A Summary of Evira’s research on fishes from bodies of water affected by the Talvivaara mine and comparison lakes
On 12 November 2012, the Finnish Ministry of Agriculture and Forestry tasked the Finnish Game and Fisheries Research Institute (Riista- ja kalatalouden tutkimuslaitos, RKTL), the Finnish Food Safety Authority (Elintarviketurvallisuusvirasto, Evira) and Kainuu ELY Centre with creating a plan for performing fishing tests, sampling and analysis regarding the bodies of water in areas affected by the Talvivaara mine area in Sotkamo. The intention of this task was finding out whether the waste waters that had possibly entered the bodies of water due to a leak in the mine's gypsum pool had caused any body tissue changes in fishes and what were the concentrations of heavy metals in fish body tissues. Test fishing was performed by RKTL and the body tissue and chemical element analyses by Evira.
The first sampling round was performed on 15 November - 27 November 2012, the second on 17 January - 26 February 2013 and the third on 28 May - 19 June 2013. The samples were collected from Oulujoki River drainage basin of Lake Kalliojärvi, which is located downstream from the area of the mine, from Lake Kolmisoppi and Lake Jormasjärvi and from Vuoksi drainage basin of Lake Kivijärvi and Lake Laakajärvi, downstream from the mine area, and from the river basins at the area of the mine, in both bodies of water.
The control samples were collected from the drainage basin of River Varisjoki - River Kongasjoki, which flow from Lake Kiantajärvi, Lake Kivesjärvi, Lake Teerijärvi and Lake Ukonjärvi.
Common fish species of the area, such as perch, pike, pike-perch, burbot, whitefish and roach, were selected for the research. Roach is known to be more sensitive to changes in the acidity of water levels than perch or burbot. In the waters located downstream from the Talvivaara mine, waste water has been found to accumulate at the bottom of the lake. For this reason, burbot was included in the tests as a typical demersal fish.
Heavy metal and trace element studies
Fish muscle samples were investigated for heavy metals like arsenic, mercury, cadmium, chrome, lead, nickel and uranium. The same samples were also tested for aluminium and the trace elements copper, manganese, iron and selenium.
During the first round, muscle samples from a total number of 83 fishes were studied. Sixty-six of them were from bodies of water of the area impacted by the mine-affected area (Lake Jormasjärvi, Lake Laakajärvi, River Kalliojoki, River Kivijoki) and 17 from a comparison lake (Lake Kivesjärvi).
During the second round, muscle samples from a total of 117 fishes from the lakes of the area impacted by the mine (Lake Jormasjärvi, Lake Laakajärvi, Lake Kalliojärvi and Lake Kivijärvi) and fishes from 78 comparison lakes (Lake Kiantajärvi, Lake Kivesjärvi, Lake Teerijärvi and Lake Ukonjärvi) were studied.
The third round had 115 fishes from the lakes in the area impacted by the mine (Lake Jormasjärvi, Lake Laakajärvi, Lake Kalliojärvi and Lake Kivijärvi) and fishes from 28 comparison lakes (Lake Kiantajärvi, Lake Teerijärvi).
Regarding fish meat, only mercury, cadmium and lead have maximum concentration limits, which, according to EC decrees 1881/2006 and 629/2008, are the following: mercury 1.0 mg/kg (pike) and 0.5 mg/kg (other researched fish species), cadmium 0.050mg/kg and lead 0.30 mg/kg.
Results from the first, second and third rounds
The results of the first round did not show any concentrations that would exceed the background values. The measurement results of the first round are shown in tables 1 - 5.
The most important observation of the second round was the increased cadmium content in roaches from Lake Jormasjärvi and Lake Kolmisoppi. The average cadmium concentration of roaches from Jormasjärvi (0.063 mg/kg) exceeded the maximum concentration limit (0.050mg), and seven out of thirteen fishes exceeded the maximum concentration limit image 1. The average cadmium content of all the fishes from Jormasjärvi was larger than during the first round. The cadmium content of all the roaches (11) at Lake Kolmisoppi exceeded the maximum concentration limit, with the average being 0.18 mg/kg. The measurement results of the second round are in tables 6 - 14.
The third round had three fishes (two roaches, one whitefish) with a cadmium content of over 0.050 mg/kg (the limit set by the EU for fish and fishing products). Lake Jormasjärvi and Lake Kolmisoppi roaches still showed increased cadmium concentration, but these were smaller than during the second round image 1. The cadmium concentration of one whitefish caught from Kiantajärvi (comparison lake) was 0.15 mg/kg, and the manganese, copper, zinc and iron concentrations were also high when compared with other fishes from the same lake or, in general, compared with the manganese concentrations in fishes from other lakes. The measurement results of the third round are shown in tables 15 - 21.
Mercury concentration in all three rounds was at normal inland water levels, 0.071-2.0 mg/kg, and the average was 0.38 mg/kg. Mercury content in inland water predator fishes (large perch, pike, pike-perch and burbot) may be high, and according to Evira's recommendations for eating fish, pike caught from a lake may be eaten 1 - 2 times a month. It is recommended that people who eat a lot of fish reduce the share of predator fishes in their diet, and due to mercury, it is recommended that women who are pregnant or breastfeeding do not eat pike.
During three fishing rounds, comparison fishes for chemical element definition were collected from Lake Kiantajärvi, Lake Kivesjärvi, Lake Teerijärvi and Lake Ukonjärvi, 122 in all. The first round's comparison fishes came from Lake Kivesjärvi, second round's comparison fishes came from all four lakes and the third round's fishes came from Lake Kiantajärvi and Lake Teerijärvi. Heavy metal concentrations in all comparison fishes were small, near the method's definition limit. The clearest difference with the regular samples was the manganese concentrations of the fishes, which were somewhat lower in comparison fishes than the fish samples from the lakes of the area impacted by the mine. Manganese content in fishes from the areas impacted by the mine was between 0.11 - 28 mg/kg (median 0.9 mg/kg and average 2.6 mg/kg). In control fishes, it was <0.10 - 9.2 mg/kg (median 0.65 mg/kg and average 1.2 mg/kg).
In 2012, the Joint authority of Kainuu region recommended that people refrain from using water from these bodies of water for domestic and refreshment purposes (such as using swimming water to throw on a stove in a sauna). The Joint authority of Kainuu region also recommended refraining from eating fishes from these lakes. This recommendation was intended to prevent possible health hazards.
Milk samples from farms near the Talvivaara mine were also researched, ten in all. Their heavy metal or trace substance concentrations did not differ from milk samples from elsewhere in Finland, which are researched annually to monitor for contaminants.