- 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.
Total fluoride intake and implications for dietary fluoride supplementation
This paper reviews the history and validity of recommended "optimal" levels of systemic fluoride intake and the available information on levels of fluoride intake in young children from foods and beverages (including water), dentifrices, dietary fluoride supplements, mouthrinses, and gels. Most of the studies emphasize the substantial variation in ingestion among individuals. Often, a substantial
Filled dietary fluoride supplement prescriptions for Medicaid-enrolled children living in states with high and low water fluoridation coverage.
BACKGROUND: Although dietary fluoride (F) supplements (DFS) are recommended for children who use F-deficient drinking water, no studies have examined filled DFS prescriptions across multiple states to examine the dosage consistency with current recommendations or prescription length. METHODS: This sequential cross-sectional analysis used Medicaid claims data for children aged 0.5 through
Anthropogenic fluorine accumulation in the Waikato and Bay of Plenty regions of New Zealand: comparison of field data with projections.
Application of phosphate (P) fertilizers to farmland is projected to be causing worldwide accumulation of fluorine (F) in agricultural soils and associated ecosystems, but wide-scale field data have been lacking. We report results of sampling across two large regions of New Zealand involving soils of 298 native and farmed properties.
A case of thick but brittle bones and instant tea
CASE DESCRIPTION A 45-year-old white male was found to have radiographic findings of a diffusely dense appendicular skeleton, mild trabecular thickening, and multiple thoracic compression fractures indicating structural weakness. Bone mineral density was above the expected range for his age on the lumbar spine and femoral neck. Social history was significant
Assessment of fluoride intake from groundwater and intake reduction from delivering bottled water in Chiang Mai Province, Thailand.
Fluoride intake from tap water supplied by fluoride-containing groundwater has been the primary cause of fluorosis among the residents of Buak Khang Subdistrict, Chiang Mai Province, Thailand. To reduce fluoride intake, bottled water treated using reverse-osmosis membranes has been made available by community-owned water treatment plants. This study aimed to
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