STUDY ON HEAVY METALS CONCENTRATION IN IRRIGATED SOIL SAMPLES OF SOME SELECTED LOCATIONS ALONG RIVER KADUNA, NIGERIA

Abstract

The use of dumpsites for irrigation farming is a common practice in urban and sub-urban areas in
Nigeria because of the fact that decayed and composted wastes enhance soil fertility. These
wastes often contain heavy metals in various forms and at different contamination levels. This
study was conducted to ascertain the level of contamination of heavy metals in irrigation soil.
Thirty composite soil samples (0-30cm depth) representing irrigation soils in Karji, Gamji resort,
Stadium-under the bridge, Tudunwada and Kudandan were sampled during November to April
2015/2016 (pick irrigation period) and heavy metals such as Chromium (Cr), Cadmium (Cd),
Lead (Pb), Mercury (Hg) and zinc (Zn) were determined using Atomic Absorption
Spectrophotometer, after digestion by nitric acid procedure. The heavy metal concentration in the
soil ranged from: Cadmium, 17.89±3.13 to 31.75±1.27; Chromium, 37.32±12.32 to 88.14±4.34;
Mercury, 0.01±0.00 to 0.32±0.50; Lead, 46.00±12.18 to 99.45±33.67 and Zinc, 26.34± 6.48 to
98.53±24.98 mg/kg. The concentrations of Cadmium and Lead were above standard limit set by
E.U and DPR therefore advocating a health risk to the consumers of produce from these
locations since plants absorbs heavy metals from soils through the root. The significant
variations observe in concentration of heavy metals from one location of study to another was
traced to different levels of pollution, caused by different degree of industrial and domestic waste
dumps and other waste deposits on the soil