[Evaluation of the efficacy of the sewage treatment plant of Toledo, Spain in the elimination of drugs of abuse and the estimation of consumption]. / Estimación del consumo de drogas de abuso y sus metabolitos a partir de su presencia en el agua residual de Talavera de la Reina y en el río Tajo.

BACKGROUND: in the last years, the presence of new contaminants in water has been rising. There are only few studies which analyze such presence. The aims were to determine the occurrence of drugs of abuse and their metabolites in the influent and effluent of the Sewage Treatment Plant (STP) in Talavera de la Reina, and the River Tagus, as well as to evaluate the STP removal efficiency in the elimination of these substances and to estimate the consumption of drugs in Talavera. METHODS: whe samples were taken on June 28, 2010. The presence of 5 groups of drugs (10 drugs of abuse and 9 metabolites) was quantified. The efficiency was calculated from the percentage of reduction of the concentration in the influent and effluent of the STP. Drug consumption was calculated from influent concentrations. Using a specific methodology, based on the assumption the drugs after they are consumed and metabolized in the human body are excreted as parent compounds or metabolites. Whose metabolic pathways are known, and the amount of drug or metabolite quantified corresponds to the dose consumed. RESULTS: ten substances were detected. In all sampling points appeared: Benzoiclegonina (BE) (cocaine metabolite), ephedrine, methadone and its metabolite EDDP. The highest concentrations were of BE (239 ng/L), and THC-COOH (35 ng/L), both in influent. In the Tagus River, the highest concentrations were of BE (5.38 ng/L) and EDDP (4.4 ng/L). The STP removal efficiency was up to 80% for all substances except for methadone (which was zero) and EDDP (increasing to leave the STP). The estimated consumption shows that the most consumed substances were cannabis (1.88 grams / day) and cocaine (0.46 grams / day). CONCLUSION: the presence of drugs of abuse in River Tagus in Talavera demonstrates that these substances are not eliminated completly by STPs. Drug consumption estimate indicates that the population of Talavera mainly consumed cannabis and cocaine. Thus this methodology can complement epidemiological surveys.

Estimación del consumo de drogas de abuso y sus metabolitos a partir de su presencia en el agua residual de Talavera de la Reina y en el río Tajo / Evaluation of the efficacy of the sewage treatment plant of Toledo, Spain in the elimination of drugs of abuse and the estimation of consumption

Fundamentos: en los últimos años se ha evidenciado la presencia de nuevos contaminantes en el agua, existiendo pocos estudios que analicen dicha presencia. Los objetivos fueron determinar drogas de abuso (DAs) y sus metabolitos en el influente y efluente de la Estación Depuradora de Aguas Residuales (EDAR) de Talavera de la Reina y en el río Tajo, evaluar el rendimiento de la EDAR en la eliminación de estas sustancias y estimar el consumo de drogas en la ciudad de Talavera. Métodos: el muestreo fue realizado, el día 28 de Junio de 2010. En todas las muestras se analizaron 5 grupos de drogas (10Das y 9 metabolitos). Se calculó el rendimiento a partir del porcentaje de reducción de la concentración a la entrada y salida de la EDAR y el consumo de drogas a partir de las concentraciones del influente y utilizando una metodología específica, basada en la asunción de que las drogas después de ser consumidas y metabolizadas en el cuerpo humano, son excretadas como compuestos principales o metabolitos, cuyas rutas metabólicas son conocidas; y que la cantidad de droga o metabolito cuantificado corresponde con la dosis consumida. Resultados: se detectaron 10 sustancias. La presencia de Benzoiclegonina (BE) (metabolito de la cocaína), efedrina, y metadona junto su metabolito EDDP fue hallada en todas las muestras. Las mayores concentraciones fueron de BE (239ng/L), y de THC-COOH (35 ng/L), ambas en influente. En el río Tajo las concentraciones mas altas fueron de BE (5,38 ng/L) y EDDP (4,4 ng/L). El rendimiento de la EDAR fue mayor del 80 % para todas las sustancias excepto para metadona (que fue nulo) y EDDP (con mayor concentración en el efluente de la EDAR). Las sustancias más consumidas fueron cannabis (THC) (1,88 g/día) y cocaína (0,46 g/día). Conclusiones: Se detectó la presencia de Das en el río Tajo a su paso por Talavera de la Reina, lo que evidencia que estas sustancias no son eliminadas totalmente por la EDAR. El consumo de drogas estimado indica que la población de Talavera consume principalmente cannabis y cocaína. Demostrando que esta metodología puede complementar las encuestas sobre consumo de drogas (AU)

Background: in the last years, the presence of new contaminants in water has been rising. There are only few studies which analyze such presence. The aims were to determine the occurrence of drugs of abuse and their metabolites in the influent and effluent of the Sewage Treatment Plant (STP) in Talavera de la Reina, and the River Tagus, as well as to evaluate the STP removal efficiency in the elimination of these substances and to estimate the consumption of drugs in Talavera. Methods: whe samples were taken on June 28, 2010. The presence of 5 groups of drugs (10 drugs of abuse and 9 metabolites) was quantified. The efficiency was calculated from the percentage of reduction of the concentration in the influent and effluent of the STP. Drug consumption was calculated from influent concentrations. Using a specific methodology, based on the assumption the drugs after they are consumed and metabolized in the human body are excreted as parent compounds or metabolites. Whose metabolic path ways are known, and the amount of drug or metabolite quantified corresponds to the dose consumed. Results: ten substances were detected. In all sampling points appeared: Benzoiclegonina (BE) (cocaine metabolite), ephedrine, methadone and its metabolite EDDP. The highest concentrations were of BE (239 ng/L), and THC-COOH (35 ng/L), both ininfluent. In the Tagus River, the highest concentrations were of BE (5.38 ng/L) and EDDP (4.4 ng/L). The STP removal efficiency was up to 80 % for all substances except for methadone (which was zero) and EDDP (increasing to leave the STP). The estimated consumption shows that the most consumed substances were cannabis (1.88 grams/day) and cocaine (0.46 grams/day). Conclusion: the presence of drugs of abuse in River Tagus in Talavera demonstrates that these substances are not eliminated ompletly by STPs. Drug consumption estimate indicates that the population of Talavera mainly consumed cannabis and cocaine. Thus this methodology can complement epidemiological surveys (AU)