| 结果显示，NDMA重复施毒所产生的氧化和肝毒素效应大于单剂量投药的效应。2010年，一项最新的研究评估了亚硝基二乙胺（NDEA）和亚硝基二甲胺（NDMA）两种亚硝胺类物质作用于lymphocyteTK6的细胞毒性和遗传毒性作用。此实验首先测定了细胞暴露于NDMA和NDEA之后的稳定度来确定细胞毒性，其次采用单细胞凝胶电泳测定DNA损伤，采用微核实验来测定染色体断裂等其他遗传损伤。结果表明NDEA和NDMA无论浓度的高低均不体现细胞毒性，而只有在添加了S9之后，NDMA在10mM的高浓度下才能显示出遗传毒性，NDEA在5mM浓度时显示出遗传毒性。
4消毒副产物的毒理学研究方法
近三十年来，科学界对DBPs毒理学效应的研究正在不断深入，已有的毒理学研究也运用不同的受试生物和不同的检测方法阐述并比较了多种DBPs的毒理学大小。表2对这些毒理学研究方法进行了总结概括。
表2DBPs的毒理学研究方法
|
物质
|
受试生物
|
测试方法
|
测试指标
|
文献
|
|
C-DBPs
|
|
THMs
|
male rat F-344
|
口头暴露
|
ALT, AST, BUN, CRE, LDH, TPR, SDH, NAG
|
[15]
|
|
S. typhimurium RSJ100
|
hisG46突变光谱
|
GC → AT
|
[23]
|
|
CHO AS52
|
测细胞密度
|
%C /
|
[25]
|
|
单细胞凝胶电泳
|
拖尾率
|
|
HAAs
|
S. typhimurium TA100
|
Ames变异反应突变实验
|
定性观察颜色
|
[27]
|
|
E.coli PQ 37
|
SOS显色实验
|
β-牛乳糖甘酶和碱性磷酸酶活性
|
|
Pleurodeles waltl
|
微核实验
|
红细胞微核数
|
|
S. typhimurium TA100
|
微孔板细胞毒性实验
|
OD
|
[28]
|
|
CHO AS52
|
测细胞密度
|
%C /
|
[29]
|
|
单细胞凝胶电泳
|
拖尾率
|
|
人小肠上皮细胞 FH74
|
测细胞密度
|
%C /
|
[30]
|
|
单细胞凝胶电泳
|
拖尾率
|
|
RT -PCR
|
DNA结合、修复，细胞周期调控与细胞凋亡
|
|
N-DBPs
|
|
HNMs
|
S. typhimurium
|
致突变试验
|
突变体的数量
|
[32]
|
|
CHO AS52
|
测细胞密度
|
%C /
|
[17]
|
|
单细胞凝胶电泳
|
拖尾率
|
|
lymphocyte TK6
|
单细胞凝胶电泳
|
拖尾率
|
[33]
|
|
微核实验
|
微核数目
|
|
HANs
|
E.coli PQ 37
|
SOS显色实验
|
β-牛乳糖甘酶和碱性磷酸酶
|
[35]
|
|
S. typhimurium TA100
|
Ames变异反应突变实验
|
定性观察颜色
|
|
Pleurodeles waltl
|
微核实验
|
红细胞微核数
|
|
CHO AS52
|
测细胞密度
|
%C /
|
[9]
|
|
单细胞凝胶电泳
|
拖尾率
|
|
HAcAms
|
CHO AS52
|
测细胞密度
|
%C /
|
[10]
|
|
单细胞凝胶电泳
|
拖尾率
|
|
NDMA
|
neural cells
|
免疫印迹分析
|
细胞提取物
|
[40]
|
|
荧光显微镜观察
|
神经细胞
|
|
rat
|
毒物体内注射
|
GSH，MT
|
[41]
|
|
lymphocyte TK6
|
单细胞凝胶电泳
|
拖尾率
|
[42]
|
|
微核实验
|
微核数目
|
依据模式生物选择上的不断发展，毒理学研究分成以下几个阶段。最早，选用细菌S.typhimurium或Escherichiacoli为模式生物，测定了几类DBPs的毒性效应，常用的几种测试实验有SOS显色反应，Ames变异反应突变实验，微核实验等，用以测定DBPs对于细菌的细胞毒性和基因突变的影响。但是以细菌为模式生物测定DBPs的毒理学效应所得到的数据无法准确预测DBPs对哺乳动物所产生的毒性效应，由于无法为人体的健康风险评价提供准确的理论依据，应用价值大大降低，因此需要选取新的模式生物。
