The full extent of the pollution is still unknown, but its scale and intensity is believed to exceed any previously known incidents. No assessment of long-term effects has been carried our, but it is possible that the contamination could prove to be as great an ecological disaster for Kazakhstan as the better known problem of the Aral Sea and the Semipalatinsk test site. The project provides an unprecedented opportunity to study mercury pollution in a natural laboratory at large scale. The intensity of contamination makes it possible to observe mechanisms for distribution of the mercury and transformation between forms. The information gained can then be used to enhance understanding of less acute examples of contamination in Europe and elsewhere. The project will contribute to the stabilization of existing research and development potential by allowing highly qualified and experienced scientists to continue working together in this field, and by providing new opportunities for employment of young researchers.
Accidental release of mercury from the acetaldehyde plant AO Karbide in the Karaganda region of north-central Kazakhstan has resulted in serious contamination of the surrounding region. Mercury is highly toxic at very low concentrations, due to its ability to accumulate in the food chain. Soluble mercury has been measured at 20 times maximum permitted levels in the water of the river Nura, and 30 times in the soil of the city of Temirtau. This has immediate serious implications for the health of the people of the region. In the long term it also poses a threat to the unique ecology of the lakes of the Kurgaldzhinskaya nature reserve.
Preliminary investigations suggest there are approximately 130 tonnes of mercury in the river bed near Temirtau. In most areas the contamination decreases with depth, but in the region of the plant it increases sharply, suggesting that substantial quantities of mercury were deposited during earlier periods of operation. The total quantity of mercury in the vicinity of Termitau is believed to be on the order of 1000 tonnes.
During spring floods, sediments are transported down the river Nura and dispersed over the floodplain. Water is also abstracted along the river to irrigate thousands of hectares of land. As a result, raised levels of mercury are found in the soil far downstream. Mercury is the sub-oil of Termitau is transported by groundwater, and eventually enters the river as an additional source of pollution? Mercury is both soil and water evaporates, diffuses and re-condenses in a new location. The contamination is therefore spreading outward from the site by a number of mechanisms, and attempt to find methods of limiting the damage and restoring the conditions necessary for a safe environment. The objectives of the proposed research programme are :
(i) to study the distribution of mercury and the mechanisms by which it is transported
(ii) to develop a model capable of predicting the spread of pollution and simulating the effect of different interventions
(iii) to identify a set of economically feasible technical options and management strategies for damage limitation and for remediation of the polluted area.
Funding SchemeCSC - Cost-sharing contracts