Order Number |
4643566573 |
Type of Project |
ESSAY |
Writer Level |
PHD VERIFIED |
Format |
APA |
Academic Sources |
10 |
Page Count |
3-12 PAGES |
What is the pesticide controversy?
Ma W a 95 a b a Na G a a H a . Fearful the British would poison him, Hitler made sure to only eat food after it was eaten by Margot and fourteen other girls serving as his official tasters.22 Hitler may have been evil but he was not stupid. He knew that poisons affect people differently, and knew that any food which harmed one girl might harm him (then pity what would happen to the cook!).
Every year we spray something akin to poison on our food, and use something akin to H system of making sure we are not harmed. The motives are polar opposites Hitler cared only for the preservation of his person, while we seek the safety of all humans. Whether they are synthetic pesticides a a a , a a three types of pests: insects, weeds, and pathogens (e.g., fungi and viruses).
At some level they could poison us also. Many contain carcinogens, cause neurological disorders, and the like. Yet, our food seems safe to most people, and since 1992 cancer incidence rates have even fallen or remained the same,23 cancer death rates have fallen,24 and life expectancy in the U.S. has been steadily increasing.25
Can we be absolutely sure pesticides are used safely? Not entirely, but like Hitler (and according to movies, every Roman emperor, Catholic Pope, and Medieval king) we employ testers not in the form of humans, but animals. All pesticides must be approved by the Environmental Protection Agency (EPA), where the pesticide under consideration is given to laboratory animals at different levels.
The animals a time and used to gauge the threats to human health a pesticide may pose. The EPA then determines whether the pesticide should be allowed, and if it is, the specific instructions on how it should be applied.
Is it cruel to test pesticides on animals? It cer a , b on animals will cause us to harm humans a notion in which 90% of toxicologists agree.26 Pesticides decrease the cost of food, and make fruits and vegetables more affordable.
Raise the price of these healthy foods and cancer rates and other health problems in humans will rise.27 Help the lab animals, and you harm some humans. Modern, democratic societies must make a tradeoff between harm to ab a a a a a a . I a , , a the overall harm to animals and humans as low as possible.
Hitler was willing to sacrifice fifteen girls to save himself. The modern world is willing to sacrifice a small number of laboratory animals to protect millions of humans. Moreover, the EPA continues to find ways to reduce testing on animals without sacrificing food safety, like recent developments in molecular and computational sciences, which can sometimes be substituted for animal experimentation.28
In June of 2013 The Wall Street Journal a ba , W A a B B Ea a Mostly Organic Diet? a enter on pesticides. It featured one person who answered
a a , a a answers describes the pesticide controversy nicely. One person argued in favor of organic foods under the belief that regulatory agencies do an inadequate job of protecting public health, and the other argued that conventional food is not only safe, but that the use of pesticides makes fruits and vegetables more affordable.
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Lu (Alex) Chensheng: Ma a he e icide f d i f d a e hi g fea beca e he le el fall ell bel fede al afe g ideli e a d h a e da ge B fede al g ideli e d ake i acc ha effec e ea ed exposure to low levels of chemicals might have on humans over time.
And many pesticides were eventually banned or restricted by the federal government after years of use when they were discovered to be harmful to the environment or h a heal h. Janet H. Silverstein: Gi e he lack f da a h i g ha ga ic f d lead be e heal h, i ld be c e – productive to encourage people to adopt an organic diet if they end up buying less produce as a re l A f e icide exposure, the U.S. in 1996 established maximum permissible levels for pesticide residues in food to ensure food safety. Ma die ha e h ha e icide le el i c e i al d ce fall ell bel h e g ideli e .
The Wall Street Journal. J e 17, 2013. W ld A e ica Be Be e Off Ea i g a M l O ga ic Die ? R3.
The pesticide controversy boils down to whether the regulatory agencies are making wise decisions about how pesticides are used or whether we must take measures to protect ourselves. In the U.S., that agency is the Environmental Protection Agency (EPA), and it is charged with permitting pesticides only when it does not present an unreasonable risk to man or the environment, while also taking into account its economic costs and benefits.29 The controversy is whether it fulfills this charge.
