Cytogenotoxicity screening of untreated hospital wastewaters using the <i>Allium cepa</i> test

Abstract

Cytogenetoxicity of University Teaching Hospital (UTH) wastewaters was investigated using the Allium cepa assay. Heterogeneous samples of untreated wastewaters from four sections of the hospital comprising the laboratories, mortuary, laundry and the kitchen were collected twice daily for six months and designated as complex mixtures. Physico-chemical parameters of the wastewaters were determined in accordance with standard methods. Onions root growth inhibition test was used to assess the toxic status of the wastewaters, while cytogenotoxicity was measured by microscopic investigation of the chromosomal aberrations. Onion bulbs were exposed to 1%, 5%, 10% 25% and 50% concentrations of the effluent samples in the dark for 72 hours before measuring the root lengths of the onion bulbs. Results of BOD, COD, TSS and pH showed levels above the maximum permissible limits for discharge of hospital effluent into the environment. There was inhibition of root growth of A. cepa in a concentration dependent pattern compared to control. An effective concentration EC 50 of 8.20% and 9.1% was deduced for the 1 st and 2 nd samples respectively. Various morphological defects of the onions roots were also observed. Cytological analysis of root tips after 48 hrs exposure to the different concentrations showed reduction in frequency of mitosis in the meristematic zones of the root tips. Various types of structural chromosomal aberrations and micronucleus were induced in the treated cells. The University Teaching Hospital wastewaters samples are believed to contain potent toxic substances that provoked the cytogenotoxic responses herein and should be treated before discharge into the environment. ©JASEM

Evaluation of Cyto-Genotoxicity of Pharmaceutical Industrial Effluent in Kano Metropolis, Kano State, Nigeria, Using Allium Cepa L. Assay

“…It was observed that the mitotic index of Allium cepa root cells decreased with an increase in the concentrations of the industrial effluent (The mitotic index ranges from 32, 11, 8, 5, 0% in 0%, 2.5%, 5%, 7.5% and 10% of the Pharmaceutical effluent as shown in table 03). The results of Babatunde, et al (2016), who found that the mitotic index showing the proportion of diving cells reduced with increasing concentration of UTH effluents, are consistent with this result. The mitotic index of control groups was found to be greater than that of the treatment groups.…”

Toxicological and Genotoxic Effects of Used Drilling Fluid: Histopathology and Genotoxicity Assessment

“…Prior to the start of the experimental observation for the Allium Cepa Assay, the onions were kept in a dry environment for a period of 14 days (2 weeks) to dry out, as recommended by Bakare (2002). The outer peel of the onions was removed, and any dried roots were carefully eliminated using a sharp razor blade, following the procedure demonstrated by Babatunde and Bakare (2006).…”

“…Additionally, this experiment involved the assessment of induced chromosomal aberrations using the root tips from two onion bulbs for each test concentration. These root tips were cut and immersed in a mixture of methanol and glacial acetic acid (3:1 v/v) at 48 hours, as described by Babatunde and Bakare (2006). Subsequently, they were hydrolyzed in hydrochloric acid (HCl) at 65°C.…”