Institute of Environmental Assessment and Water Research (IDAEA-CSIC) , Water and Soil Quality Research Group, Department of Environmental Chemistry , Barcelona , 08034 , Spain.
Marie Curie Fellow, National Health and Environmental Effects Research Laboratory , U.S. Environmental Protection Agency , Research Triangle Park , North Carolina 27711 , United States.
Environ Sci Technol. 2018 Nov 20;52(22):13047-13056. doi: 10.1021/acs.est.8b04625. Epub 2018 Nov 5.
Iodinated contrast media (ICM) are nonmutagenic agents administered for X-ray imaging of soft tissues. ICM can reach μg/L levels in surface waters because they are administered in high doses, excreted largely unmetabolized, and poorly removed by wastewater treatment. Iodinated disinfection byproducts (I-DBPs) are highly genotoxic and have been reported in disinfected waters containing ICM. We assessed the mutagenicity in Salmonella of extracts of chlorinated source water containing one of four ICM (iopamidol, iopromide, iohexol, and diatrizoate). We quantified 21 regulated and nonregulated DBPs and 11 target I-DBPs and conducted a nontarget, comprehensive broad-screen identification of I-DBPs. We detected one new iodomethane (trichloroiodomethane), three new iodoacids (dichloroiodoacetic acid, chlorodiiodoacetic acid, bromochloroiodoacetic acid), and two new nitrogenous I-DBPs (iodoacetonitrile and chloroiodoacetonitrile). Their formation depended on the presence of iopamidol as the iodine source; identities were confirmed with authentic standards when available. This is the first identification in simulated drinking water of chloroiodoacetonitrile and iodoacetonitrile, the latter of which is highly cytotoxic and genotoxic in mammalian cells. Iopamidol (5 μM) altered the concentrations and relative distribution of several DBP classes, increasing total haloacetonitriles by >10-fold. Chlorination of ICM-containing source water increased I-DBP concentrations but not mutagenicity, indicating that such I-DBPs were either not mutagenic or at concentrations too low to affect mutagenicity.
含碘造影剂（ICM）是用于软组织 X 射线成像的非诱变剂。由于它们的用量大、大部分未经代谢排泄，以及废水处理去除效果差，因此会在地表水达到μg/L 水平。含碘消毒副产物（I-DBPs）具有高度遗传毒性，并且在含有 ICM 的消毒水中已有报道。我们评估了含有四种 ICM（iopamidol、iopromide、iohexol 和 diatrizoate）之一的氯化水源水提取物在沙门氏菌中的致突变性。我们定量测定了 21 种受管制和不受管制的 DBPs 以及 11 种目标 I-DBPs，并进行了非目标、全面的广谱 I-DBP 鉴定。我们检测到一种新的碘甲烷（三氯碘甲烷）、三种新的碘酸（二氯碘乙酸、氯二碘乙酸、溴氯碘乙酸）和两种新的含氮 I-DBPs（碘乙腈和氯碘乙腈）。它们的形成取决于 iopamidol 作为碘源的存在；当有可用的标准品时，通过其确认了它们的身份。这是在模拟饮用水中首次鉴定出氯碘乙腈和碘乙腈，后者在哺乳动物细胞中具有高度细胞毒性和遗传毒性。iopamidol（5μM）改变了几种 DBP 类别的浓度和相对分布，使总卤乙腈增加了 10 多倍。含 ICM 的水源水的氯化增加了 I-DBP 的浓度，但没有增加致突变性，这表明此类 I-DBPs 要么没有致突变性，要么浓度太低，不会影响致突变性。
