Abstract
Water sources are imperative natural resources, as living organisms cannot do without water. However, pollution of surface water is very common in the contemporary world, as people are struggling to increase crop productivity using chemicals. Pesticides prove to be a threat to surface water, as they always reach non-targeted destinations. Pesticides find their way into rivers and streams through runoffs, percolation, soil erosion, or through industrial discharges. Once the pesticides are in the water, they affect aquatic life and the entire organisms in the food chain. Pesticides can enter the humans’ bodies orally when they consume contaminated food or water, and the pesticide can accumulate in the bodies over time to have fatal effects. Pesticides play a critical role in killing aquatic life, causing cancer in humans, and in affecting human and animals’ reproductive systems. Apparently, diversified planting, use of biodegradable pesticides, use of alternative ways to control pests, and initiation of community educational programs would play a great role in addressing the pollution issue.
Introduction
Pesticides are very useful in destroying harmful pests that destroy crops; however, the pesticides are proving to be a threat to the ecological system, as they reach non-targeted destinations. Pesticides play a great role in increasing agricultural productivity, but they have adverse effects to the environment. Water-soluble pesticides always find their way into the streams and rivers, which threatens aquatic lives and the lives of people that depend on water from these sources (Lamberth, Jeanmart, Luksch, & Plant, 2013). Since agricultural practices are on the rise globally, there is an increase in the use of pesticides to increase productivity. However, from one time to another, pesticide geological surveyors find pesticide residues in streams and rivers among other water sources. Water is a basic need for all living organisms, and the harmful effects of pesticides in rivers and streams are beyond imagination.
The pesticide concentrations may vary from one stream to another, but pesticide concentrates in several tributaries are too high for human consumption. It is worth noting that the tributaries feed large water bodies, thus, the poisonous chemicals affect more organisms than expected. Fisheries and aquatic resources are valuable natural assets that provide people with financial and non-financial benefits; however, the use of pesticides is always raising great concerns owing to the high levels of toxic chemicals that threaten aquatic life (Damalas & Eleftherohorinos, 2011). Pesticides ought to kill or have adverse effects on living organisms; therefore, when they reach the unintended target, they have serious effects.
Objectives
This research paper aims at clarifying details about the effects of pesticides on rivers and streams. It analyzes the manner in which pesticides reach their non-target destinations, and the affected population. Its objectives include:
- To find out the main routes through which pesticides reach the streams and rivers
- To find out the factors facilitating the contamination of streams and rivers
- To find out the effects of the pesticides on fish and other animals living in streams and rivers
- To find out how pollution of streams and rivers affects humans
- To find out the most viable ways to address the pollution issue
Methods
This paper makes a critical analysis of the pollution issue that is imperative in the contemporary world. It will include a wide range of research from peer-reviewed articles and recognized documents among other viable sources. The paper will scrutinize some special cases of pesticide pollution that raised the eyebrows of the affected people, and the actions that they took. The following sub-section analyzes some of the threatening reports in the research on effects of pesticides on rivers and streams.
Chronic illnesses
Endosulfan, a pesticide used to control pests in crops, caused several health risks in humans in India. For more than 20 years, farmers sprayed their cashew nuts with the pesticide without a clear knowledge of its dangers. The terrain of most of the farms was unsuitable for aerial spraying, but the naïve farmers used the inappropriate method to control pests and insects. Owing to the high rainfall and the geographical structure, most of the chemicals in the pesticide ended up in the streams and rivers. The consequences were unimaginable, as the Indians experienced unusual diseases and deaths around the region. The unusual occurrences triggered researchers to investigate the pesticide and its chemical contacts. It was apparent that endosulfan contains highly poisonous chemicals that do not dissolve in water easily. Once in the soil particles, runoff water carries the chemicals to streams, rivers, and into large water bodies. When humans consume water or food products from such water sources, they ingest the endosulfan chemicals. The chemicals can cause acute and chronic illnesses, mental impairment, reproductive toxicity, epilepsy, or even death. Indeed, it was necessary to stop using the poisonous endosulfan pesticide, and adopt alternative measures to control pests.
Human reproduction
Cases of men having low sperm count increased drastically in Missouri for several years. This unusual occurrence raised eyebrows, and researchers investigated the underlying cause. After tireless struggles, they discovered that men with low quality and low sperm count had high concentrates of certain chemicals found in pesticides in their metabolic system. Alaachlor, diazinon, and atrazine are chemicals found in pesticides, and the men in question must have ingested the chemicals through drinking water. Moreover, cases of low birth rates arose, and they were associated with herbicide-contaminated waters. The most painful episode was that women in Kentucky were highly exposed to Triazine herbicides, which causes breast cancer. Other than using alternative pest control methods, the affected people had to ensure that drinking water was safe before consumption.
