In the 1960s, Rachel Carson’s Silent Spring provoked a nationwide controversy about the use of harmful pesticides and brought environmental concerns to the forefront. She argued that the government should regulate and drastically reduce pesticide usage because even trace amounts can be dangerous to humans. Some have called this approach to regulation the precautionary principle, but scholars have recently questioned the soundness of this thinking. In his book The Laws of Fear, Cass Sunstein writes that “The Precautionary Principle. . .is paralyzing: It stands as an obstacle to regulation and non-regulation, and to everything in between” ((Cass Sunstein, The Laws of Fear (Cambridge: Cambridge University Press, 2005), 33.)) In other words, an extreme form of the principle is useless because there are risks associated with regulation as well. Frank Cross, a Law professor at Washington and Lee University, asserts that “The theory [the precautionary principle] can be traced back to Rachel Carson’s Silent Spring. ((Frank B. Cross, “Paradoxical Perils of the Precautionary Principle,” Washington and Lee Law Review 53 (1996): 851.)) If Silent Spring is based on this faulty principle, how can we justify implementing its recommendations? I believe that Carson’s argument does not rely on the precautionary principle and that the research she presents strongly supports regulation of the pesticide industry. Silent Spring presents clear evidence to support claims about the dangers of pesticides and does not rely on faulty logic.
Carson argues for risk management and precaution when dealing with very potent and harmful substances, but successfully avoids basing her argument on the precautionary principle. Silent Spring is a model for successful science writing for all generations.
Sunstein explains the precautionary principle and its flaws by way of the simple adage “better safe than sorry.” The most cautious version of the principle is that evidence of harm should not be a ground for refusing to regulate.” ((Sunstein, Laws, 18.)) For example, even without concrete proof that widespread pesticide use harms human health, the government could still justify limiting their application. The weak precautionary principle successfully refutes some objections to regulation, but does not direct policymakers. The stronger version, on the other hand, suggests that “regulation is required whenever there is a possible risk to health, safety, or the environment, even if the supporting evidence remains speculative and even if the economic costs of regulation are high.” ((Sunstein, Laws, 24.)) Although it may seem appealing at first, this theory contradicts itself because regulation can, however ironically, harm society as well.
The genetic modification (GM) of food is one example. GM food could potentially damage human health, but banning GM food could result in less nutritious food. Proponents of the precautionary principle would usually say that it tells us to ban GM food. However, we do not know the exact risks associated with regulation, and therefore the principle does not help regulators decide which course to take. If the government claims to base a decision upon the precautionary principle, they have prioritized some risks over others. As Sunstein reminds us, it is not possible to “adopt a general form of risk aversion. ((Sunstein, Laws, 34.)) If Carson’s book were based on the strong precautionary principle, critically thinking regulators would not have been able to justify banning DDT and other chemicals.
There are two conditions for the strong precautionary principle, as defined by Sunstein. First, there must be an unknown and potentially high economic cost of regulation. Silent Spring does not fulfill the first requirement because Carson assembles an enormous data set of proven, not speculative, harms associated with the groups of pesticides that she mentions. She uses government-sponsored research published in scientific journals, and even includes the reports of non-scientists that conclusively support her statements about pesticides. Carson’s work partially fulfills the second condition because there are potential economic costs to dramatically reducing pesticide use. Crop yields could decrease, and perhaps more importantly, we might be unable to combat malaria. However, these risks are not unknown. Farmers have grown crops and governments have fought malaria for decades without the newest and most potent insecticides. Additionally, Carson proposes other proven methods, including biological control and lower doses of less potent pesticides that could at least partially prevent lowered crop yields as well as malaria. Carson offers two related arguments–one concerning the detrimental effects of pesticide use on the environment, and the other concerning human health–that help to refute the precautionary principle in yet another way.
