Centre for Advanced Research in Environmental Genomics, Department of Biology, University of Ottawa, ON, Canada.
Arch Environ Contam Toxicol. 2011 Jan;60(1):1-7. doi: 10.1007/s00244-010-9515-4. Epub 2010 Apr 21.
The environmental fate and persistence of steroidal estrogens is influenced by their photodegradation. This can potentially occur both in the presence of the ultraviolet (UV) portion of solar radiation and in tertiary wastewater treatment plants that use UV radiation for disinfection purposes. To determine patterns of UV photodegradation for estrone (E1) and 17α-ethinylestradiol (EE2), water samples containing these compounds were exposed to levels of UVB radiation that would simulate exposure to ambient sunlight. E1 degraded with a pseudo-first-order rate law constant that was directly proportional to UVB radiation intensity (R² = 0.999, P < 0.001) and inversely proportional to dissolved organic carbon (DOC) concentration (R² = 0.812, P = 0.037). DOC acted as a competitive inhibitor to direct photolysis of E1 by UV. In contrast to E1, EE2 was more persistent under similar UVB treatment. A reporter gene assay showed that the estrogenicity of UVB-exposed estrogens did not decrease relative to non-UVB-exposed estrogens, suggesting that some of the photoproducts may also have estrogenic potency. These results show that environmental degradation rates of steroidal estrogens are predictable from the UV intensity reaching surface waters, and the DOC concentrations in these surface waters.
甾体雌激素的环境归宿和持久性受其光降解的影响。这种情况可能会同时发生在太阳辐射的紫外线（UV）部分存在的情况下，以及使用紫外线进行消毒的三级废水处理厂中。为了确定雌酮（E1）和 17α-乙炔基雌二醇（EE2）的紫外线光降解模式，将含有这些化合物的水样暴露于模拟环境阳光的 UVB 辐射水平下。E1 的降解遵循伪一级速率定律常数，该常数与 UVB 辐射强度成正比（R²=0.999，P<0.001），与溶解有机碳（DOC）浓度成反比（R²=0.812，P=0.037）。DOC 作为一种竞争性抑制剂，直接阻碍了 E1 的光解。与 E1 相反，EE2 在类似的 UVB 处理下更持久。报告基因测定表明，与未暴露于 UVB 的雌激素相比，暴露于 UVB 的雌激素的雌激素活性并没有降低，这表明一些光产物也可能具有雌激素活性。这些结果表明，甾体雌激素的环境降解速率可以根据到达地表水中的紫外线强度和这些地表水的 DOC 浓度来预测。