Aquatic life
Streams and rivers house a variety of aquatic animals, which experience much suffering whenever pesticides contaminate the water. Apparently, pesticide contaminants played a great role in killing millions of fish in the Great Lakes, and in reducing the number of fish and several invertebrates in Europe’s Rhine River.
Discussion of results and viable solutions
Main routes into surface water
When farmers spray their crops, they do not intend to make any form of pollution; however, in one way or another, the harmful pesticides usually find their way into streams and rivers. While applying pesticides to plantations, users may ingest some of the chemicals, some of it may evaporate into the air, and some may end up in water bodies. In case farmers spray their crops on a windy day, the pesticides may drift outside the intended area. Any pesticide that volatilizes into the atmosphere will always fall back as rain, and it will find its way into surface water. Moreover, pesticides may percolate through the soil and find their way into the streams and rivers. During the rainy seasons, runoff water acts as the main agent for carrying the pesticides into streams, rivers, and lakes. In some cases, eroding soil with traces of pesticides ends up in rivers and streams. It is worth noting that some industries are so inconsiderate, as they discharge effluents containing pesticides into waterways. Finally, the probability of accidents is also worth considering, as the pesticides may spill into streams and rivers by accident or through neglect.
Facilitating factors
Research indicates that pesticides have different abilities to contaminate water in streams and rivers. Firstly, it is imperative to consider the solubility of a pesticide, as highly soluble pesticides have a high ability to contaminate water. The distance between the farm and the water body also matters, as farms situated near streams and rivers are more likely to contaminate water than those that are located at distant places. Moreover, certain weather conditions facilitate the movement of the pesticides from the application site to the water bodies. On a windy or rainy day, for example, pesticides are more likely to find their way into the water bodies than during calm and dry weather. It is also very important to consider the type of soils, the terrain, and the method of applying the pesticides.
Fish and other living organisms
Water houses various animals that are very important in the eco-system. Fish, for example, is food for human beings and other animals, and it lives in water. Whenever pollutants like pesticides affect fish, they affect humans and other animals indirectly. Poisoning fish would mean poisoning the birds, human beings, and other organisms that feed on the fish remnants. In the case of pesticides that can cause bioaccumulation, the effect can be worse, as the chemicals build up to toxic levels in the bodies of the consumers over time.
Water with highly intoxicated chemicals from pesticides is very dangerous to the living organisms in streams and rivers, as it can inhibit the growth of plants needed by the animals to survive. Pesticides can kill insects and zooplankton, on which young fish feed. In such cases, the helpless creatures can starve to death if they do not relocate. Sub lethal doses of pesticides affect fish greatly by changing their physiology and by affecting their sex hormones. Low ratios of estrogen to testosterone sex hormones disrupt the endocrine system, which causes potential abnormalities in the behavior of the fish. Other than compromising proper development of the fish, the immunity levels of fish reduce drastically, fish fail to avoid predators, and they can even abandon their nests and broods when the toxicity levels are too high.
Jeopardy of aquatic lives
It is worth noting that pesticides can affect the reproduction cycle of plants and animals in the streams and rivers. Organochlorine pesticides have always proved to be a threat to egg laying organisms, as they affect calcium metabolism in the organisms, which causes eggshell thinning. Egg-laying fish and fish-eating birds are highly affected owing to the eggshell thinning process, which reduces the probability of hatching. Apparently, pesticides affect the food chain by reducing the reproduction of invertebrates living in water. The most devastating environmental impact is the death of fish and marine invertebrates due to the contamination of streams and rivers by pesticides (DeLorenzo, Scott, & Ross, 2001). Plants are likely to die when the toxicity levels of pesticides are extremely high, and in the process of decomposing, they consume oxygen, which is essential for the survival of fish and other aquatic animals. It is worth noting that water plants are the main fish habitats, and whenever they die, fish become exposed to predators.
Apparently, there is an alarming decline of aquatic animals owing to the industrial revolution. Some endangered species of animals might be extinct in the near future. Although various factors contribute to their decline, pesticides also play a great role in endangering their lives.
