[News] from [guardian.co.uk]
[News >UK news > Food safety]
Sheep farmers still stuck under a Chernobyl cloud
Ever since radiation from Chernobyl rained down on the UK 23 years ago, sales of sheep in affected areas have been restricted. But frustrated farmers now claim the meat is safe – and that testing should stop
Leo Hickman
The Guardian, Tuesday 29 December 2009 Article history
Lakeland sheep farmers, like the rare-breed Herdwicks many still rear today, are of hardy stock and refuse to be moved by a forecast of rain. It was no different during the first few days of May 1986, when an unseasonably intense downpour lashed down on the Cumbrian fells, topping its tarns and lakes, and driving walkers and day-trippers towards the sanctuary of the tea rooms.
David Ellwood – then a 30-year-old sheep farmer who had just taken on a National Trust tenant farm above the hamlet of Ulpha in the Duddon valley – remembers that week well. "It was lambing time," he recalls. "It was really, really wet. And then we got the message from the ministry. All the sheep farmers in the area were told there was to be a fortnight-long restriction on the sale and movement of our sheep."
A week earlier, on 26 April 1986, reactor number four at the Chernobyl nuclear power plant in what was then the Soviet Socialist Republic of Ukraine exploded, sending a plume of radio- active particles – equivalent in toxicity to 400 Hiroshima bombs – more than seven kilometres up into the atmosphere and due east in the breeze. In the days that followed, as a fire raged unchecked inside the twisted, white-hot remains of the reactor, the wind direction reversed and the plume, now a kilometre tall, headed west towards north-western Europe. It wasn't until workers at a nuclear reactor in Finland detected abnormally high doses of radioactivity on their clothes - up to 100 times normal background levels – that anyone outside the Soviet Union realised the true severity of the accident.
On 2 May 1986, the plume finally passed over parts of the UK and, with fateful timing, so too did a column of cloud carrying heavy rain. The rain fell hardest where it always falls hardest – on the uplands. As the droplets of water fell from the sky, they carried with them the radionuclides – in particular, caesium-137, iodine-131 and strontium-90 – that had been dispersed from Chernobyl. It is estimated that 1% of the radiation released from the reactor fell on the UK. In an effort to prevent these radionuclides entering the food chain once they had settled on the upland soil, the ministry of agriculture, fisheries and food, as it was then known, ordered an immediate restriction on the movement and sale of sheep within the most affected areas – particularly north Wales, south-west Scotland, Northern Ireland and the Lake District, where the landscape is predominantly suited to grazing sheep. In total, almost 9,000 farms, and four million sheep, were placed under restriction.
"We couldn't believe it at first," says Ellwood today, leaning on his crook and looking up from his farmhouse towards the smooth dome of Hesk Fell – an ascent that Alfred Wainwright, the fellwalker's guidebook guru, said would lead nobody to "drop dead with excitement or suffer spasms of emotion" – where the majority of his 600 sheep still roam. "The radiation had come from 3,000 miles away and you couldn't see it. For many farmers around here, it brought back memories of the Windscale nuclear accident in 1957. My father, who was a sheep farmer at that time up near Eskdale, reassured me by saying he didn't have any problems with Windscale, but we didn't know anything about these sorts of things back then."
In fact, Ellwood still lives under the cloud of Chernobyl's legacy today. Baskell Farm, the 1,000-acre tenant farm he operates with his wife Heather, is one of the farms still under government restriction due to the risks of any remaining radionuclides passing into the human food chain via sheep meat. The vast majority of affected sheep farms – 355, to be precise – are located in and around Snowdonia in Wales, whereas nine, including Baskell Farm, are still being monitored in England and seven in Scotland. (All the farms in Northern Ireland were "derestricted" in 2000.)
Ellwood says the annoyance among many of the restricted farmers has grown steadily over the years because of a combination of poor communication from the Food Standards Agency (FSA), the government body responsible for overseeing the monitoring scheme, and woeful levels of compensation. For every sheep that has to be separately penned and cleared for sale by a government inspector, a farmer receives £1.30 in compensation – exactly the same amount as in 1986.