Only four of Carson’s twelve chapters directly mention humans. Her work is clearly not precautionary from an environmental standpoint because there is indisputable evidence that manmade pesticides harm the natural world. There are innumerable statistics about increasing bird and fish deaths since the widespread use of inorganic pesticides, and controlled studies of lab animals indicate that exposure can lead to disability or death. Clear Lake, California, is one especially potent example. The government applied DDT to the lake in a ration of 1 part DDT to 70 million parts of water, a very dilute measure by any standard. Within months, the western grebe population near the lake began to die. DDD concentrations in their fatty tissues exceeded 1600 parts per million. ((Rachel Carson, Silent Spring (New York: Mariner Books, 1962), 46.)) A similar type of event has occurred with soil and herbicides. Even very small concentrations of powerful pesticides can cause enormous damage.
As frightening as these studies are, to mobilize large groups of people to change, Carson had to make a viable connection to human health. Harms to human health are the most difficult to substantiate because it is unethical to experiment on humans, and symptoms of the damage from chemical buildup could take a long time manifest. Carson’s chapter, “The Human Price,” must demonstrate the danger of pesticides to humans and convince the public of their harm without relying on the precautionary principle alone. In this chapter, Carson attempts to prove that pesticides have proven negative effects on human health, implying that their usage should be minimized. She begins with examples of spray men, farmers, and pilots who have died suddenly due to very acute exposures, but she acknowledges that we “must be more concerned with the delayed effects of absorbing small amounts of the pesticides that invisibly contaminate our world.” ((Carson, 188.)) There are several difficulties associated with linking human diseases to their causes. In addition to the ethical constraints of experimentation on humans, the body is so complex that, as Carson reminds us, “cause and effect are seldom simple and easily demonstrated relationships” ((Carson, 189.)) Given these sticking points, Carson’s task–to substantively prove the harmful effects of pesticides on humans–is even more difficult.
Pesticides are stored in fatty tissue, which means their residues stay in the body for a long time, and the liver can be damaged by many of the pesticides. One of the liver’s functions is to neutralize pesticides, which it cannot do as well once damaged by pesticides. Interestingly, the incidents of cirrhosis and hepatitis are increasing. Other pesticides affect the nervous system. We are never exposed to only one pesticide, and they are much more damaging in combination. At the end of the chapter, she focuses on medical histories of people who either intentionally or unintentionally exposed themselves repeatedly to DDT and either died or became violently ill. Several British researchers exposed themselves to DDT and experienced “extreme irritability. . .mental incompetence. . .violent joint pains. . .insomnia” and other unpleasant symptoms. ((Quoted in Carson, 193.)) Also, the University of Melbourne reported sixteen cases of mental disease in patients with “a history of prolonged exposure to organic phosphorus insecticides” known to cause nervous system deterioration in animals. ((Quoted in Carson, 198.)) These medical histories, combined with many research tests in animals discussed in other portions of Silent Spring, are the only real way of ethically testing the danger of pesticides to humans. Carson acknowledges that we cannot ascertain the exact implications of pesticide use for years after the public has been widely exposed, and more extensive research has been completed. But by combining compelling circumstantial evidence with the available case studies and research on animal populations, Carson builds a compelling case that pesticides can harm humans and should therefore be regulated much more stringently.
Although there are significant obstacles to definitively proving Carson’s claim, she successfully argues that pesticide use should be reconsidered and dramatically 
reduced. She does not argue that all pesticides should be banned, since at the time there were no suitable alternatives to DDT in combating global malaria. Her fifty-five-page bibliography and extensive research clearly indicate the harm of pesticides. She argues for risk management and precaution when dealing with potent and potentially deadly substances, but successfully avoids anchoring her argument to the precautionary principle. Silent Spring provided an effective model for persuasive science writing for generations to come.
Bibliography
Carson, Rachel. Silent Spring. New York: Mariner Books, 1962.
Cross, Frank B. “Paradoxical Perils of the Precautionary Principle.” Washington and Lee Law Review 53 (1996): 843-862.
Sunstein, Cass. The Laws of Fear. Cambridge: Cambridge University Press, 2005.
