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

Abstract

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.

Keywords: chromosomal aberrations; environmental pollution; genotoxicity; micronucleus; wastewater management.

Fig. 1

Frequency of distinct types of CA in Swiss albino mice treated with different concentrations of HWW collected in different months. B&F=breaks and fragments; RC = ring chromosomes; S&P=stickiness and pulverization; SCA = scored CA. Serial nos. 1–9 represent groups I–IX as mentioned in Tables 1 and 2.

Fig. 2

The induction of PCE, MNPCE, NCE, and MNNCE in Swiss albino mice treated with different concentrations of HWW collected in different months. Serial nos. 1–9 represent groups I–IX as mentioned in Tables 1 and 3.