Commonly Asked Questions about Water and Crop Protection
Benefits of Crop Protection Products
Questions and Answers
Water Issues: Commonly Asked Questions About Water and Crop Protection
Public debate over protecting water quality touches everyone. We need look no further than our own community. Grade school classes adopt water protection projects, local newspapers cover water quality studies and parents closely monitor where their children swim.
There are many factors which constitute water pollution. But founded or unfounded, crop protection products often become the major focus of attention. Misinformation or no information can further cloud the public’s and lawmakers’ perception of crop protection products and the environment.
Early in the 1970’s, our industry recognized that a few crop protection products, such as DDT, had unacceptable environmental risks. The crop protection industry voluntarily worked with the Environmental Protection Agency to discontinue the use of these products. Hence, DDT has not been sold in the US for 25 years.
Growers have made great strides in protecting the environment through better stewardship practices. More than one billion tons of soil per year have been saved using conservation practices during the last 13 years. Through state-of-the-art technology and enhanced regulatory processes, our industry is capable of feeding a growing world population while protecting our natural resources.
As representatives of the crop protection industry, we often face questions about water quality from parents, teachers, environmental groups, civic organizations, local and state government officials, and our neighbors. We need to be articulate spokespeople for agriculture when questioned about pesticides and water quality. Answers must be concise, factual and documented.
When activist groups bombard the media with misinformation, the industry systematically provides sound, factual corrections for reporters. In the same way, we can answer questions on an individual basis.
This publication is your reference. It answers common questions about pesticides and health issues, ecosystems, research, drift, wildlife, farming practices and regulations. Contained in these pages are more than 30 questions and multiple answers with supporting references.
If we educate the public, even one person at a time, we can hope to avoid unnecessary and excessive regulation which can effect our ability to produce a safe and abundant food supply. Water quality is everyone’s concern. Directly answering those concerns is our responsibility.
Some Benefits of Crop Protection Products
Crop protection products help protect our food from hundreds of insects, plant diseases and weeds. Without their use, America’s abundant food and fiber supply – fresh fruits, vegetables and even cotton – would be greatly reduced, and much more expensive.
World Food Supply
World population will nearly double before it stabilizes around 2040. And Third World incomes are rising faster than ever before. The Third World demand for high protein foods like meat, milk and eggs, as well as fiber, is soaring. Increasing our yields on the best land is critical to meeting this demand.
Habitat Preservation
Pesticides reach far beyond our affordable food and fiber supply. By enabling growers to produce more food in a smaller area, pesticides also help reduce the amount of cropland needed, reducing soil erosion and preserving fragile ecosystems for endangered plants and wildlife. High yield agriculture has already saved 10 million square miles of wildlife habitat from being plowed down for food. That’s an area equal to North and Central America.
Soil Protection
Soil erosion, which poses the greatest threat to the environment, is reduced on average by 90 percent with no-till farming, in conjunction with the use of crop protection products. The use of pesticides in modern high yield agriculture will ensure an adequate world supply of food without having to use land that would infringe on wildlife habitat or increase risk of erosion.
Question 1.
Are pesticides leaching to groundwater from treated fields?
Answer
a) Cases of well contamination by pesticides have often been traced to inappropriate mixing and disposal of products near wells. In Iowa, 80% of herbicide detects in public drinking water wells were traced to such point sources. Water-tight containment systems are now required in most states to prevent this problem at mixing and loading sites.
b) In vulnerable sites, such as sandy soils with shallow groundwater and high rainfall/ irrigation, certain pesticides can leach in small quantities. Label restrictions are in place to limit use of these products in vulnerable sites. In one study USDA installed over 700 wells directly beneath cornfields across the Midwest to monitor for the herbicide atrazine. Atrazine was rarely detected at most sites.
c) Some states have implemented pesticide management areas in extremely vulnerable sites to further reduce the likelihood of contamination, for example CA, AZ, IA, FL, NY, MD, WI and KS.
d) US EPA’s state management plans will create additional protections.
See reference 1
Question 2
Are pesticides the primary polluters of surface water?
