Millions of Kenyans are at risk of serious bone defects and dental discolouration as a result of high levels of fluoride in their drinking water, researchers have warned.
The risk is made worse by the fact that, as the rest of the world moves to treated and piped water systems, more than half of Kenyans (56 per cent) still rely on underground water, which the Kenya National Bureau of Statistics (KNBS) defines as, among others, water fetched from wells and boreholes.
Scientists say that most of Kenya’s underground water contains fluoride levels that are higher than the 1.5 milligrams per litre recommended by the World Health Organisation.
As a result, KNBS Principal Quality Assurance Officer, Mr Barrison Akolo, during a recent consultative forum in Nakuru, urged caution among consumers, saying that water derived from underground sources “tends to have higher levels of fluoride than that obtained from surface sources”.
Fluoride is a chemical compound that occurs naturally on the earth’s crust. It is formed during rock formation and is a chemical ion of chlorine.
“All rocks have fluoride,” says Mr James Gichana, a water engineer, “but the quantity differs, depending on where the rock is located.
During water formation within the rocks, fluoride naturally becomes one of its components.
However, the quantity of fluoride in the water depends on the saturation of the chemical compound in the rock or layer.
So some have very high concentration while others have only small amounts.”
Two decades ago, the University of Nairobi’s Department of Dental Surgery and Faculty of Engineering conducted a study on the levels of fluoride in Kenyan waters.
The findings were startling, with exposure levels ranging between 5mg/l to 10mg/l.
The Kenya Society for Fluoride Research (KSFR), which corroborates the findings, further shows that 19 million Kenyans suffer from fluorosis, a condition that can affect the teeth or skeleton, depending on the length of time one has been exposed to water with a high concentration of fluoride, and their geographical location.
“As fluoride sediments in the body,” explains Mr Julius Kubai, a water engineer, “it begins to destroy parts of the body, especially the bony skeleton and teeth.”
Depending on the quantity of the fluoride, he adds, the effects may begin to show two years after one starts consuming water with high levels of fluoride.
Unfortunately, says Mr Kubai, the effects are only preventable, and cannot be reversed.
Dental fluorosis mainly affects children with developing teeth, although it affects adults as well.
Effects worse in children
“There is no cure for dental fluorosis, the condition of the damaged teeth cannot be restored,” he explains.
In adults, the teeth lose their white colour and develop yellowish spots within two years.
Mr Kubai says the effects are even worse in children, who can lose their teeth due to the weakening of the jaw.
In areas where the water has more than 10 milligrams of fluoride per litre, the adults’ whole teeth turn black and become fragile.
In severe cases, they sometimes chip.
Skeletal fluorosis, which in its acute stage causes total immobility, develops slowly and can take up to 30 years.
The skeletal bones develop outgrowths and become deformed.
This is common in areas where the fluoride content in the water exceeds 4 mg/l, like Nakuru, Naivasha and Baringo.
The effects of fluoride have social implications for those affected, notes Nakuru County Executive Member for the Environment, Water, Energy and Natural Resources, Mr Richard Rop.
“You often find people with the discoloured or black teeth covering their mouth while laughing in public.
It makes them self-conscious and uncomfortable, thus denying them a chance to socialise freely. It is not a nice feeling.”
Locked out of jobs
In fact, the effects go beyond socialising and affect one’s career.
There are people who get locked out of jobs whose main requirements are good physical condition and teeth, such as the army, police force, and reporting or anchoring on TV.
The KSFR notes that more than 80 per cent of the potential recruits who turn up for recruitment into the armed forces in central Kenya fail due to the bad condition of their teeth, which is attributable to fluoride.
Notably, the government and non-governmental organisations are the largest suppliers of underground water in both urban and rural areas.
However, they only remove excess chlorine but not fluoride from the water.
This means that families take the responsibility of ensuring that the water they consume is safe.
“It is very expensive to run an industrial deflouridation plant,” explains Mr Gichana, who is the managing director of Naivasha Water, Sewerage and Sanitation Company.
“What we are encouraging are the small deflouridation units, some which can be used at home.”
Among such products is one invented by the Nakuru Defluoridation Company, a firm run by the Catholic Diocese of Nakuru, that removes excess fluoride from cooking and drinking water.
The product, curiously, is made from the bones of domestic, herbivorous animals such as cows, goats, sheep and camels.
“Bone char is efficient as it can reduce the fluoride content in water to 0.1mg/l,” explains the company’s production manager.
“To make it, we use only goat, cow, sheep and camel bones. We do not use bones from any other animals.”
The bones are put through four steps to transform them into defluoridation material.
First, they are burnt, then crushed and sieved before being washed and then dried.
The final product is a greyish and porous granular material whose main components are calcium phosphate, calcium carbonate and activated carbon, and it is this peculiar chemical composition, the developers believe, that gives the char its specific ability to absorb fluoride from water.
The main purpose of burning the bones is to remove all organic impurities, with minimal reduction in their defluoridation capacity.
Afterwards, they are washed with sodium hydroxide to remove dust and other impurities from the charring and crushing processes before being dried and stored.
Fluoride in drinking water has always been a contentious subject, and not just in Kenya.
In 2008, for instance, a fierce debate kicked up in the UK over whether to put the chemical in tap water for about 200,000 residents in Southampton.
While the chemical had been added to water supplies in other towns in the UK for decades, tooth decay had been proven prevalent among children in Southampton, and there were fears that more fluoride in water would make the problem worse.
The authorities, however, argued that the reverse would be true, that more fluoride would actually remedy the situation.
Government officials had kicked up the controversy by calling for fluoride to be added to more water supplies in areas populated by some of UK’s poorest and most vulnerable.
Prof Michael Lennon, chairman of the British Fluoridation Society, also believed there were major health benefits for deprived areas and people were wrong to oppose the move.
“About 10 per cent of the UK is currently fluoridated and our view is we should extend that to about 30 per cent of the population,” Prof Lennon was quoted by the BBC as saying.
“Fluoridation is not a new idea that’s been dreamt up, it’s as old as the hills.”
Do not stack up
Prof Lennon added that opponents to the move would “use all sorts of statistics about fluorosis”.
“If this is true,” he challenged, “how come two million people in Birmingham have been drinking fluoridated water since 1964?
These arguments just don’t stack up.”
But those against the move would hear none of it.
The All Party Parliamentary Group Against Fluoridation, through chairman Brian Donohoe, said it wanted the public to get the full facts about fluoridation and not be “duped” into accepting it.
“I don’t think anything should be added to the water as a medicine, because it’s the beginning of the end,” said Donohoe.
“What’s to stop you adding other things as medicine? I don’t think it should be imposed upon people without them having a say.
There has to be a poll of the public.”
In the US, a growing number of communities are choosing to stop adding fluoride to their water systems, even though the federal government and federal health officials maintain their full support for a measure they say provides a 25 per cent reduction in tooth decay nationwide.
About 200 jurisdictions from Georgia to Alaska have chosen to end the practice in the last four years, motivated by both tight budgets and skepticism about its benefits.
A report released last year by the CDC linked fluoride to an increase among children in dental fluorosis, which causes white or yellow spots on teeth, allowing the movement to gain traction.
In Kenya, however, because of the over-reliance on ground water, fluorine occurs naturally in large amounts in drinking water, and while other jurisdictions are debating ways to add the chemical in their supply systems, the country’s greatest need, at least in some parts, is how to reduce it.