Changes of fluoride content in the sand from sandboxes located on children playgrounds in Police (West Pomerania, Poland)

Abstract

The aim of the study was to determine the fluoride content in the sand from sandboxes in Police town (West Pomerania, Poland). This area is exposed to excessive emissions of fluoride compounds because of the proximity of chemical plants. The sand samples were collected five times in the period from March to November in 2016. The fluoride content was determined using the potentiometric method with an ion-selective fluoride electrode. The obtained results showed that the fluoride content ranged from 0.09 to 1.48 mg·kg-1 dm. The lowest fluoride content was recorded in the sand collected in the place, which was the closest to the emitter, and the highest one in the samples from sandbox, which was the furthest from the emitter. Analyzing the changes in the content of this element over time, the largest fluoride concentration of sand occurred in July or September depending on the location. Pearson correlation coefficient at p < 0.05 (r = 0.925) showed a significant positive correlation between the fluoride content and the distance from fluoride emitter.