Answer
a) No, soil sedimentation is the primary pollutant of surface water.
b) Pesticides were estimated to affect only 2% of total river miles.
c) EPA’s National Water Quality Inventory summarizes state reports which estimate percentages of waters impaired in any way by pollutants. The 1992 report ranks surface water quality concerns in the following order:
1) Sediment (soil)
2) Nutrients (minerals)
3) Pathogens
4) Pesticides
5) Organic Enrichment
6) Metals
7) Suspended Solids
8 ) Salinity
9) Habitat Alteration
10) Flow Alterations
See reference 2
Question 3
Do pesticides contaminate natural ecosystems and harm animal reproduction?
Answer
a) No, concentrations of modern pesticides found in the environment are well below safe levels as determined by animal studies.
b) Modern pesticides must be thoroughly tested for potential reproductive, health, safety and environmental effects before they are registered. Each EPA-registered pesticide undergoes a minimum of 120 tests. On average, only one in 20,000 chemicals ever makes it out of the laboratory. Pesticide development, testing and EPA registration take eight to 10 years and cost manufacturers $35 million to $50 million per final product.
c) Publicity about potential reproductive effects of pesticides comes from a few studies where high concentrations of no longer used, persistent, bio-accumulative pesticides and industrial chemicals, due to spills and inappropriate disposal, have been investigated for possible links to reproductive defects in wildlife.
See reference 3
Question 4
Do we know the long-term effects of pesticides in water?
Answer
a) Yes, many pesticides have been used for more than 20 years. As a result, scientists have extensively studied a wide range of potential impacts of pesticides on the aquatic environment and wildlife.
b) Yes, sophisticated computer models are able to predict potential pesticide impacts. Modeling of the Great Lakes has shown that concentrations of the most widely used herbicide will be hundreds of times below concentrations harmful to aquatic organisms.
c) Yes, a review of aquatic studies on one herbicide contained references of 118 different studies monitoring that herbicide in water.
d) Yes, environmental fate and ecotoxicology studies are an important component of the requirements by EPA registration.
See reference 4
Question 5
Is agriculture the biggest nonpoint pollution source?
Answer
a) Because many surface water pollutants generated by agriculture (nutrients, bacteria, sediment) are also generated by other industries and by urban areas, it is not easy to accurately determine agriculture’s contribution to nonpoint pollution.
b) Soil sedimentation is the largest polluter and there are many sources of soil erosion. For example, eroded soil comes from construction, roadways, logging, and agriculture.
c) Agriculture dominates land use in many regions. In those areas. best management practices such as terraces, grass water ways, reduced tillage, cover crops and vegetative filter strips, are used to reduce the potential for nonpoint pollution. More than 1 billion tons of soil per year have been saved through conservation practices during the past 13 years.
d) Controlled studies have revealed that, on average, no-till reduced pesticide run-off by 70 percent compared with conventional tillage, while reducing erosion and sediment by more than 90 percent because of the crop residue cover left on the soil.
See reference 5
Question 6
Is agriculture the primary source of contaminated sediment?
Answer
a) No, agriculture is a minor source of contaminated sediment compared to other industries and municipal sewage effluent.
b) The Lake Michigan Lakewide Management Plan identifies eight sediment contaminants of concern, none of which are pesticides or of agricultural origin.
c) The Lake Superior Lakewide Management Plan lists 16 sediment contaminants of concern. Four of these are obsolete pesticides, none or which exceeded water quality criteria. Eleven are heavy metals, five of which exceeded criteria, and one PCB, is an industrial chemical.
See reference 6
Question 7
Are pesticides being detected in the environment with increasing frequency?
Answer
a) Concentrations of pesticides in the environment (air, water, soil profile) are decreasing and detections are rarely above health-based standards.
b) Increased monitoring frequency and methods may create the impression that detection of pesticides are increasing. However, long-term studies have shown that detections are decreasing due to improved management.
c) For example, in Iowa, herbicide concentrations in vulnerable wells decreased by 87% between 1986 and 1994 due to adoption of best management practices by growers.
d) Herbicide concentrations declined or disappeared in 78% of rural Wisconsin wells over a four year period.
