1. Show students empty containers of several household pesticides items. Read the labels, conveying the trade name and chemical name. Ask students to make an educated guess on the anthropogenic purpose all the chemicals have in common.
2. Ask students to define what a pesticide is and where and how they are used. Be sure everyone is clear on the definition of a pesticide and a pest, and then ask students to predict the prevalence of pesticides in their own communities. You can guide them by asking if pesticides would be something easy or difficult to find.
3. Have them take notes in their science journals on the general classification of pesticides:
Pesticides are grouped according to the pests they control. Examples include:
- Algicides – chemicals used to manage algae in areas, such as swimming pools and indoor aquariums
- Avicides – chemicals used to manage birds
- Disinfectants – chemicals used to destroy harmful microorganisms
- Fungicides – chemicals used to manage fungi
- Herbicides – chemicals used to manage unwanted plants
- Insecticides – chemicals used to manage insects and other arthropods, such as ticks, spiders or centipedes
- Microbial Insecticides – naturally occurring insect-disease microorganisms that are lethal to specific groups of insects
- Molluscicides – chemicals used to manage snails or slugs
- Pheromones – chemicals used to attract insects
- Repellents – chemicals used to repel insects or other pests
- Rodenticides – chemicals used to manage rats, mice and other rodents
Option: Student groups research a type of pesticide. Have them take a systems approach to understanding its chemistry and the risks and benefits associated. Students could present what they learned on the day you reconvene to discuss the results of their pesticide prevalence search. Depending on students’ research skills, additional class time may be necessary.
4. Distribute the Pesticide Prevalence Search worksheet. Have students write their statement regarding the prevalence of pesticides in their community and why they think pesticides would be easy or difficult to find. If computers with internet access are available in the classroom, have students do the “home tour” at the EPA’s website (see related and resource websites section). They should take notes in their science journals. The remainder of the worksheet will be done outside of class for homework. Encourage students to be as thorough as possible and talk to as many people as possible. Also encourage them to visit a grocery store and/or hardware store. Give them about a week to conduct their search. Remind students that pesticides are chemicals that could be dangerous to humans. Have the students wash their hands after touching any pesticide containers.
One week later reconvene as a class to discuss students’ findings. Spend at least 30 minutes debriefing the types of pesticides students found within the community. You could extend this lesson to take a system’s approach to the cost/benefits of pesticides.
Students will complete the Pesticide Prevalence worksheet outside of class.