Text by Marilyn Smith / Photos by Nigel Dickinson
Twenty years after Chernobyl, health officials continue to identify ‘new’ cases of human exposure to ionizing radiation, i.e., individuals who are coming into direct or indirect contact with radionuclides that were released in 1986. According to government documents, as many as 80% of these cases in the regions of Belarus that are affected by the Chernobyl accident are directly linked to food consumption.
That is not to suggest that the large quantities of food are unsafe; quite to the contrary. Rather, it points to poor understanding of how radionuclides travel through the food chain and producer-to-consumer supply routes that bypass safety systems. To appreciate the challenge the government faces in reducing internal exposure through food consumption, consider the simple act of buying a pound of butter.
|Every truckload of raw milk that arrives at the gates of the Khoiniki butter and dairy plant is initially tested for overall quality.|
Just three days after the disaster, Ms. Galina Bondar, director of the Khoiniki butter and dairy plant, located only 30 km from the Chernobyl exclusion zone, received equipment designed to analyse radiation levels in raw milk. Twenty years on, every truckload of milk that arrives at the main gate undergoes even more stringent testing in biochemistry and radiological laboratories that were recently upgraded through support from the TC programme of the IAEA. Thanks to this equipment and the training provided by TC, the laboratory can detect and accurately measure levels of both caesium-137 and strontium-90. The test results determine whether the raw product will end up as milk, yogurt, butter, cheese or casein.
|Additional tests inside the radiological lab determine the level of radioactivity – and the end-product for which the raw milk will be used. Clean milk (left) can be used for any product; milk with higher levels of radioactivity (right) requires additional processing to separate out radionuclides.|
“Milk that has higher levels of radiation requires additional processing,” says Ms. Bondar. “It is best suited for producing butter because fats naturally repel radionuclides; they become concentrated in the by-product, not in the end product.”
This combination of testing and selective processing ensures that all dairy products in supermarkets meet government guidelines for food safety. In fact, every year more than 1000 laboratories and radiation control posts, equipped with necessary radiometric and spectrometric gear, test more than 11 million food samples for caesium-137 and about 18 000 samples for strontium-90.
|A peasant woman at a local market proudly displays her home-made butter, which can be purchased for less than that at local grocery stores.|
A visit to a local market, also in a village on the fringe of the exclusion zone, reflects an entirely different storyline – with a potentially disastrous ending. A peasant farmer proudly displays her wares, assuring reporters that “Yes, she made the butter herself…by hand”. It is easy to imagine that she and her husband also grow their own vegetables, hand till a small plot of land and allow their cows (if they have more than one) to graze in open pastures or nearby forests.
In this scenario, radionuclides pass directly from contaminated soil through the digestive tract of the cow, into the hands of a woman who makes butter “exactly as she did 30 years ago”, and onto the sliced bread of unsuspecting customers.
Rural markets are rife with such contamination hazards. Foodstuffs harvested in the forest such as mushrooms, berries and wild game also draw radionuclides out of contaminated soil. Fresh fish may have been ‘hooked’ in a contaminated river or lake.
|These common mushrooms and vegetables may well be grown under controlled conditions and are completely safe. In contrast, wild mushrooms and berries harvested from the forest or locally caught fish may be mildly or highly contaminated.|
It is well documented that new cases of exposure to radiation from food are most likely to occur amongst rural populations. But there’s a further complication. Despite the fact that rural dwellers are a target population, they are among the least likely to participate in programmes designed to monitor individual radiation exposure. It’s largely a problem of logistics: medical centres and radiological laboratories are concentrated in urban areas. If one’s only mode of transport is horse and cart, a simple test may require a full day of travel.
|TC helped develop a prototype ‘mobile radiation monitoring lab' that travels to remote regions to test local citizens and servicemen who work in or near the Exclusion Zone.|
To address these interrelated issues, TC hit the road – quite literally – with an innovative solution. A fleet of customized vans, each equipped with a full body radiation counter, a spectrometer and a computer, now takes radiation testing to target populations.
“The mobile radiation unit is very effective on several fronts,” says Andrei Chupov. “First, it allows us to monitor individual doses of people who might not otherwise be ‘on record’. Second, by testing local foods, we can identify the actual source of contamination. The computer printout allows people to “see” the link between what they eat and what we find in their bodies.”
|Testing food sources in the mobile unit allows people to ‘see’ the radiation levels in foods they commonly consume.|
The mobile lab is accredited to perform whole body measurements and has been in operation since May 2003. To date, more than 10 000 civilians and servicemen from the Belarusian Border Guards have undergone radiation testing, along with more than 1200 food samples. Clearly, it cannot serve local markets or protect rural dwellers in the way that laboratory testing supports safety in large-scale food processing. However, it can identify individuals whose exposure levels warrant additional attention by medical professionals and help raise awareness about local risks.
Ultimately, the mobile units have the potential to play a role in encouraging rural dwellers to modify risky behaviours. But butter that has been bought in a store may continue to be a hard sell. Ms. Bondar admits that with all the monitoring and testing required, butter from the Khoiniki factory is more expensive than brands shipped in from uncontaminated regions. And both have higher price tags than the butter produced by hand and sold at the local market.
|The processes involved in making butter separate radionuclides from the raw milk, thereby delivering a ‘clean’ end product. However, the required testing results in higher prices on the supermarket shelves.|
For rural farmers who still suffer economic hardship as a result of Chernobyl, a penny saved today might have more immediate meaning than the long-term effect of accumulating small doses of radiation exposure.
Aside from determining what milk goes into which end products, radiological testing at dairy factories serves another purpose: it helps pinpoint contaminated farmland. Modern dairy farming in Belarus still reflects the former Soviet regime. Large tractors and big barns signify the continuation of state farming practices; rickety stables and wooden ploughs identify private farms that typically comprise only a few acres.
|Large herds reflect the heritage of state farms in the Chernobyl region but many rural peasants still survive on a few acres of land and one or two cows. Each approach has specific challenges vis-à-vis soil remediation and providing raw milk for markets.|
State farms have a distinct advantage in the dairy sector. Not surprisingly, dairy factories pay higher prices for ‘cleaner’ raw milk. State farms may have enough land to rotate crops for soil remediation and to let cows roam in different pastures, as well as enough cattle in their herds to average contamination levels downward in their bulk delivery to the plant.
In contrast, even when a private farmer opts to sell supplies to a factory rather than at the local market, various factors may conspire against him. What little farmland he has typically must be devoted to growing crops and vegetables rather than to grazing cattle. Clean feed products available on the market may be prohibitively expensive, leaving no option but to let cattle graze in open fields and forests known to be contaminated. Finally, in adding his milk to a tanker truck that services several small farms, he may have the cleanest milk in a lot which is relatively high in radioactivity. But the factory pays on the basis of the results of the entire tanker truck – and he earns less than his own milk is really worth.
The end result is that with lower income, the private farmer typically has less money to invest in activities that could help remediate his soil and allow his cows to produce cleaner milk. Now that tools, technologies and techniques that support remediation are tried and tested, the time is right to focus developing mechanisms to support their broader application and thereby encourage social and economic recovery. The IAEA TC programme is directly involved in several projects that aim to bring agricultural and forestry products from the Chernobyl region back into local, national and international markets.