the group at EPA that manages Section 18s) will teach participants how to develop a Section 18 exemption to pass EPA scrutiny.
The second day will focus on how to obtain a Section 24(c) Special Local Need registration. A session will be conducted by Alan Schreiber on how to obtain support from Washington State University, the IR-4 Project and the Washington Commission on Pesticide Registration.
The workshop will be in the Natural Resources Building, First Floor,
Room 175. To attend the workshop, contact Robin Schoen-Nessa at
360-902-2027 or Michele Hauff at 509-575-2595.
WPPCA Plastic Pesticide Container Recycling Program
October 1995 Collection Sites
| Date/Time | Location | Sponsor and Contact |
| 10/16 8-11 | Waterville | Western Farm Service John Massey, ph: (509) 924-9213 |
| 10/16 1-4 | Mansfield | Western Farm Service |
| 10/17 8-11 | Almira | Western Farm Service John Massey, ph: (509) 924-9213 |
| 10/17 1-4 | Coulee City | Western Farm Service |
| 10/18 8-11 | Harrington | Western Farm Service John Massey, ph: (509) 924-9213 |
| 10/18 1-4 | Davenport | Western Farm Service |
| 10/19 8-11 | Reardon | Western Farm Service John Massey, ph: (509) 924-9213 |
| 10/19 1-4 | Rosalia | Western Farm Service |
| 10/20 8-11 | Latah | Western Farm Service John Massey, ph: (509) 924-9213 |
| 10/20 1-4 | St. John | Western Farm Service |
The Washington Pest Consultants Association recycles plastic pesticide containers. Listed above are recycling dates and locations for the month of October. Consult the AENews for future collection sites or contact WPCA representative Steve George at (509) 457-3850.
**Containers not meeting above specifications cannot and will not be accepted.
If you or your organization have an interest in sponsoring a recycling event this year, please
contact: Steve George at (509) 457-3850 or Gary Pelter at (509) 754-2011.
Return to Table of Contents
Pesticide residues in U.S. food
Note: A violative residue is a
residue that exceeds a tolerance, or a residue at a level of
regulatory significance for which no tolerance has been
established in the sampled food.
The Food and Drug Adminstration released results recently from its 8th
annual pesticide residue monitoring survey on domestically produced and
imported foods. In 1994, FDA analyzed 11,348 food samples from the U.S.
and from 101 other countries. Of these samples, 10,814 were surveillance
samples, meaning that they were collected when there was no evidence that
the food might contain illegal residues. Survey results, according to the
FDA, confirm what seven previous surveys have indicated: frequency of
violative levels of pesticide residues in the U.S. food supply is small,
and the safety of the food supply relative to pesticide residues is intact.
A total of 783 types of food items were sampled in 1994, with the FDA devoting greater effort than ever before to sampling foods eaten frequently by infants and children. These foods include bananas, carrots, fruit juices, green beans, oranges and peaches.
Of nearly 300 pesticides tested for, 74 different pesticides or metabolites were detected in food samples. No pesticide residues were found in 63% of 5,366 domestic food samples. Fewer than 1% of domestic food samples had residues of a pesticide for which there was no established tolerance. Of the 5,448 import surveillance samples, 67% had no detectable residues. About 3% of imported food samples had residues for which there was no tolerance.
Of the import samples, 11 or more were taken from the imports of 48 countries, while 10 or fewer were taken from the imports of 53 others. Countries with the greatest number of samples were those exporting the most food to the U.S. Following are the ten countries having the greatest number of samples tested: Mexico (1518), Chile (499), Guatemala (318), The Netherlands (284), Italy (283), China (258), Canada (253), Thailand (190), Costa Rica (176) and Spain (135). These samples accounted for 72% of all import samples. The remainder came from less obvious exporters, including Cayman Islands, Faeroe Islands, Fiji, Nepal, Singapore, Tonga and Vietnam.
Insecticides were the most commonly detected group of pesticides. The 10 most commonly detected pesticides in U.S. food were malathion (19%), chlorpyrifos-methyl (Lorsban metabolite) (16%), DDE (DDT metabolite) (15%), chlorpyrifos (Lorsban) (12%), endosulfan (Thiodan) (11%), dieldrin (7%), chlorpropham (Sprout Nip) (6%), methamidophos (Monitor) (5%) and diazinon (5%). The number in parethenses is the percentage of detections of each pesticide within the total number of detections.
State survey programs provided data that ranged from five samples from Delaware to 2,340 samples from Florida and 4,756 samples from California. Most states provided between 200 and 800 samples. California and Hawaii had the highest percentage of violative or "unusual" reports. Arkansas, Indiana and Minnesota reported no violative residues.
A number of domestically produced foods had no reported violative pesticide residues. These foods included corn, corn products, rice, rice products, soybeans, eggs, shellfish, blueberries, cranberries, grapes, raspberries, pears, apricots, cherries, peaches, all melons, all fruit juices, asparagus, broccoli, cauliflower, celery, potato, radish, dried vegetables, peanuts, vegetable oil, honey and all baby foods.
Food items without any pesticide residues included asparagus, cauliflower, mushrooms, hazelnuts, vegetable oil and honey. A few domestically produced food items had relatively high levels of violative pesticide residues. For okra, 25% of samples (n=12) had residues for pesticides for which no tolerance had been established. A number of leafy green vegetables (collards, romaine lettuce, spinach and others) and red beets had similar problems, although the percentage of violative residues was in the 5% to 13% range.
