San Antonio, TX -

More than 10 years after San Antonio began adding fluoride to the water supply, concerns are growing in some sectors that the chemical is doing more harm than good.

In 2002, San Antonio became one of the last major cities to add fluoride to the water to improve dental health.

Henry Rodriguez, of LULAC No. 4383, did not vote for it then and has been fighting it ever since.

Rodriguez said fluoride is poisoning children.

"What they're saying is that mothers should use bottled water, you know, fluoride free," Rodriguez said.

A Centers for Disease Control report does say if mothers all the time are mixing formula powder "with fluoridated water, there may be an increased chance for mild dental fluorosis."

Fluorosis is defined as a pitting and discoloring of the teeth.

Former Ambassador and Atlanta Mayor Andrew Young has come out against fluoride. And San Diego dentist Dr. David Kennedy has produced a documentary.

"They're using hazardous waste and they're adding it to our water supply," Kennedy said on camera in the documentary.

Plus, a Harvard study published last year found "children in high-fluoride areas had significantly lower IQ scores than those who lived in low-fluoride areas."

"There's a possibility of 10 percent lowering of your IQ if you use fluoride in the water," Rodriguez said.

He wants the city to do a study here.

Dr. Jennifer Bankler, a dentist with the city’s Metro Health Department, said the benefits of fluoride have been proven in so many other studies that it would be a waste of money here.

"The City of San Antonio would not do a study to prove that smoking causes lung cancer,” Bankler said. “It's sort of the same principle."

Metro Health said a study would not be worth the cost because fluoride is a proven health benefit.

At the UT Health Science Center, Dr. Kevin Donley is a professor and Chairman of the UTHSC, Developmental Dentistry Department. He said the science for fluoride is solid.

"There's overwhelming evidence that community water fluoridation is quite effective,” Donly said. “And safe."

Donly said one thing to remember is that not every published study represents good science. He said fluoride's benefits have been studied for more than 60 years.

He said those benefits include fewer cavities, less severe cavities and less need for fillings and tooth extractions.

The San Antonio Water System board just authorized the utility to spend $1.1 million dollars to fluoridate the water.

The yearly estimate was just $300,000 dollars when fluoridation started.

SAWS said the cost of fluoride has stayed steady over the last four years but before that it went up steeply because of market conditions.

SAWS also said it's treating more water now that it has absorbed Bexar Met customers.

The utility spent nearly $420,000 dollars just on fluoride last year.