Seasonality in the fluoride concentrations of pasture grass subject to ambient airborne fluorides

Abstract High winter and low summer levels in grass fluoride concentrations have been commonly attributed to growth dilution. A large number of grass fluoride records obtained from routine monitoring around two different major sources of industrial airborne fluoride pollution were considered and there were no real indications of seasonality. Further investigations carried out on grass fluoride, airborne fluorides and meteorological data indicated that grass fluoride levels were positively related to the previous seven days' ambient airborne fluorides levels. It was concluded that meteorological, microclimatic and biological factors were directly or indirectly influencing grass fluoride levels.