A comparative study of the sensitivities of Salmonella typhimurium strains TA 98, TA 100 and TA 102 to hospital waste waters

Assessment of genotoxic potential of the treated hospital wastewater using cytogenetic assays

The cytogenetic study using hospital effluent was carried out engaging three cytogenetic end points—chromosomal aberration (CA) assay, mitotic indices (MIs), and micronucleus (MN) Analysis. These bioassays were performed in hematopoietic bone marrow cells of Mus musculus. The experiment commenced with the collection of hospital effluent from the final outlet when wastewater gets collected after undergoing treatment by a multistep process. The pure treated sample water was collected at different times between March 2019 to January 2020 and was given ad libitum to mice at its low (90% dilution) and high (pure form), i.e. 100% concentration for 3 different durations i.e. 7, 15, and 30 days, respectively. The results indicated a significant (P < 0.01) decrease in the MI in all the groups but was more pronounced in the group which was given 100% concentrated sample water collected in the month of March 2019. Besides this, the major finding was presence of CAs like breaks, fragments, rings, and pulverization in bone marrow cells in different groups; however, the frequency of these aberrations varied from group to group. A significant (P < 0.01) increase in MN Induction and decreased ratio (P < 0.01) of polychromatic to normonochromatic erythrocytes were observed in samples collected in month of March both at 10% and 100% concentrations. However, decrease in the ratio was observed in the samples of September and January at low-concentration sample water. The results thus indicated that there was some lacuna in the treatment process earlier in the month of March, which was rectified to some extent in the subsequent months. Hence, the treated wastewater collected in the month of January next year was more suitable for its use than other samples. Summary: These findings thus draw attention toward ensuring efficiency of the treatment plant and quality of water by the hospital management before it being disposed off into the municipal supply; a step that can help society to live a healthy life. With these findings, it is conveyed that all the hospitals, diagnostic labs, and other health care establishments must pay utmost attention at liquid waste disposal mechanism to make environment pollution-free.

Environmental risk assessment of widely used anticancer drugs (5-fluorouracil, cisplatin, etoposide, imatinib mesylate)

Anticancer drugs are among the most toxic chemicals, which are commercially produced; therefore, their release in aquatic ecosystems raised concerns in regard to potential adverse effects. This article describes the results of risk assessments concerning their environmental safety, which are based on data generated in the frame of a coordinated EU project ("Cytothreat"). Eight research institutions participated in the project and four widely used anticancer drugs with different mechanisms of therapeutic action (5-fluorouracil 5FU, cisplatin CDDP, imatinib mesylate IM and etoposide ET) were tested in a variety of indicator organisms (cyanobacteria, algae, higher plants, rotifers, crustacea, fish and also in human and fish derived cell lines) in acute/subacute/chronic toxicity assays. Furthermore, genotoxic effects in micronucleus assays, single cell gel electrophoresis experiments and γH2AX tests were studied in plants, crustacea, fish and in various cell lines. We used the results to calculate the predicted no effect concentrations (PNEC) and risk quotients (RQ) by comparing PNEC with predicted environmental concentrations (PEC values) and measured concentrations (MEC) in wastewaters. The most sensitive species in experiments concerning acute toxic and long term effects were in general crustacea (daphnids) after chronic treatment the most pronounced effects were detected with IM followed by CDDP and 5FU. Comparisons between PNEC and PEC values indicate that it is unlikely that the release of these drugs in the aquatic environments leads to adverse effects (RQ values < 1). However, when the assessments were performed with MEC found in highly contaminated municipal wastewaters and hospital effluents, RQ values were obtained which are indicative for moderate adverse effects of IM. Calculations with data from genotoxicity experiments and PEC values are indicative for increased RQ values for all compounds except ET. The most sensitive species were fish (Danio rerio) which were highly responsive towards 5FU and daphnids which were sensitive towards CDDP and IM. When environmental data (from waste waters) were used for the calculations, high RQ values (>100) were obtained for CDDP and IM. These overall conclusions were not substantially altered when the effects of other frequently used cytostatic drugs and combined effects of mixtures of anticancer drugs were taken into consideration. The results of these assessments underline the importance of efficient removal of these chemicals by improved sewage treatment strategies and the need for further investigations of adverse the long term effects of cytostatics in aquatic biota as a consequence of damage of the genetic material in highly sensitive species.