- Regular phosphorus fertiliser inputs (63?years) have significantly increased the amount of fluorine in the topsoil.
- Fluorine has moved and accumulated to a depth of least 50?cm in the soil.
- Fluorine movement wasn’t enhanced by irrigation but moved mainly in drainage after fertiliser application in mid-winter.
An understanding of the rate at which fluorine (F) accumulates in soil from phosphorus fertiliser and how much is lost via leaching are important because of the challenge elevated F may pose to soil, plant and animal health. This study measured F accumulation in a soil under pasture (Inceptisol) that received single superphosphate (SSP) fertiliser over 63?years in a long-term fertiliser trial. It also assessed the downward movement of F in soil and effect of irrigation in a long-term irrigation trial. Results showed total F concentrations in topsoil (0–7.5?cm) that received 188?kg SSP?ha?1 and 376?kg SSP?ha?1 fertiliser increased from 251?mg?kg?1 to 349 and 430?mg?kg?1, respectively. The rates of F accumulation were estimated at 1.1 and 2.1?kg?ha?1?yr?1 respectively, low compared to previous studies. The F concentration in the 376?kg SSP ha?1 treatment decreased with depth, but was significantly higher than the control treatment to 50?cm, suggesting movement of F down the soil. Fluorine concentrations also decreased with depth to 50?cm in soils that received either no irrigation or up to 770?mm?yr?1 from irrigation. However there was no significant difference in the amount of F with depth between irrigation treatments. We postulate that F was moving predominately in drainage water in the period immediately after P fertiliser application in mid-winter and wasn’t enhanced by irrigation. This study should be repeated for other soil types to help our understanding of the potential for ongoing F accumulation in soil and implications this may have on future land use.
Systemic fluoride. Sources, amounts, and effects of ingestion
Fluoride may be ingested from a variety of sources, including many foods and beverages. Fluoride intake varies greatly among individuals and is dependent on dietary constituents and use of fluoride products. Although ingestion of toxic amounts of fluoride is rare, the prevalence of dental fluorosis has increased in North America, suggesting that the levels of fluoride ingestion
Neurobehavioral evaluation of soil and structural fumigators using methyl bromide and sulfuryl fluoride.
Neurobehavioral functions affected by methyl bromide exposure were evaluated in California structural and soil fumigators using methyl bromide and sulfuryl fluoride. Sampling data revealed that structural fumigators are exposed for up to 1.5 hrs/day to 0-2.2 ppm methyl bromide and/or 10-200 ppm sulfuryl fluoride, and soil fumigators can be exposed
Tealeaves may release or absorb fluoride, depending on the fluoride content of water.
As the tea plant (Camellia sinensis) is known to accumulate fluoride from the soil, the tealeaves may contain high concentrations of fluoride, which is easily released during infusion. In this study, we have tested the possible effect of original fluoride concentration in the water on the fluoride release from tea.
Relationships between fluoride intake, urinary fluoride excretion and fluoride retention in children and adults: an analysis of available data.
The aim of this study was to examine the relationship between total daily fluoride intake (TDFI), daily urinary fluoride excretion (DUFE) and fractional fluoride retention (FFR) using available data, in order to clarify the ability of DUFE to predict TDFI and, therefore, the risk of fluorosis development. Examination of published
A randomised oral fluoride retention study comparing intra-oral kinetics of fluoride-containing dentifrices before and after dietary acid exposure.
Highlights Fluoride can protect enamel from demineralisation and promote remineralization. A sodium fluoride/potassium nitrate/cocamidopropyl betaine dentifrice was examined. Compared to a NaF/KNO3/sodium lauryl sulphate/tetrasodium pyrophosphate dentifrice. Greater salivary fluoride/calcium ion concentration found with the test dentifrice. Formulation excipients may impact fluoride and calcium ion oral cavity retention. OBJECTIVE: This exploratory,
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