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BackgroundOseltamivir phosphate (OP; Tamiflu) is a prodrug of the anti-influenza neuraminidase inhibitor oseltamivir carboxylate (OC) and has been developed for the treatment and prevention of both A and B strains of influenza. The recent increase in OP resistance in influenza A virus (H1N1; commonlly called “swine flu”) has raised questions about the widespread use of Tamiflu in seasonal epidemics and the potential ecotoxicologic risk associated with its use in the event of a pandemic.ObjectivesThe objectives of this study were to develop an analytical method for quantitative determination of OC in sewage treatment plant (STP) effluent and receiving river water, and to investigate the occurrence of OC in STP effluent and river water in Japan during a seasonal flu outbreak.MethodsWe developed an analytical method based on solid-phase extraction followed by liquid chromatography–tandem mass spectrometry. Using this method, we analyzed samples from three sampling campaigns conducted during the 2008–2009 flu season in Kyoto City, Japan.ResultsThe highest concentration of OC detected in STP discharge was 293.3 ng/L from a conventional activated-sludge–based STP; however, we detected only 37.9 ng/L from an advanced STP with ozonation as a tertiary treatment. In the receiving river water samples, we detected 6.6–190.2 ng/L OC, during the peak of the flu season.ConclusionOC is present in STP effluent and river water only during the flu season. Ozonation as tertiary treatment in STP will substantially reduce the OC load in STP effluent during an influenza epidemic or pandemic.

Groundwater through hand-operated tubewell (a type of water well) tapping is the main source of drinking water in Bangladesh. this study investigated iron and manganese concentration in groundwater across Jashore district-one of the worst arsenic contaminated area in Bangladesh. one working tubewell that had been tested previously for arsenic and marked safe (green) was selected from each unions of the district. Results revealed that approximately 73% and 87% of groundwater samples exceeded the limits for iron and manganese in Bangladesh drinking water, respectively. Additionally, spatial distribution of iron and manganese indicate that only 5% of the total surface area of groundwater is covered by safe level of iron and manganese. Human health risk due to ingestion of iron and manganese through drinking water was evaluated using hazard quotients (HQ) for adults and children. the result of the health risk assessment revealed that the non-carcinogenic health risks due to ingestion of iron (HQ up to 1.446 for adults and 0.590 for children) and manganese (HQ up to 2.459 for adults and 1.004 for children) contaminated groundwater are much higher among adults than children. on the basis of occurrences, spatial distribution and health risk assessment results, the area can be categorized as a high-risk zone for iron and manganese-related problems and needs special attention in order to protect public health of local residents. Groundwater is the main source of drinking water in Bangladesh and over 90% of the country's drinking water source is groundwater. Now, it is estimated that close to 98% of the population of Bangladesh have access to 'technologically improved water source' but this level is likely lower than 39% when considering Sustainable Development Goal water target (SDG goal 6.1) 1 of 'safely managed water' 2. Safely managed water services ensure access to a technologically improved water source which is available when needed, located on premises and free of fecal and priority chemical contamination. In Bangladesh, access to technologically improve water source came mainly due to installation of tubewells-a type of water well, a low-cost technology used to withdraw groundwater by hand powered. Since their large scale installation in the 1970s and 1980s for obtaining microbiologically safe water, tubewells have become popular in Bangladesh, with close to 95% of rural people and 70% of urban people using them today 3. Even though groundwater can be a safe and reliable source of drinking water, it can also be affected by geogenic contaminants, such as arsenic, iron and manganese. Therefore, increased consumption of groundwater in some area has led to long-term exposures to arsenic 4 , iron 5 and manganese 6,7 that are associated with adverse health effects. Iron and manganese are naturally occurring metals, and coexist in groundwater as they have many common chemical properties including similar valence charge in physiological conditions, ionic radius and absorptive mechanisms for individuals 8,9. Iron and manga...

The occurrence and elimination of seventeen antibiotics (three macrolides: azithromycin, clarithromycin and roxithromycin; five quinolones: ciprofloxacin, enrofloxacin, levofloxacin, nalidixic acid and norfloxacin; five sulfonamides: sulfadimethoxine, sulfadimizine, sulfamerazine, sulfamethoxazole and sulfamonomethoxine; and others: tetracycline, lincomycin, salinomycin and trimethoprim) were investigated at four full-scale sewage treatment plants in Japan. The highest concentration was recorded for clarithromycin (1,129 to 4,820 ng/L) in influent, followed by azithromycin (160 to 1,347 ng/L), levofloxacin (255 to 587 ng/L) and norfloxacin (155 to 486 ng/L). A vary inconsistence picture was obtained with negative to over 90% removal. Nalidixic acid (53 to 100%) exhibited higher removal efficiency followed by norfloxacin (75 to 95%), levofloxacin (40 to 90%), ciprofloxacin (60 to 83%) and enrofloxacin (38 to 74%). Among macrolides, clarithromycin (50 to 88%) and azithromycin (34 to 86%) showed relatively higher removal efficiency than roxithromycin (-32 to 59%). For most of the antibiotics removal efficiency was higher in A2O and AO based secondary treatment process than CAS process. The effect of the antibiotics on bacterial ammonia oxidation determined by oxygen uptake rate presented that there was no significant effect below 0.05 mg/L of each antibiotics. Even at the same concentration, antibiotics in mixed condition had higher inhibition effects than individuals.

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