The government of Britain is again looking at fluoridation of the public water supply as a possible means of achieving nationwide improvements in dental hygiene. To the casual observer, given the highly erroneous impression that the presence of fluoride in toothpaste is beneficial in the prevention of dental caries, such a measure may understandably appear desirable and worthy of public support. However, many water authorities across the country have long understood the risks associated with fluoridation; but the government and the various official organizations that support such a measure continually deny these risks. It should be realized that there are two forms of fluoride. One of these is calcium fluoride, which is a natural substance occurring in water at very low levels of 0.01-1 parts per million and a substance which the various organizations involved in promoting fluoridation constantly draw attention to when attempting to justify their case. The other form of fluoride is sodium fluoride, which occurs alongside various related substances such as fluosilicic acid and is an extremely dangerous industrial by-product produced by such industries as aluminum, ceramics, phosphate fertilizers and nuclear power. This form of fluoride is an accumulative poison even more toxic than lead and only slightly less toxic than arsenic.
The writer of the passage informs us that, contrary to the facts, a great many people believe that ___.
the public water supply is slowly being polluted by fluoride from industrial waste
both types of fluoride are extremely dangerous
fluoride helps to keep teeth strong and healthy
the water supply could be fluoridated at little expense
no risks would be entailed if the water supplies were fluoridated
We learn from the passage that calcium fluoride ___.
in the public water supply could in time endanger the health of the people
is used in toothpaste because it cures dental cavities
is an important ingredient in many fertilizers
and sodium fluoride can be used interchangeably
is naturally present in water but in minute amounts
The writer of the passage puts great emphasis on the fact that one type of fluoride ___.
is an industrial by-product and highly toxic
certainly helps to prevent tooth decay
leads to lead poisoning
is being factory produced so that the water supplies can be fluoridated
only occurs naturally in such small amounts that ways of supplementing it must be found