Assessment of Cytotoxicity and Genotoxicity Potential of Effluents from Bahir Dar Tannery Using Allium cepa

Table 3

Average number of cells and dividing cells of A. cepa roots per slide in three replicated slides for each concentration and cytological effect of tannery effluent on A. cepa cells.

Treatment concentrations (%)	Total number of cells	Dividing cells	Mitotic index (%)	Mitotic inhibition (%)
Control group	6625.66 ± 257.9	613 ± 3.46	9.55	0
20	6480.33 ± 90.17	555 ± 27.61	8.64	9.53
40	6413.66 ± 69.57	477.33 ± 18.48	7.43	22.18
60	6433.33 ± 122.38	337.66 ± 6.69	5.23	45.23
80	6441.33 ± 251.59	247 ± 19.35	3.85	59.68
100	6129.66 ± 136.46	165.33 ± 25.40	2.57	73.09

Note: mitotic index had a significantly negative relationship with tannery effluent concentration percentage at P = 0.00005988 and r² = 0.9873 checked with simple linear regression analysis; increase of tannery concentrations (P < 0.05).