See reference 7
Question 8
Are we testing for all the pesticides that could be found in water?
Answer
a) Water utilities test for more than 80 regulated and 15 unregulated chemicals per drinking water standards set by EPA, including several common pesticides. Extensive monitoring for a wide range of pesticides is also conducted by manufacturers, public and private agencies, including the US Geological Survey, US EPA, state environmental agencies, crop protection companies and universities.
b) For example, in one study EPA looked for 126 different pesticides and breakdown products in over 1,300 wells nationwide.
c) An Iowa study of all public drinking water supplies monitored for 35 different pesticides commonly used in the state.
See reference 8
Question 9
Are pesticides tested for their impacts on water and aquatic organisms?
Answer
a) Yes, all pesticides must undergo extensive environmental testing in order to be registered for use by EPA. Both laboratory and field-scale testing are required.
b) Pesticides are tested for degradation rates in soil and water and leaching potential.
c) Tests are conducted to determine potential short and long term or reproductive effects on many species including fish, birds, invertebrates, shrimp, crabs, oysters, bees, beneficial insects, microarthopods, earthworms, as well as mice, rats and other vertebrate animals.
d) Model ecosystem studies are conducted to make sure pesticides do not accumulate in food chains. Once crop protection products are registered for use, environmental monitoring and aquatic organism studies continue, conducted by both independent scientists and manufacturers.
See reference 8
Question 10
Are we using the best available science to detect pesticides in water?
Answer
a) Yes, each new study incorporates the many remarkable improvements made in laboratory detection techniques.
b) In the 1960’s, levels below several parts per million could often not be detected. Today, parts per trillion are routinely monitored. A part per trillion is one million times less than a part per million. A part per trillion is equal to one second in 32,000 years.
c) The cost of monitoring is decreasing due to development of new techniques. A lab test for a pesticide that may have cost $100 in the past can now be conducted for $10. The speed of conducting these tests is also increasing. This reduction in cost and increased speed allow for more frequent monitoring.
See reference 10
Question 11
What are the study results of municipal surface water supplies regarding pesticides?
Answer
a) Extensive year-round monitoring of municipal tap water in states across the nation has shown that pesticide concentrations very rarely exceed drinking water standards.
b) Considering all surface water monitoring in Iowa from 1975 to 1993, annual concentrations of atrazine (the most widely used corn herbicide) were below the drinking water standard at 97.5% of sites.
c) The drinking water source for large cities is often surface water — rivers and lakes — which is susceptible to contamination by many natural and manmade chemicals. certain pesticides, especially a few widely used herbicides, can run off farm fields and appear in surface water in late spring and summer. However, concentrations are well below the Safe Drinking Water Guidelines. Best management practices are used to reduce possible run off, such as monitoring, careful application, filter strips and set-backs.
See reference 10
Question 12
Is there evidence of lingering effects of obsolete pesticides in water?
Answer
a) Several persistent bioaccumulative insecticides which were banned in the 1970’s can sometimes be detected in sediment of lakes or rivers at very low concentrations. New pesticides have been and are being introduced that have very little environmental impact.
b) One of the reasons that some older chemicals are bioaccumulative is due to very low water solubility and very tight absorption to sediments, making them unavailable to degrading micro-organisms. These products could not be registered for use today.
See reference 12
Question 13
Is drift from pesticide applications causing problems in rivers and streams?
Answer
a) Drift can be a concern over short distances, but does not add significant quantities of pesticides to water systems.
b) Drift prevention is a major topic in pesticide applicator training conducted by the Cooperative Extension Service in all states and a high priority for aerial applicators. Two major principles are taught: minimize spray drift in all situations and avoid drift into areas where off-target effects are likely to occur.
c) Growers are reducing drift by operating sprayers that deliver coarse sprays which are less subject to drift, and by avoiding windy conditions.
See reference 13
Question 14
Should pesticides be eliminated because they can be detected in water?