Imported foods without violative pesticide residues included rice and rice products, bakery products, pasta, cheese and milk products, fish, limes, oranges, apples, apricots, avocados, cherries, plums, all fruit juices, pumpkins, bamboo shoots, broccoli, cabbage, cauliflower, kale, lettuce, mushrooms, potatoes, vegetable oil and chocolate. Food items without pesticide residues of any kind included plantains, bamboo shoots and water chestnuts.
Several imported food items had relatively high levels of violative pesticide
residues. These foods included wheat, grains other than wheat or rice,
blackberries, berries other than blackberries, blueberries, raspberries and
strawberries, pears, peas, string beans, spinach and nuts other than cashews.
| Relative percentage of pesticide residues detected in domestic and imported foods for which no pesticide tolerances have been established. Only crops with 5% or more of samples having pesticide residues for which no tolerance has been established are included. | |||
| Food | #samples | %violative | source |
| oats | 49 | 7 | domestic |
| eggplant | 22 | 5 | domestic |
| okra | 12 | 25 | domestic |
| romaine | 67 | 5 | domestic |
| spinach | 37 | 8 | domestic |
| misc. veg | 30 | 13 | domestic |
| red beets | 12 | 8 | domestic |
| wheat | 27 | 7 | imported |
| other grains | 28 | 11 | imported |
| blackberries | 68 | 13 | imported |
| strawberries | 84 | 14 | imported |
| misc. berries | 12 | 42 | imported |
| pears | 104 | 16 | imported |
| kiwi fruit | 21 | 5 | imported |
| watermelon | 29 | 7 | imported |
| misc. fruits | 17 | 6 | imported |
| peas | 97 | 10 | imported |
| string beans | 88 | 13 | imported |
| eggplant | 30 | 7 | imported |
| okra | 53 | 7 | imported |
| peppers, hot | 223 | 8 | imported |
| peppers, sweet | 223 | 8 | imported |
| misc. vegs. | 28 | 7 | imported |
| celery | 14 | 7 | imported |
| endive | 74 | 5 | imported |
| spinach | 24 | 13 | imported |
| other leafy vegs. | 44 | 14 | imported |
| spices | 20 | 5 | imported |
| other nuts | 39 | 8 | imported |
| honey | 76 | 5 | imported |
| other foods | 62 | 8 | imported |
Available Reports
Adoption of Integrated Pest Management in U.S. Agriculture.USDA, ERS, Agriculture Information
Bulletin Number 707. September 1994.
Chronological Landmarks in American Agriculture.USDA, ERS, Agriculture Information Bulletin Service Number 425. November 1990.
Methyl Bromide: Risks, Benefits and Current Status in Pest Control. Ragsdale and Wheeler. Rev. Pestic. Toxicol., Vol. 3, Pages 21-44 (R.M. Roe and R.J. Kuhr, Eds) Toxicology Communications Inc., Raleigh, NC. 1995.
How to Obtain Information from OPP.Pesticide Regulation (PR) Notice 94-3. USEPA. June 1994.
IR-4 Newsletter, IR-4 Reports.IR-4. IR-4 Project, NJ AES, New Brunswick, NJ.
September 1995.
Return to Table of Contents
Land apply materials when possible Contaminated wastewater, soils or sediments can be applied on land, provided they meet certain criteria. If the material is to be used as pesticide product, it can be applied legally only to a treatment site specified on the pesticide label. If it is simply non-dangerous waste one wishes to dispose of, approval for land application of the wasteshould be obtained from the county health district. Caution should be practiced before applying these materials. Applications are often scrutinized by neighbors, owners of land where treatment occurred and commodity buyers concerned about crop residues. Records should be kept of any applications of contaminated residuals. These records should note the ingredients, quantity and field locations of these applications _ just as one would document any other pesticide application.
On-site waste treatment & disposal Choosing methods for waste treatment or disposal requires caution. Although some processes have proven effective, on-site treatment may require hazardous waste treatment permits. On the other hand, certain wastes, usually within closed tanks or containers, may be treated on-site without special permits.
The Department of Ecology (Ecology) strongly encourages on-site Treatment-By-Generator (TBG). Ecology published TBG guidance to provide facilities more flexibility in their waste treatment options without requiring case-by-case department approval. Before planning a treatment, one should ask for TBG guidance from the local Ecology regional office.
Remediating contaminated soils Owners of contaminated sites should clean up their property themselves if possible, without involving Ecology. If an owner decides to conduct an independent cleanup action, Ecology can provide general technical advice before or at any time during the cleanup action. Ecology also has many guidance documents about how to conduct an independent cleanup.
Sites best suited to independent cleanup are those where the extent of contamination is well defined, confined to soil (i.e. not involving groundwater) and the cleanup method is commonly used. For more complex sites, consider involving an environmental consultant. When an independent cleanup action has been completed, it must be reported to Ecology.
Under the Independent Remedial Action Program (IRAP), Ecology can provide property owners with a timely review of independent cleanup reports and a written determination of "no further action needed". This strictly voluntary program (there is a fee for the formal review) can be beneficial to persons who require a bank loan or who wish to sell their property. The agri-chemical industry can benefit also from this IRAP. As more cost-effective agri-chemical cleanup methods are proven through this program, more practical options will become available for industry wide use.
