Increase in cancer in Sweden can be traced to Chernobyl
The incidence of cancer in northern Sweden increased following the accident at the nuclear power plant in Chernobyl in 1986. This was the finding of a much-debated study from Linköping University in Sweden from 2004.
Was the increase in cancer caused by the radioactive fallout from Chernobyl or could it be explained by other circumstances? New research from Linköping University provides scientific support for the Chernobyl connection.
“This issue is important because the indicated increased risk may come to influence the prevailing exposure limits for the population. Enhanced knowledge of the risks entailed by radioactive radiation is key to work for radiation safety and makes it possible to prevent diseases,†says Martin Tondel, a physician and researcher in environmental medicine who will soon be defending his doctoral dissertation Malignancies in Sweden after the Chernobyl Accident in 1986.
In two studies using different methods, Martin Tondel has shown a small but statistically significant increase in the incidence of cancer in northern Sweden, where the fallout of radioactive cesium 137 was at its most intense.
A monument to the victims of the Chernobyl disaster at Moscow’s Mitino cemetery, where some of the firefighters who battled the flames and later died of radiation exposure are buried.
The nuclear meltdown provoked a radioactive cloud which floated over Russia, Belarus, Ukraine and Moldova, but also the European part of Turkey, Bulgaria, Greece, Romania, Lithuania, Finland, Denmark, Norway, Sweden, Austria, Hungary, the Czech Republic and the Slovak Republic, Slovenia, Poland, Switzerland, Germany, Italy, Ireland, France (including Corsica [14]) and the United Kingdom (UK) [15] [16]. The initial evidence that a major exhaust of radioactive material was affecting other countries came not from Soviet sources, but from Sweden, where on April 27 workers at the Forsmark Nuclear Power Plant (approximately 1100 km from the Chernobyl site) were found to have radioactive particles on their clothes.[17] It was Sweden’s search for the source of radioactivity, after they had determined there was no leak at the Swedish plant, which led to the first hint of a serious nuclear problem in the western Soviet Union. The rise of radiation levels had at time already been measured in Finland but it had not been published.
Contamination from the Chernobyl accident was not evenly spread across the surrounding countryside, but scattered irregularly depending on weather conditions. Reports from Soviet and Western scientists indicate that Belarus received about 60% of the contamination that fell on the former Soviet Union. However, the TORCH 2006 report stated that half of the volatile particles had landed outside Ukraine, Belarus and Russia. A large area in Russia south of Bryansk was also contaminated, as were parts of northwestern Ukraine. In Western Europe, measures were taken including seemingly arbitrary regulations pertaining to the legality of importation of certain foods but not others. In France some officials stated that the Chernobyl accident had no adverse effects – this was ridiculed as pretending that the radioactive cloud had stopped at the German and Italian borders.
The monument from Chisinau, Moldova dedicated to the victims of the Chernobyl disaster and the people who participated in the rescue mission.
In the immediate aftermath of the accident, two hundred and thirty-seven people suffered from acute radiation sickness, of whom thirty-one died within the first three months.[18][19] Most of these were fire and rescue workers trying to bring the accident under control, who were not fully aware of how dangerous the radiation exposure (from the smoke) was (for a discussion of the more important isotopes in fallout see fission products). 135,000 people were evacuated from the area, including 50,000 from Pripyat.
[edit] Rivers, lakes and reservoirs
The Chernobyl nuclear power plant lies next to the river Pripyat which feeds into the Dnieper river-reservoir system, one of the largest surface water systems in Europe. The radioactive contamination of aquatic systems therefore became a major issue in the immediate aftermath of the accident.[20] In the most affected areas of Ukraine, levels of radioactivity (particularly radioiodine: I-131, radiocaesium: Cs-137 and radiostrontium: Sr-90) in drinking water caused concern during the weeks and months after the accident. After this initial period, however, radioactivity in rivers and reservoirs was generally below guideline limits for safe drinking water.[20]
Bio-accumulation of radioactivity in fish[21] resulted in concentrations (both in western Europe and in the former Soviet Union) that in many cases were significantly above guideline maximum levels for consumption.[20] Guideline maximum levels for radiocaesium in fish vary from country to country but are approximately 1000 Bq/kg or 1 kBq/kg in the European Union.[22] In the Kiev Reservoir in Ukraine, activity concentrations in fish were several thousand Bq/kg during the years after the accident.[21] In small “closed” lakes in Belarus and the Bryansk region of Russia, activity concentrations in a number of fish species varied from 0.1 to 60 kBq/kg during the period 1990–92.[23] The contamination of fish caused concern in the short term (months) for parts of the UK and Germany and in the long term (years-decades) in the Chernobyl affected areas of Ukraine, Belarus and Russia as well as in parts of Scandinavia.[20]
[edit] Groundwaters
Groundwaters were not badly affected by the Chernobyl accident since radionuclides with short half-lives decayed away a long time before they could affect groundwater supplies, and longer-lived radionuclides such as radiocaesium and radiostrontium were adsorbed to surface soils before they could transfer to groundwaters.[24] Significant transfers of radionuclides to groundwaters have occurred from waste disposal sites in the 30 km exclusion zone around Chernobyl. Although there is a potential for off-site (i.e. out of the 30-km exclusion zone) transfer of radionuclides from these disposal sites, the IAEA Chernobyl Report[24] argues that this is not significant in comparison to current levels of washout of surface-deposited radioactivity.
[edit] Fauna and vegetation
After the disaster, four square kilometres of pine forest in the immediate vicinity of the reactor turned ginger brown and died, earning the name of the “Red Forest“, according to the BBC.[25] Some animals in the worst-hit areas also died or stopped reproducing. Most domestic animals were evacuated from the exclusion zone, but horses left on an island in the Pripyat River 6 km from the power plant died when their thyroid glands were destroyed by radiation doses of 150-200 Sv.[26] Some cattle on the same island died and those that survived were stunted because of thyroid damage. The next generation appeared to be normal.[26]
In the years since the disaster, the exclusion zone abandoned by humans has become a haven for wildlife, with nature reserves declared (Belarus) or proposed (Ukraine) for the area. Many species of wild animals and birds, which were never seen in the area prior to the disaster, are now plentiful, due to the absence of humans in the area.[25]
