A group of researchers that has been investigating why there are high levels of fluoride in the Rift Valley has found high contents of the mineral in chicken feathers.
The substance that weakens bones, was found in chicken in high quantities. The scientists found out that consuming a quarter chicken from the area exposes someone to fluoride levels as high as 14 milligrams, which is more than seven times the allowable daily intake.
The researchers, under the Flowered project funded by the European Union, started the study in 2016 with the aim of finding solution to fluoride contamination in water, soils and food in some African Rift Valley countries which include Ethiopia, Kenya and Tanzania.
In Kenya, they have been focusing on Nakuru County where they said the effects of fluoride have been felt most in the Kenyan Rift Valley.
Their latest report is titled Levels of Fluoride in Various Samples and Occurrence of Dental Fluorosis in Livestock in Nakuru County.
The research focused on poultry, where they collected chicken feathers from representative poultry farms from Nakuru County which they analysed for fluoride content.
One of the researchers was Dr Enos Wambu from the Department of Chemistry and Biochemistry in the University of Eldoret.
Dr Wambu said the water that is provided to the chickens for drinking and maize samples from the farms was also collected and analysed.
In the samples of water used by the poultry, highest levels were found in areas around Lakes Nakuru and Elmentaita at the Rift Valley floor.
“A large percentage of poultry water from Nakuru East, Nakuru West, and Naivasha sub-counties, which are in close proximity, contained levels above World Health Organisation (WHO) allowable standards of 1.5 ppm (milligrams per kilogram),” said Dr Wambu.
Extreme levels of high accumulation of the content result in skeletal fluorosis, where bones become fragile.
All areas recorded high fluoride content in poultry water, feathers and in maize samples from the farms where the chicken were reared.
“A typical quarter of a chicken is about 375 grams and if it is assumed that the fluoride content in the feathers is equivalent to the average of the concentrations in bones and meat, a serving of quarter in a meal exposes the consumer to between about 1.0 mg of fluoride to 14.1 mg of fluoride with an average of 4.5 mg of fluoride per meal. This will exceed recorded average total fluoride intake of 2.2 mg per day,” he added.
The scientists also conducted an epidemiological survey to determine the extent of dental fluorosis among ruminant domestic animals which include cattle, sheep and goats.
“Out of 575 animals including 251 cattle, 296 sheep and 28 goats, were inspected. The sheep were generally more affected than cattle and goats,” says the report.
Fluorosis levels among goats were similar to those among cattle but scores among the latter were slightly higher.
According to Professor Elias Acakuwun, a geologist from the University of Eldoret, with the evolution of the Rift valley over the years, there is production of fluoride which doesn’t exist purely but as a compound in rocks.
Prof Acakuwun explains that during the process, there is formation of rocks which come in combination of a number of compounds.
“The fluoride that then finds its way to the soil and water bodies and eventually in to human and animal bodies,” said Prof Acakuwun.
From the findings, the researchers said results have negative implications on the productivity of the affected livestock, their production costs and on the food safety and contribution to food security situations in the affected areas.