More Information
Details about site cleanup under the Independent Remedial Action Program
may be obtained by inquiring into the Toxics Cleanup Program at a local
Ecology regional office. Information about hazardous waste designation
and Treatment-By-Generator may be obtained at a local Ecology regional
office from a representative of the Hazardous Waste and Toxics Reduction
Program.
Department of Ecology
Regional Offices
Central Regional Office, Yakima (TDD) (509) 454-7673
Eastern Regional Office, Spokane (TDD) (509) 458-2055
Northwest Regional Office, Bellevue (TDD) (206) 649-4259
Southwest Regional Office, Olympia (TDD) (360) 407-6306
Return to Table of Contents
Inside an analytical lab
...Carol Weisskopf
Regular readers of my contributions may recall the statement that
operation of an analytical laboratory was occasionally similar to being
a car mechanic. The past weeks have proven this similarity with a vengeance.
Some instrumentation in the Food and Environmental Quality Lab had
experienced little previous use, and as we became familiar with
operation and maintenance we anticipated some difficulties. Last month
it seemed that everything that could go wrong did go wrong all at once.
It was like owning a very expensive sports car that looked nice in the
garage but couldn't be taken out on the road.
Our most persistent problem has been with a vacuum pump on our GC-HPLC-mass spectrometer. This large (and at 80 pounds fairly heavy) pump has been problematic since our arrival. We spent several days rebuilding the pump (twice). It makes rebuilding carburetors look simple. As this did not solve the problem, we traded it in for a replacement. During Murphy's Law week, this replacement pump went down in a shower of sparks and a frenzy of rocking.
During this same week, only one of eight GC detectors was fully operational. Two others were marginal. Our liquid scintillation counter (for measurement of concentrations of radioactive material) blew a circuit board. We were also trying to track down an apparent air leak in our other GC-mass spectrometer. At one point, nearly all of our equipment was non-functional for one reason or another. Sometimes, the smartest move is to close the garage door and go home early.
Most of our problems could be attributed to two factors: whenever new equipment is brought into service minor problems are to be expected, and power supply to the instrumentation was inadequate. Since all of the instrumentation is new, the only unusual aspect was the time frame in which the problems occurred. Most were truly small matters that only became frustrating in aggregate. As far as our power was concerned, we started tripping circuit breakers as more instrumentation became operational . We had the instrumentation area rewired, and increased the number of circuits from 8 to 20. This work required the instrumentation to all be shut down twice - once to determine the current circuitry and once when the rewiring took place. Findings from this experience are: THERE IS NO SUCH THING AS TOO MANY CIRCUITS, and EQUIPMENT DOESN'T LIKE TO BE TURNED OFF.
At this point, we seem to have a happy shop. Nearly everything is now
working very well, and my goal is to have every piece of equipment
operational at the same time at least once this month. In any laboratory,
this accomplishment would be relatively rare as there is usually something
that needs a little work. So, at the moment the sports car is running
pretty well. As the driver, I can report that it's dynamite at road
handling, and the view is great.
Return to Table of Contents
...Alan Schreiber
Based on my interpretation of the 8th annual report by the Food and Drug Adminstration on pesticide residues, there is some good news and some bad news for American agriculture.
The good news is that once again the FDA has taken the position, which is backed up by an impressive monitoring program, that our food supply is safe relative to pesticide residues. For the majority of domestically produced and imported food, there were no detectable pesticide residues. Very few food items contained residues over tolerance. The mere presence of a violative residue is not automatically considered a health concern.
The bad news is that the rate of violative pesticide residues for imported foods is more than 300% higher than for foods produced domestically. The specific problem is that foreign growers, in their production of food for U.S. import, use pesticides unavailable to U.S. growers.
For example, while none of the 53 samples of pears produced in the U.S. had violative residues, 16% of the samples of imported pears were illegally treated with pesticides that could not be used in the U.S. The rate of detection for such violative residues on imported wheat was seven times greater than for domestically produced wheat.
From the table on page 5 of this issue, it is obvious that, despite a similar number of samples from domestic foods (5,366) and imported foods (5,448), imported foods were much more likely than domestic foods to be illegally treated with pesticides that U.S. growers cannot use.
EPA will allow pesticides not registered in the U.S. to be present on imported food in certain situations after an import tolerance has been established. However, in many cases foreign growers are not following EPA requirements for establishment of import tolerances.
Use of pesticides unavailable to U.S. growers can place American growers at a competitive disadvantage. This is seen particularly with Mexico, which is considered the worst offender. The widespread use in Mexico of illegal pesticides on food products imported to the U.S. has become so bad that it is becoming a major trade irritant.
The appropriate response to these illegal practices by foreign producers is three-fold. First, enforcement actions should be taken against countries with a history of high rates of violations. Second, the process of obtaining import tolerances should be streamlined. Third, and most important, in cases where a pesticide is being used legally on an imported crop and the same crop is raised domestically, EPA should allow use of registration data from the importing country. This would hasten registration of the pesticides in the U.S. Of course, data should be accepted only from countries with credible registration processes such as exist in Canada and Europe.
These three steps would result in a level playing field for all growers.
