Is Drinking Fluoridated Water Safe?

Fluoride plays an important role in maintaining human health. Small quantities, around 0.7 to 1.5 mg/L in water, are beneficial, particularly in strengthening tooth enamel and preventing dental cavities. It supports bone health and helps in the remineralization of teeth. In some areas where fluoride levels in water are low, authorities intentionally add fluoride to the municipal water supply to reduce tooth decay, especially in children.

Though beneficial, excessive fluoride exposure has been linked to various health issues. Studies suggest fluoride levels of 2.5 mg/L or higher may increase the risk of:

• Dental fluorosis
• Skeletal fluorosis
• Arthritis
• Bone damage
• Osteoporosis
• Muscular damage
• Fatigue
• Joint-related problems

In extreme cases, high fluoride levels can harm the heart, arteries, kidneys, liver, endocrine glands, nervous system, and other delicate parts of the body.

Fortunately, there are methods to reduce high fluoride concentrations in drinking water. Besides common chemical and membrane-based defluorination methods, alternative approaches that are natural, eco-friendly, and cost-effective have been studied. Recent research on tamarind has shown promising results in enhancing fluoride excretion from the body and adsorbing fluoride from drinking water.

Tamarind - Fluoride Fighter

A study by AL Khandare, GS Rao, and N Lakshmaiah, published in the European Journal of Clinical Nutrition, evaluated the effect of tamarind (Tamarindus indicus) ingestion on fluoride excretion, particularly in school children.

Twenty healthy boys consumed 10 grams of tamarind with their daily lunch for 18 days. The researchers periodically analyzed urine samples to observe the effects. The study showed that tamarind intake led to a decrease in the excretion of magnesium and zinc, and a significant increase in fluoride excretion in urine. The researchers concluded that tamarind intake might help slow the progression of fluorosis by increasing the excretion of fluoride through urine.

A subsequent study, published by the Indian National Institute of Nutrition, investigated the effects of tamarind consumption on fluoride ingestion and its benefits in mobilizing fluoride from bones after children are given defluoridated water. Conducted on 30 adolescent boys from a fluoride-endemic area, the study found that those supplemented with tamarind experienced a significant increase in fluoride excretion and urinary pH, along with a reduction in urinary calcium and copper levels.

Removal of Fluoride from Drinking Water Using Tamarind Fruit Shell

Research published in Emerging Trends in Engineering and Development explored using tamarind fruit shells as an adsorbent for fluoride removal. The tamarind shell-based adsorbent exhibited the highest fluorine removal efficiency of about 85% at a pH of 2.

Another study in the Journal of the Chilean Chemical Society conducted water defluoridation using tamarind fruit cover (TNFC) as a natural adsorbent, showing that both untreated and acid-treated tamarind covers are effective biosorbents for removing fluoride ions from water.

Chemical Ways of Water Defluoridation

Several chemical methods effectively reduce fluoride levels in water:

• Precipitation methods: Using chemicals like calcium hydroxide, aluminum sulfate, or ferric chloride to precipitate fluoride ions, followed by sedimentation or filtration.
• Adsorption methods: Fluoride ions are adsorbed using activated alumina, bone char, or other high-affinity adsorbents.
• Ion exchange: Resin exchanges fluoride ions with other ions, reducing fluoride concentration.
• Electrocoagulation: An electric current coagulates and precipitates fluoride ions using aluminum or iron electrodes.
• Chemical coagulation: Adding aluminum sulfate or polyaluminum chloride to water incorporates fluoride ions, which are then removed through sedimentation or filtration.

Water Defluoridation Using Membranes

Two common membrane-based defluoridation methods include:

• Reverse Osmosis (RO): Uses a pressurized filtration system with a semi-permeable membrane that allows water molecules to pass while capturing fluoride ions and other contaminants.
• Electrodialysis (ED): Employs ion-exchange membranes and an electric field to transport fluoride ions across the membranes, separating them from water.

Conclusion

Tamarind is a promising natural agent for reducing fluoride exposure, capable of increasing fluoride excretion through urine and potentially slowing fluorosis development. Beyond its internal benefits, tamarind fruit shells have shown potential as eco-friendly, cost-effective adsorbents for removing fluoride from water, achieving up to 85% efficiency under ideal conditions. While chemical and membrane-based methods remain effective, exploring natural alternatives like tamarind provides new possibilities for sustainable water treatment, especially in areas with limited access to advanced technologies.

How to Reduce the Risks of Excessive Fluoride Exposure?

Water is the most common source of fluoride exposure. Here are some steps to reduce it:

• Use fluoride-free oral care products, such as toothpaste and mouthwash.
• Avoid drinking or using untreated water for food and drink preparation.
• Install a water filtration system. Browse Oasis water and filter ratings.
• Stay informed about your local water quality by reviewing annual reports from your water utility.