Brown A C, Canosa-Mas C E, Parr A D, Pierce J M, Wayne R P
Physical Chemistry Laboratory, University of Oxford, UK.
Nature. 1989 Oct 19;341(6243):635-7. doi: 10.1038/341635a0.
Concern has been expressed over the use of the halogenated anaesthetics halothane (CF3CClBrH), enflurane (CF2HOCF2CFClH) and isoflurane (CF2HOCHClCF3) because of their potential for stratospheric ozone destruction. Halogenated species also contribute to global warming. The significance of the anaesthetics in stratospheric ozone loss or in 'greenhouse' heating depends on their atmospheric lifetimes. Because reaction with hydroxyl (OH) radicals is likely to be the main homogeneous sink for these species in the troposphere, we have measured absolute rates of reaction with OH. Comparison with a one-dimensional model indicates that the lifetimes of halothane, enflurane and isoflurane with respect to this reaction are 2, 6 and 5 years, respectively. Thus the small production of the anaesthetics is not offset by anomalously long atmospheric lifetimes to give a large atmospheric burden of the compounds. The anaesthetics will contribute at most a fraction of approximately 5 x 10(-4) to the total atmospheric content of chlorine-containing species.
由于卤代麻醉剂氟烷（CF3CClBrH）、恩氟烷（CF2HOCF2CFClH）和异氟烷（CF2HOCHClCF3）有可能破坏平流层中的臭氧，人们对其使用表示担忧。卤代物质也会导致全球变暖。这些麻醉剂对平流层臭氧损耗或“温室”升温的影响程度取决于它们在大气中的寿命。由于与羟基（OH）自由基的反应可能是这些物质在对流层中的主要均相汇，我们已测量了它们与OH反应的绝对速率。与一维模型的比较表明，氟烷、恩氟烷和异氟烷相对于该反应的寿命分别为2年、6年和5年。因此，这些麻醉剂产量虽小，但不会因异常长的大气寿命而导致其在大气中的含量大幅增加。这些麻醉剂对含氯物种的总大气含量的贡献最多约为5×10⁻⁴。
