Toxicity Evaluation of Selected Dyes Commonly used for Clothing Materials in Urban Kano, Nigeria

The study was focused on four selected commercial dyes widely used in urban Kano to re-dye fabrics. The dyes were defined by the colours, blue, red, orange and yellow. The aim was to assess and evaluate the concentration of dangerous metallic compounds in the dyes and subsequent toxicity of these compounds in experimental animals (brine shrimps, Artemia salina). The results showed that the concentration levels of cadmium, chromium, lead, copper and zinc varies among the dyes, however, the concentration exceeded permissible limits set by standard authorities such as FEPA (1991) and DOE (2008). The LC50 of the various dyes on the test animals indicated that the blue dye was the most toxic, followed by yellow, red and orange respectively. This finding highlights public health and environmental implication because of direct contact of these dyes with tissue systems of individuals involved in the re-dyeing activity, aquatic organisms, food and other route of administration. Therefore, the use dyes such as those found in this study should be restricted, as they are causing widespread contamination of some areas in urban Kano.