Answer
a) No, hundreds of natural and manmade chemicals are routinely detected in monitoring conducted by water utilities. These generally are below safe consumption levels, meeting strict standards set in the Safe Drinking Water Act. These standards include large safety margins to protect children and adults. When chemicals exceed standards, their concentration must be reduced either by treating water or reducing their presence in source water.
b) While pesticides rarely exceed drinking water standards, in cases where they have, standards have been met by either changing how products are used or by water treatment.
c) The Safe Drinking Water Act sets standards for more than 80 chemicals, primarily industrial and naturally occurring contaminants. Eliminating all contaminants from drinking water would be extremely expensive, if not impossible. By supplying water which meets health-based standards, rather than striving for elimination of chemicals, society is protected, yet growers are allowed to economically produce the food and fiber we need.
See reference 14
Question 15
Is broader regulation of pesticides needed?
Answer
a) No, pesticides are strictly regulated under the Federal Insecticide, Fungicide, and rodenticide Act, the Federal Food, Drug and Cosmetic Act, Clean Water Act, Safe Drinking Water Act, The Endangered Species Act and other statues.
b) Congress has provided for an increasingly comprehensive regulatory system through numerous amendments to these acts, and has mandated the re-evaluation and reregistration of all chemicals registered prior to November 1984.
c) States further regulate pesticides to ensure that unique local conditions will not lead to environmental problems.
d) States are moving forward in developing state pesticide management plans to address the use of specific products where groundwater may be vulnerable.
See reference 15
Question 16
Are pesticides a major cause of well contamination?
Answer
a) No, chloroform bacteria is the major contaminant frequently detected.
b) Other contaminants are more common in wells. In Iowa, 45% of rural wells contained coliform bacteria. In a survey of all public water supplies in Iowa, 8% of water from wells had a detected pesticide, while 64% had other synthetic chemicals detected, such as industrial solvents and components of fuel from leaking storage tanks.
c) In the largest and most comprehensive study of its kind, US EPA monitored for 126 different pesticides and breakdown products in over 1,300 wells representative of 10.5 million wells nationwide. Only 16 products were detected anywhere, with 10% of public wells having detects and 4% of rural wells with detects. Less than 1% of wells had pesticide levels that exceeded drinking water standards.
d) Many state groundwater monitoring programs detect little, if any pesticide contaminants. When detects occur management steps are taken to correct the problem, such as identification of the source and a plan to reduce or eliminate the contamination.
See reference 16
Question 17
Do pesticides cause cancer in people?
Answer
a) No pesticide products used today are known human carcinogens. Almost half of all natural and manmade substances tested in high-dose, lifetime lab animal studies have produced tumors. Some pesticides do too. Scientists do not believe that these extremely high-dose tests accurately predict what happens in the real world at lower doses.
b) No, FDA routinely detects little, if any, residues of pesticides on food. EPA finds little, if any, pesticides in wells or tapwater. Thus, people are rarely exposed to pesticides.
c) Pesticides must undergo extremely highdose lab animal tests to determine human health effects, unlike most other chemicals in the home, workplace or environment.
See reference 17
Question 18
Are pesticides causing unknown endocrinic and estrogenic effects?
Answer
a) At high concentrations many chemicals, both natural and manmade, can influence endocrine (hormone-mediated) systems in sensitive cell culture tests.
b) While some pesticides can mimic estrogen at high concentrations in test tube experiments, levels found in the environment are far below active concentrations. For example, DDT (banned in 1972) is 10 billion times less active in mimicking estrogen than common components of birth control pills.
c) Foods contain many natural compounds which more potently mimic estrogen and are found at much higher concentrations than pesticides. Consumers can buy Melatonin, which is a potent hormone, in health food stores. Recent news reports have covered the use of Melatonin as a “feel-good pill.”
See reference 18
Question 19
Do we know the effects of combinations of pesticides in drinking water?
