Pest Management and Pesticides: A Historic Perspective

Transcription

1 Pesticide Education Program Pest Management and Pesticides: A Historic Perspective Learning Objectives: Pests have existed for centuries. The control of these pests has evolved over time, including the development of synthetic chemicals and pesticide regulations. This lesson plan provides a perspective of pest problems and events over the years, the progression of pest control, the introduction of pesticides, and the current use of pesticides including best practices to help prevent environmental contamination. Suggested Audience: 6 th 8 th Grade Suggested Time: This lesson could be covered in a forty-five minute class period. More time may be needed depending on use of activities. Determine what is best for your class depending on students and available time. Pennsylvania Academic Standards: Environment and Ecology C. Environment and Ecology B. Environment and Ecology A. Science and Technology and Engineering Education B2. English Language Arts CC A. Lesson Instructions: Identify key people and events that shaped the environmental history in the United States. Describe the impact of pests in different geographic locations and techniques used to manage those pests. Explain how Best Management Practices (BMP) can be used to mitigate environmental problems. Explain how decisions to develop and use technologies may be influenced by environmental and economic concerns. Engage effectively in a range of collaborative discussions, on grade-level topics, texts, and issues, building on others ideas and expressing their own clearly. A History of Pesticides video, available on the Penn State Pesticide Education Program YouTube channel, is an eightminute video that provides information on the content of this lesson plan, including pest problems, early pest control, current regulations, and pesticide safety education. Consider showing the video during this lesson when you think it is most appropriate for your students. Section 1: Pest Problems Over the Years Pests are organisms living and growing where they are not wanted and can cause damage to plants, humans, structures, and other creatures. A pest can interfere with food and fiber production, affect animals, damage ornamentals in a lawn, or the even compromise the structure of a house or building. Pests can also transmit disease. Pests include four categories: 1) Vertebrate Pests, 2) Invertebrate Pests, 3) Weeds, and 4) Diseases.

2 Discussion: Have students share an example of a time that a pest has bothered them around the home or school. Ask them if they know of widespread pest problems, whether current or in the past. Pests have existed for centuries and, just as they do today, caused damage to crops, animals, people, buildings, and more. Throughout history, several significant events have been caused by pests. Bubonic Plague: In the 1300s, the Bubonic Plague, or the Black Death, occurred when rat fleas became infected with bacteria. As rats became unavailable as a food source, the fleas turned to humans. The Plague is estimated to have killed up to 60 percent of Europe s citizens. Irish Potato Famine: In the 1840s, light blight, a fungal disease, plagued the Irish potato crop. Potatoes were destroyed in the field and rotted during storage. As potatoes were a primary agricultural crop and food source, the result was thousands of starving Irish men, women, and children. More than a million Irish immigrated to the United States. Malaria from Mosquitoes: Malaria is caused by mosquitoes that transmit parasitic microorganism when feeding on humans. This disease has long affected civilizations and human populations. In War Word II, over a half million soldiers were infected, with 60,000 deaths documented from the disease. Malaria continues to cause devastation, with over 200 million cases and over 600,000 deaths to date. In combatting this disease, certain antimalarial drugs, insecticides, mosquito nets, and environmental modifications have helped to provide solutions. A Step Further: Have students conduct further research on these pest problems or explore other significant events caused by pests including crop loss from weeds, habitat destruction from gypsy moths, and disease spread such as Lyme Disease, West Nile Virus, and Zika. Section 2: Pest Control and Pesticides Over the Years Before discussing historic pest control with students, review how integrated pest management (IPM) is a process that uses different ways to control pests. After identifying the pest and monitoring the situation, if a pest problem is determined, control methods are chosen, including cultural, biological, mechanical, and chemical. Pesticides are chemicals, such as sprays, dusts, and baits, which are poisonous to pests. As pests have been around for centuries, early approaches for pest control included pulling weeds, picking insects off plants, smashing rats, using fishnets over beds to prevent bites, and trying rodent-proof storage components. In 1000 AD, the first case of natural enemies involved Arabian farmers who were trying to grow date palms. The farmers moved a predator ant from the local mountains to feed on pest ants that were damaging their crops. The beginning years of chemicals for pest control include the Ancient Sumerians using sulfur compounds to kill insects, as far back as the 2500 BC. For body lice, the Chinese were using mercury and arsenic in 500 BC. Early insecticides were plant based, such as from herbs and pyrethrins. In France, the Bordeaux mixture - lime and copper sulfate to control downy mildew - was discovered by accident. The lime and copper sulfate were originally sprayed on grape vines by a farmer to deter travelers from eating grapes along the road, but it was discovered that the mixture was controlling disease. The first synthetic chemicals included the use of DDT in the 1930s and 1940s, which was used to kill insects that carried diseases like malaria and typhus. In many circumstances, larger quantities of these chemicals were applied in an attempt to completely eradicate pests, with less concern for potential environmental impact.