...Alan Schreiber
Selling pesticides is big business. Global sales by major manufacturers
in 1995 are estimated to be $25 billion, or more than double 1980 sales
of $12 billion. Little increase in agricultural chemical sales is
projected; by the year 2000, global pesticide sales are expected to total
$28 billion.
Pesticide availability is largely controlled by a small group of big
companies. Continued access to pesticides depends on what happens to
these firms. Conventional wisdom holds that one or more of the large
companies will either be purchased or merged with another company. This
would result in a few bureaucratic corporate behemoths. Creation of ever
larger companies could have dire implications for pesticide availability
to minor crop growers. The cost of doing business increases as the size
of a pesticide company increases, creating disincentives to register
pesticides for use patterns that have limited potential for high returns.
It is likely that, as pesticide companies grow, their interest in
registering pesticides on minor use patterns will decrease correspondingly.
How a company is positioned globally will determine its future viability.
For example, DuPont is the second largest and most diversified pesticide
company in the world. It makes money in virtually every global agchem
market. Despite paying out close to $1 billion in benomyl-related claims,
DuPont will remain a major force in pesticides.
American Cyanamid could be a different story. Am Cy was bought by American
Home Products (a company with little historical interest in ag-related
businesses). Am Cy's largest source of income is from sales of herbicides
for use on soybeans. The company has a 32% share of the world soybean
herbicide market, and 47% of the North American soybean herbicide market.
Soybeans genetically altered to be resistant to Roundup (glyphosate) are
being brought to market by Monsanto. Introduction of such soybeans has
the potential to make a major dent in Am Cy's income within five years.
Should American Home Products sell American Cyanamid to a larger company,
the resulting entity would probably be the largest pesticide company in
the world, with annual sales in excess of $3 billion. Such a company would
probably be hard pressed to justify to stockholders the wisdom of pursuing
pesticide registrations on crops produced on a few thousand acres.
Since 1995, the requirements, and therefore the costs, of conducting
the field trials, laboratory analyses and petition preparations for
registering a pesticide have increased in a near exponential fashion.
In order to register a pesticide, field trials are required in every
state in which the target crop is grown. Laboratory analysis must account
for every molecule of the parent compound and its metabolites applied to a
crop. The revised Good Laboratory Operating Practices (GLOP) are so strict
that teams of Quality Assurance Officers are required for each field trial
and laboratory test. A single registration application package prepared
for EPA consists of 2,000 500-page volumes. The entire IR-4 budget is
required to complete one registration effort on a single crop.
The impact of the increased cost of registering pesticides has been severe
in the private sector, because the private sector was excluded from the
pesticide regulatory reforms enacted by the Minor Crop Protection Acts of
1995, 1997, 1998, 2001, 2003, 2005, 2008 and 2009. The cost to pesticide
companies to bring a single new active ingredient to market is hundreds of
millions of dollars. Environmental studies are required to determine the
impact of a pesticide on each animal species with which it may potentially
come into contact. Studies are also required on potential health implications for every ethnic group and socio-economic subpopulation in the country. The costs of registering a pesticide have become so great that the private sector can no longer afford
t
The need for a secret location for the IR-4 planning meeting became a
requirement more than five years ago, when agricultural groups began to
realize that the USDA-sponsored program could only afford to register a
single pesticide on a single crop each year. Competition for new
registrations became fierce. Huge, elaborate campaigns by grower
organizations promoting their crops for IR-4 selection were planned
years in advance and were rivaled only by the competitions held every
four years by cities vying to host the Olympic Games. Some organizations
became quite adept at raising public awareness of their plight. Artichoke
growers took hostages to call attention to the difficulties of controlling
the artichoke plume moth. It was an extreme but ultimately successful
step that led to IR-4 registration of an insecticide for use on artichokes. Eventually, the U.S. became the world leader in artichoke production. Other organizations, particularly those representing okra, blueberry and hop growers, took even more drast
i
Due to the tremendous resources required to register a pesticide, a
number of hostile takeovers, bankruptcies, buyouts and mergers swept
the pesticide industry. Only two pesticide companies remained. These
were locked in an all-out war to bring the next new pesticide to the corn
market. Ciba-Monsanto-Rhone-Cyanamid-Sumitomo-RohmHaas brought a product
to market one year. The next year, DuPont-Zeneca-Bayer-DowElanco-BASF-FMC
got a product through EPA. Each company struggled to register products
under EPA's Total Environment Protection Project (TEPP) (The name of
which was developed by the only remaining disgruntled EPA employee).
TEPP was established to provide private sector incentives to develop
the ultimate pesticide _ a chemical that would control all pests
afflicting corn by just setting a container full of the product at the
edge of the field.
As if the events since 1995 are insufficient to make the IR-4 staffers
nervous, they are faced also with death threats from a renegade group of
mushroom growers called Save and Protect, Regardless, Our Underground
Truffles (SPROUT).
The staffers know that only one of 11,486 requests for assistance will
be selected this year; many commodities not selected will be left
defenseless, because almost all pesticides have been canceled. Each of
the last 10 years has ended with as many as 100 commodities that can no
longer be produced in the U.S. Soon, the only crops grown in the U.S.
will be field corn and whatever commodities for which IR-4 is able to
obtain a registration. (As soon as IR-4 announces the crop it has
selected, stock in companies dealing in the commodity soars, making
growers of the crop millionaires many times over). Because of IR-4
efforts during the last 10 years, the U.S. is the leading producer
of artichokes, okra, blueberries, hops, mushrooms, kenaf, asparagus,
bell peppers, mint and horseradish. Unfortunately, little else is
produced anymore in the U.S., which has sunk from being the leading
agricultural producer in the world in 1996 to 45th in the year 2010.
