March 19, 2012
Insecticides, Biocides, Algicides, Herbicides, Rodenticides–what do all of these have in common? These terms are all part of a larger group of 34,000 pesticides, defined as “a substance or mixture of substances intended for preventing, destroying, repelling or mitigating any pest.” Pesticide use in both 2006 and 2007 amounted to an estimated 5.2 billion pounds worldwide, with 1.1 billion in the United States alone. However, the use of pesticides is quite controversial and is debated from all ends of the spectrum, including health advocates, environmentalists, politicians, consumers, and the agricultural industry. It comes as no surprise that most of these pesticides are toxic–after all, that is the purpose for which they were created. The following article outlines the pros and cons to pesticide use in hopes of determining whether the risk of using pesticides is worth the benefit.
The benefits of pesticide use are extensive and provide a strong basis for pesticide advocates. First, pesticides provide the United States with huge economic profit–the industry made $12.5 billion dollars in 2007, exporting 40% of domestically created pesticides (US EPA). In addition, pesticides have saved millions of lives, eradicating many disease-carrying insects. Pesticides have also helped the forestry ecosystems by helping trees to resist disease-carrying insects like the gypsy moth. However, the largest benefit of pesticides has to do with increased agricultural yield. Worldwide, “90% of the damage sustained by crops is caused by less than 100 species of weeds, insects, fungi and microbes – all considered pests” (Food Safety Factoidz). With the use of pesticides, crop productivity increases by 20 – 50%, thereby making it possible for consumers to choose from an “abundant supply of fresh, high-quality foods that are affordable and accessible year-round” (Crop Life America). Millions of products rely on agricultural products, and without the proper use of protection, a domino-effect of damage and deficiency could lead to serious losses.
Pesticide use also has its cons that affect crops, pests, and humans all around the world. For one, although pesticides are effective in killing or repelling pests, that effect lasts very shortly as many pest species develop resistance to pesticides rapidly, and the number of resistant species has increased since pesticides were first used in the 1950s. Pesticides are also nonspecific, meaning they affect pests and non-pests wherever they are spread. Also, pesticides are mostly sprayed aerially over a field of crops and only 5% of the pesticides reach their target while the other 95% spreads out to the environment: “the air we breathe, the water we drink, and the food we eat” (“Pros and Cons,” Factoidz). Because of the increased use in pesticides, ground water sources have been contaminated, and have also caused farmers to abandon the use of crop rotations which, in turn, has increased pesticide dependence.Lastly, pesticides have caused the acute poisoning and death of millions of people worldwide, according to the World Health Organization.
Clearly, the use of pesticides have posed a risk on humans and the environment. They have prevented the worldwide spread of disease which, many proponents argue, have saved many lives. The mass production and mass use of pesticides, however, has also threatened the environment with contamination and has threatened human, plant, and animal health through poisoning. The risk has not gone unnoticed and people are aware now that pesticide use must be reduced to minimize risk. One way proposed to reduce pesticide use is through integrated pest management (IPM) which involves mainly cultural, biological, and chemical methods and techniques collectively in farming to control pests. Exposure to pesticides must also be reduced and there are several “how-to methods” people can follow at home to minimize exposure after purchasing organic produce. Pesticides have largely remained a risk but the efforts to reduce their use and better management should be considered in order to minimize their risk to the environment.
Sergio Avelar and Caroline Smith are undergraduates in the USC Dana and David Dornsife College of Letters, Arts and Sciences.
In the 1960’s Rachel Carson’s book Silent Spring began to expose the issue of DDT and the possible health threats it had on plants, organisms and humans. As pesticide and herbicide use became popular as a way of creating more productive agricultural land, the widespread use was not only destroying the insects and weeds, but the entire environment was targeted with these strong chemicals. Although we have limited our use of DDT today, it is a chemical that does not naturally deteriorate. It stays in groundwater and the soil and continues to harm plants, animals, and humans. Contrary to popular belief, the weeds and insects that we try to eliminate by using DDT can actually benefit the environment. Certain weeds prevent bad insects from destroying plants or crops and insects such as ants aerate the ground with their tunneling as well as eating other harmful bugs. By using DDT we are not only destroying natural solutions to our problems, but also innocent organisms who cannot escape the treatment. Birds may not be in the area when crops are sprayed with chemicals, but they eat the worms that are in the soil. These worms are contaminated and therefore poison the birds. Some may die, while others may become infertile or their eggs cannot hatch. Just like bird populations, fish populations have decreased because of DDT spraying and the runoff from DDT treated agricultural lands that seeps into streams and rivers close by, therefore poisoning the fish and killing them.
For many years, we thought our actions of using DDT were not significantly affecting the environment. Instead, it turned out that we were not only harming the environment but also humans. But because we live off of the land and the crops that are sprayed by DDT, the poison bio-accumulates in the crops we eat from fields sprayed by pesticides and herbicides. Aerial spraying was also a detrimental practice, which harmed many animals and poisoned humans without their knowledge. Because of our lack of knowledge of the dangers of DDT, to this day most people have DDT in their body. Some people still contain DDT because it is stored in fat and as we metabolize that fat, we release the poison into our body, which can cause severe neurological and liver problems.
This controversial use of DDT has triggered a debate over whether or not using pesticides and herbicides is beneficial enough to continue the practice. The variety of harmful effects that DDT has on not only the environment, but also on humans, is reason enough to limit or even eliminate our use of DDT. DDT poses a risk based on how it negatively affects the survival of various organisms. For example, multiple studies have determined that the bioaccumulation of DDT has compromised the ability of birds to create healthy eggs. Some cows are producing milk that has traces of DDT, and all organisms, including humans, that are exposed to the poisons inevitably pass it on to their offspring.
The scientific risk of DDT is assessed by determining the health threats towards organisms and humans and how severe these threats are to their survival. Even though DDT was used in low concentrations around humans, the contaminant had adverse effects because of its poisonous properties. Based on the number of organisms and people affected negatively by DDT, the risk of using it is not worth the very few benefits associated with it. When studying the acceptable exposure levels, lab tests are not accurate enough to prove that DDT is safe for use because a very specific amount is used in highly artificial conditions which does not accurately replicate a real life exposure situation. Different demographics of people also deal with different levels of exposure and those effects. The concentration of DDT increases as it moves down the food chain, therefore we cannot be too sure of the exact exposure to humans.
After years of debate and scientific research, the widespread use of DDT is not worth the risk towards humans and the environment. The pesticides and herbicides do not benefit the land as much as they harm the land. Even though the actual damage due to DDT came before the risk assessment, it has allowed us to be aware of the dangerous effects and to greatly limit our DDT use.
Alanna Waldman and Chantal Morgan are undergraduates in the USC Dana and David Dornsife College of Letters, Arts and Sciences.