3 Published in 1962, Rachel s Carson book Silent Spring brought attention to the potential effects of pesticides on the environment. Carson shared studies documenting the long lasting residual effects and persistence of DDT and chlorinated hydrocarbons that were being used as pesticides at the time. The lasting effects of these chemicals contributed to the harm of other organisms, such as through bioaccumulation and biomagnifcation. Bioaccumulation is how an organism can accumulate and store chemical residues in their fatty tissue and biomagnification is when organisms accumulate chemical residues from the organisms they are eating in the food chain. Activity: Biomagnification Activity Prep: Cut 20 pieces of paper in a 2 square. Using a marker, write Bird on the top of 1 square, write Fish on the top of 3 squares, and write Zooplankton on the top of 6 squares. Write Algae on the top of the remaining 10 squares and write.5 underneath the word Algae. The squares represent parts of the food chain. The.5 represents the DDT chemical concentration in the planktonic algae from the contaminated water. Ensure there is enough space on the squares for participants to tally the DDT chemical concentrations or draw a line underneath the letter for the DDT chemical concentration total. If desired, could scale the pieces of paper to be similar to the creatures, such as a larger piece for the bird and smaller pieces for the planktonic algae. Please note the number of materials will depend on the number of participants in this activity. If you have less participants, make less pieces of the Fish, Zooplankton, and Algae. Be sure to have representation for each part of the food chain. Activity Facilitation: Explain that biomagnification is when organisms accumulate chemical residues from the organisms they are eating underneath them in the food chain. An animal higher up on the food chain would tend to have a greater concentration of chemical. While there might be very little concentration in the tissue of an organism at the bottom of the food chain, as you go up the food chain, the concentration can increase, as the creature at the top of the food chain can have the highest concentration of pesticide residue in them. For this activity, explain that a body of water has a low amount of DDT contamination. From the food chain, organisms can pick up those contaminants, beginning with the planktonic algae that incorporate the contaminated water into their tissues. Zooplanktons consume the planktonic algae. The level of residue in the each organism up the food chain continues to rise, as fish eat the zooplankton. At the top of the food chain, a bird would eat the fish, in which the bird would contain a higher amount of residue. Even as the level of contaminant is initially very low in the water, biomagnification occurs when organisms accumulate chemical residues from the organisms they are eating underneath them in the food chain. 1. Distribute the pieces of papers to participants. Explain how the.5 on the planktonic algae represents the DDT amount in parts per million of chemical that was taken up by the algae from the contaminated water. Review the food chain if necessary, in that the planktonic algae are eaten by the zooplankton, the zooplanktons are eaten by the fish, and the fish are eaten by the birds. 2. Have the students with Planktonic Algae squares stand up and come to the center of the room. Ask participants what creature would eat the planktonic algae; response would be zooplankton. Have participants demonstrate the food chain, instructing participants with Zooplankton on their square to stand and eat the planktonic algae by going to the center of the room and collecting the pieces of paper from the planktonic algae. Zooplankton may eat more than one planktonic algae. The zooplankton should then calculate the amount of chemical concentration in them. For example, if a zooplankton collected two pieces of paper from the algae, with.5 on each piece, they would add to get 1. The zooplankton participant would then write 1 on their square to represent having 1 DDT parts per million of chemical in them.

