The toxicity effects of industrial effluents of paint industry (at 0, 5, 10. 20, 40, 60, 80, 100% concentration) were evaluated using macroscopic parameters of onion bulb roots and lettuce seeds. In this study the root length and root numbers were the parameters observed for the onion bulbs and the seed growth, average root length and root elongation were estimated for the lettuce seeds. A 96h effective concentration (96 h EC50) gave acute toxicity of the paint industrial effluent at 48% concentration. Analysis using Pearson correlation revealed that the root length of onion bulb has highly negative correlation with the toxic effluent concentration (P < 0.01, r = -0.903). This also verified that the root growth inhibition was concentration dependent. Anova result shows there is high significant different (0.995) in root length between the concentrations. A 120h assay was also done on the lettuce seeds, the result of the lettuce seed shows significant toxicity at 40%. A positively low correlation was obtained between (P < 0.01, r = 0.148) between the concentration and the seed germination rate. A high negative correlation (P < 0.01, r = -0.969) exist between the concentration and the average root length. A high negative correlation (P < 0.01, r = -0.970) exist between the concentration and the root elongation. Conclusively assay with lettuce seeds and onion bulbs are confirmed to be a good means of monitoring industrial discharge into the environment.
