Chlororganic compounds in Ukrainian waters - an almost unrecognised problem                         

1. Introduction

This article focuses on the pollution of Ukrainian rivers and streams with chlororganic compounds. These compounds are widely used as solvents to degrease metals, to clean clothes etc. Others are used as insecticides (HCH, DDT) and many compounds are formed in huge quantities because of disinfecting of raw and drinking water and even of waste water.  Chlororganics can evaporate but are nevertheless washed out through rain. Even when they infiltrate the underground, they can reach streams and rivers. In running waters, unpurgeable, stable compounds (most of them unknown!) dominate (YAMAMOTO et al. 1992). Under favourable conditions, they are degradable, supported by light energy, UV radiation, bacteria. Environmental conditions are, however, not always favourable for the break-down of this matter. Redox potential, temperature, pH are a few of the more important factors influencing the fate of these substances.

Unfortunately, chlororganics are also taken up by living organisms and some compounds are known to be accumulated in the food chain. Humans are mainly concerned through the consumption of drinking water and fish. Studies published in the US and other countries have shown that regular consumption of chlororganics through drinking water over a longer time (10 - 15 years) significantly contributes to the risk of developing various forms of cancer and other illness.

So far, information about the distribution of chlororganics in the environment is scarce in Ukraine. This is not surprising because only a few compounds are regularly monitored. The bigger amount of regular controls concerns raw and drinking water. A few chlorinated pesticides are also monitored in rivers and other environmental media.

The main obstacle for a reasonable control program is a lack of analytical facilities: only few gaschromatographs are usually available for this tasks. A limited choice of compounds can be detected by this way. HPLC and AOX-analyser would be needed to get a more complete picture. Furthermore,  the state organisation "GOSSTANDARD" should officially introduce AOX in Ukraine and give "green light" (certification) for the analysis of AOX for example. Therefore, analytical results of AOX measurements presented in this article don't have official status. They are nevertheless published to motivate authorities, NGOs and the public to care about the problem and how it can be controlled in the future.

2. Results of random samplings

Dnepr water was analysed for AOX (using a standard method) from time to time since 1996, in smaller rivers and streams since 1997. A few results are shown in the following two figures to provide an overview.

Fig. 1: results of AOX measurements along the river Dnepr and its tributaries in July  2000
 
 

Fig. 2: results of AOX measurements (maxima)  in Kiev between 1998 and 2000 (black marks within the column show some singular results)

For the evaluation of the AOX concentrations we refer to thematical maps, which are published by state control organs in the German districts, Baden-Wuerttemberg, Nordrhein-Westfalen, Hessen.

Tab.1: Scale of water quality classes for the parameter AOX in Hessen (1997)

quality class	I	I-II	II	II-III	II	III-IV	IV
AOX, ug/L	0 (not  detected)	0-10	10-25	25-50	50-100	100-200	>200

In these publications, AOX concentrations > 50 ug/L (in Baden-Wuerttemberg > 40 ug/L) are evaluated as to be high and the river is considered as to be polluted. Recently, 50 ug/L AOX have been defined as quality objective in the list of priority substances (synthetic pollutants) of the Water Framework Directive and WFD annex VIII.  More details about river water quality assessment ----> .

More detailed investigations to evaluate the ecotoxicological effects of chlororganic compounds, have been published by YAMAMOTO et al. 1992. Extracts of urban running waters were shown to have a mutagenic effect, which is obvious for concentrations > 50 ug/L TOX. Further GC-analyses led to the conclusion that halogen-organic compounds found in river water, as far as known, are not less dangerous than those found in chlorinated drinking water.

Summarising those facts, one has to state that the chlororganic loads of Ukrainian rivers must be considered as a serious problem. Especially in larger cities like Kiev, extremely high AOX concentrations in river water are no exception. Concentration > 100 ug/L are probably not only due to diffuse pollution but caused by direct discharges, which should be possible to detect by state control organs. One can expect that the situation is even worth with regard to the big, industrial cities in the South like Donetzk, Zaporoshie, Krivoi Rog etc.

The Dnepr with its huge reservoirs dilutes the concentration of organochlorine substances, photochemical and bacteriological degradation further decrease the load. But nevertheless maximal observed concentrations reach figures as high as 160 ug/L.

3. Conclusions

The most important aim of water quality monitoring and management is the improvement of the ecological valence of natural systems. It is therefore important to use screening methods for controls, which allow to detect pollution quickly and cost effective. For Ukraine, first of all bio-indicators should be used to asses general water quality. High concentrations of chlororganic insecticides can be detected by chronic toxicity tests (using Ceriodaphnia sp. or other organisms). Beside this, it would be the best choice for Ukraine, to officially introduce the parameter AOX that has already proofed to be an efficient instrument for water quality management in western Europe.

 

http://www.cemu.kiev.ua/en/projects/aox-study.htm

http://www.cemu.kiev.ua/en/projects/chlor-presentation.pdf

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