4 3. Have the zooplankton remain in the center of the room. Ask participants what creature would eat the zooplankton; response would be fish. Have participants demonstrate the food chain, instructing participants with Fish on their square to stand and eat the zooplankton by going to the center of the room and collecting the pieces of paper from the zooplankton. Fish may eat more than one zooplankton. The fish should then calculate the amount of DDT chemical concentration in them. For example, if a fish collected two pieces of paper from the zooplankton, with 1 on each piece, they would add to get 2. The fish participant would then write 2 on their square to represent having 2 DDT parts per million of chemical in them. (If the fish only collect one piece of paper from the zooplankton, they would write that amount on their paper.) 4. Have the fish remain in the center of the room. Ask participants what creature would eat the fish; response would be the bird. Have participants demonstrate the food chain, instructing participants with Bird on their square to stand and eat the fish by going to the center of the room and collecting the pieces of paper from the fish. The bird may eat more than one fish. The bird should then calculate the amount of DDT chemical concentration in them. For example, if a bird collected three pieces of paper from the fish, with 2, 2, and 1.5 written on each piece, they would add to get 5.5. The bird participant would then write 5.5 on their square to represent having 5.5 DDT parts per million of chemical. Conclude the activity by reviewing the biomagnification definition and discussing how the activity represents how organisms accumulate chemical residues from the organisms they are eating underneath them in the food chain. Section 3: Current Pest Control and Pesticide Regulations Along with the publishing of Silent Spring and state governments beginning to set environmental laws, the need became evident for federal legislation to govern environmental policy. The United States Environmental Protection Agency (EPA) was created in 1970 to implement laws and regulations to protect the environment and human health. DDT was banned by EPA in Among many other responsibilities, EPA manages the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), which regulates the production, registration, transportation, sale, use, and disposal of pesticides in the United States. When reviewing products for registration, EPA uses detailed assessments on potential human health and environmental effects when the product is used according to label directions. Upon a product being registered for sale by the EPA, the labeling is the law. Using a pesticide in any manner that is inconsistent with the label is illegal and a violation of FIFRA. Several key components of pesticide labels include: Signal Word: Represents the product s relative acute toxicity to humans and animals. Signal words include Danger- Poison (with a skull and crossbones), Danger, Warning, and Caution. EPA Registration Number: Indicates the product has met registration requirements and the label has been approved by EPA. Each pesticide product has a unique registration number related to the manufacturer and product. EPA Establishment Number: Identifies the manufacturer and where the product was made, often with the abbreviation for the state. The Establishment Number can be important if contamination or other problem may arise. Precautionary Statements: Provides information to protect the user, other people, animals, and the environment, such as potential routes of entry, specific action statements, and protective clothing. May also be listed as Hazards to Humans and Domestic Animals.

5 Environmental Hazards: Provides information on potential product impacts on the environment, including precautions and procedures to avoid environmental contamination and any particular hazards for wildlife and water. Directions for Use: Explains how the product should be used, including pests that can be controlled, sites where the product can be applied, instructions for mixing and applying, and more. A Step Further: Have students research pesticide labels that may be found around their homes or schools, such as insect repellent, flea collar, weed control, and more. Have students examine the pesticide label to find the Signal Word, EPA Registration Number, EPA Establishment Number, Precautionary Statements, Environmental Hazards, and Directions for Use. Ask students about their comprehension of the label directions and how the product should be used for compliance with the pesticide label, such as following the proper rates. EPA classifies pesticides as Restricted Use or Unclassified Use (General Use), based on the potential hazards of how the pesticides will be used. Unclassified pesticides (commonly referred to as general use) have a lower toxicity than restricted-use products. For this reason, the general public can purchase and use general-use pesticides without needing a permit or applicator license. Restricted-use pesticides may only be purchased, used, and applied by certified pesticide applicators or individuals permitted to apply under the supervision of a certified applicator. Those individuals using restricted-use pesticides must demonstrate knowledge of pesticide label comprehension, application procedures, and other safety practices; participate in continuing education; and maintain pesticide application records. Whether applying restricted-use or general-use pesticides, best management practices (BMPs) can help prevent environmental contamination. Best management practices (BMPs) are methods that can improve efficiency, optimize resources, and can prevent or help reduce pollution. BMPs for pesticide application include: - Read the entire pesticide label for instructions. Follow the directions to learn what pests are controlled, where the product can be used, and other safety precautions. - Wear the appropriate gear and personal protective equipment. Consult the pesticide label. Even as most homeowner products do not have a detailed PPE section, long pants, long sleeves, shoes, and gloves are good recommendations. -Mix and apply pesticides at labeled rates. From reading the pesticide label, an individual can learn how much product can be used and how it can be applied on a certain area. Never use more than indicated on the label. - Store pesticides in appropriate locations. Pesticides should be stored on a high shelf or locked cabinet, and out of reach of children. Put the product away immediately after use and leave the product in its original container with attached label. - Dispose of unneeded pesticide products properly. Contact your local recycling center or solid waste authority to learn about available household hazardous waste collection programs or pick-up options. Reading and understanding the pesticide label before buying, mixing, applying, storing, and disposing of pesticides is critical for anyone using pesticide products in order to protect the environment, others, and themselves while controlling problematic pests. A Step Further: Visit the Penn State Pesticide Education Program website for more resources. The Penn State Pesticide Education Program website can be found at