| Objective: Combining the use of SOS/umu experiments, comet assay and humanperipheral blood lymphocyte micronucleus test, genotoxicity of shallow groundwater,deep groundwater and surface water in the monitoring areas were tested. At the sametime, identify the correlation between the experimental monitoring results with localmalignant tumor mortality. Based on the investigation of the groundwater pollutionand its genotoxicity, identify whether the groundwater pollution in these areas isrelated to the pollution of the Huaihe River and the relationship between waterpollution and the high incidence of cancer.Method: Within the15counties included in the Huaihe River Basin ComprehensiveCancer Control, a region of the middle and lower reaches was selected as themonitoring area. Four monitors and a comparison town in the region were selectedsampling shallow groundwater, deep groundwater and surface water. Organic matterwas enriched by solid-phase extraction techniques. Organic extracts were then testedby SOS/umu experiment, comet assay and micronucleus test in human peripheralblood lymphocytes to get its degree of mutagenicity, and effects on DNA damage andchromosomal damage. Finally, the experimental data and cancer mortality dataprovided by local CDC were analyzed with Correlation method.Results: Z town、 K town、L and M town were selected as monitors while R town ascontrol in the monitoring area. A total of63sampling points were set in these fivetownships, three of them were chosen to collect duplicate samples as quality controlsamples.66water samples consist of47copies of groundwater (decentralized watersupply) samples,5copies of deep groundwater (centralized water supply) and11copies of surface water.3quality control samples were from decentralized watersupply.1. SOS/umu without S9experimental results show that genotoxicity of0.5L shallow groundwater samples in Z, L and R town were positive and genotoxicity of0.25L was only positive in L town. And the IR values of both samples from the Ltown were significantly higher than that of the control area (p<0.05). SOS/umu withS9activation show that genotoxicity of0.5L water samples from K, L and R townwere positive and genotoxicity of0.25L was positive only in samples from L town.IR values of both samples from L town were significantly higher than that of thecontrol area (p<0.05). There was no correlation between cancer mortality in the fivetowns and the IR values of shallow groundwater (p>0.05).2. The comet assay showthat the OTM values of shallow groundwater in Z town and M town weresignificantly higher than that of the control R town (p<0.05), while there was nosignificant difference between K、 L and R town. There was significant positivecorrelation between the OTM values of five towns’ shallow groundwater samples of2L、1L and0.5L and cancer mortality of residents (p<0.05). R~2is0.267,0.342and0.223respectively.3. The micronucleus test show that the micronucleus rates ofshallow groundwater samples from K and M town was significantly higher than thatof the control area (p<0.05). Z and L town were slightly polluted. K and M town weremoderately polluted. The micronucleus frequency of shallow groundwater in fivetowns and total cancer mortality rates showed a significant positive correlation (p<0.01), with a R~20.306.Conclusion: Genetic toxicity of shallow groundwater in Z, K, L and M town weresignificantly higher than that of the control town R. The genetic toxicity includesmutagenicity, DNA damage and chromosomal damage. The surface water from Z, Kand L town which are located along the bank of Ying River, are severely polluted. It ispossible that the groundwater contamination in the monitoring area was associatedwith the Ying River by distance. The reason of shallow groundwater pollution in Mtown will be explored further. The DNA damage effects and chromosomal damageeffects were significant different between monitoring and control areas andsignificantly correlated with the cancer mortality of local residents. This study couldreflect the comprehensive genetic toxicity of environmental pollution and provide thebasic data to confirm the relationship between water pollution and health risks. |
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