Answer
a) Yes, typical combinations of pesticides have been studied and have no harmful effects to people in drinking water.
b) Based on Iowa and California well monitoring, scientists at the National Institute of Environmental Health Sciences fed animals mixtures of 5 to 6 pesticides plus nitrate at concentrations of 1X, 10X and 100X concentrations found in contaminated wells. None of the combinations caused any harmful effect on animals or their offspring.
See reference 19
Question 20
Are pesticides threatening endangered species?
Answer
a) No, modern pesticides degrade more rapidly than products used 20 years ago, and therefore greatly reduce risk to any species.
b) Extra precautions are taken to protect endangered species, in accordance with the Endangered Species Act.
c) EPA has identified species which potentially could be impacted by certain pesticides, and designed methods to protect them.
d) Pesticide labels alert users if these species are present in their county and refer to Endangered Species Bulletins. These bulletins contain maps describing where use of the product is restricted to protect endangered species.
e) The use of pesticides in modern high yield agriculture provides a world food supply without having to use land that is best suited for wildlife habitat.
See reference 20
Question 21
Do pesticides degrade or are they accumulating in animals?
Answer
a) Modern pesticides degrade more rapidly and do not bioaccumulate.
b) Several older insecticides such as DDT were able to bioaccumulate, risking harm to animals at the top of food chains. For this reason, these products were banned in the 1970’s and 1980’s.
c) Pesticides must now be tested for ability to bioaccumulate and chemicals which do not meet EPA requirements are not registered.
See reference 21
Question 22
Is organic farming best? Does it protect wildlife and watersheds?
Answer
a) No, some organic practices such as tillage can contribute to habitat destruction and increase soil loss.
b) If yields returned to levels of the 1950’s in absence of modern agricultural chemicals, 148 million more acres of land would have to be converted from present uses (wildlife habitat) to agriculture to maintain current production levels. Noted among these lands are the rainforests.
c) Intensive soil tillage used for weed control in place of herbicides results in erosion, and soil sediment has profound negative impacts on aquatic systems.
d) Organic farming can increase nitrate and phosphate runoff into streams and lakes, leading to excessive algae growth.
See reference 22
Question 23
Does no-till crop production increase the use of pesticides, causing more, not less, water contamination?
Answer
a) No, research indicates that the types of pesticides may change but the total environmental load remains the same or in some cases is reduced.
b) Controlled studies revealed that, on average, no-till reduced pesticide runoff by 70% compared to conventional tillage, while reducing erosion and sediment by more than 90%
c) USDA surveys show that rates of herbicides applied are very similar for all tillage systems.
See reference 23
Question 24
Do growers routinely apply excessive rates of pesticides?
Answer
a) No, according to USDA surveys, average application rates of pesticide products are consistently lower than maximum labeled rates.
b) These products are costly, so using too much reduces grower profits.
c) Excessive rates can injure crops, reducing yields.
d) Using greater than labeled rates is a violation of state and federal law and is punishable by fine or imprisonment.
See reference 24
Question 25
Are growers properly trained to apply pesticides?
Answer
a) Yes, applicators must pass state tests to become certified in order to buy and use products. Pesticides are classified as either “general use” or “restricted use.” Pesticides with potential risks to either the applicator for environment are classified as “restricted use.”
b) The Cooperative Extension Service provides pesticide applicator training to help growers become certified. Regular continuing education sessions are also required to keep certifications valid. Water quality protection is a major topic in certification training and in continuing education.
c) Growers are increasingly hiring professional pesticide applicators. These applicators are trained and certified, using the latest precision application and safety equipment. In Illinois, 40% of agricultural herbicides are applied by professional applicators.
See reference 25
Question 26
Traditionally, growers are thought to be good stewards of water and other natural resources. Are they continuing these conservation practices?
Answer
a) Yes, as their families would be the first affected if water quality is harmed, growers are managing their use of pesticides to minimize any potential for water contamination.
b) Cropland soil erosion has been reduced more in the last decade than at any time in history.
c) Nationwide erosion was reduced by 25% from 1982 to 1992, largely due to adoption of USDA conservation programs and conservation tillage systems. These tillage systems also provide better habitat for wildlife.
d) Growers routinely provide habitat for wildlife. For example, a North Carolina study revealed that no-till soybean fields were better habitats for bobwhite quail than natural areas.