"It's bloody ridiculous," spits Ellwood, as with his splayed knees he guides the first of 30 five-month-old lambs into a pen in preparation for the imminent arrival of an inspector from the Rural Payment Agency (RPA), the body charged by the FSA with monitoring the restricted farms in England. "I have to go through all this hassle every time I want to move sheep off the fell for sale. We get 8-10 visits a year from RPA inspectors. They keep saying it's going to last one more year. Nothing seems to ever get derestricted round here, though." Ellwood shrugs his shoulders in resignation.
As the clouds thicken overhead, Steve Pottinger, the local RPA inspector, drives up the claggy lane leading to Baskell Farm. Six-feet-high dry-stone walls flank the car. Once parked, Pottinger throws a familiar wave to Ellwood in the holding pen before lifting a large Geiger counter out of his boot. He then heaves himself over the fence into the pen with Ellwood and switches on the machine to measure the background radiation levels.
"We call this the 'Chernobyl monitor' and we first take six background readings to work out the average," explains Pottinger, as the digital display shows "17" and then "18" before returning to "17". "If a reading on a sheep is 13 above the background reading, we classify that as a failure."
The machine costs about £3,000 and it can detect levels of caesium-137 – the only remaining radionuclide from Chernobyl to give concern to the FSA – both in the atmosphere and in the body tissue of an animal. Ellwood says it's been two to three years since any of his animals tested positive.
Pottinger directs Ellwood to hold tightly on to one of his lambs and then the counter is pressed hard into the animal's rump muscle. Three readings are taken over about a minute, and range from 18 up to 22 for each animal, well within the safety level.
But what exactly is "safe"? The FSA's official maximum limit of caesium-137 in meat is 1,000 becquerels per kilo. This limit echoes the internationally recognised standard established in the immediate aftermath of Chernobyl – but for extra precaution, the FSA works to a 600 becquerels per kilo limit. Caesium-137 has a radiological half-life of 30 years, so the point will soon be reached where the radioactive dose in the soil of the affected uplands will be half the levels immediately after Chernobyl.
The reason why certain uplands remain affected is largely down to their soil type. Unlike clay soils, which can retain radionuclides permanently, the peaty soil found on the slopes of many upland fells and mountains allow the radionuclides to transfer to the grass and hence into the grazing sheep. Once ingested into an animal, though, the so-called "biological half-life" of caesium-137 is about 10 days, meaning it is excreted from the body relatively fast. As a result, once a sheep has been moved off the affected uplands and received a negative test result within 24 hours of being moved, it can be released for sale. Any animal that tests positive is – as Ellwood describes it – "butched" and the farmer receives compensation equal to the animal's market value.
One of the questions Ellwood, and other affected farmers, want answered is whether the FSA is being overly cautious. Just how much risk does this meat now pose to the health of a consumer? The Health Protection Agency has calculated that if someone were to eat 8kg of sheep meat a year – the average consumption in the UK – that contained the maximum limit of caesium-137 it would give the consumer a dose of 0.1 millisieverts. This is just one tenth of a person's accepted annual limit.
But in the UK, we are, on average, exposed to a "natural" annual dose of 2.23 millisieverts from sources such as radon gas and cosmic rays, which in total account for about 85% of our total radiological exposure. The average annual dose from artificial radiation is 0.42 millisieverts and is mainly derived from medical procedures such as dental x-rays. (The recommended annual dose limit for anyone working with radiation is 20 millisieverts, and 1,000 millisieverts, or one sievert, is the level when radiation sickness would be expected. Death is predicted at a dose of eight sieverts and above.)
As with anything to do with our exposure to radioactivity, the question of "safe levels" provokes a range of passionate views. Paul Johnston, a toxicologist based at the Greenpeace research laboratory at the University of Exeter, is "deeply sceptical" about what constitutes a safe dose of radiation.
