Writing prompt Grade 8 Health & Consumer Science
Dunstan Ferry's Fluoride Vote: A Grade 8 Argument Prompt
Students argue whether a fictional town should keep adding fluoride to its water, weighing cavity prevention, fluorosis, recent studies, and choice, with a counterclaim.
Objectives
- Students will write an argument that states a claim about community water fluoridation and supports it with cited evidence.
- Students will acknowledge the strongest opposing claim and respond to it with reasoning and evidence.
- Students will explain how fluoride protects tooth enamel and why the amount of a substance matters to its health effects.
Vocabulary
Key words: fluoride, enamel, tooth decay, dental fluorosis, dose, counterclaim
Teacher overview
Whether a town should add fluoride to its drinking water is an open public question, and in recent years some states and towns have voted to stop the practice while others have voted to keep it. This prompt places eighth graders in the fictional town of Dunstan Ferry, whose council votes next month, and asks for an argument that acknowledges and answers the strongest opposing claim. The background gives accurate, qualitative evidence for both positions, and either position can earn the top rubric score; the exemplar argues one side only to model structure. Teaching note: many students think of a substance as either safe or harmful in any amount, so they treat "fluoride helps teeth" and "fluoride may harm children" as a contradiction. The idea to teach before drafting is that dose matters, because the same mineral can strengthen enamel at a low level and cause harm at higher levels, and much of the scientific disagreement is about where those levels fall.
Prompt
Read the background, then write your essay.
Background: the Dunstan Ferry vote
Dunstan Ferry is a fictional town of about 9,000 people. Its water comes from two wells. Like almost all natural water, the well water already contains a small amount of fluoride, a mineral found in rocks and soil. For many years, the town's water plant has added a little more fluoride to bring the level up to a low target meant to help prevent tooth decay. Next month, the town council will vote on whether to keep doing that.
How fluoride affects teeth. Bacteria in the mouth turn sugar into acid. The acid pulls minerals out of tooth enamel, the hard outer layer of a tooth. Over time, this can make a cavity. Fluoride helps enamel rebuild those minerals, and it makes the enamel harder for acid to dissolve.
Evidence supporters use. For decades, dental and public health groups have supported adding fluoride to town water. They point to studies showing fewer cavities in towns that add it, with the largest benefit for children whose families cannot easily get to a dentist. Fluoride in the water reaches everyone who drinks from the tap, and no one has to remember a treatment or pay for one.
Evidence critics use. Fluoride toothpaste is now common, and some researchers argue that fluoride in water adds less benefit than it did when towns first began adding it. Too much fluoride while children's teeth are forming can cause dental fluorosis, which shows up as faint white marks on the teeth and is usually mild. Some recent studies have linked fluoride exposure to lower IQ scores in children, mostly at levels higher than those used in American town water. Scientists disagree about whether there is any effect at the lower levels towns add. Some residents also argue that adding a substance to everyone's water takes away a personal choice.
Local facts (in our scenario).
- The fluoride program costs Dunstan Ferry about 11,000 dollars a year, which is a little over 1 dollar per resident.
- The nearest dentist who accepts public insurance is a 50-minute drive away.
- The school nurse reports that many students have never had a dental checkup.
- People who want to avoid fluoride in their tap water can buy a reverse osmosis filter, which removes most of it but costs several hundred dollars.
- People who want fluoride without it being in the water can use fluoride toothpaste and ask a dentist about fluoride treatments.
Your task. Write an argument essay for the Dunstan Ferry town newsletter. State a clear claim: should the town keep adding fluoride to its water, or should it stop? Support your claim with at least two reasons and evidence from the background. Acknowledge the strongest opposing claim, and explain why your position still holds. End with a conclusion that follows from your argument. Write five paragraphs.
Planning Organizer
Fill in every row before you draft. Each row becomes part of your essay.
| Part of my essay | My notes |
|---|---|
| My claim (keep fluoride or stop it) | |
| Reason 1 | |
| Evidence for reason 1, from the background | |
| Reason 2 | |
| Evidence for reason 2, from the background | |
| The strongest opposing claim | |
| Evidence the other side would use | |
| My response to the opposing claim | |
| My conclusion |
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Exemplar & Rubric
Exemplar response
Dunstan Ferry should keep adding fluoride to its water. The town has a real problem with children's teeth and very little access to dental care, and fluoride in the water is the one form of protection that reaches every child who drinks from the tap.