有科学家选取龋齿类动物大鼠为模式生物，给它们定期染毒，测定毒物在体内所引起的毒性效应，常用的测试器官有肝脏、大肠、肾脏。也有学者选取黑腹果蝇来测试卵母细胞中染色体受毒物的影响情况。
随着DBPs毒性研究的不断深入，越来越多的学者选用中国仓鼠卵巢细胞（CHO）为受试细胞，测定了多类DBPs的慢性细胞毒性和急性遗传毒性。所选用的方法均为细胞密度测试来表征慢性细胞毒性，单细胞凝胶电泳实验来表征急性遗传毒性，由于所选用的测试手段和受试细胞相同，所以这些实验所得出的数据可以直接用以比较分析。
然而，为了更好的模拟DBPs作用于人体的健康效应，探究DBPs对于人体肝脏、小肠、肾脏的毒性作用，最新的研究较集中于选用人体细胞为受试细胞。
除了在模式生物的选择上需要不断改进，实验方法也开始备受关注。纵观以往研究所采用的分析方法，过多集中在Ames实验，SOS显色反应，一些代表酶类的含量改变分析，微核实验，细胞密度测定实验，单细胞凝胶电泳等一些体外测试方法，以及染毒实验等一些体内测试方法。由于这些方法大多比较传统和陈旧，故选用更加新颖和敏感的测试方法也是今后研究的重要发展方向。
5展望
（1）对于含卤原子的饮用水消毒副产物（H-DBPs）的毒性大小的研究，发现无论是细胞毒性还是遗传毒性，其总趋势均为I>Br>>Cl。因此为了有效降低DBPs对人体产生的毒性作用，我们必须加强对碘代和溴代的消毒副产物的研究控制。
（2）为了更好地模拟和预测DBPs作用于人体所引起的健康风险，对于DBPs毒性作用的研究在选取模式生物上不断更新。现今选取较多的受试细胞为CHO，DBPs作用于CHO毒性作用的研究也已经形成系统性。建议在今后的研究中可以较多侧重于研究DBPs对人体细胞的毒性影响。
（3）DBPs的毒理学研究方法较传统，大多集中于一些基本的体内测试和体外测试方法，对于遗传毒性的影响是基于基因突变、染色体突变和DNA损伤三个层面，而方法也缺乏一定创新性。在今后的研究中可以采用新颖的毒理学测试方法，从而更好地为癌症发生的机理和控制方法提供理论依据。
参考文献
1 Krasner SW, McGuire MJ, Jacangelo JG, et al. The occurrence of disinfection by-products in US drinking water [J]. Journal of the American Water Works Association, 1989, 41 ~ 53.
2 Bethesda. Report on carcinogenesis bioassay of chloroform, carcinogenesisprogram [R]. National cancer institute (U.S.). Division of cancer cause and prevention, 1976.
3 伍海辉,高乃云,乐林生,等. 高级氧化技术降解卤乙酸效果及动力学研究[J]. 哈尔滨工业大学学报,2007,39(15): 1974 ~ 1978.
4 楚文海,高乃云,Deng Yang. 饮用水新型N-DBPs类别及毒理学评价[J]. 现代化工,2009,29(2): 86 ~ 89.
5 Krasner SW, Weinberg HS, Richardson SD, et al. Occurrence of a new generation of disinfection byproducts [J]. EnvironmentalScience and Technology, 2006, 40 (23): 7175~7185.
6 Letterman RD. Water quality and treatment. 5th edition [M]. American Water Works Association,Mcgraw-Hill Inc, 1999: 87.
7 张绍园,姜兆春,王菊思. 饮用水消毒副产物控制技术研究现状与发展[J]. 水处理技术,1998,24(1): 7 ~ 13.