Human exposure to pesticides through water
Humans depend on streams and rivers for water and food, and the pesticides in question can enter human body orally when they consume food or water sourced from contaminated areas (Lorenz, 2009). It is worth noting that humans have limited access to information about the safety of the water, thus, their exposure to the harmful pesticides is significantly high. Occasionally, the traces of pesticides in the water can be too small to affect humans directly, but the small residues can be carcinogens, and they can play a critical role in disrupting the endocrine activities in the human body. Numerous people have died knowingly or unknowingly due to the exposure to pesticides in different ways. Since most of the pesticides accumulate in the body over time, many people die of poisoning, but they cannot make out that the poisoning resulted from an oral consumption of food or water from contaminated water sources.
Viable solutions and recommendations
The main approach to reduce the effects of pesticides on rivers and streams is reducing or eliminating the use of pesticides in major farming practices through the following ways.
Diversified planting: Many farmers have a habit of planting one type of crop in straight rows, which encourages pest infestation and easy travel of the pests. If farmers can try mixing different types of plants in farms, pests and insects would find it difficult to move from one host plant to another (Lotter, Seidel, & Liebhardt, 2003). Whenever the pests try to move from one host plant to another, they may fall into the trap of predators, and the entire process eases the role of controlling pests and insects.
Low toxicity pesticides: The environmental ministry should make efforts to ensure that industries manufacture biodegradable pesticides. Such products would be eco-friendly, as they have low toxicity levels to living things, and they only last for a short period in the environment (Damalas & Eleftherohorinos, 2011). Moreover, the government should make an initiative of banning harmful and non-biodegradable pesticides. The best approach would be insisting on the registration of all pesticides, which would call upon the Environmental Protection Agency (EPA) to impose strict regulations. EPA should analyze the ingredients, chemical properties, toxicity levels, and carcinogenic properties of every pesticide to determine its suitability for use. Moreover, manufacturers must label their pesticides with information about the product name, ingredients, use, and safety measures in case of direct or indirect ingestion.
Alternative ways of pest removal: Although the process might be tedious, farmers might find it efficient to remove pests from plants manually. They can apply the heat method to suffocate the pests, trap the pests, or cover weeds and infected crops with plastics to prevent further infections. In case farmers discover places that pests breed, they should destroy the places and work towards maintaining healthy soils using inorganic materials. Moreover, planting native species of crops that are resistant to pests would be a very smart way to prevent pest infection. Most importantly, farmers ought to know that the alternative ways to control pests are more efficient than control of insects using pesticides. Apparently, some pests become resistant to pesticides, and the use of the chemicals only harms the environment without necessarily achieving the intended goal.
Community educational programs: Surface water is highly important to humans, and it is upon the entire community to safeguard waters in the rivers and streams. The local government should establish educational programs that enlighten the community about the dangers of pesticides and the best way to address the issue. Communities should develop the desire to work towards managing natural resources and adopt practices that minimize the use of pesticides. It is worth noting that an enlightened community is the only way to eliminate the ongoing pollution of rivers, streams, and other water bodies. Schools, hospitals, organizations, and industries should all adopt policies that guard all water sources.
Conclusions
From the discussions, it is evident that pesticides are beneficial chemicals that protect crops and aid efficient food production. They are the only practical methods to control certain pests in some extreme situations; however, it is very important to use pesticides cautiously. Users must ensure that humans, animals, and the environment are safe in the course of using the pesticides. To ensure pesticides do minimum damage, farmers should use biodegradable pesticides using the safest methods. The local governments and the community should make it their obligation to take care of rivers and streams, which are the core tributaries that feed large water bodies. People should take the initiative to reduce pollution of water by using alternative ways to control pests, as the fatal consequences of water pollution affect everybody.
References
Damalas, C., & Eleftherohorinos, I. (2011). Pesticide exposure, safety issues, and risk assessment indicators. International Journal of Environmental Research and Public Health, 8(12), 1402-1419.
DeLorenzo, M., Scott, G., & Ross, P. (2001). Toxicity of pesticides to aquatic microorganisms: A review. Environmental Toxicology and Chemistry, 20(1), 84-98.
Lamberth, C., Jeanmart, S., Luksch, T., & Plant, A. (2013). Current challenges and trends in the discovery of agrochemicals. Science, 341(6147), 742-746.
Lorenz, E. (2009). Potential health effects of pesticides. Ag Communications and Marketing, 11(1), 1-8.
Lotter, D., Seidel, R., & Liebhardt, W. (2003). The performance of organic and conventional cropping systems in an extreme climate year. American Journal of Alternative Agriculture, 18(3), 146-154.