LAKELAND, Fla., Aug. 11— A growing number of cities are facing severe shortages of fluoride additives used in water supplies to prevent tooth decay.
Twelve cities in the West and Middle West, including Seattle, Youngstown, Ohio, and Green Bay, Wis., have been forced to halt their fluoridation programs, according to Arthur Jackson, a public health specialist at the national Centers for Disease Control in Atlanta. In addition, shipments to several other cities, including San Francisco and Washington, have been curtailed by 30 to 50 percent since June.
A spokesman for the New York City Department of Environmental Protection said, ”We have been getting our supplies as usual, with no problem at all.” John Cunningham, the spokesman, said, however, that the agency’s storage space holds only a seven-day supply of fluoride additive.
The New York City Department of Health checked the fluoride level in municipal water last Friday, and found it to be normal, at one part per million, a department spokesman said.
There is a shortage because of a sharp drop in production in the phosphate mining and processing industry, in which fluoride is produced as a byproduct in the manufacture of chemical fertilizer. Phosphate processing has fallen to less than 65 percent of capacity in Florida, where most of the nation’s fertilizer and fluoride compounds are manufactured, according to a spokesman for the Florida Phosphate Council, an industry trade group.
The depressed market for fertilizer products was attributed by the council to reduced revenues and high interest rates facing the nation’s farmers and to the current strength of the dollar in relation to foreign currencies, which makes United States products more expensive to overseas purchasers.
The American Dental Association issued a statement recently warning that the worsening shortage ”could cause a temporary setback in the battle against tooth decay.” Robert H. Griffiths, president of the association, said ”young children in particular could be at risk” if the shortage persisted.
Fluoridation of public water supplies is considered a primary factor in the 33 percent drop in the incidence of tooth decay over the last 10 years, according to a recent study by the National Institute of Dental Research. More than 123 million people in 4,600 cities and towns in the United States benefit from fluoride treatment, the researchers said.
Mr. Jackson at the disease control centers said the shortage was expected to last at least several more months. Chemtech Inc. of St. Louis has warned its fluoride customers that they could face a reduction to 50 percent of normal allocations in the coming months. Recent shipments have been reduced to 70 percent of normal allocations, according to John Cerrone, the company’s vice president for manufactured products. Chemtech is the nation’s largest distributor of fluosilicic acid, the compound used by most large water systems for fluoridation.
Mr. Cerrone said most of the company’s customers, including New York City, had some backup inventory on hand, although those supplies were diminishing. Smaller municipalities are less vulnerable to the current shortage, he said, because they use fluoride in a different form and usually purchase a year’s supply at a time. New York uses about 40,000 pounds of fluosilicic acid every day at an annual cost of less than 30 cents a person, Mr. Cerrone said.
Officials at the disease control centers have recommended to state health departments that water systems continue to fluoridate their water at full strength until their supplies are exhausted, since a slight drop from optimum levels results in a major loss of dental benefit.
The American Dental Association estimates that every dollar spent on fluoridation of public water supplies saves $50 in dental costs. In 1960 Antigo, Wis., a town of 8,600 people, halted the fluoridation of its water. In the next four years, tooth decay rates among preschoolers rose by 92 percent.