CONTINUED ON newsgdn2
[News >UK news > Food safety]
Sheep farmers still stuck under a Chernobyl cloud
Ever since radiation from Chernobyl rained down on the UK 23 years ago, sales of sheep in affected areas have been restricted. But frustrated farmers now claim the meat is safe – and that testing should stop
Leo Hickman
The Guardian, Tuesday 29 December 2009 Article history
Lakeland sheep farmers, like the rare-breed Herdwicks many still rear today, are of hardy stock and refuse to be moved by a forecast of rain. It was no different during the first few days of May 1986, when an unseasonably intense downpour lashed down on the Cumbrian fells, topping its tarns and lakes, and driving walkers and day-trippers towards the sanctuary of the tea rooms.
David Ellwood – then a 30-year-old sheep farmer who had just taken on a National Trust tenant farm above the hamlet of Ulpha in the Duddon valley – remembers that week well. "It was lambing time," he recalls. "It was really, really wet. And then we got the message from the ministry. All the sheep farmers in the area were told there was to be a fortnight-long restriction on the sale and movement of our sheep."
A week earlier, on 26 April 1986, reactor number four at the Chernobyl nuclear power plant in what was then the Soviet Socialist Republic of Ukraine exploded, sending a plume of radio- active particles – equivalent in toxicity to 400 Hiroshima bombs – more than seven kilometres up into the atmosphere and due east in the breeze. In the days that followed, as a fire raged unchecked inside the twisted, white-hot remains of the reactor, the wind direction reversed and the plume, now a kilometre tall, headed west towards north-western Europe. It wasn't until workers at a nuclear reactor in Finland detected abnormally high doses of radioactivity on their clothes - up to 100 times normal background levels – that anyone outside the Soviet Union realised the true severity of the accident.
On 2 May 1986, the plume finally passed over parts of the UK and, with fateful timing, so too did a column of cloud carrying heavy rain. The rain fell hardest where it always falls hardest – on the uplands. As the droplets of water fell from the sky, they carried with them the radionuclides – in particular, caesium-137, iodine-131 and strontium-90 – that had been dispersed from Chernobyl. It is estimated that 1% of the radiation released from the reactor fell on the UK. In an effort to prevent these radionuclides entering the food chain once they had settled on the upland soil, the ministry of agriculture, fisheries and food, as it was then known, ordered an immediate restriction on the movement and sale of sheep within the most affected areas – particularly north Wales, south-west Scotland, Northern Ireland and the Lake District, where the landscape is predominantly suited to grazing sheep. In total, almost 9,000 farms, and four million sheep, were placed under restriction.
"We couldn't believe it at first," says Ellwood today, leaning on his crook and looking up from his farmhouse towards the smooth dome of Hesk Fell – an ascent that Alfred Wainwright, the fellwalker's guidebook guru, said would lead nobody to "drop dead with excitement or suffer spasms of emotion" – where the majority of his 600 sheep still roam. "The radiation had come from 3,000 miles away and you couldn't see it. For many farmers around here, it brought back memories of the Windscale nuclear accident in 1957. My father, who was a sheep farmer at that time up near Eskdale, reassured me by saying he didn't have any problems with Windscale, but we didn't know anything about these sorts of things back then."
In fact, Ellwood still lives under the cloud of Chernobyl's legacy today. Baskell Farm, the 1,000-acre tenant farm he operates with his wife Heather, is one of the farms still under government restriction due to the risks of any remaining radionuclides passing into the human food chain via sheep meat. The vast majority of affected sheep farms – 355, to be precise – are located in and around Snowdonia in Wales, whereas nine, including Baskell Farm, are still being monitored in England and seven in Scotland. (All the farms in Northern Ireland were "derestricted" in 2000.)
Ellwood says the annoyance among many of the restricted farmers has grown steadily over the years because of a combination of poor communication from the Food Standards Agency (FSA), the government body responsible for overseeing the monitoring scheme, and woeful levels of compensation. For every sheep that has to be separately penned and cleared for sale by a government inspector, a farmer receives £1.30 in compensation – exactly the same amount as in 1986.