What are the benefits and harms of pesticide use?
Before delving into the regulation of pesticides we must develop a better appreciation of the benefits and potential harms of pesticides. The benefits are that they protect crops from damage by insects, weeds, and pathogens, allowing farmers to produce more food using the same amount of inputs. For consumers, this means greater availability of foods and lower prices.
Peanuts are one of the healthiest foods and are relatively inexpensive. If no pesticides were allowed peanut yields would fall by 78%; about one-third of this reduction is due to the absence of herbicides and two-thirds for insecticides and fungicides combined.
As less peanuts are sold on the market, prices would be expected to rise by 150%. Rice is staple food for much of the world, and without pesticides yields would fall by 57%. If denied pesticides, the yield for some of our healthiest foods like apples, lettuce, tomatoes, and oranges would fall by more than 50% (all are U.S. numbers).30 These are the same fruits and vegetables experts keep telling us to eat in greater portions.
Pesticides allow us to produce the same amount of food using less land, and makes it easier for farmers to employ no-tillage farming techniques where no plowing is performed, thereby reducing soil erosion and fertilizer runoff. Many of the genetically modified crops today are valued because of their resistance to pesticides, but we defer this issue to another chapter.
A Chinese cook recently demonstrated the potential harms of pesticides when he mistook a pesticide for a spice. One person died and twenty others were sickened.31 Pesticides per se are not poisons though. The First Law of Toxicology, established in the sixteenth century, is that it is the dose, not the chemical, that makes a poison.32 We are constantly exposed to natural pesticides in our daily life. After all, plants make their own pesticides to ward away pests, and we eat many of these plants.33
If exposed at unsafe dosages, pesticides can cause cancer and a variety of neurological disorders like Pa ki di ea e. To what extent has pesticide use over the last few decades harmed human health? The more we learn the more difficult it is to say. In the early eighties research concluded that pesticides played a very minor role in human health problems34 leading some to conclude that virtually nobody dies of cancer caused by pesticides.35 Since then we have learned how difficult it is to determine the impact of pesticides on health, given the variety of carcinogens we encounter
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(including charred meat,36 acrylamide in French fries and coffee,37 and household cleaning supplies38) and the long delay between exposure and health impacts. Scientists are fairly certain that about one- third of cancer is caused by smoking and another one-third is caused by diet, weight, and exercise, but the sources of the remaining third are difficult to assign.39
Of this other third of cancers, pesticide use certainly seems to play some role. Non-H dgki lymphoma, prostate cancer, melanoma, and a variety of other cancers are correlated with pesticide use. People applying pesticides, living on farms, or employed in pesticide manufacturing seem to have higher cancer rates than their counterparts who rarely encounter pesticides.40
The issue becomes even more complex when one considers the many indirect ways pesticides affect humans. Honeybee colonies have reduced dramatically in recent years in something called the Colony Collapse Disorder, and though he ca e i ce ai , e icide c d be a b a e.41 Since we rely on bees to pollinate much of our fruits and vegetables, this indirect effect could negate any direct benefits of certain pesticides.
There is little controversy over whether pesticides may pose a potential harm. What is questionable is whether actual harms are observable, and if they are, whether the benefits of pesticides outweigh those health harms. For instance, a pesticide may directly increase cancer rates slightly, but indirectly cause a larger reduction in cancer rates by reducing substantially the price of fruits and vegetables.
When the Mayo Clinic listed seven tips to reducing risk of cancer, the first tip was to abstain from tobacco and the second was to eat a healthy diet, which was described as lots of fruits and vegetables, a limited amount of fat, and avoiding too much alcohol. Avoiding foods produced using pesticides was not even on the list.42
Now that we recognize this trade-off between pesticide harms and benefits we turn to the regulation of pesticides in western democracies, focusing mostly on the U.S. regulatory system. While the legal framework for regulating pesticides differs in western Europe, the methods, challenges, and goals are very similar. Much of what is said about the EPA can be extrapolated to the EU and the UK.43
How are pesticides regulated?
