By The Arusha News Reporter.
A new scientific study has revealed that residents in Arusha may be unknowingly ingesting dangerous levels of fluoride through a cherished daily ritual: Drinking tea.
A recent study, jointly conducted by researchers from Duquesne University and the University of Virginia in the United States and published online, found that groundwater in rural areas near Mount Meru contains nearly 3.2 milligrams of fluoride per litre – more than double the World Health Organisation (WHO) recommended limit of 1.5 mg/L.
“Communities may be unknowingly contributing to long-term health problems through routine tea consumption. There is an urgent need to explore alternative water supply sources and safer tea preparation methods,” said one of the lead researchers, Ms Sophia Bakar.
When that water is used to brew tea, fluoride jumps even higher, reaching 6.4 mg/L. In Arusha, perhaps owing to the cold weather, tea is more than just a beverage – it’s a cultural cornerstone, commonly prepared with equal parts water and milk, says the report.
While milk slightly affects fluoride absorption in the body, researchers found that adding milk after steeping the tea raises fluoride content by up to 15 per cent. In contrast, brewing tea with milk alone reduces fluoride levels by as much as 40 per cent, although the exact chemical process remains under investigation.
The study also revealed that most households drink more tea than plain water – consuming an average of two litres of tea daily. This makes tea the primary source of fluoride intake, significantly increasing the risk of health conditions such as dental and skeletal fluorosis – ailments marked by discoloured teeth, brittle bones and long-term physical disability.
Despite the growing risk, 74 per cent of households surveyed do not treat their water, relying mainly on boiling, which does not remove fluoride.
“We need to create more awareness. The public must be informed that boiling water doesn’t solve the fluoride problem,” said Dr Mark Bura, a retired medical doctor.
Ongoing technological and scientific innovations in the region include the development of NanoFilters – designed at Arusha-based Nelson Mandela African Institution of Science and Technology – to remove fluoride and other harmful contaminants from drinking water.
The Arusha Urban Water Supply and Sewerage Authority (AUWSA) recently confirmed through media reports that water sources in Meru, Longido and Arusha Rural districts are contaminated with fluoride concentrations ranging from 5 mg/L to 30 mg/L — far exceeding the WHO’s recommended limit of 1.5 mg/L.
Dr Bura also emphasised the importance of education on the issue. “We need to raise awareness about the dangers of fluoride exposure, particularly among residents living near volcanic soils,” he added.
The study authors recommend immediate government and community-level interventions, including public awareness campaigns, subsidised access to fluoride-removing filters and further research into low-fluoride tea preparation techniques.
As Arusha’s communities continue to embrace their cherished tea traditions, they may unwittingly be brewing a health crisis – one cup at a time.
FAST FACTS
• WHO safe fluoride limit: 1.5 mg/L.
• Arusha groundwater average: 3.2 mg/L.
• Brewed tea fluoride level: Up to 6.4 mg/L.
• Households consuming >2L of tea/day.
• 74% of households do not treat their water.
• Boiling does not remove fluoride.