The leading agricultural producer is now Laos, which allows registration
of pesticides in 30 days for $30. Most of the world's food is produced
by the food cartel FOODPEC (Food prOduced Only with pesticiDes-Producing
and Exporting Counties.)
FOODPEC price controls caused U.S. consumer spending on food to increase
from 10% of disposable income in 1995 to 58% by 2005. Agricultural
research limited to corn, and the accompanying absence of agricultural
price supports, helped balance the national budget by 1998 and to wipe
out the national deficit by 2000. Now, however, the U.S. is once again
heavily in debt.
With field corn representing 90% of U.S. agricultural output, field corn
has become a major portion of the national diet. Food scientists have
learned how to make almost any kind of food from field corn. Corn burgers
are not too bad after you get used to them (and use a lot of corn ketchup).
Although the potential for these levels to cause acute toxicity is widely
viewed as nil, the EWG nevertheless emphasized unacceptable hazards of
human exposure to these residues. EWG's conclusion seemed based solely
on U.S. EPA's ranking of some of the detected compounds as suspected
carcinogens.
According to EPA's classification system, some pesticides fall into either
Group B2 (probable human carcinogen) or Group C (possible human carcinogen).
The classification is based largely on risk assessments using rodent
life-time feeding studies. Although the system of classification has
been in place for nearly a decade, its validity may be reaching an end.
Many biochemists now suspect that the designs of chronic feeding studies
are inadequate to extrapolate experimental animal exposures (high parts
per million over a life-time) to human exposures (parts per billion
intermittently). Furthermore, EPA has recently drafted new cancer risk
assessment guidelines that will replace the old system of classification
(Pesticide & Toxic Chemical News, August, 1995).
Current testing procedures are flawed in their use of an exposure level
known as the maximum tolerated dose (MTD). The National Academy of Science
(NAS) has recently critiqued the validity of this dosage in carcinogenicity
testing (Issues in Risk Assessment, NAS 1993).
Carcinogenicity tests are actually tests for the development of malignant
and benign tumors in mice and rats. The sensitivity of tests for detecting
tumors increases with the number of animals tested, but costs and animal
maintenance problems limit the numbers that can be used. Reduced ability
to detect a statistically significant tumor incidence among low numbers of
exposed animals is compensated for by using very high doses. The highest
dose estimated to cause no clinical signs of toxicity and no more than a
10% weight loss is considered the MTD.
The current test system was designed for qualitative information, i.e.,
whether a chemical has the potential to cause cancer. Studies usually
involve 50 test animals of both sexes orally exposed to either no dose,
the maximum tolerated dose, and one or two additional doses of one-half
or sometimes one-fourth of the MTD. The information is considered
unreliable at doses below one-half the MTD.
Quantitative information can be derived by examining the range of doses
producing a significant increase in tumors; this information defines the
potency. EPA calculates a potency rating, called Q*, that is based on
the slope of the dose-response curve, or the change in tumor incidence as
a function of the change in dose. By extrapolating the high dose responses
in a linear manner to untested low doses, the EPA uses Q* in combination
with food and water residue data (i.e., measures of potential exposure)
to estimate carcinogenic risk.
Extrapolation of data from doses near the MTD to doses representing worst
case exposure levels (i.e., residues at tolerance levels for every registered
crop) causes a problem when a pesticide has a very low oral and dermal
toxicity. For example, a group of fungicides known as the ethylene
bisdithiocarbamates (EBDCs, which include maneb, mancozeb (Dithane), and
zineb) have acute oral and dermal LD50s greater than 5,000 mg/kg body weight
(bw) (for comparison, table salt is 4,000 mg/kg). Despite the tremendous
safety in using compounds of such low toxicity, EPA has classified these
pesticides as B2 carcinogens, and these pesticides were recently on the
verge of suspension.
The low acute toxicity of the EBDCs actually worked against them when it
came to carcinogenicity testing. The MTD for these compounds was as high
as 10,000 mg/kg diet/day (or 700 mg/kg bw/day), but the extrapolation of
effects had to be applied to human exposures of less than 0.0003 mg/kg bw/day
(i.e., nearly a million-fold extrapolation) (Regulating Pesticides in Food, NAS
1987). Ironically, even at the MTD, evidence for tumor production was
negative (Pesticide Residues in Food-1993, Part II, Toxicology, International
Program on Chemical Safety, FAO/WHO 1993).
In light of the above evidence, why would EPA still consider EBDCs
carcinogenic? When food containing EBDC residues is cooked, the compounds
partially break down into ethylene thiourea (ETU), which is also a suspected
carcinogen. Small amounts of ETU also form during metabolism but are largely
excreted within 24 hours.
In contrast to the EBDC parent pesticides, ETU has been associated with a
statistically significant incidence of thyroid tumors in mice and rats.
One study showed that a dose of 25 mg/kg diet/day (1.3 mg/kg bw/day) could
produce hyperplasia of the thyroid (a pre-cancerous condition), but tumors
were seen at doses above 80 mg/kg diet/day (or 4 mg/kg bw/day) (FAO/WHO 1993).