It is not unusual to hear about salespeople in the early days of synthetic pesticides (1940s) who would drink the chemical to prove its safety. One always suspects the salesmen were playing a ruse, but it is a testimony to how safe people once considered pesticides. The pesticide DDT was called a
a i f a ki d d i g W d Wa II, as it was the first war where more people died of casualties than disease. Farmers began using DDT on a large-scale and governments would spray generous amounts to waters to kill mosquitoes.
Rachel Carson was not so impressed though, as she began to document the cumulative effect of DDT in animals. In 1962, she published her scathing indictment of DDT in her book Silent Spring. This book launched an environmental movement that continues today.
Her book is widely credited with convincing President Richard Nixon to establish by executive order the Environmental Protection Agency eight years later.44 The EPA acknowledges in its official history that it was Silent Spring that prompted the federal government to address the threat of pesticides, along with other environmental problems.45
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Pesticides have been used since ancient times. In The Odyssey, Homer has Ulysses bellow to his nurse, Bring blast-averting sulf , , ! / T I . 46 It is likely that
the Greeks used sulfur as long as they could remember, and that experience taught them how to use it safely. Today synthetic pesticides are typically created in a factory. New formulations are continually introduced, ones humans do not have generations of experience using, so controlled experiments are needed to determine what health threat they may pose.
T U.S. EPA, and older pesticides are continually reviewed to make sure they meet the newer safety requirements. When a pesticide is registered it can then be used but only in settings and at dosages approved by the EPA. If the EPA makes wise decisions about registering pesticides and determining approved dosages then little to no harm should come from pesticide use.
To determine whether a pesticide is safe the EPA first requires the pesticide company to provide data regarding the largest amount of pesticide residues one would expect to see on the crops in the field (when pesticides are applied at their highest dosage) and in processed food made from those crops.
Then they seek to determine if those residues are harmful. This is where the tasters laboratory animals are used. By exposing animals to different levels of the pesticides they can determine the threshold beyond which will cause harm to the animals. This threshold can be stated
, appropriate threshold for humans.
In toxicology this threshold may be specified as a median lethal dose, or LD50, which refers to the dose required to kill half of the animals exposed in experiments. It is a standardized dosage that allows us to compare the relative dangers posed by different chemicals, and in doing so it sometimes shows how safe many pesticides are.
The herbicide glyphosate used on almost all soybean acres has an LD50 of 4,320. This seems safer than table salt (LD50 = 3,300) and much safer than caffeine (LD50 = 192).47 If you do not fear the caffeine in your coffee then there seems little to fear from the herbicides applied to soybeans.
Measures like the LD50 are mostly used to determine the potential hazard to farm workers applying . T , EPA LD50 as a
measure but some N O A E L NOAEL. T is the highest dose of a pesticide which results in no negative response in the animal, and that negative response could be almost anything, including weight-loss or changes in t production of an enzyme. These studies are so comprehensive they sometimes observe animals over multiple generations.48
Human biology is not the same as that of lab animals, so to be extra safe, that NOAEL threshold (again, in units like residues per pound) is then divided by a a large number from 100 to 1,000 so that the EPA is comfortable deeming the pesticide as safe.49 This threshold takes into account all the avenues by which residues may reach the consumer, so it considers the total diet of consumers, including food imports and even drinking water. 50
So pesticides are only expected to harm humans when they are exposed to a dosage a hundred or a thousand times larger than the dosage observed to harm animals. To understand the importance of this safety factor, try this experiment. Consume large portions of chocolate in one day more than you ever imagined eating in your life. Chances are that you will be okay. Then feed a dog the same
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amount of chocolate per pound of weight actually, d d ha , a he d g d bab die. This is why the EPA uses such a large safety factor. If you fed a dog 1/100 as much chocolate as you ate, it would probably be okay.
The bodies of infants and children react different to pesticides, so other factors must be considered to protect kids. For instance, the Food Quality Protection Act states that if reliable data on threshold effects for a child are not available, the safety factor should be increased by a factor of ten, perhaps increasing from 1,000 to 10,000.51
Why must we experiment on animals? Because controlled experiments are absolutely necessary for determining when a pesticide causes health harms. In the real world, greater exposure to pesticides may be correlated with poor health, but the correlation may not be causation. Someone who eats non-organic food may also tend to eat less vegetables, smoke, and rarely exercise.