8 王杨,田一梅.饮用水消毒技术现状及未来发展[J]. 安徽农业科学,2007,35(5):1471 ~ 1472.
9 Muellner MG, Wagner ED. Haloacetonitriles vs. regulated haloacetic acids: Are nitrogen – containingDBPs more toxic [J]? Environmental Science and Technology, 2007, 41(2): 635 ~651.
10 Plewa MJ, Muellner MG, Richardson SD. Occurrence, synthesis, and mammalian cellcytotoxicity and genotoxicity of haloacetamides: An emerging class ofnitrogenous drinking water disinfection byproducts [J]. Environmental Science andTechnology, 2008, 42(3), 955 ~ 961.
11 高超,王启山,夏海燕. 饮用水消毒副产物控制工艺的国内外研究动态[J]. 中国高新技术企业,2010, (6): 96 ~ 97.
12 中华人民共和国卫生部,GB 5749 – 2006 生活饮用水卫生标准(2006年版)[S].
13 韩畅,刘绍刚,仇雁翎,等. 饮用水消毒副产物分析及相关研究进展[J]. 环境保护科学,2009, 35(1): 12 ~ 16.
14 Lilly PD, Simmons JE, and Pegram RA. Dose-dependent vehicle differences in the acutetoxicity of bromodichloromethane [J]. Fundamental and Applied Toxicology, 1994,23(1): 132 ~ 140.
15 Lilly PD, Ross TM, Pegram RA. Trihalomethane comparative toxicity: acute renal andhepatic toxicity of chloroform and bromodichloromethane following aqueousgavage [J]. Fundamental and Applied Toxicology, 1997, 40(1): 101 ~ 110.
16 楚文海,高乃云. 饮用水含氮消毒副产物卤化硝基甲烷研究进展[J]. 给水排水, 2008, 37(7) : 32 ~ 36.
17 Plewa MJ, Wagner ED, Jazwierska P, et al. Halonitromethane drinking water disinfectionbyproducts: Chemical characterization and mammalian cell cytotoxicity andgenotoxicity [J]. Environmental Science and Technology, 2004, 38(1): 62 ~68.
18 Zhao YY, Boyd J, Hrudey SE, et al. Characterization of new nitrosamines in drinking waterusing liquid chromatography tandem mass spectrometry [J]. Environmental Scienceand Technology, 2006, 40(24): 7636 ~ 7641.
19 Bellar TA, Lichtenberg, JJ, Kroner, RC. The occurrence of organohalides in chlorinateddrinking waters [J]. Journal of the American Water Works Association, 1974, 66(12): 703 ~ 706.
20 Dunnick JK, Melnick RL. Assessment of the carcinogenic potential of chlorinated water:Experimental studies of chlorine, chlo-ramine, and trihalomethanes [J]. NationalCancer Institute, 1993, 85(10):817~822.
21 Melnick RL, Dunnick JK, Sandler DP, et al. Trihalomethanes and other environmental factorsthat contribute to colorectal cancer [J]. Environmental Health Perspectives,1994, 102(6-7): 586 ~ 588.
22 Black BD, Harrington GW, Singer PC. Reducing cancer risks by improving organic carbonremoval [J]. Journal of the American Water Works Association, 1996, 88(8): 40 ~52.
23 DeMarini DM, Shelton ML, Warren SH, et al. Glutathione S-transferase-mediated induction ofGC→AT transitions by halomethanes in Salmonella [J]. Environmetal and MolecularMutagenesis, 1997, 30(4): 440 ~ 447.
24 Regram RA, Andersen ME, Warren SH, et al. Glutathione S-transferase-mediated mutagenicityof trihalomethanes in Salmonella typhimurium: Contrasting results withbromodichloromethane and chloroform [J]. Fundamental and Applied Toxicology,1997, 144(1): 183 ~ 188.
25 Richardson SD, Fasano F, Ellington JJ, et al. Occurrence and mammalian cell toxicity ofiodinated disinfection byproducts in drinking water [J]. Environmental Scienceand Technology, 2008, 42(22): 8330 ~ 8338.
