Identification and prioritization of bioaccumulable pharmaceutical substances discharged in hospital effluents

The consumption of pharmaceuticals and their excretion in wastewater is a continuous source of pollution for aquatic ecosystems. In certain cases these compounds are found in the environment at concentrations high enough to cause disturbance in aquatic organisms. Aware of this problem hospitals are giving increasing attention to the nature of their effluents and their impact on the environment, by implementing more efficient effluent management policies. This concern is justified in view of the large volumes of toxic products consumed (detergents, disinfectants, pharmaceuticals, chemical reagents, radioactive elements, etc.). Moreover, these effluents usually do not undergo any specific treatment before being discharged into urban sewage networks. In this article, we present a method for selecting the pharmaceuticals discharged in hospital effluents that have the worst impact on the aquatic ecosystem, primarily based on their bioaccumulation potential. This study focused on the pharmaceuticals consumed at the Hospices Civils de Lyon (HCL), the second largest hospital structure in France (5200 hospital beds). Of the 960 substances consumed in HCL hospitals, a shortlist of 70 substances considered as being potentially bioaccumulable was established. The use of aggravating factors of risk has then led to the final selection of 14 priority compounds. They include 4 compounds consumed in large quantities in HCL hospitals, 6 endocrine disruptors and 4 potentially ecotoxic compounds. For all these compounds, it is now advisable to verify their bioaccumulation potential experimentally and confirm their presence in the environment. In addition, in order to monitor the risk relating to possible contamination of the food chain, it will be necessary to measure accumulated dose levels in species of different trophic levels. Lastly, chronic ecotoxicity tests will permit evaluating the danger and risk that some of these substances may represent for aquatic ecosystems.

Daily physicochemical, microbiological and ecotoxicological fluctuations of a hospital effluent according to technical and care activities

The problem of hospital effluents falls into the framework of hazardous substances due to the specific substances used and discharged for the most part into urban drainage networks without prior treatment. This in-depth study has led to greater understanding of the effluents discharged by hospitals. The experimental program implemented consisted in carrying out parallel sampling of the effluents of one hospital: a 24 h-average sample and 5 periodic samples corresponding to fractions of times and hospital activities. The samples were characterized by physicochemical, microbiological and ecotoxicological analyses. The results highlight that the effluents contained very little bacterial flora and a moderate organic pollution. However, a numerous of specific pollutants were detected: AOX, glutaraldehyde, free chlorine, detergents, Freon 113 as well as alcohols, acetone, formaldehyde, acetaldehyde, ammonium, phenols and several metals. The battery of bioassays showed that the effluents had a high level of ecotoxicity partly linked to particles in suspension and, that pollution fluctuated greatly during the day in connection with hospital activities. Finally, the PNEC values compared to the concentrations of pollutants dosed in the effluents highlighted that their toxicity was mainly due to several major pollutants, in particular free chlorine. Some hypotheses require additional experiments to be carried out. They concern: reactions of fermentations likely to occur in the drainage network and to form secondary toxic compounds, retention of chlorine by particles and physicochemical characterization of suspended solids.

[Hemodynamic effect of enflurane in man]

The following hemodynamic parameters: cardiac frequency, peripheral arterial pressure, pulmonary pressure and cardiac output were measured by direct catheterisation, as the total peripheral vascular resistance and the systolic ejection volume were calculated from the registered results. The cardiac frequency and the pulmonary arterial pressure were practically not modified in our patients, though we have observed a statistically significant decrease of systolic (-30p. 100) and diastolic (-27p. 100) arterial pressure. The total peripheral vascular resistance shows a marked diminution (-20p. 100) after giving Ethrane? for ten minutes. If it is possible that one part, surely important, of the cardiac output, is preserved under Ethrane anesthesia by a significant decrease of the total peripheral vascular resistance, a myocardial depression might be questionned, the decrease of cardiac output at 30 minutes being more important than the decrease of the total peripheral vascular resistance.