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Environ Sci Pollut Res (2012) 19:7285 DOI 10.1007/s11356-011-0536-y
RESEARCH ARTICLE
Biodegradability and ecotoxicitiy of tramadol, ranitidine, and their photoderivatives in the aquatic environment
Marlies Bergheim & Reto Gier & Klaus Kmmerer
Received: 4 March 2011 /Accepted: 24 May 2011 /Published online: 17 June 2011 # Springer-Verlag 2011
AbstractPurpose This study was designed to assess the fate and the overall potential impacts of the widely prescribed drugs ranitidine and tramadol after their introduction into the aquatic environment.
Methods The probability to detect these two drugs in the aquatic environment was studied by analyzing their abiotic and biotic degradation properties. For this purpose, samples were irradiated with different light sources, and three widely used biodegradability tests from the OECD series, the closed bottle test (OECD 301 D), the manometric respirometry test (OECD 301 F) and the ZahnWellens test (OECD 302 B), were conducted. The ecotoxicity of the photolytically formed transformation products was assessed by performing the bacterial growth inhibition test (EN ISO 10712). Furthermore, quantitative structureactivity relationship analysis and a risk analysis based on the calculation of the predicted environmental concentrations have also been con-
ducted to assess the environmental risk potential of the transformation products. The possible formation of stable products by microbial or photolytical transformation has been investigated with DOC and LC-MS analytics.
Results In the present study, neither ranitidine, nor tramadol, nor their photoderivatives were found to be readily or inherently biodegradable according to test guidelines. The photolytic transformation was faster under a UV lamp compared to the reaction under an Xe lamp with a spectrum that mimics sunlight. No chronic toxicity against bacteria was found for ranitidine or its photolytic decomposition products, but a low toxicity was detected for the resulting mixture of the photolytic transformation products of tramadol.
Conclusions The study demonstrates that transformation products may have a higher environmental risk potential than the respective parent compounds.
Keywords Aquatic environment . Degradation . Irradiation . Transformation . Ecotoxicology. Ranitidine . Tramadol
1 Introduction
Pharmaceuticals were first found in the aquatic environment in the late 1970s (Hignite and Azarnoff 1977) and ever since have become an increasing environmental concern. Most pharmaceuticals used in medicine enter wastewater as excretion with urine or through the improper disposal of unused or out-of-date drugs. In sewage treatment...