See reference 26
Question 27
Are pesticides contaminants or pollutants?
Answer
a) A contaminant is considered to be a material not normally present or naturally present at much lower levels.
b) Pesticides could be considered contaminants but are almost never pollutants.
c) A pollutant is a contaminant at levels high enough to make water unfit for a desired use.
Question 28
Is pesticide use increasing?
Answer
a) No, pounds of pesticide use are decreasing due to newer products which are used at low rates and to adoption of Integrated Pest Management which includes monitoring of pest populations and combined use of chemical and nonchemical control methods, such as crop scouting and use of beneficial insects.
b) For example, according to USDA data, use of soybean herbicides declined by 50% from 1982 to 1992. Use of cotton insecticides declined by more than 75% from 1971 to 1992
See reference 28
Question 29
Is the detection of any pesticide bad?
Answer
a) Risk from any chemical depends both on toxicity and exposure. Risk follows the old adage – the dose makes the poison. Modern laboratory techniques allow detection of chemicals at concentrations far below harmful levels. These techniques can be used in environmental monitoring to ensure that pesticides do not move off-site in harmful quantities.
b) Many pesticides are low in toxicity to humans and animals. Out of the 39 most widely used herbicides, 20 are less toxic than table salt, and 30 are less toxic than aspirin.
See reference 29
Question 30
Do pesticides really benefit society?
Answer
a) Yes, judicious use of pesticides allows growers to produce high quality food at a lower cost to consumers. For example, a Texas A&M study found that without use of pesticides, food costs would increase 12%.
b) Pesticides contribute to society by controlling disease-carrying insects such as mosquitoes. Also, disinfectants kill disease causing micro-organisms in drinking water supplies.
c) We see the benefits of pesticides every day. The bluish liquid in which hair salons soak combs is a pesticide. Used combs are placed in the fungicide solution to kill any bacteria or germs.
d) Pesticides also produce environmental benefits. Largely due to conservation tillage made possible by herbicides, soil erosion decreased by 25% from 1982 to 1992, reducing sediment in rivers and lakes, and preserving the productivity of farmland.
e) Productive agriculture allows more land to be preserved for wildlife habitat and other recreational uses.
See reference 30
Question 31
Are pesticides environmental stressors?
Answer
a) Pesticides are not unique in potential for environmental impact. Any chemical, natural or manmade, present in excessive quantities can have undesirable environmental impacts. Even our daily activities impact the environment. For example, driving a car contaminates the air.
b) Pesticides are used to control specific pests on specific sites.
c) Modern pesticides degrade quickly, reducing chances for off-site impacts.
d) Use of Best Management Practices by growers helps pesticides stay in place, keeping any off-site movement below harmful levels.
See reference 31
Question 32
Are new pesticides kinder and gentler as manufacturers claim?
Answer
a) Yes, remarkable advances in our understanding of how pesticides work at the molecular level, and how they behave in the environment have allowed manufacturers to design products which are more specific in the organisms they affect, are applied in lower amounts, and degrade more quickly.
b) While herbicide application rates have often been measured in pounds per acre in the past, many new herbicides are applied in fractions of ounces, and are extremely low in toxicity to mammals.
c) Some new insecticides are derivatives of natural compounds, degrade quickly, and are low in toxicity.
d) New biopesticides are highly pest-specific, having no effect on non-target organisms.
See reference 32
Benefits
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2. EPA. 1994. National Water Quality Inventory 1992 Report to Congress. EPA 841-R-94-001.
3. CropLife America. 1994. From Lab to Label, the research, testing and registration of agricultural chemicals. CropLife America, Washington, DC.
Hilleman, B. 1994. Environmental estrogens linked to reproductive abnormalities, cancer. Chem. Eng. News. Jan 31:19-23.