If those people are more likely to develop cancer, was it the pesticides that caused it? Or was it too few vegetables, or insufficient exercise? One cannot tell, and so controlled experiments are necessary for determining what happens to an animal when pesticide use increases but everything else stays the same. They are so necessary that around 90% of toxicologists disagree with the statement: animal testing is not needed.52
This threshold mostly relates to the prevention of non-cancer health problems. If a pesticide is shown to cause cancer in laboratory animals when given in high doses the EPA will assume there is no safe dosage, and the pesticide is denied registration. The EPA certainly is not lax when it comes to allowing pesticides to be applied, and generally will not approve a pesticide if it increases e e risk of having cancer by even one-in-one million.53
Regulators do j ea e he e ia ha h a b he e i e a a e . The EPA considers a broad array of environmental impacts, and even assesses the potential harm to threatened and endangered species.54 When the neonic class of pesticides was approved for use it could not have been anticipated that it might cause a collapse in bee colonies. Later, when research determined they might be partly responsible, the European Union placed a two-year ban on their use, and the EPA is studying the situation to see if new restrictions are desirable.55
Pesticide regulation does not just take into account the safety of a pesticide but its benefits also. A chemical can directly harm humans through exposure but can benefit human health by keeping the price of healthy foods low especially prices of fruits and vegetables.
Thus a pesticide with a lower low NOAEL may pose less harm than one with a higher NOAEL if it does an even better job of providing affordable fruits and vegetables. The EPA would be remiss if it did not consider the benefits of a pesticide on farm productivity when articulating how it should be used.
Finally, regulation does not stop with the animal trials. Humans may respond differently to pesticides than animals, and there is no guarantee that the safety factors used offer enough protection. Also, experiments cannot reveal the cumulative danger of exposure to all the pesticides that are used.
I ike d i ki g e i f a , a b e f i e. Each b e had a negligible effect on your ability to drive, but taken together, you do not belong behind the wheel. Researchers are constantly collecting data on the health of individuals and their exposure to toxic chemicals like pesticides, to detect any alarming correlations. This field of research is called epidemiology, and it serves as a second opinion on the effectiveness of pesticide regulations.
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Epidemiological studies are used to revise established regulation and to help the government develop better guidelines on the regulations of new pesticides in the future.
How effective are pesticide regulations?
It should be apparent by now that the EPA and their European counterparts set high safety standards regarding pesticides based on controlled animal experiments and epidemiological studies. The question is whether those standards are achieved. If pesticides only impact humans as they do animals in experiments, and if pesticide regulations are properly enforced, then the use of pesticides in agriculture is very safe.
Safe use of pesticides is possible today partly because new technologies can detect residues at around one part per quadrillion (like detecting a grain a salt in an Olympic- sized swimming pool!).56 To illustrate, you would have to eat more than 7,000 tomatoes per day throughout your life to reach the maximum residue level of pesticides inherent in conventional tomatoes. Since you eat far, far less than this, there is no reason to fear conventional tomatoes.57
Government agencies sample and check foods to ensure tolerance levels are being observed, and for the most part they are. Of the grain, dairy, seafood, and fruits sampled in 2008 none displayed e d e e e ab e EPA tolerance level. Only 1.7% of vegetables exceeded the tolerance level.
The numbers were slightly higher for imported food, though still less than 5% (save for food group he a 8.3%).58 Other studies support this finding that pesticide residues only rarely exceed the
EPA maximum.59 Remember, even the rare food that does exceed the limit is still at a far lower level than that which causes health problems in laboratory animals.
Epidemiological studies however do find that pesticides impact human health. For three years one of the authors has printed and filed almost every article about pesticides from ScienceDaily.com. What percent of these articles find that pesticides harm human health? Almost 100%! One says that prenatal exposure to DDT causes high blood pressure later in life.60 Another suggests a link between he e c de be a d Pa d ea e.61 And another links a pesticide additive PBO with
noninfectious coughing of young children.62 There are many others (to see for yourself, go to c e ceda .c a d ea ch f he d e c de ).
