[Innovative SARS-CoV-2 crisis management in the public health sector: Corona dashboard and wastewater surveillance using the example of Berchtesgadener Land, Germany]. / Innovatives SARS-CoV-2-Krisenmanagement im öffentlichen Gesundheitswesen: Corona-Dashboard und Abwasserfrühwarnsystem am Beispiel Berchtesgadener Land.

BACKGROUND: The rise of an infectious disease crisis such as the SARS-CoV­2 pandemic posed significant challenges for the administrative structures of the public health service, which resulted in varying levels of efficiency in outbreak management as a function of staffing and digital resources. This substantially impeded the integration of innovative pandemic outbreak management tools. Innovative crisis management, such as cluster tracking, risk group testing, georeferencing, or the integration of wastewater surveillance recommended by the EU Commission, was made significantly more difficult. AIM: In this case study in Berchtesgadener Land, we present the integration of an area-wide georeferenced wastewater surveillance system that captured 95% of the entire population since November 2020. METHODOLOGY: Sampling occurred twice a week at nine municipal wastewater treatment plants and directly from the main sewer at three locations. Samples were pre-treated by centrifugation and subsequently analyzed by digital droplet polymerase chain reaction (PCR) targeting four specific genes of SARS-CoV­2. RESULTS: The integration of an area-wide georeferenced wastewater surveillance system was successful. Wastewater occurrences are plotted for each municipality against cumulative infections over seven days per 100,000 inhabitants. Changes in the infection pattern in individual communities are noticeable ten days ahead of the official case numbers with a sensitivity of approximately 20 in 100,000 inhabitants. DISCUSSION: The integration of this innovative approach to provide a comprehensive overview of the situation by employing a digital dashboard and the use of an early warning system via quantitative wastewater surveillance resulted in very efficient, proactive management, which might serve as a blueprint for other municipalities in Germany.

Matrix composition during ozonation of N-containing substances may influence the acute toxicity towards Daphnia magna.

Micropollutants reach the aquatic environment through wastewater treatment plant effluents. Ozonation, applied in wastewater treatment for micropollutants abatement, can yield transformation products (TP), which might be of ecotoxicological concern. Previous studies on TP formation were mostly performed in ultrapure water. However, the water matrix can have a substantial influence and lead to unpredictable yields of TPs with toxicological potential. In this study the acute toxicity (immobilization) of the parent substances (isoproturon and metoprolol) and also of available TPs of isoproturon, metoprolol and diclofenac towards Daphnia magna (D. magna) were investigated. Further, the acute toxicity of TP mixtures, formed during ozonation of isoproturon, metoprolol and diclofenac was evaluated in the following systems: in the presence of radical scavengers (tert-butanol and dimethyl sulfoxide) and in the presence of hypobromous acid (HOBr), a secondary oxidant in ozonation. For all tested substances and TP standards, except 2,6-dichloroaniline (EC50 1.02 mg/L (48 h)), no immobilization of D. magna was detected. Ozonated pure water and wastewater did not show an immobilization effect either. After ozonation of diclofenac in the presence of dimethyl sulfoxide 95% (48 h) of the daphnids were immobile. Ozonation of parent substances, after the reaction with HOBr, showed no effect for isoproturon but a high effect on D. magna for diclofenac (95% immobilization (48 h)) and an even higher effect for metoprolol (100% immobilization (48 h)). These results emphasize that complex water matrices can influence the toxicity of TPs as shown in this study for D. magna.

Ecotoxicological effects of micropollutant-loaded powdered activated carbon emitted from wastewater treatment plants on Daphnia magna.

In order to eliminate micropollutants from wastewater, the use of powdered activated carbon (PAC) is a suitable and common technique. Many studies already proved the successful elimination of micropollutants from wastewater using PAC. However, it still remains a challenge to completely retain the applied PAC within the wastewater treatment plant (WWTP) without considerable emission of PAC into receiving waters. The present study investigates possible toxic effects of micropollutant-loaded PAC from a WWTP in acute and chronic tests with the aquatic organism Daphnia magna. Furthermore, the well-studied micropollutant diclofenac as well as unloaded, native PAC and experimentally diclofenac-loaded PAC were tested. The acute tests resulted in median effect concentrations (EC50) after 48 h of 53 mg/L for diclofenac, 217 mg/L for native PAC and 414 mg/L for diclofenac-loaded PAC. No effects were detected for the loaded PAC from the WWTP although D. magna ingested the PAC. The chronic tests revealed that diclofenac had effects on growth, reproduction and mortality (median lethal concentration 17.0 mg/L). Exposure to native and diclofenac-loaded PAC showed clear effects on growth and a reproduction inhibition of 80% in the highest tested concentrations. The calculated reproduction EC10 values were 0.8 mg/L for native PAC and 0.3 mg/L for diclofenac-loaded PAC. For the loaded PAC from the WWTP, no effects were observed on reproduction, growth and mortality during the 21-day exposure albeit the fact that the animals ingested the PAC into their gastrointestinal system. Based on these findings PAC from WWTP can be considered as not harmful to D. magna even if complete retention of the PAC at the WWTP cannot be guaranteed.

Ecotoxicological effects prior to and after the ozonation of tamoxifen.

The endocrine disrupting micropollutant tamoxifen can induce several effects on aquatic organisms. It is introduced into the environment mainly by wastewater treatment plant effluents. To reduce the discharge of micropollutants into surface waters, ozonation can be used as additional wastewater treatment option. For only few transformation products (TPs) formed by ozonation ecotoxicological data are available. To enable an initial estimation of ecotoxicological potentials of the TPs formed after the ozonation of tamoxifen, acute toxicity (immobilization) to Daphnia magna and green algae growth inhibition using Desmodesmus subspicatus were determined for several ozone doses spiked at pH 3 and pH 7. The initial immobilization of D. magna by tamoxifen was not further observed after ozonation. In contrast, the green algae growth inhibition increased due to ozonation of tamoxifen. Overall, five transformation products were observed. For three TPs, positive correlations of green algae growth inhibition and peak area were determined, whereas two TPs do not induce the residual effects. Based on our observations, TP 270 can be assumed as most potent of the formed TPs concerning green algae growth inhibition. Since the effect is not induced by formed N-oxides, green algae growth inhibition could be reduced by sufficient ozone exposure during wastewater treatment.