U.S. Fluoride Shortage Called a Byproduct of Midwestern Farm Crisis

Fallout from the Midwestern farm crisis is spreading from the nation’s breadbasket to its bathrooms.

Plummeting demand for petrochemical fertilizers has resulted in a shortage of liquid fluoride, a fertilizer byproduct that is added to tap water in many cities because it toughens teeth against cavities.

Several major cities, including San Francisco and Cincinnati, already have exhausted their supplies of the chemical, and other cities such as Baltimore and Philadelphia expect to run out this week. Louisville, Ky., and a number of small towns in Maryland, New York and Ohio also have reportedly run out of the liquid fluoride or are very close to doing so.

Dental health experts estimate that fluoridation reduces tooth decay by 55% to 60%. Benefits are especially noticeable in children. But the shortage is unlikely to result in additional cavities unless it continues for several months, according to experts at the Centers for Disease Control in Atlanta and at the National Dental Institute in Bethesda, Md.

Called Short-Term Problem

A CDC spokesman said the shortage will probably last only about a month, but Warren Hanson of San Francisco’s municipal water department is not so sure. Resumption of fluoride deliveries “could be as soon as two weeks and it could be as long as six months,” Hanson said.

The Los Angeles Department of Water and Power does not add fluoride to its water, in part because 80% of the water contains natural fluoride--enough, in fact, to constitute 75% of the ideal fluoride level, said Larry McReynolds, assistant chief engineer for water.

The Metropolitan Water District, which supplies adjacent cities, also does not add fluoride to its water, although one of its customers, the city of Beverly Hills, does, said a MWD spokesman. But Beverly Hills uses a solid form of fluoride that is not in short supply.

The shortage affects only cities that use the liquid fertilizer byproduct, hydrofluosilicic acid, to fluoridate their drinking-water supplies. Such systems employ a drip method of fluoridation that cannot use the solid forms.

San Francisco, like most other cities, adds one part fluoride to 1 million parts of water. Fluoride is employed by about 5,600 of the nation’s municipal water systems, serving 63% of all Americans who depend on such systems.

Times staff writer Patt Morrison contributed to this story.