SOURCES AND ENVIRONMENTAL IMPLICATION OF HEAVY METALS POLLUTION IN PLANTS GROWN AROUND CONTAMINATED SITE IN EDO STATE, NIGERIA

Abstract

Dietary exposure to heavy metals, namely Arsenic (As), Lead (Pb), Cadmium (Cd) and Chromium (Cr), has been identified in Oluku and Otofure in metropolitan Benin City, Nigeria, as a risk to human health through the consumption of food crops and other edible plants. This study investigates the sources and the magnitude of heavy metals contamination in soils and food crops, cultivated close to mechanic workshop, refuse and waste currency dumpsites; this will help in creating public awareness of the imminent danger of food crops grown around contaminated sites. Thirty six (36) samples of food crops (cassava tuber and plantain fruits) were analysed from three different sites using atomic absorption spectrometer (AAS) with the aim of determining the level of concentration and the magnitude of exposure of the heavy metals investigated to human health. The results obtained when compared to standards revealed that the metals investigated were above threshold value; consequently exposing humans that consume such food crops grown in the area of study to health risk. The decrease in concentration from around and away from the sites as well as correlation range r = (P<0.01-0.001) shows anthropogenic source of contamination. The results obtained are presented in tables as mean plus or minus standard deviation (mean ± SD) with super and subscript defining the degree of significant differences in distance. Temperature obtained from the soil range from 24-280 C while the PH recorded was from 2.99-6.80.