The fluoridation controversy
Read The fluoridation controversy and check the IELTS Reading answers. Fluoridation is the addition of fluorine to public water supplies with the aim of reducing tooth decay. The fluorine, when mixed with water, becomes fluoride and the desired concentration of fluoride in public water is approxima…
Passage preview
Fluoridation is the addition of fluorine to public water supplies with the aim of reducing tooth decay. The fluorine, when mixed with water, becomes fluoride and the desired concentration of fluoride in public water is approximately one part per million, depending on the regional temperature and hence the amount of water people are likely to drink. Many studies, such as those by McClure in 1970 through to Burt in 1983, have shown that when children drink fluoridated water, their average rate of tooth decay seems greatly reduced. A typical figure claimed is 50 percent reduction. This apparently enormous benefit for children’s teeth is the major argument in favor of fluoridation.
Vocabulary from this passage
12 words worth learning before you sit the test, each with the sentence it appears in.
- assert verb
To state something firmly and confidently as true, especially when others may be inclined to disagree
Historians assert that the treaty, not the war itself, transformed the region's economy.
- bound up in adjective
Closely and inseparably connected with or involved in something else
National identity is often bound up in language, history and shared cultural traditions.
- downplay verb
To make something seem less important, serious, or significant than it really is
The company tried to downplay the safety concerns raised in the internal report.
- dubious adjective
Hesitating or doubting; not to be relied upon; suspect or uncertain in quality or truth
Many economists remain dubious about claims that the new tax will boost long-term growth.
- eminent adjective
Famous and highly respected within a particular profession or field of study
An eminent physicist delivered the keynote lecture at the international conference last spring.
- exempt adjective
Free from a duty, payment, or rule that applies to other people or groups
Charities are exempt from corporation tax on income used for their stated purposes.
- incontrovertible adjective
Impossible to deny or dispute because the evidence supporting it is so clear and convincing
Detectives presented incontrovertible proof that the signature on the contract had been forged.
- inevitably adverb
In a way that cannot be avoided or prevented; as a certain and unavoidable result
Rapid urban growth will inevitably put pressure on housing, transport and public services.
- infringement noun
The action of breaking the terms of a law or agreement; a violation of rights
Critics view compulsory medical treatments as an infringement on personal liberty.
- methodological adjective
Relating to the system of methods used in a particular area of study or activity
Reviewers criticised the methodological flaws in the survey, including its small and biased sample.
- proponent noun
A person who publicly supports and argues in favour of a theory, policy, or course of action
Proponents of the policy argue that it benefits the majority of the population.
- rationality noun
The quality of being based on or in accordance with reason or logic
The debate is not about the rationality of the decision, but about differing values.
Answers with explanations
- 27. A
The question asks what the **optimum amount** of fluoride is partly **calculated** from. The first paragraph gives the **desired concentration** of about one part per million, **depending on the regional temperature** and the amount of water people drink. So the factor is the climate of the area, which matches the option about how hot the area is. The temperature of the water itself is not mentioned, and dental problems and community choice are not factors. Answer: A.
- 28. C
The question asks for a **reason the writer gives for opposing** fluoridation. The paragraph listing **three main grounds for opposition** gives as the third that fluoridation is **an infringement on individual rights** because it is **compulsory medication**. This matches the option about obligatory fluoridation taking away **personal freedom**. The risks named are allergic reactions and discoloration, not tooth decay, cost is never raised as an objection, and excess fluoride is linked to heavy water drinkers, not to mistakes. Answer: C.
- 29. D
The question asks why the writer **mentions Kuhn**. Kuhn is described as arguing that the shift between scientific ways of thinking is **not made solely** on clear rules of formal scientific practice but can include **social factors**. Social factors are non-scientific considerations, so the writer uses Kuhn to show that science can be **influenced** by them. Collins is said to take the idea **further**, not to contrast with it, and the remark that Kuhn never gave a full analysis is a side comment, not the writer's purpose. Answer: D.
- 30. A
The question asks what **Sutton's research** found about **earlier studies in North America**. The passage says he analyzed the **classic North American studies** and found that each showed significant **methodological shortcomings**, which paraphrases failings in the way they were carried out. The scientists' results are not called unique, long-term effects are not discussed, and Sutton's work **throws doubt** on the size of the reduction in tooth decay rather than showing a greater effect. Answer: A.