The problem with epidemiological studies is that it is very easy to establish correlations between health impacts, food, and the environment, but establishing causation is impossible. If consumers who eat organic food and consume less pesticide residues also tend to eat healthier foods and exercise more, and one finds these individuals have lower cancer rates, how can you tell whether the cancer reduction was caused by less pesticides, better food, or more exercise.
Suppose for arguments sake that correlation did mean causation. Could it really be that every single epidemiological study finds a link between pesticide use and health problems? No, but only those studies that do find a link are deemed interesting enough to publish.
Would you read an article titled, Use of Popular Pesticide Not Linked to Health Problems? What about an article titled, Use of Popular Pesticide Shown to Cause Infant Death, Early O P Disease, and Brain Cancer? Both academic and popular publishers know the answer, and are consequently more likely to publish the second article and reject the first. Only the researchers who know about the both published and unpublished studies know a e c de e mpact.
In the end, as with many agricultural controversies, opinions about the use of pesticides often boil down to whether regulators are making wise judgments. Wise judgments require experience,
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knowledge, and also the proper incentives. If one believes that politicians, regulatory agencies, and pesticide corporations engage in corruption, like a revolving-door system where the same individual works for the pesticide company and then the regulator, the decisions about pesticide regulations may not protect the public. Those with this belief decide to protect themselves by consuming organic food where [synthetic] pesticides are not used. Some surveys suggest this is a major reason consumers in the U.K. and U.S. buy organic.63
We, the authors, have confidence in the U.S. and EU regulators, and believe pesticides in agriculture pose very few dangers to the safety of our food supply. In our view, the potential dangers of pesticides are outweighed by the benefits they provide in lowering the price of fruits and vegetables. However, we recognize that some readers will disagree, and will thus seek to protect themselves by purchasing organic food.
Is organic food free of pesticides?
No, organic food does contain pesticide residues. Synthetic pesticides are found on organic food, around 25% for organic fruits and vegetables. Such pesticides are not allowed under organic certification standards, suggesting that not all farmers are following the rules (note that conventional farmers sometimes deceive too, as residues from banned pesticides are sometimes found on food64). Still, the residues are in much smaller amounts compared to conventional food.
When organic food is said to contain less pesticide residues, he e ea ch i ig i g he a a e icide ga ic producers are allowed to use. These are chemicals, biological agents, and minerals found in nature that do not need to be transformed using advanced chemistry and big factories.
Rotenone is acquired from the roots of certain plants, and can cause neurological disorders. Bacillus thuringiensis is a bacteria found in the soil. Copper and sulfur products are minerals, and are both toxic at high levels. All of these are applied to crops to protect them from pests, and all can pose considerable health harms if use recklessly.65
How dangerous are these organic pesticides, and do they make organic food less safe to eat than conventional food? First, it should be noted that organic farmers in most of the developed world can only use government-approved organic pesticides, and these are approved because they are deemed to be safe.
There are natural pesticides that are not allowed due to their toxicity, such as nicotine, lead, and arsenic. Those that are allowed are usually exempt from the maximum tolerance levels because they have low toxicity, are unlikely to be detectable in foods, or decompose quickly, thereby posing few health risks.66 Most organic pesticides must be approved by the EPA and are subject to the same safety standards, so pesticide residues on organic food pose no more danger than residues on conventional food.67
The consensus is that, while organic food contains fewer synthetic pesticide residues, it does not seem to improve health but neither is it worse for health. The National Academies of Sciences has determined that both pesticides are equally safe,68 and 85% of toxicologists disagree with the statement that organic/natural products are safer in regards to chemical exposure.69
In a comprehensive review of organic foods researchers find that consumption of organic produce d e i c ea e ones exposure to pesticides, but that farmers who apply the pesticides face the most risk.70 Perhaps we need to worry less about pesticides in our food and more about pesticide exposures to farm workers? That said, the EPA does account for farm worker exposure to pesticides (and even pesticides used in the home, including insect repellent).71
In regards to organic food, one must make a personal judgment. There is no compelling reason to fear organic foods, but no overwhelming evidence to express confidence in its safety either. Most people probably have an intuitive opinion about which foods offer the best combination of safety and nutrition. Hopefully this chapter on pesticides has made that intuition better grounded in facts.