Although this dosage represents only a fraction of the MTD (acute oral LD50 for
ETU is about 4000 mg/kg bw), it represents a nearly 1,000-fold higher exposure
than the estimated worst case dietary intake of ETU (0.004 mg/kg bw/day,
NAS 1987).
Although EPA assumes no threshold for carcinogenicity (thus, any dose is
hazardous), the rodent testing with ETU clearly showed that no tumors were
detected when diets contained less than 25 mg/kg/day. Furthermore, a
majority of cellular toxicity tests for mutagenic ability of ETU were
negative. Even epidemiological evidence based on workers exposed to ETU
in rubber plants or pesticide formulation plants showed no increase in
thyroid tumors or adverse effects on thyroid function (FAO/WHO 1993).
Fortunately, food residue monitoring for the EBDC fungicides by manufacturers
showed very minor dietary exposure, and EPA relented in its intention to
cancel the registration of these fungicides (Chemical & Engineering News,
Feb. 1992). Based on a critical examination of the toxicity data for the
EBDCs, it is clear that EPA mischaracterized these chemicals as carcinogens
by over-reliance on tumors produced at unrealistic exposure levels.
The NAS study that critiqued the MTD highlighted new hypotheses regarding a
relationship among high doses, cellular toxicity, and tumor formation,
further eroding the validity of the MTD (NAS 1993). Rather than abandoning
the MTD, the NAS instead chose to recommend that more attention be given to
pharmokinetic studies (like metabolism and cell physiology). For example,
only a small fraction of the EBDC pesticides are actually metabolized to ETU.
ETU is excreted essentially unmetabolized within 24-48 hours after exposure.
Consideration of these facts along with the negative carcinogenicity tests on
the parent pesticides and the negative epidemiological studies should have
tipped the "weight-of-evidence" conclusion about the EBDCs to the
noncarcinogenic category.
The EBDC story probably applies to all modern pesticides. Because about
50% of all synthetic and natural chemicals in the cancer potency database
could be classified as carcinogenic, any chemical with a low acute toxicity
has a good probability of testing positive for chronic effects when animals
are given doses at the MTD.
While organic chemists continue to create chemicals safer for workers and
consumers, an archaic system of carcinogenicity testing and classification
perpetuates an illusion of hazard.
**The Senate has recommended that the 1996 budget for IR-4 be $5.7 million,
no increase from 1995. The House has recommended a $1 million increase in
IR-4's budget. In the past, when the two legislative bodies have recommended
differing budget allocations, a value closer to the lower figure is the more
usual result.
**Dan Barola, Office Director of EPA's Office of Pesticide Program, has
proposed a complete restructuring of OPP. The reorganization plan calls
for an antimicrobial division, biopesticide division, information and systems
division and an assortment of units dealing with policy and outreach. There
will also be two risk/benefit management divisions (one for herbicides and
fungicides and one for insecticides and rodenticides) and two risk assessment
divisions (one for herbicides and fungicides and one for insecticides and
rodenticides). The plan calls for the dissolution of the Biological and
Economic Analysis Division. Since this is the entity that determines the
benefits associated with pesticide use, it is important to agriculture that
this function be retained. The reorganization is on hold temporarily until
the EPA budget is determined.
**Governor Lowry has appointed the members of the Commission on
Pesticide Registration. Voting members include Bob Berger, Dan Elmore, Paul
Figueroa, Ann George, Warren Henniger, Doug Muse, Stuart Pfaff, Mike
Robinson, Bryan Sukuma, Dale VanderHoff, Geraldine West and Tedd Wildman.
Non-voting members include Ginny Hamilton, Ted Maxwell and Alan Schreiber.
House and Senate agriculture committees are holding hearings on the status
of the commission September 21 and 22.
As a pesticide, methyl bromide is registered by EPA under FIFRA (Federal
Insecticide, Fungicide and Rodenticide Act). Independent of FIFRA
registration requirements, methyl bromide is subject to the provisions
of the Clean Air Act. The CAA requires phase out of chemicals having
ozone depletion potential (ODP) greater than 0.2. The latest international
scientific assessments estimate the ODP of methyl bromide at 0.6. Therefore,
under the CAA, EPA is required to phase out methyl bromide.
On December 10, 1993, EPA issued a final rule under the CAA that froze
methyl bromide production at 1991 levels starting in 1994 and eliminates
production and importation by the year 2001.
The annual economic loss to U.S. producers and consumers resulting from a
ban on the soil fumigation and citrus post-harvest uses included in a recent
USDA National Agricultural Pesticide Impact Assessment Program report was
an estimated $1 billion. The major portion of crop losses would occur to
fresh market tomatoes, ornamentals, tobacco, peppers and strawberries.
Florida production would be particularly hard hit; tomato production would
decline 45%-50%, strawberry production would fall 65%-70%, and cucumber,
eggplant and pepper production would virtually cease.
Methyl bromide is particularly important in quarantine treatments, because
it is effective against a variety of pests and can be applied easily and
economically to small and large shipments. Exports of several commodities
require fumigation with methyl bromide. The economic loss on these exports
due to a ban on methyl bromide is estimated to be $206 million annually.
For example, if methyl bromide were canceled, the U.S. would not be able to
export cherries to Japan and Korea, a market worth more than $40 million.
