Department of Environmental Science & Toxicology, Nippon Soda Co., Ltd., Odawara, Kanagawa, Japan.
PLoS One. 2021 Feb 19;16(2):e0247426. doi: 10.1371/journal.pone.0247426. eCollection 2021.
Aquatic organisms have been used to investigate the safety of chemicals worldwide. One such assessment is an algal growth inhibition test. Algal growth inhibition tests are commonly performed using a growth chamber with fluorescent lamps as the lighting source, as test guidelines require continuous uniform fluorescent illumination. However, fluorescent lamps contain mercury, which has been identified as hazardous to humans and other organisms. The Minamata Convention (adopted in 2013) requires reduction or prohibition of products containing mercury. On the other hand, light-emitting diodes do not contain mercury and provide a photosynthetically effective wavelength range of 400-700 nm which is an adequate light intensity for algal growth. Light-emitting diodes are thus preferable to fluorescent lamps as a potential light source in algal growth inhibition tests. In this study, we investigated if light-emitting diodes could be substituted for fluorescent lamps in growth inhibition studies with green alga (Pseudokirchneriella subcapitata), diatom (Navicula pelliculosa), and cyanobacteria (Anabaena flos-aquae). Algal growth inhibition tests were performed using five different chemicals known to have different modes of action and are assigned as reference substances in the test guidelines. The results of each algal test showed similar values between light-emitting diodes and fluorescent lamps in terms of conditions for the growth inhibition rate and percent inhibition in yield of each chemical. It was therefore concluded that using light-emitting diodes instead of fluorescent lamps as a lighting source had no effect on the algal growth inhibition test results.
水生生物已被用于在全球范围内评估化学品的安全性。其中一种评估方法是藻类生长抑制测试。藻类生长抑制测试通常在带有荧光灯的生长室中进行，因为测试指南要求连续均匀的荧光照明。然而，荧光灯中含有汞，汞已被确定对人类和其他生物具有危害性。《水俣公约》（2013 年通过）要求减少或禁止含有汞的产品。另一方面，发光二极管不含汞，并且提供 400-700nm 的光合有效波长范围，这是藻类生长的足够光强。因此，发光二极管比荧光灯更适合作为藻类生长抑制测试的潜在光源。在这项研究中，我们研究了发光二极管是否可以替代荧光灯，用于绿藻（Pseudokirchneriella subcapitata）、硅藻（Navicula pelliculosa）和蓝藻（Anabaena flos-aquae）的生长抑制研究。使用五种不同的化学品进行藻类生长抑制测试，这些化学品已知具有不同的作用模式，并被分配为测试指南中的参考物质。每种藻类测试的结果表明，在每种化学物质的生长抑制率和产量抑制率的条件方面，发光二极管和荧光灯的结果相似。因此，可以得出结论，使用发光二极管代替荧光灯作为光源不会影响藻类生长抑制测试结果。
