NEOSHO, Mo. – Advocates say the substance helps prevent tooth decay, while opponents contend it’s toxic and can damage human tissue if ingested.

Voters in Neosho will have the final say April 5 on whether to add fluoride to the municipal water supply and increase water bills to pay for it.

The City Council voted unanimously last fall to send the issue to the voters, ending months of lobbying from proponents and opponents.

If the proposition passes, the city plans to increase water rates by 6.8 percent, effective June 1, to cover the initial $89,000 for start-up costs. After the first year, it is estimated that the service will cost about $24,000 annually.

Currently, the minimal water rate is $7.27 a month for 2,000 gallons. The increase would push it to $7.76.

City Manager Jim Cole said the city has no other choice but turn to water rates to pay for fluoridation.

“First of all, we don’t have $89,000,” he said. “The only other option would be to borrow, but it’s not recommended.”

According to city specifications, the fluoride would be fed at a rate of one part per million – or 1 milliliter of fluoride for every liter of water – from the city’s filtration plant and wells. City utility personal would implement the changes.

Water rates could decrease at the discretion of the City Council, but no such time frame has been adopted. For the time being, Cole said, the rate increase would remain in effect, with revenue generated above the $24,000 a year to be used for water-system repairs and upgrades.

Neosho dentist Darrell Hedrick, a fluoride supporter, said that for the average homeowner, the rate increase would be considerably less than the cost of one surface restoration needed to fill a cavity, even accounting for insurance.

For instance, a customer using 20,000 gallons of water a month now pays $52.45. Under the plan, that customer’s bill would go up $3.55, to $56 a month. The increase would be $42.60 per year.

“That $3 to $4 will benefit the entire family,” said Hedrick, a family dentist for 15 years who says fluoride is a safe and effective way to ward off tooth decay.

While it is by no means a “magic wand” or a substitute for tooth brushing, Hedrick said, water fluoridation also would benefit those younger than 5 who often do not have the dexterity to thoroughly brush their teeth.

Hedrick said he notes dental illnesses weekly among his patients. He said tooth decay is five times more frequent than asthma and accounts for 51 million hours of lost classroom time.

Warren Johnson, a fluoride opponent, said fluoridation is “mass medication,” and that what might be considered healthy for one may not be for another. Johnson, a member of Joplin Pure Water Association, has been working with Neosho residents to rally against the proposition.

Johnson said studies showing the benefits of fluoride are flawed. He said fluoride is toxic.

Neosho resident Betty Wilson said she doesn’t buy the argument that fluoridation will help her teeth. She said that as a child, brown spots appeared on her teeth, and a dentist informed her family that they likely were caused by dental fluorosis, or overexposure to fluoride. While it was never tested, a well was deemed the likely source of her ailment.

Wilson said she is opposed to the addition of fluoride to the water supply because she contends enough of the compound naturally exists in water. She said the type used for fluoridation – hydrofluosilicic acid – is known to be corrosive because of its high toxicity. Additionally, she has expressed concern about how much fluoride will actually pour from her faucet.

“They say one part per million, but there is no way to really know,” Wilson said. “It doesn’t sound like much, but it’s like tobacco: It’s what happens year after year and day after day. It’s a cumulative poison.”

On the contrary, Hedrick said, the fluoride concentration in toothpaste, which contains sodium fluoride, is higher than that in hydrofluosilicic acid.

Hedrick added that no court of last resort has determined that fluoridation is unlawful, but instead it is “a means of furthering public health and welfare.” Hedrick points to a designation by the Centers for Disease Control and Prevention listing community water fluoridation as one of the 10 greatest public-health achievements of the 20th century.

“There are all sorts of claims,” he said. “Sure, if you drank a cup full of fluoride, you’d be sick, but one part per million is not very much.”