- 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.
Using High Fluoride Concentration Products in Public Policy: A Rapid Review of Current Guidelines for High Fluoride Concentration Products.
Despite improvements in dental caries levels since the widespread introduction of fluoride toothpastes, it is still a disease which is considered to be a priority in many countries around the world. Individuals at higher risk of caries can be targeted with products with a high fluoride concentration to help reduce
Comparing Fluoride Exposures in Pregnant Canadian Women: Fluoridated versus Nonfluoridated Drinking Water.
Fluoridated water is piped to more than one-third of the Canadians1 and nearly three-quarters of the Americans2 who use public water systems. Although fluoride helps prevent dental cavities, some studies have suggested that higher prenatal exposures may affect neurodevelopment.3,4 Those findings make it important to understand exposure levels in general
Fluoride content of infant foods
Excessive fluoride consumption during the first 2 years of life is associated with an increased risk of dental fluorosis. Estimates of fluoride intake from various sources may aid in determining a child's risk for developing fluorosis. This study sought to assess the fluoride content of commercially available foods for infants,
Skeletal fluorosis due to inhalation abuse of a difluoroethane-containing computer cleaner
Skeletal fluorosis (SF) is endemic in many countries and millions of people are affected worldwide, whereas in the United States SF is rare with occasional descriptions of unique cases. We report a 28-year-old American man who was healthy until two years earlier when he gradually experienced difficulty walking and an abnormal gait,
Two New Members of CsFEXs Export Fluoride Coupled Proton Gradients and Participate in Reducing the Fluoride Accumulation in Low-Fluoride Tea Cultivars
The accumulation of fluoride in tea leaves from various cultivars exhibits significant differences. However, the molecular basis and mechanism remains largely unknown. Here, we reported that two genes of CsFEXs (Fluoride export genes in C. sinensis), CsFEX1 and CsFEX2 transport fluoride out of cells, alleviate the cellular fluoride toxin and
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