The contribution of drinking water fluoride to the risk of dental fluorosis in Estonia

2014

IJERPH

Fluoride is a naturally occurring contaminant in groundwater in Estonia. There are several regions in Estonia with fluoride contents in public water supplies as high as 7 mg/L. Long-term exposure to high-fluoride drinking water may have several adverse health effects, primarily dental fluorosis. The opportunities for exposure reduction rely highly on water treatment technologies. Since 2004 public water suppliers in Estonia have made efforts to diminish fluoride content in drinking water systems. A follow-up study on a country level was carried out in 2004–2012 to analyze the changes in population exposure to excessive (over 1.5 mg/L) fluoride in drinking water and to get information about the reduction methods applied by public water supplies (PWS) to optimize the fluoride levels in public water system. The results showed that bigger PWS have been more effective in fluoride reduction measures than small PWS. The main methods used to lower the fluoride content were reverse osmosis technology and replacement of water sources with new ones (new drilled wells). As a result of all the measures taken the overall high-fluoride exposure has been reduced substantially (82%).

Section: Introductionmentioning

confidence: 99%

Reducing Exposure to High Fluoride Drinking Water in Estonia—A Countrywide Study

Indermitte

Saava

2014

IJERPH

“…Endemic dental fluorosis is a common sight in many parts of the world with high fluoride drinking water. Our case study on Tartu showed there is up to six times higher risk of dental fluorosis among 12 year old school-children living in high fluoride (about 4 mg/L) region in comparison with children living in low-fluoride (about 0.2 mg/L) region [ 10 ].…”

Section: Discussionmentioning

confidence: 99%

“…The diagnosis of dental fluorosis followed the criteria of Dean [ 12 ]. The second study [ 10 ] was part of the all-Estonian survey of dental health of 12-years-old schoolchildren, conducted according to the uniformed methodology of the World Health Organisation [ 13 ]. The sub-sample was selected from town of Tartu, where the fluoride content in drinking water varied significantly between regions.…”

Section: Methodsmentioning

confidence: 99%

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Exposure to High Fluoride Drinking Water and Risk of Dental Fluorosis in Estonia

Indermitte

Saava

2009

IJERPH

The purpose of this study was to assess exposure to drinking water fluoride and evaluate the risk of dental fluorosis among the Estonian population. The study covered all 15 counties in Estonia and 93.7% of population that has access to public water supplies. In Estonia groundwater is the main source for public water supply systems in most towns and rural settlements. The content of natural fluoride in water ranges from 0.01 to 7.20 mg/L. The exposure to different fluoride levels was assessed by linking data from previous studies on drinking water quality with databases of the Health Protection Inspectorate on water suppliers and the number of water consumers in water supply systems. Exposure assessment showed that 4% of the study population had excessive exposure to fluoride, mainly in small public water supplies in western and central Estonia, where the Silurian-Ordovician aquifer system is the only source of drinking water. There is a strong correlation between natural fluoride levels and the prevalence of dental fluorosis. Risk of dental fluorosis was calculated to different fluoride exposure levels over 1.5 mg/L.

“…The health risks in Estonia arising from drinking water are mainly due to the high levels of fluoride and boron in groundwater (Saava 1998;Indermitte et al 2006;Indermitte 2010). A strong relationship between the fluoride content in drinking water and the prevalence of dental fluorosis among 12-year-old schoolchildren in Estonia has been found (Indermitte et al 2007).…”

Section: Introductionmentioning

confidence: 98%

Geological sources of boron and fluoride anomalies in Silurian–Ordovician aquifer system, Estonia

Uppin

2011

Environ Earth Sci

The objective of this study was to examine the possible natural sources of fluorides and boron in SilurianOrdovician (S-O) aquifer system, as the anomaly of these elements has been distinguished in groundwater of western Estonia. Water-rock interactions, such as dissolution and leaching of the host rock, are considered to be the main source of high fluoride and boron concentrations in groundwater. Altogether 91 rock samples were analysed to determine if high F -and B levels in groundwater could be attributed to certain aquifer forming rock types. Fluorine and boron contents in limestones and dolomites vary from 100 to 500 mg/kg and 5 to 20 mg/kg, reaching up to 1,000 and 150 mg/kg in marlstones, respectively. K-bentonites, altered volcanic ash beds, are rich in fluorine (400-4,500 mg/kg) and boron (50-1,000 mg/kg). Thus, clay-rich sediments, providing ion-exchange and adsorption sites for F -and B, are the probable sources of both elements in S-O aquifer system in western Estonia.