New developments in fluoride emissions from phosphate processing plants.

Abstract

The problem of monitoring for ambient fluoride emissions near a phosphate fertilizer processing plant in Manatee County, Fl., are discussed. Results of a study conducted to determine the emission of fluorides from the surface of a gypsum settling pond at the Borden Chemical Company plant are given. Conclusions reached as a result of the study are: (1) That fluorides are emitted from such a pond at a minimum rate of about 0.16 pound per acre of surface area per day, (2) that a breakpoint of about one-half mile from the pond occurs in concentration of fluoride in the ambient air, (3) that concentrations of fluorides in excess of 75 ppm were found in young citrus leaves in groves near the gypsum pond, and (4) that, although a one-mile protective buffer zone for a phosphate plant might be considered adequate for citrus groves, it would not necessarily be adequate for row crops or ornamental flowers such as gladiolas.