Toxicity Bio-Indices as Indicators of Water Portability

Genotoxicity testing represents a powerful line of evidence for assessing impacts from chemical contaminants in drinking water. In this study, fifteen brands of sachet water, five of which do not have the National Agency for Food and Drug Administration and Control (NAFDAC) registration numbers, were collected in the Benin metropolitan city square in Edo State of Nigeria and subjected to cytological evaluation using the macroscopic and microscopic parameters in Allium cepa L. A series of five small onion bulbs were cultivated in the different sachet water samples and after 48 hours, two root tips from each bulb were harvested and processed for cytological observation using the aceto-orcein squash technique. Results of the root growth inhibition assessment of the onion bulbs after cultivation in the sachet water samples for 96 hours showed that the mean root length ranged between 2.36±0.14 - 5.37±0.30 cm while cytological evaluation revealed that all, except the University-based brand, induced mitotic abnormalities at significant levels. The considerable variations among the examined samples with respect to the cyto-genotoxic parameters indicate that they are a reflection of the amount of chemical constituents present in the sachet water brands. There is therefore need for NAFDAC to enforce drinking water regulatory guidelines and ensure frequent monitoring to safeguard lives of consumers of sachet water in the study area