| Objective: The purpose of this study is to evaluate the genotoxicity and estrogenic activity of raw,finished and tap water in a city in northern Zhejiang Province.It provides a basis for further improving the quality of drinking water and related hygiene management and supervision,and also provides support and reference for the revision of drinking water quality standards.Methods: The raw,finished and tap water were taken as samples from two drinking water treatment plants,A(Taihu Lake as water source)and B(reservoir as water source),in March,June and November,2018,respectively.Non-volatile organic compounds in samples were concentrated by macroporous resins and solid phase extraction,respectively.Three kinds of biological toxicity tests,the Salmonella typhimurium recovery mutation test(Ames test),the SOS/umu test and the Recombinant yeast estrogen screen(YES test),used the reverse mutation rate(MR),induction rate(IR)and estradiol equivalent(EEQ)as the main indicators.At the same time,gas chromatography,liquid chromatography-tandem mass spectrometry method and gas chromatography-electron bombardment mass spectrometry were used to detect the chemical quantitative results of disinfection by-products,microcystins,and phthalates and phenols in water samples,then analyzing the relationship between the results and the characteristics of biological toxicity,so as to evaluate the sanitation of drinking water comprehensively.Results:(1)Except for the 4 L/plate(-S9)(MR=2.26)of the finished water from A drinking water treatment plant in November,all the other water samples were negative in the whole year of 2018.The finished water of B drinking water treatment plant showed positive results in 2 L/plate(-S9)(MR = 2.24)?4 L/plate(-S9,+S9)(MR = 2.79,MR = 2.44),in March and 4 L/plate(-S9)(MR = 2.12)in June,while the other water samples showed negative results except 4 L/plate(-S9,+S9)of raw water in June.(2)In the SOS/umu test,in the whole year of 2018,the 4 L/well(IR = 2.11)of the raw water in March was positive,and the other results were negative.In March,2 L/well(IR = 2.03),4 L/well(IR = 2.00)and in June,4 L/well(IR=2.04)and 4 L/well(IR = 2.45)were positive results.The rest were negative.(3)In the Recombinant yeast estrogen screen,the estradiol equivalent was 0.56 ~ 0.89 ng/L in raw water of Plant A in March,June and November,2018,and finished water and tap water were not detected.In 2018,the estradiol equivalent was 0.16 ~ 0.31 ng/L in raw water of Plant B in March,June and November,2018,and finished water and tap water were not detected.(4)The results of disinfection by-products test showed that no disinfection by-products were detected in the source water of Plant A in 2018.The concentration of trichloromethane in finished water and tap water were < LOD ~ 0.0034 mg/L and < LOD ~ 0.0020 mg/L,respectively;tribromomethane were < LOD ~ 0.0082 mg/L and < LOD ~ 0.0072 mg/L;dichloromonobromomethane were < LOD ~ 0.0047 mg/L and 0.0017 ~ 0.0092 mg/L;dibromochloromethane were 0.0076 ~ 0.1020 mg/L and 0.0035 ~ 0.1050 mg/L;dichloroacetic acid were 0.014 ~ 0.049 mg/L and 0.013 ~ 0.043 mg/L;and trichloroacetic acid were 0.035 ~ 0.125 mg/L and 0.024 ~ 0.026 mg/L.In 2018,the concentration of trichloromethane in raw,finished and tap water were < LOD ~ 0.0074 mg/L,0.0034 ~ 0.0072 mg/L and 0.0046-0.0110 mg/L.Tribromomethane was not detected in raw water or tap water,and the concentration in finished water was < LOD ~ 0.0022 mg/L.Dichloromonobromomethane was < LOD ~ 0.0048 mg/L,0.0022 ~ 0.0092 mg/L and < LOD ~ 0.1070 mg/L in raw,finished and tap water,respectively;dibromochloromethane were < LOD,< LOD ~ 0.0062 mg/L and < LOD-0.0057 mg/L;dichloroacetic acid were < LOD,0.023 ~ 0.088 mg/L and < LOD ~ 0.120 mg/L;and trichloroacetic acid were < LOD,0.053 ~ 0.125 mg/L and < LOD ~ 0.009 mg/L.(5)MC-RR and MC-YR were detected only in raw water of plant A,and the concentrations of MC-RR and MC-YR were 0.005 ~ 0.037 ug/L and < LOD ~ 0.045 ug/L,respectively.No other water samples were detected.None were detected in Plant B.(6)In Plant A,the concentration of dibutyl phthalate(DBP)were 0.19 ~ 1.30 ug/L,0.19 ~ 0.71 ug/L and 0.58 ~ 0.81 ug/L in raw,finished and tap water,respectively;diisobutyl phthalate(DIBP)were 1.99 ~ 3.99 ug/L,2.35 ~ 4.46 ug/L and 3.27 ~ 4.21 ug/L;and di(2-ethylhexyl)phthalate(DEHP)were 0.15 ~ 2.29 ug/L,0.17 ~ 4.60 ug/L and 0.14 ~ 4.60 ug/L.In Plant B,the concentration of DBP were 0.69 ~ 0.77 ug/L,0.79 ~ 0.89 ug/L and 0.40 ~ 0.82 ug/L in raw,finished and tap water,respectively;DIBP were 3.33 ~ 4.56 ug/L,3.84 ~ 5.29 ug/L and 5.52 ~ 7.31 ug/L;and DEHP were 0.20 ~ 5.51 ug/L,0.32 ~ 6.64 ug/L and 2.16 ~ 5.83 ug/L.(7)No phenolic compounds were detected.Conclusions:(1)Genotoxicity: the genotoxicity of finished water of Plant A is higher than that of raw water and tap water,and the genotoxicity in dry period is higher than that in average period and wet period.No indirect mutagens were detected.The genotoxic of Plant B ranged as follows: raw water > finished water > tap water;the wet period > the average period > the dry period.The direct mutagens and indirect mutagens coexist,mainly direct mutagens.(2)Estrogenic activity: the estradiol equivalent of raw water of Plant A is higher than that of finished water and tap water,the latter two are not detected,and there is no seasonal difference among them.So it is of Plant B.At the same time,the estradiol equivalent of raw water of Plant A is higher than that of Plant B.(3)Chemical analysis:As for disinfection by-products,the concentration of finished water and tap water were higher than those of raw water,and the concentration of haloacetic acid compounds were higher than those of trihalomethane compounds.As for microcystins,MC-RR and MC-YR existed in raw water of Plant A,and finished water and tap water were not detected microcystins.Microcystins were not detected in all water samples of Plant B.The concentration of DBP,DIBP and DEHP were higher in Plant A and Plant B,while their concentrations are higher in dry period in Plant A. |
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