ANALYSIS OF THE COMPOSITION OF TWO LOCALLY MANUFACTURED PESTICIDES USED BY FISH TRADERS IN UYO, NIGERIA.
The use of locally made chemical pesticides often exerts deleterious effects on man and his environment. In recent times, there has been an observed increase in the indiscriminate use of locally made chemical pesticides for the protection of food materials including fishes in Uyo metropolis. As a result, it has become necessary to analyze the composition of some locally made pesticides used by fish traders in Uyo metropolis, Akwa Ibom state, Nigeria. Test pesticides (“Diamond Knockdown” and “Best Fighter”) were purchased from traders in Uyo. The pesticides were subjected to physico-chemical, chemical composition and heavy metal analysis using High Performance Liquid Chromatography (HPLC), Mass Spectrometry (MS) and Atomic Absorption spectrophotometer. The two pesticides were found to be acidic, with a pH value of 3.6 for “Diamond Knockdown” and 3.8 for “Best Fighter”. Formaldehyde, isopropyl alcohol, camphor, dichlorvos (2,2-dichlorovinyl dimethyl phosphate) and naphthalene were detected in both pesticides. However, “Diamond Knockdown” had I-hexene as one of the chemical constituents but it was not found in “Best Fighter” while Xylene was detected in “Best Fighter” but was absent in “Diamond Knockdown”. Dichlorvos had the highest chemical concentration for the two pesticides while formaldehyde had the lowest. Chromium, cadmium, mercury and lead were the heavy metals detected in concentrations of 0.012, 0.205, <0.001 and <0.001mg/l respectively for “Diamond Knockdown” while “Best Fighter” had 0.019, 0.039, <0.001 and <0.001mg/l concentrations respectively for chromium, cadmium, mercury and lead. The concentration of cadmium in “Diamond Knockdown” (0.205mg/l) slightly exceeded the World Health Organization (WHO) permissible limit (0.2mg/kg). Mercury and lead constituted the lowest amount (<0.001mg/l) of heavy metals for both pesticides. Repeated exposure to pesticides often results in bioaccumulation leading to deleterious effect on human health as well as the environment. Therefore, the indiscriminate manufacture and use of pesticides should be strongly discouraged and stiff penalties to offenders should be enforced.