A large number of emerging contaminants (ECs) are known to persist in surface waters, and create pressure on wastewater treatment works (WWTW) for their effective removal. Although a large database for the levels of these pollutants in water systems exist globally, there is still a lack in the correlation of the levels of these pollutants with possible long-term adverse health effects in wildlife and humans, such as endocrine disruption. The current study detected a total of 55 ECs in WWTW influent surface water, 41 ECs in effluent, and 40 ECs in environmental waters located upstream and downstream of the plant. A list of ECs persisted through the WWTW process, with 28% of all detected ECs removed by less than 50%, and 18% of all ECs were removed by less than 25%. Negative mass balances of some pharmaceuticals and metabolites were observed within the WWTW, suggesting possible back-transformation of ECs during wastewater treatment. Three parental illicit drug compounds were detected within the influent of the WWTW, with concentrations ranging between 27.6 and 147.0 ng L-1 for cocaine, 35.6-120.6 ng L-1 for mephedrone, and 270.9-450.2 ng L-1 for methamphetamine. The related environmental risks are also discussed for some ECs, with particular reference to their ability to disrupt endocrine systems. The current study propose the potential of the pharmaceuticals carbamazepine, naproxen, diclofenac and ibuprofen to be regarded as priority ECs for environmental monitoring due to their regular detection and persistence in environmental waters and their possible contribution towards adverse health effects in humans and wildlife.

Background.: Pseudomonas aeruginosahas been increasingly recognized for its ability to cause significant hospital-associated outbreaks, particularly since the emergence of multidrug-resistant strains. Biofilm formation allows the pathogen to persist in environmental reservoirs. Thus, multiple hospital room design elements, including sink placement and design, can impact nosocomial transmission ofP. aeruginosaand other pathogens.Methods.: From December 2004 through March 2006, 36 patients exposed to the intensive care unit or transplant units of a tertiary care hospital were infected with a multidrug-resistant strain ofP. aeruginosa. All phenotypically similar isolates were examined for genetic relatedness by means of pulsed-field gel electrophoresis. Clinical characteristics of the affected patients were collected, and a detailed epidemiological and environmental investigation of potential sources was carried out.Results.: Seventeen of the infected patients died within 3 months; for 12 (71%) of these patients, infection with the outbreak organism contributed to or directly caused death. The source of the outbreak was traced to hand hygiene sink drains, where biofilms containing viable organisms were found. Testing by use of a commercial fluorescent marker demonstrated that when the sink was used for handwashing, drain contents splashed at least 1 meter from the sink. Various attempts were made to disinfect the drains, but it was only when the sinks were renovated to prevent splashing onto surrounding areas that the outbreak was terminated.Conclusion.: This report highlights the importance of biofilms and of sink and patient room design in the propagation of an outbreak and suggests some strategies to reduce the risks associated with hospital sinks.

A degradative microbial consortium consisting of at least nine bacterial and one algal species was isolated from soil with diclofop methyl as the sole carbon source. In continuous flow culture, the presence of the algae increased diclofop methyl degradation and removal by 36%. Batch culture experiments with ¹⁴C-labeled diclofop methyl confirmed algal involvement in the mineralization of diclofop methyl as there was no significant difference in the amount of ¹⁴CO₂ evolved by the bacterial consortium with and without the algal activity when the consortium was cultivated in the dark to inhibit algal growth, while 11% more ¹⁴CO₂ was produced in the light by the algal–bacterial consortium. Pure cultures isolated from the bacterial consortium could not individually mineralize diclofop methyl as the sole carbon source. However, when supplied with an additional carbon source, two strains could mineralize diclofop methyl. Addition of either the complex growth medium, or a cell-free filtrate from the algal–bacterial consortium to batch systems containing ¹⁴C-labeled diclofop methyl resulted in a significant increase in the production of ¹⁴CO₂ by the bacterial consortium, suggesting co-metabolism of diclofop methyl in the presence of a labile carbon source. Removal of diclofop methyl by the bacterial consortium was increased by 36% when a larger surface to volume ratio was provided by glass beads that allowed extensive biofilm formation. The requirement for exogenous carbon sources and the inability of isolated pure cultures to degrade diclofop methyl indicated that interspecies interactions are necessary for degradation. The positive effect of sessile growth suggested that spatial organization of cells may also be important for degradation.Key words: consortium, degradation, herbicide, microbial interactions.