Other exports that would be affected include peaches, nectarines,
strawberries, walnut, cotton and oak logs.
No alternative to methyl bromide is currently available that can provide the
same level of broad-spectrum pest control for post-harvest commodity and
quarantine treatments and soil fumigation. Current approaches, both
chemical and non-chemical, have a narrower spectrum of activity and
generally result in lower crop yields and quality.
For information on the status of methyl bromide and alternatives to methyl
bromide, contact Paul Schuda, Chair of the Methyl Bromide Alternatives Task
Force at 703-305-7565 or Tracy Perry of the Policy and Special Projects
Staff, OPP at 703-305-7461.
Note: Much of the information presented on methyl bromide was taken
from Ragsdale and Wheeler, 1995, Methyl Bromide: Risks, Benefits and
Current Status in Pest Control. Review of Pesticide Toxicology, Vol. 3,
pages 21-44. Contact Alan Schreiber for a copy of this article.
Note: Ozone depletion potential is a numerical value that provides
a measure of the capacity for a chemical, relative to a reference chemical,
to destroy ozone.
For additional information on any reregistration notification, contact the individual(s) listed or
contact:
Alan Schreiber
Alan Schreiber, Allan Felsot, Catherine Daniels, Mark Antone, Carol Weisskopf, Eric Bechtel
If you would like to include a piece in a future issue of the Agrichemical and Environmental
News, please contact Catherine Daniels, Food and Environmental Quality Laboratory, Washington State University, Tri-Cities campus, 2710 University Drive, Richland, WA 99352-1671. Phone: 509-372-7495. Fax: 509-372-7491.
E-mail:
cdaniels@tricity.wsu.edu
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Future pesticide availability
Company ($ millions) Rank Country
Ciba-Geigy 2,966 1 Switzerland DuPont 2,140 2 USA Monsanto 2,130 3 USA Zeneca 2,078 4 Britain AgrEvo 2,054 5 Germany Bayer 1,962 6 Germany Rhone-Poulenc 1,796 7 France DowElanco 1,737 8 USA American Cyanamid 1,650 9 USA BASF 1,262 10 Germany Sandoz 1,005 11 Switzerland Sumitomo 603 12 Japan FMC 504 13 USA Kumiai 492 14 Japan Rohm and Haas 439 15 USA
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Pesticides in the year 2010
...Alan Schreiber
Note: This is a work of fiction. I am just kidding
about the artichoke and mushroom growers.
It is November 14, 2010, in a secret location in the Pennsylvania
Appalachians. The various members of the IR-4 Project are holding an
annual planning meeting to discuss the 2011 field season, and they are
feeling the pressure. How do they spend the $150 million allotted for
registering pesticides on minor use crops?
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Carcinogenicity testing of low toxicity pesticides:
Do maximum tolerated doses create an illusion of hazard?
...Allan Felsot
Notice: LD 50 is defined as the lethal dose for 50 percent of the
test population.
During the last two years, the Environmental Working Group (EWG), a
Washington, D.C. based environmental research and advocacy organization,
has released several reports about low levels of pesticide residues detected
in food and water.
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Officially Unofficial
Officially Unofficial is a regular feature that may include information considered
politically inappropriate by some.
**The Rotenone Task Force is not supporting continued registration of
rotenone for any uses other than fish control and flea and lice control
on pets. I am under the impression that rotenone is an important tool for
insect control by organic growers. Currently, IR-4 has requests for
assistance to help keep the insecticide registered on such crops as
potato, snap beans, eggplant, tomato, apple, pear, cherry and blueberry.
Anyone wanting to keep rotenone available for organic or conventional uses
needs to speak up now. Comments may be directed to: Mr. Joe Conti, The
Rotenone Task Force, Phone: 201-307-3366 or Allan Schreiber at 509-372-7378.
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Methyl bromide
Methyl bromide is a broad spectrum fumigant used against insects, fungi,
bacteria, nematodes and weeds in soil, structural and commodity/quarantine
fumigation. The major use of methyl bromide in agriculture is soil
fumigation. It is important to the production of strawberries, tree fruits,
nuts, small fruits, solanaceous crops, forest, nursery and horticultural
crops.
State Issues
Special Local Needs (Section 24c)
Label restrictions for Special Local Needs in Washington: The following
pesticide uses have been granted label registrations by the Washington
State Department of Agriculture under the provisions of Section
24 (c) amended FIFRA.
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A=adjuvant D=desiccant
D/H=desiccant, herbicide F=fungicide FA=feed additive
G=growth regulator H=herbicide I-insecticide N=nematicide
P=pheromone V=vertebrate repellent
(a)= Import tolerance only. There are no U.S.
registrations as of Aug. 16, 1995.
