Pesticide contamination of groundwater and human health effects

¶ … Pesticide Use on the Environment in the United States

Managing pests, such as weeds, insects, plant diseases, and nematodes, has been on of the greatest challenges in both agricultural and nonagricultural environments throughout history.

Mainstream use of synthetic pesticides in the United States began shortly after the World War II, during a time of significantly increasing crop production. Since the 1950's, American agriculture has relied heavily on pesticides, dumping 30 billion pounds of pesticide into the environment.

Pesticides are chemical substances that are used to control pests. Pesticides are basically economic poisons that are used for controlling, preventing, destroying, or mitigating pests (Kobal, 1999). Synthetic organic compounds, as well as inorganic products like sulfur, natural botanical products like pyrethrum, and biological products, are commonly found in pesticides, which are produced commercially for pest control.

There are many benefits to using pesticides, as they protect animal health and enhance plant production (Kobal). Pesticides play a key role in the evolution of agricultural production to today's agricultural system and are used in modern plant breeding, fertilization, and irrigation methods.

While there are many benefits of using pesticides offer, it is also important to note that pesticides increase risks to human health and the environment. Recent increases in productivity have caused many social and environmental consequences. The consequences of using pesticides include documented cases of pest resistance and pesticide-induced pest outbreaks, as well as public concern for environmental contamination, human exposure, and residues on food.

Facts about Pesticides

It is estimated that about 1.1 billion pounds of pesticides are used in the United States annually (Larson, 1997). The uncontrolled use of pesticides over the past few decades has led to the contamination of many of the nation's hydrologic systems. Pesticide contamination of ground water has become a major environmental issue as ground water is used for drinking water by approximately half of the American population.

The immediate health effects that are associated with pesticides found in drinking water can include diarrhea, nausea, vomiting, abdominal pain, profuse salivation and sweating, blurred vision, skin and eye irritation, upper respiratory tract distress, edema of the lungs, acute gastro-intestinal distress, headache, dizziness, drowsiness and seizure (Larson, 2000).

Long-term exposure may include liver and lung cancer, as well as other types of cancer, genetic mutation and fetal deformities, depending on how long the body was exposed to chemicals, how harsh the chemical was, and how quickly the compound is removed from the body (Larson, 1997).

One of the main problems with pesticides is that about 90% of these agents fail to reach their intended targets. Instead, they unintentionally poison other organisms in the environment, including humans.

In 1989, the World Health Organization and United Nations Environmental Program published its "Public Health Impact of Pesticides Used in Agriculture," which revealed that, every year, one million people are poisoned by pesticides and 20,000 of these people die.

In addition, millions of animals are poisoned by pesticides, which are not even effective in killing pests. According to the United Nations Environment Program, approximately 500 pest species have developed resistance to one or more pesticides, meaning that the pesticides are useless on them.

Pesticide Groups

The word "pesticide" is a blanket term for many specific chemical substances, which are grouped according to the type of pest they aim to control: herbicides, insecticides, fungicides, and rodenticides. (Norris et al. 1991). Of these, the most controversial pesticides that are used in the U.S. are herbicides and insecticides.

Herbicides are used to control unwanted plant species that compete for light, water, and nutrients with the conifer tree species that are commercially desirable (PALCO 1999). Insecticides control unwanted insects. Fungicides control unwanted molds and fungus, and rodenticides control unwanted mammals. (Norris et al. 1991).

Many herbicides have been found in surface water such as ditches, rivers and lakes, as well as in coastal waters. This negatively affects the water system of the U.S. In addition, herbicides have been found to destroy wildflowers and wildlife, whether it is by spraying or through indirectly damaging habitat or food sources.

Many insecticides are unable to break down chemically so they contaminate soil, animal and fish tissue, plants, and water (Hamm, 1982). Insecticides have been proven to kill bird, fish, and other animals.

Surprisingly, few studies have proven the negative environmental effects of fungicides. However, some studies suggest it may be toxic to aquatic organisms, including clams, mussels and salmon.

As for rodenticides, these cannot discriminate between rodents and other non-target animals, including domestic pets. Therefore, these pesticides place a threat to all organisms.

Conclusion

While pesticides are definitely beneficial in the U.S., they also pose a great danger to the environment. It is a fact that pesticides kill insects, weeds, fungi, rodents and other unwanted organisms, as well as help diseases, yet these powerful agents are often unpredictable. If pesticides are not used carefully and conservatively, they can seriously damage the environment.