US drinking water: Fluoridation knowledge level of water plant operators

Objectives: We determined the knowledge level of wafer plant operators who fluoridate drinking water, and we compared small and large water plants. Me thods: A pretested survey was sent to 2,381 water plant operators in 12 sta tes that adjust the fluoride concentration of drinking wafer. A z-test for proportion was used to test for statistical difference between small and la rge plants at alpha =0.05. Small water plants were those treating less than 1 million gallons of water daily Results: Eight hundred small and 480 larg e water plant operators responded, resulting in a response rate of 54 perce nt. Two-thirds of wafer plant operators correctly identified the optimal fl uoride level, but more than 20 percent used a poor source for choosing the optimal level. Only one-fourth of operators were able to maintain the fluor ide concentration to within 0.1 mg/L of the optimal concentration. A signif icantly greater proportion of operators at large water plants than at small water plants reported that they were able to maintain a fluoride concentra tion to within 0.1 mg/L of the optimal concentration (33.5% vs 21.3%, z=4. 74, P < .05). Conclusions: Although most operators correctly identified the optimal fluoride level, small wafer plant operators were less likely to us e accurate reasoning for choosing that level and in maintaining fluoride co ncentrations within 0.1 mg/L of that level than large water plant operators .