"It's bloody ridiculous," spits Ellwood, as with his splayed knees he guides the first of 30 five-month-old lambs into a pen in preparation for the imminent arrival of an inspector from the Rural Payment Agency (RPA), the body charged by the FSA with monitoring the restricted farms in England. "I have to go through all this hassle every time I want to move sheep off the fell for sale. We get 8-10 visits a year from RPA inspectors. They keep saying it's going to last one more year. Nothing seems to ever get derestricted round here, though." Ellwood shrugs his shoulders in resignation.
As the clouds thicken overhead, Steve Pottinger, the local RPA inspector, drives up the claggy lane leading to Baskell Farm. Six-feet-high dry-stone walls flank the car. Once parked, Pottinger throws a familiar wave to Ellwood in the holding pen before lifting a large Geiger counter out of his boot. He then heaves himself over the fence into the pen with Ellwood and switches on the machine to measure the background radiation levels.
"We call this the 'Chernobyl monitor' and we first take six background readings to work out the average," explains Pottinger, as the digital display shows "17" and then "18" before returning to "17". "If a reading on a sheep is 13 above the background reading, we classify that as a failure."
The machine costs about £3,000 and it can detect levels of caesium-137 – the only remaining radionuclide from Chernobyl to give concern to the FSA – both in the atmosphere and in the body tissue of an animal. Ellwood says it's been two to three years since any of his animals tested positive.
Pottinger directs Ellwood to hold tightly on to one of his lambs and then the counter is pressed hard into the animal's rump muscle. Three readings are taken over about a minute, and range from 18 up to 22 for each animal, well within the safety level.
But what exactly is "safe"? The FSA's official maximum limit of caesium-137 in meat is 1,000 becquerels per kilo. This limit echoes the internationally recognised standard established in the immediate aftermath of Chernobyl – but for extra precaution, the FSA works to a 600 becquerels per kilo limit. Caesium-137 has a radiological half-life of 30 years, so the point will soon be reached where the radioactive dose in the soil of the affected uplands will be half the levels immediately after Chernobyl.
The reason why certain uplands remain affected is largely down to their soil type. Unlike clay soils, which can retain radionuclides permanently, the peaty soil found on the slopes of many upland fells and mountains allow the radionuclides to transfer to the grass and hence into the grazing sheep. Once ingested into an animal, though, the so-called "biological half-life" of caesium-137 is about 10 days, meaning it is excreted from the body relatively fast. As a result, once a sheep has been moved off the affected uplands and received a negative test result within 24 hours of being moved, it can be released for sale. Any animal that tests positive is – as Ellwood describes it – "butched" and the farmer receives compensation equal to the animal's market value.
One of the questions Ellwood, and other affected farmers, want answered is whether the FSA is being overly cautious. Just how much risk does this meat now pose to the health of a consumer? The Health Protection Agency has calculated that if someone were to eat 8kg of sheep meat a year – the average consumption in the UK – that contained the maximum limit of caesium-137 it would give the consumer a dose of 0.1 millisieverts. This is just one tenth of a person's accepted annual limit.
But in the UK, we are, on average, exposed to a "natural" annual dose of 2.23 millisieverts from sources such as radon gas and cosmic rays, which in total account for about 85% of our total radiological exposure. The average annual dose from artificial radiation is 0.42 millisieverts and is mainly derived from medical procedures such as dental x-rays. (The recommended annual dose limit for anyone working with radiation is 20 millisieverts, and 1,000 millisieverts, or one sievert, is the level when radiation sickness would be expected. Death is predicted at a dose of eight sieverts and above.)
As with anything to do with our exposure to radioactivity, the question of "safe levels" provokes a range of passionate views. Paul Johnston, a toxicologist based at the Greenpeace research laboratory at the University of Exeter, is "deeply sceptical" about what constitutes a safe dose of radiation.
CONTINUED ON newsgdn2
※コメント投稿者のブログIDはブログ作成者のみに通知されます