26 Smith MK, Randall JL, Read EJ , et al. Teratogenic activity of trichloroacetic acid inthe rat [J]. Teratology, 1989, 40 (5): 445 ~ 451.
27 Giller S, Crieux FL, Erb F, et al. Comparative genotoxicity of halogenated acetic acidsfound in drinking water [J]. Mutagenesis, 1997, 12(5): 321~328.
28 Kargalioglu Y, McMillan BJ, Minear RA, et al. Analysis of the cytotoxicity and mutagenicityof drinking water disinfection by-products in Salmonella typhimurium [J].Teratogenesis, Carcinogenesis, and Mutagennesis, 2002, 22 (2): 113~128.
29 Plewa MJ, Kargalioglu Y, Vankerk D, et al. Mammalian cell cytotoxicity and genotoxicityanalysis of drinking water disinfection by-products [J]. EnvironmentalMolecular Mutagenesis, 2002, 40 (2): 134~142.
30 Attene-Ramos MS, Wagner ED, Plewa MJ.Comparative human cell toxicogenomic analysis of monohaloacetic acid drinking water disinfection byproducts [J]. Environmental Science and Technology, 2010, 44: 7206 ~ 7212.
31 Kundu B, Richardson SD, Granville CA, et al. Comparative mutagenicity of halomethanesand halonitromethanes in Salmonella TA100: structure – activity analysis andmutation spectra [J]. Mutation Rearch, 2004, 554(1-2): 335 ~ 350.
32 Kundu B, Richardson SD, Swartz PD, et al. Mutagenicity in Salmonella of halonitromethanes: a recently recognized class of disinfection by-products indrinking water [J]. Mutation Research, 2004, 562(1-2): 39 ~ 65.
33 Liviac D, Creus A, Marcos R. Genotoxicity analysis of two halonitromethanes, a novelgroup of disinfection by-products (DBPs), in human cells treated in vitro [J].Environmental Research, 2009, 109(3): 232 ~ 238.
34 Osgood C, Sterling D. Dichloroacetonitrile, a by-product of water chlorination, inducesaneupoloidy in Drosophila [J]. Mutation Research, 1991, 261(2): 85 ~ 91.
35 Curieux FL, Giller S, Gauthier L. Study of the genotoxic activity of six halogenatedacetonitriles, using the SOS chromotest, the Ames-fluctuation test and the newtmicronucleus test [J]. Mutation Research, 1995, 341(4), 289 ~ 302.
36 Plewa MJ, Wagner ED, Muellner MG, et al. Comparative mammalian cell toxicity of N-DBPs andC-DBPs, Disinfection By-Products in Drinking Water [J]. American ChemicalSociety Symposium Series, 2008, 995: 36 ~ 50.
37 Hrudey SE. Chlorination disinfection by-products, public health risk tradeoffs and me [J].Water Research, 2009, 43(8): 2057 ~ 2092.
38 Jobb DB, Hunsinger RB, Meresz O, et al. Removal of N-Nitrosodimethylamine from the Ohsweken(six nations) water supply: Final report [R]. Ontario Ministry of environmentand energy: Toronto, ON, 1994.
39 Najm I, Trussell RR, Am J. NDMA formation in water and wastewater-This study evaluatedthe formation of NDMA during chlorination and chloramination, ozonation, andion exchange [J]. Journal of the American Water Works Association, 2001, 92.
40 Couratier PH, Lesort M, Sindou PH, et al. Modifications of neuronal phosphorylatedimmunoreactivity induced by NMDA toxicity [J]. Molecular and ChemicalNeuropathology, 1996, 27(3): 259 ~ 273.
41 Taniguchi M, Yasutake A, Takedomi K, et al. Effects of N-nitrosodimethylamine (NDMA) on theoxidative status of rat liver [J]. Molecular Toxicology, 1999, 73(3): 141 ~146.
42 Liviac D, Creus A, Marcos R. Genotoxic evaluation of the non-halogenated disinfectionby-products nitrosodimethylamine and nitrosodiethylamine [J]. Journal ofHazardous Materials, 2010, 185(2-3): 613 ~ 618. 4/4 首页 上一页 2 3 4 |