4. Tierney, D.P. et al. 1995. Estimation of atrazine concentrations in the Great Lakes over time; implications for biological effects. Proceedings 38th Conference of the international Association for Great Lakes Research.
Huber, Wilfried. 1993. Ecotoxicological relevance of atrazine in aquatic ecosystems. Environ. Tox. Chem. 12:1865-1881.
5. Smith, R.A., et al. 1993. Stream water quality in the conterminous United States – status and trends of selected indicators during the 1980’s. U.S. Geological Survey.
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6. EPA. 1993 Revised Lake Michigan Lakewide Management Plan for Toxic Pollutants. USEPA, Region 5, Chicago, IL.
Superior Bi-National Program. 1993. State of Lake Superior Basin Reporting Series. Volume II: Lakewide Management Plan.
7. Quade, D.J., et al. 1994. A preliminary evaluation of the atrazine management areas in Floyd and Mitchell Counties, IA. Iowa Dept. of Natural Resources. pp 45.
Postle, J. 1994. Report on the DATCP/Ciba 200 well sampling program. Wisconsin Dept. of Agriculture.
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Iowa Department of Natural Resources. 1988. Pesticide and Synthetic Organic Compound Survey.
9. CropLife America. 1994. From Lab to Label, the research, testing and registration of agricultural chemicals. CropLife America, Washington, DC.
Society of Environmental Toxicology and Chemistry. 1994. Aquatic Dialogue Group: Pesticide risk assessment and mitigation. SETAC, Pensacola, FL.
10. Soni, M., et al. 1995. Direct determination of organic compounds in water at parts-per quadrillion levels by membrane introduction mass spectrometry. Anal. Chem. 67:1409-1412.
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11. Richards, R.P. et al. 1993. Pesticide concentration patterns in agricultural drainage networks in the Lake Erie Basin. Env. Tox. and Chem. 12:13-26
Tierney, D.P., et al. 1994. A review of historical surface water monitoring for atrazine in Iowa, 1975-1993. Ciba Crop Protection Technical Report 2-94.
12. Bollag, J. 1991. Enzymatic binding of pesticide degradation products to soil organic matter and their possible release. Pesticide Transformation Products. Chapter 9. Amer. Chem. Soc. Symposium Series 459.
Witowski, P.J. et al. 1987. A review of surface-water sediment fractions and their interactions with persistent manmade organic compounds. U.S. Geological Survey Circular 993.
13. Bode, L.E. 1991. The three D’s: droplet size, deposit, and drift. Proc. W. Weed Sci. soc. 44:8-14.
14. American Water Works Association. 1994. The Safe Drinking Water Act. A guide for water system operators. American Water Works Association, Washington, DC.
15. CropLife America 1994. From Lab to Label. The research, testing and registration of agricultural chemicals. CropLife America, Washington, DC. EPA 1993. Guidance for pesticides and ground-water state management plans. EPA publication 735-B-93-005a.
16. Spalding, Roy F. 1991. Assessment of state-wide groundwater quality data from domestic wells in rural Nebraska. Water Center/Water Sciences Laboratory and the Nebraska Health Department. pp 12.
Kross, B.C. et al. 1990. The Iowa state-wide rural well-water survey water-quality data: initial analysis. Iowa DNR Technical Information Series 19.
Iowa DNR. 1988. Pesticides and synthetic organic compound survey. Iowa Dept. of Natural Resources, Des Moines, IA.
EPA. 1990. National Survey of pesticides in drinking water wells. Phase I Report. EPA 570/9-90-015.
17. National Research Council. 1987. Regulating pesticides in food. National Academy Press, Washington, DC.
Ames, B.N., et al. 1990. Dietary carcinogens, environmental pollution, and cancer; some misconceptions. Medical Onocology and Tumor Pharmacotherapy 7 (213):69-85. Whelen, E.M. 1993. Toxic terror. Prometheus Brooks, Buffalo, NY.
18. Safe, S.H. 1995. Environmental and dietary estrogens and human health: Is there a problem? Environ. Health Perspect. 103:346-351.