- 31. B
The question asks what the writer says about **scientists** in the last paragraph. The final sentence says social values are bound up in any decision about fluoridation, so this is **not an issue** on which **declarations by scientific experts** ought to be the **final word**. That means scientists should not be the ones who decide the policy. The paragraph never says scientists hide their motives or cannot agree, and it says claims of scientific authority are a strategy, not pure truth-seeking. Answer: B.
- 32. NO
The statement claims knowledge and values should be kept separate. The writer, presenting the sociological view, argues that **social values** are involved at every stage of creating scientific knowledge, and that the traditional distinction between knowledge and values **can no longer be justified**. Thus the claim that they should be separate contradicts the writer's own argument. Answer: NO.
- 33. YES
The statement says many sociologists have **disregarded** the **doubts** some scientists hold about fluoridation. In the paragraph about Sutton, the writer states that sociologists have **downplayed** an important part of the debate by **ignoring** the number of **eminent scientists who have questioned** aspects of fluoridation. The writer says this in his own voice, not as someone else's opinion, and the example of Sutton's book, cited by no sociologist, supports it. Answer: YES.
- 34. NOT GIVEN
The statement says Sutton's findings have been given insufficient attention by **scientists outside of North America**. The passage does say that **Sutton's book is not cited** in any analysis by **sociologists**, but that concerns sociologists, not scientists, and nothing is said about where any scientists work. The writer gives no view on how scientists in other regions treated the book, so the claim can be neither confirmed nor contradicted. Answer: NOT GIVEN.
- 35. YES
The statement says there are **valid arguments on both sides**. The writer sets out a supporter's argument and an opponent's argument, then says both consider the evidence but differ in assessing social benefits and costs. This difference is "not between rationality and irrationality but is a **legitimate difference** in values". Legitimate paraphrases valid, and the writer clearly gives this view, so the answer is YES. The sociological conclusion also says opposition is **not necessarily irrational**. Answer: YES.
- 36. B
The sentence begins with **the traditional view of science**. The same phrase appears in the introduction to the sociology of science: science is a **special kind of knowledge**, established through scientific methods and **objectively applied** by a scientific community. Objectively applied knowledge is knowledge free from bias, which matches the ending describing science as an **unbiased discipline**. The ending about beliefs of everyone concerned describes the later sociological challenge to this picture, not the traditional view. Answer: B.
- 37. G
The question asks what a **sociological view of science** argues. The passage says a **sociology of science** shows that scientific knowledge is **socially negotiated** and **inevitably linked to the values** of the parties involved, both scientists and nonscientists. That matches the ending saying knowledge is **affected by the beliefs of everyone concerned**. The ending about an unbiased discipline is the traditional view, and the one about results not being understood at first is Collins's specific claim. Answer: G.
- 38. A
The question asks what **Collins** believes. The passage says he **asserted** that the outcome of experiments was not something whose meaning could be **immediately comprehended**, but something needing interpretation and discussion. **Not immediately comprehended** matches the ending that results are **not always understood at first**. The ending about knowledge being affected by everyone's beliefs is the wider sociological claim, not one attributed to Collins himself. Answer: A.
- 39. D
The writer's supporter argues that the evidence for benefits is **quite substantial**, while the evidence for harm is **limited and dubious**. The supporter concludes that the likely benefits **outweigh** the possible dangers. This means the supporter sees too little proof to justify a **cautious approach**, so the ending about insufficient proof fits. The ending about serious damage outweighing benefits belongs to nobody here, and the ending about choice is the opponent's position. Answer: D.
- 40. C
The question concerns what an **opponent** of fluoridation may conclude. The opponent argues there is **some doubt** about the benefits and a slight chance of harm, then concludes: "Therefore, I oppose fluoridation of water supplies and favor the **voluntary use** of fluoride tablets by those who want to take them." Voluntary use means people should be able to **choose** whether they want fluoride. The opponent accepts that the evidence for benefits is substantial, so the ending claiming damage outweighs benefits is too strong. Answer: C.