In chapter two, the author discuss the issue of pesticides.
- Early in the semester we discussed the importance of asking the right question. There are many questions asked in the chapter. What is the primary question of the chapter?
- The title of the chapter is titled “the pesticide controversy”. What is the controversy? Or in other words, what is a moral dilemma at work here (i.e. what values are in conflict here)?
11
CHAPTER 2: THE PESTICIDE CONTROVERSY
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.
12
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
13
(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
14
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
15
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.
16
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,
17
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
18
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.