Reykjavik, Iceland - For the third summer in a row, hydrogen fluoride has been detected in vegetation samples taken near an aluminium plant in eastern Iceland, worrying farmers and horse owners who fear for their animals' well-being.
Aluminium plants emit fluoride, a chemical element that can be toxic to animals and humans in high concentrations.
The Environment Agency of Iceland found the concentration of fluoride in grass grazed by sheep exceeded the recommended limits near the town of Reydarfjordur.
Sigridur Kristjansdottir from the Environment Agency told Al Jazeera the high levels this summer were "primarily due to meteorological and geographical factors ... This resulted in the results for early June showing relatively high values".
A press release issued by the Alcoa Fjardaal aluminium plant noted that, despite the spike this summer, average fluoride levels this year are lower than they were in 2013, which in turn were lower than in 2012.
Fluoride is a cumulative poison, meaning that animals and plants often register higher levels of the element as they age. Before the Fjardaal aluminium smelter began operation, the fluoride level in Sigurdur Baldursson's sheep - who live on the only farm near Alcoa's plant - were measured as having 800 micrograms per gram (µg/g) of fluoride in their bone ash. That's well below the recommended limit of 4,000 µg/g in the bone ash of adult sheep, or 2,000 µg/g for lambs.
Usually, two to three percent of sheep do not produce lambs. Away from the plant, 2.6 percent of ewes were lambless, whereas in the area southwest of the plant, this figure was 7.4 percent.
But samples taken in 2013, recorded the sheep's fluoride levels between 3,300 and 4,000 µg/g. Baldursson said he expects the next readings to exceed 5,000 µg/g - above the recommended limit.
"The sheep that will be sampled next were born in 2007, and are thus as old as the aluminium plant itself," he told Al Jazeera.
Nevertheless, Baldursson said he has not noticed signs of ill health in his sheep.
'I only heard about it by accident'
Bergthora Andresdottir sees things differently from her farm on the other side of Iceland, 25km north of the capital Reykjavik. She said she is constantly phoning the Environment Agency to complain about smoke rising from Century Aluminium's smelter at Grundartangi, directly across the fjord from her farm.
"I phone them several times a week," she told Al Jazeera. "But there's no specific person to talk to, and they don't help much. Sometimes they claim that the smoke is coming from the neighbouring factory [the Elkem ferrosilicon smelter], but I tell them it isn't."
In August 2006, an accident at the Grundartangi plant caused a large amount of fluoride emissions. Riding school owner Ragnheidur Thorgrimsdottir said local farmers were never told about this accident, which meant that sheep, cattle and horses ate fluoride-contaminated grass. "I only heard about it by accident, two years later," she told Al Jazeera.
That same year, the capacity of the Century plant was increased from 90,000 tonnes of aluminium a year to 220,000. The firm HRV Engineering stated "the increase in fluoride for the autumn months of 2006 in the atmosphere ... can partly be traced to the increase in capacity of the smelter".
Thorgrimsdottir lives about five kilometres southwest of the Grundartangi plant, and owns 20 horses - which she said have been badly affected by fluoride, some so badly that they have had to be put down.
"This is the eighth year in a row that my horses have been sick. Currently three of them are sick, but I'm also keeping an eye on four more," she told Al Jazeera. Instead of keeping her horses outside all the time, as is the norm during Icelandic summers, she has kept them in at night and given them hay to eat because they do not digest grass properly.
Thorgrimsdottir showed Al Jazeera one of the affected horses named Silfursteinn. "The affected horses walk stiffly, like sticks. They also tend to have lumps and swellings on their bodies," said Thorgrimsdottir.
When asked about Thorgrimsdottir's horses, Solveig Bergmann - a public relations officer for Century - said she could not explain their maladies. "I have no explanation. According to veterinarians, the horses ... bear symptoms of Equine Metabolic Syndrome (EMS), which is caused mainly by obesity and lack of exercise," she said, citing a report by the Icelandic Food and Veterinary Authority (IFVA).
But Thorgrimsdottir said EMS can also be caused by fluoride, and when IFVA vets took samples from the horses she had to put down, they only measured fluoride levels in their bones, not in their soft tissue as she had requested.
Gyda S Bjornsdottir studied the birth rates and health of sheep from 2007 to 2012 in the area close to the Grundartangi plant for her Master's degree. She found in the areas southwest and northeast of the smelter - which are the most common wind directions in the region - a higher proportion of sheep did not produce any lambs.
"Usually, two to three percent of sheep do not produce lambs. Away from the plant, 2.6 percent of ewes were lambless, whereas in the area southwest of the plant, this figure was 7.4 percent," she told Al Jazeera. Northeast of the plant, she added, 4.5 percent of ewes did not bear lambs.
In research carried out since 1997 in the vicinity of the Century Aluminium smelter at Grundartangi, no evidence has ever been found of negative effects of fluoride on sheep or any other animal.
According to farmers' answers to a questionnaire, sheep in the area close to the plant also show visible signs of damage to teeth - which could be a sign of fluoride poisoning - and poor quality of wool, said Bjornsdottir.
Because the aluminium smelter is next to a ferrosilicon plant that also emits pollutants, Bjornsdottir said she cannot be sure the effects are caused by fluoride, as there were also increased concentrations of sulphur dioxide, nickel and arsenic.
"But the results are consistent with fluoride distribution," she said.
'No evidence' of negative effects
But Bergmann, the Century public relations officer, disagreed. "In research carried out since 1997 in the vicinity of the Century Aluminium smelter at Grundartangi, no evidence has ever been found of negative effects of fluoride on sheep, or any other animal," she said.
Bjornsdottir, however, pointed out in her thesis that farmers say it is not economically viable to send sick sheep to a veterinarian. Instead, they slaughter the affected sheep at home. As a result, she said she believes the figures are biased, because the sheep monitored by Century for fluoride are healthy animals that are sent to the slaughterhouse.
In a letter sent by Iceland's Food and Veterinary Authority to Alcoa in January 2013, Thorsteinn Olafsson - who was responsible for sheep and cattle diseases at that time - said: "There are reasons to suppose that the danger levels for grazing and fodder for Icelandic sheep are even lower than overseas research shows. This needs to be researched even better in the local environment of aluminium plants in Iceland."
Source: Al Jazeera