Chemical* Petitioner Tolerance
(ppm)
Commodity
(raw)
Urea Unocal Corp Exempt In or on various
agricultural
commodities when used as
a frost protectant
(I) Inclusion bodies
of multi-nuclear
polyhedrosis virus
of Anagrapha falciforaBiosys Exempt
In or on all raw agricultural
commodities
(F/N) Burkholderia
(Pseudomonas)
cepacia type
Wisconsin
Stine
Microbial
ProdExempt In or on all raw agricultural
commodities
(A) Polymethylene
Polyphenylisocyanate,
polymer with ethylene
diamine,
diethylene
triamine and sebacoyl
chloride, cross-linked
(100,000 Avg. MW)Elf Atochem
North AmericaExempt Applied to
growing crops
only
(F) Tebuconazole Bayer Inc. 0.05 bananas;
barley, grain; oat,
grain; wheat, grain
0.10 barley, forage, hay, straw;
oat, forage, hay, straw;
peanuts; wheat, forage, hay, straw
4.0 peanuts, hulls
(F) Myclobutanil Rohm & Haas 2.0
almond hulls; stone fruits
(except cherries)
0.1 almond nutmeat; cattle,
meat; goats, meat; hogs,
meat; horses, meat; sheep, meat
0.5 apples
5.0 cherries (sweet & sour)
0.02 cottonseed; eggs; poultry,
fat, meat, mbyp
1.0 grapes; cattle, liver; goats,
liver; hogs, liver; horses,
liver; sheep, liver
0.05 cattle, fat; goats, fat; hogs,
fat; horses, fat; sheep, fat
0.2 milk; cattle, mbyp (except
liver); goats, mbyp (except
liver); hogs, mbyp (except
liver); horses, mbyp (except
liver); sheep, mbyp (except liver)
(H) Clethodim EPA 0.5 potatoes
1.0 potato, flakes, granules
(I) Bacillus thuringiensis
CryIA (b) delta-
endotoxin & genetic
material necessary for
its production in corn
(plasmid vector pCIB4431)Ciba-Geigy
Exempt corn, field, sweet, pop
(I) Dimethoate EPA 1.0 (a) blueberries
(I) Occlusion bodies
of the Granulosis virus
of
Cydia pomenellaUniv. of Calif.
Berkeley
Exempt In or on all raw agricultural commodities
Phosphinothricin
acetyltransferase (PAT)
& the genetic material
necessary for its
production (plasmid
vector pCIBP3064)
Ciba-Geigy Exempt In the raw agricultural
commodities
of field corn,
sweet corn & popcorn
(I) Deltamethrin Hoechst-Roussel 0.04
cottonseed
Agri-vet Co. 0.2 cottonseed oil;
tomatoes
1.0 tomato (products) concen-
trated
(F) Flutolanil AgrEvo 0.10
cattle, fat; goats, fat; hogs,
fat; horses, fat; sheep, fat
1.0 cattle, kidney; goats, kidney;
hogs, kidney; horses,
kidney; sheep, kidney
2.0 cattle, liver; goats, liver;
hogs, liver; horses, liver;
sheep, liver
0.05 cattle, mbyp, meat, milk;
eggs; goats, mbyp, meat,
milk; hogs, mbyp, meat,
milk; horses, mbyp, meat,
milk; poultry (including
turkeys), fat, mbyp, meat; sheep, meat, mbyp, milk
0.5 peanuts
15.0 peanut hay
5.0 peanut hulls
(H) Hexazinone DuPont 5.0 sugarcane, molasses
(A) Cellulose acetate
(28,000 Avg. MW)Consep
Exempt applied to growing crops only
(I/FA) Tralomethrin AgrEvo 1.0 (b)
tomato puree
0.2 (c) cottonseed oil
1.5 (b) tomato pomace, wet
4.0 (b) tomato pomace, dry
(H) Glyphosate IR-4 200.0 spearmint;
peppermint
(I) Dimethoate IR-4 0.15 asparagus
(I) Imidacloprid IR-4 6.0 hops, dry
(I) Imidacloprid (NTN) Gustafson 0.05 (d)
beets, sugar (roots);
wheat, grain0.1 (d) beets, sugar (tops)
7.0 (d) wheat, forage
0.3 (d) wheat, straw; beets,
sugar, molasses
(b)= Time limited tolerance, expires June 1, 1997.
(c)= Time limited tolerance, expires Nov. 15, 1997.
(d)= Time limited tolerance, expires Aug. 24, 1998.
Reregistration Eligibility Document
EPA has completed the reregistration process and has issued a
Reregistration Eligibility Document (RED) for sodium propionate, methoprene
& Heliothis zea NPV. EPA is taking the following tolerance actions:
amending the exemptions from the requirement of a tolerance for methoprene,
revoking exemptions for sodium propionate, and making wording changes to the
exemption from the requirement of a tolerance for Heliothis zea NPV.
Commodity definition
EPA is expanding the interpretation, for the application of tolerances
and exemptions from the requirement of tolerance, established for pesticide
chemicals in or on the raw agricultural commodity summer squash to include
chayote fruit.
Summer squash: Fruits of the gourd (Cucurbitaceae) family that are consumed
when immature, 100% of the fruit is edible either cooked or raw, once picked
it cannot be stored, has a soft rind which is easily penetrated, and if seeds
were harvested they would not germinate; e.g., Cucurbita pepo (i,e.,
crookneck squash, straightneck squash, scallop squash, and vegetable marrow);
Lagenaria spp. (i.e., spaghetti squash, hyotan, cucuzza); Luffa spp. (i.e.,
hechima, Chinese okra); Momordica spp. (i.e., bitter melon, balsam pear,
balsam apple, Chinese cucumber); Sechium edule (chayote); and other cultivars
and/or hybrids of these.
WSU Pesticide Coordinator
100 Sprout Road
Richland, WA 99352-1643
Ph: 509-372-7462
Fax: 509-372-7460
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Contributors to the Agrichemical and Environmental News:
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