My first reason is that fluoride helps the children who need it most. Bacteria in the mouth make acid that pulls minerals out of tooth enamel, and fluoride helps enamel rebuild and resist that acid. Supporters point to studies showing fewer cavities in towns that add fluoride, with the largest benefit for children whose families cannot easily reach a dentist. In Dunstan Ferry, the nearest dentist who accepts public insurance is a 50-minute drive away, and the school nurse reports that many students have never had a checkup. For those students, the water may be their main protection.
My second reason is that the program is inexpensive and works without anyone having to remember it. It costs the town about 11,000 dollars a year, which is a little over 1 dollar per resident. A family does not have to buy anything or schedule anything for a child to benefit. Toothpaste works only if a child has it and uses it, and a dental treatment works only if a family can get to a dentist.
The strongest argument against fluoride is about safety and choice. Some recent studies have linked fluoride exposure to lower IQ scores in children, and too much fluoride while teeth are forming can cause the white marks called fluorosis. Opponents also say that adding fluoride to everyone's water takes away a personal choice. These concerns deserve to be taken seriously. However, the background explains that the IQ studies mostly looked at levels higher than those used in American town water, and that fluorosis is usually mild. Families who still want to avoid fluoride can use a filter, even though it costs more. The amount matters, and the evidence of harm is strongest at levels Dunstan Ferry does not use.
For these reasons, the council should vote to keep fluoride in Dunstan Ferry's water. It should also ask the water plant to report the town's fluoride level to residents every year, so families can see that the amount stays low. Protecting children's teeth in a town with few dentists is worth a small cost, as long as the town keeps paying attention to new research.
Rubric
Either position can earn every level of this rubric, so score the quality of the argument regardless of the side chosen.
| Criterion | Emerging | Developing | Proficient | Advanced |
|---|---|---|---|---|
| Claim | No clear position is stated. | A position is stated but shifts or stays vague. | One clear position on keeping or stopping fluoride is stated and held throughout. | A clear position is stated and the introduction previews the reasons that support it. |
| Evidence and reasoning | No evidence from the background is used. | One piece of evidence is restated without explaining how it supports the claim. | At least two specific pieces of evidence are cited and each is explained. | Evidence is cited for every reason, including a local fact, and the essay explains why that evidence matters for Dunstan Ferry in particular. |
| Opposing claim and response | No opposing claim appears. | An opposing claim is mentioned without a response. | The strongest opposing claim is stated fairly, with its evidence, and answered with a reasoned response. | The opposing claim is stated fairly, answered with evidence, and the response uses the idea that dose matters or offers a practical compromise. |
| Organization and conventions | Ideas are disconnected, and errors interfere with meaning. | Paragraphs exist but transitions are weak, and errors are noticeable. | Five organized paragraphs with clear transitions and few errors. | Purposeful organization, a conclusion that follows from the argument, and nearly error-free writing. |
Differentiation
Support
Provide sentence starters for each organizer row, such as "One reason Dunstan Ferry should ___ is ___" and "People on the other side argue that ___, but ___." Allow these students to write four paragraphs by combining the two reasons into one body paragraph.
Extension
Ask students to add a second opposing claim from a different group of residents, such as renters who cannot install filters, and answer it in its own paragraph. Students can also propose a compromise the council could vote on and explain why it would or would not satisfy both sides.
ELL supports
Pre-teach "enamel," "decay," "fluorosis," "dose," and "opposing claim" with a labeled drawing of a tooth showing enamel and a cavity. Allow the planning organizer to be completed with short phrases, and provide the transition words "however," "for example," and "for these reasons" on a card at each desk.
Extensions
Students can find out whether their own town or water system adds fluoride by checking the utility's annual water quality report and share what they find without judging the choice. A local dentist or public health nurse can be invited to explain how they talk with families about fluoride from toothpaste, treatments, and tap water.