For your teeth, fluoride is a wonderful thing. Commonly used in modern toothpastes and dental rinses, it helps make teeth more resistant to decay and inhibits the production of acids that can harm teeth.
In the 1950s, however, fluoride was nearly disastrous for several agricultural industries in Polk County. Cattle grew gaunt and starved. Leaves on citrus trees turned brown and brittle.
“Between 1953 and 1964 . . . an estimated 150,000 acres of cattle land were abandoned, and 25,000 acres of citrus groves in the county were damaged,” Ron Linton wrote about Polk County in “Terracide: America’s Destruction of Her Living Environment.” “Truck crops were lost, and the commercial gladiolus industry in an adjacent county was blighted.”
The problem, scientists determined, was that unhealthy amounts of fluoride were being released into the air by the phosphate industry.
“This industry, located mostly in Polk and Hillsborough counties to the east of Tampa, became the most serious air polluter in Florida and one of the most notorious in the nation,” Scott Hamilton Dewey wrote in the spring 1999 issue of the Florida Historical Quarterly.
Fluoride comes from fluorine, a natural element that is found in high concentration in Polk County’s phosphate deposits. In the phosphate industry’s early years, the fluorine didn’t pose a problem — the mines simply dug up the phosphate and shipped it off.
In 1948, however, phosphate companies “began to branch out into the chemical processing of fertilizer,” Dewey wrote. The new processes required the naturally occurring fluorides to be removed from the phosphate in order to make the phosphate more potent.
“The various sulfur and nitrogen oxide byproducts of the chemical processing of phosphates were potentially harmful when released into the environment, but even more damaging to local residents were the fluoride emissions released during the processing, drying, and curing of phosphates,” Dewey wrote. “Fluorides from the phosphate processing plants were emitted as dusts or gases to blow freely through the surrounding countryside.”
Although the fluorides posed a threat to humans, they proved to be extremely damaging to area agriculture. The fluorides drifted into citrus groves, gardens and pastures, where it was absorbed and consumed by plants and animals alike.
“Around 1953 we noticed a change in our cattle,” the president of the Polk County Cattlemen’s Association told officials, as quoted by Linton. “They failed to fleshen as they normally did. We put them in our best pastures and used all known methods to fatten. Worming, mineral drenches, changing pastures did not improve the condition. We watched our cattle become gaunt and starved, their legs became deformed; they lost their teeth.”
Local farmers, ranchers and growers were at a loss to explain the sudden decline of their plants and animals. It wasn’t until studies were conducted by the universities of Florida and Georgia that fluoride was pinpointed as the culprit.
Once the problem was identified, Polk residents were quick to call for the phosphate plants to limit their fluoride pollution. Their outrage eventually led the state to set fluoride emissions standards for the industry.