• Korean Journal of Ecology and Environment
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• v.41 no.4
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• pp.423-430
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• 2008

As of September 2008,45 Automatic Water Quality Monitoring Systems (AWQMS) have been installed at different sites on the 4 rivers to detect early the presence of pollutants in water and to issue an alarm. We count the number of issuing alarms by AWQMS, however, we will find the alarm has hardly been issued. The reasons for the scarcity of alarm issue are extensively being examined. The National Institute of Environmental Research attributes wrong alarm criteria for each AWQMS station to one the reasons. In this study, a suggestion has been made to modify the current alarm criteria to correspond with characteristics of river water quality. The current system with only two criteria (low and high) should be replaced as four-criteria systems (low, medium, high, and severe) based on cases of other advanced countries and stream conditions of Korea. The highest value of data collected for 5 years was suggested as the alarm criteria for each parameter. Meanwhile the alarm criteria for VOCs, phenol and heavy metals were established as same as drinking water quality criteria.

• Environmental Engineering Research
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• v.11 no.5
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• pp.277-284
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• 2006

The genetic toxicity of environmental pollutants, namely, nonylphenol (NP), bisphenol A (BPA) and chloropyriphos (CP) was investigated in aquatic sentinel species, freshwater crustacean, Daphnia magna, and larva of aquatic midge, Chironomus tentans, using Comet assay. Physiological effect of such pollutants was also investigated by studying the specimens' rates of reproduction, growth and survival. Acute toxicity results showed that, as expected, Daphnia was more sensitive than Chironomus to chemical exposure. The order of acute toxicity was CP > NP > BPA in D. magna and NP > CP > BPA in C. tentans. BPA may exert a genotoxic effect on D. magna and C. tentans, given that DNA strand breaks increased in both species exposed to this compound, whereas NP- and CP-induced DNA damage occurred only in C. tentans. In vivo genotoxic data obtained in aquatic sentinel species could provide valuable information for freshwater quality monitoring. The experiments with NP-exposed D. magna showed that the pollutant has long-term effects on reproduction, whereas no short-term effect on DNA integrity was found, being an example of a false-negative result from the biomarkers perspective. This result could be interpreted that other mechanism than genetic alteration might be involved in NP-induced reproduction failure in D. magna. False-positive results from the genotoxic biomarker obtained in BPA-exposed D. magna and in NP-exposed C. tentans make it difficult to use DNA integrity as an early warning biomarker. However, as the mere presence of genotoxic compounds, which are potentially carcinogenic, is of high concern to human and ecosystem health, it could also be important to rapidly and effectively detect genotoxic compounds in the aquatic system in ways that do not necessarily accompany a higher level of alteration. Considering the potential of D. magna and C. tentans as bioindicator species, and the importance of genotoxic biomarkers in ecotoxicity monitoring, DNA damage in these species could provide useful information for environmental risk assessment.