Krieger, N. et al. 1994. Breast cancer and serum organochlorines: a prospective study among white, black and asian women. J. National Cancer Institute 86-589-599.
Jones, J.M. 1992. Food Safety. Egan Press, St. Paul, MN.
19. Heindel, J.J., et al. 1994. Assessment of the reproductive and developmental toxicity of pesticide/fertilizer mixtures based on confirmed pesticide contamination in California and Iowa groundwater. Fund. and Appl. Tox. 22:605-621.
20. Whitford, F., et al. Pesticides and Wildlife. Purdue University Cooperative Extension Bulletin pp. 30.
Hartzler, R.G. 1992. Protecting Iowa’s rare and endangered plant species. Iowa State University Extension Bulleting Pn. – 1506.
21. Matsumura, F. 1985. Effects of pesticides on wildlife. In Toxicology of Insecticides. Plenem Press, New York. pp 437-487.
22. R.C. Reeder, et al. 1995. Conservation Tillage Systems and Management, Midwest Plan Service, Iowa State University, Ames, IA water erosion, p. 8-11.
Avery, D.T. 1995. Saving the planet with pesticides and plastics. The Hudson Institute, Indianapolis., IN.
Karlen, D.L. 1993. Conventional vs. alternative farming: a quantitative comparison. National Soil Tilth Laboratory Report, Ames, IA.
Fawcett, R.S. 1994. Were the good old days sustainable? Farm Journal 118(1):J4.
23. Fawcett, R.S., et al. 1994. The impact of conservation tillage on pesticide run-off into surface water: a review and analysis. J. Soil and Water Cons. 49(2):126-135.
Bull, L, et al. 1993. Analysis of pesticide use by tillage system in 1990, 1991, and 1992 corn and soybeans. Agricultural Resources: Inputs/AR-32. pp 41-54.
24. Economic Research Service. 1995. Agricultural Chemical Usage. 1994 Field Crops Summary. USDA Publications Ag Ch 1(95).
25. Wintersteen, Wendy, et al. 1992. The Iowa core manual. A study guide for pesticide applicators and handlers. Iowa State University, publication IC-445.
Pike, D.R. et al. 1991. Pesticide use in Illinois: results of a 1990 survey of major crops. University of Illinois publication DP-91-1.
26. Kellogg, R.L., et al. 1994. Highlights from the 1992 National Resources Inventory. J. Soil and Water Cons. 49(2): 521-527.
Jackson, G. et al. 1994. Farm*A*Syst progress report 1991-1994, Farm*A*Syst, Madison, WI.
Anderson, J. 1995. A bright future for the bobwhite. Friends of Wildlife 43:16.
27. No reference.
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Each EPA-registered pesticide undergoes a minimum of 120 tests designed to determine human health, safety and environmental effects.
On average, only one in 20,000 chemicals ever makes it from the laboratory to the farmer’s field. Pesticide development, testing and EPA registration takes eight to ten years to complete and cost manufacturers $35 to $50 million per final product.
Growers today use a sophisticated range of scientific practices called Integrated Pest Management to nurture and protect crops, soil and water. They include agronomic practices such as soil sampling, crop rotation and judicious use of natural and manmade products.
Many pesticides are low in toxicity to people and animals. Out of the 39 most widely used herbicides, 20 are less toxic than table salt and 30 are less toxic than aspirin.
Crop protection companies are taking responsible steps beyond those required by law to ensure that manufactured crop protection products do not threaten water quality. One company invested several million dollars in various studies to prove the water “safeness” of a single herbicide. Another monitored almost 30,000 wells in 37 sates for water quality.
The Certified Crop Advisor program is one of the industry’s greatest success stories. Now in its fourth year, more than 8,100 professional crop consultants in 43 states have voluntarily taken and passed state and national exams for certification. In addition to their past experience, certified crop advisors must participate in continuing education programs to remain certified. These committed individuals have pledged to make recommendations that are in the best interest of the farmer and the public.
Continued innovative agricultural research like precision farming is sharpening the industry’s ability to focus resources where they are needed and reduce the environmental impact of modern agriculture.