Surface Soil Pollution By Heavy Metals: A Case Study Of Two Refuse Dumpsites In Akure Metropolis
Anietie Olayemi Victoria, Labunmi Lajide
Keywords: Contamination,Dumpsites, Ecosystem,Heavy metals,Pollution, Remediation, Surface soil, Wastes.
ABSTRACT: Heavy metals can be harmful to the biota and human beings when present above certain tolerable levels in the ecosystem. This lead to the study of the accumulation, contamination and pollution of these metals in soils of two refuse dumpsites within and outskirts of Akure Township, capital city of Ondo State, Nigeria. The dumpsites are where wastes such as industrial wastes, automobile wastes, municipal wastes, agricultural wastes, etc were dumped. At each site, soil samples were collected randomly from nine different points of about 1m part at depth of about 0-30cm and analyzed for heavy metals and pH. The metals analyzed include Zn, Fe, Co, Cu, Ni, As, Ba, Pb, Cr and Cd using Atomic Absorption Spectrophotometer (AAS) with HF/Aqua regia wet digestion method. The pH of the soils ranged between 7.49 and 8.66. The results revealed heavy metal presence and implicated wastes as the major sources of the heavy metals in the soils of the dumpsites. All the metals were detected in all the soil samples except Arsenic that was not detected in three points at site A. Fe had the highest concentrations, while Ni had the least concentration in both sites. The trend in concentration was Fe > Zn >Pb> Cu> Cd> Co> Cr >As>Ba>Ni in site A, While the trend in concentration was Fe> Cr> Zn> Cu >Pb>Cd> Co> As > Ba> Ni in site B. The mean metal concentrations were compared with Department of Petroleum Resources (DPR) Standard values for soils in Nigeria, all the metals except Cr and Cu are below the DPR target values while Cd and Arsenic are above the DPR intervention values for the two sites, and this calls for immediate remediation.
 Sabine EM, Wendy G.HUMAN HEALTH EFFECTS OF HEAVY METALS ENVIRONMENTAL SCIENCE AND TECHNOLOGY BRIEFS FOR CITIZEN CENTER FOR HAZARDOUS SUBSTANCE, 2009. Available;http://www.engg.ksu.edu/CHSRnvironmental
 OladeMA. LEAD, MERCURY, CADMIUM AND ARSENIC IN THE ENVIRONMENT, Published By John Wiley & Sons Ltd, 1987.
 Sengupta AK. PRINCIPLES OF HEAVY METALS SEPARATION, Environmental Separation of Heavy Metals:Engineering Processes, Lewis Publishers, Boca Raton, FL, 2002, ISBN 1566768845
 Duffus JH. HEAVY METALS—A MEANINGLESS TERM?, Journal of Pure and Applied Chemistry, 2002, Vol. 74, No. 5, 793–807
 Page AC, Ganje TJ, Joshi MS. LEAD QUANTITIES IN PLANTS, SOIL AND AIR NEAR SOME MAJOR HIGHWAYS IN SOUTHERN CALIFORNIA. Hilgardia, 1971, 4l, 1-31.
 Goldsmith CO, Scanlon RF. Pirie ME. LEAD CONCENTRATIONS IN SOIL AND VEGETATION ASSOCIATED WITH HIGHWAYS OF DIFFERENT DENSITIES. Bull. Environment Containing Toxicolology, 1976, Volume 16, 66-70
 Fergusson JE, Hayes RW, Tans Y, Simitti Y.LEAD AND CADMIUM CONTENT OF DUST SOIL AND PLANTS SAMPLE.New Zealand Journal of Science, 1980, 23, 293-310.
 Ogundare OF. HEAVY METAL POLLUTION BY HUMAN ACTIVITIES OF SELECTED CENTRES WITHIN AKURE METROPOLIS (unpublished) 1998.
 Odukoya OO, Bamgbose O, Arowolo TA. HEAVY METALS IN TOP SOILS OF ABEOKUTA DUMP SITES. Global Journal of Pure and Applied Science, 2001, Volume 7, 467-472
 Oguntimehin II. PROFILE OF SOIL CONTAMINATION BY HEAVY METALS: A CASE STUDY OF MECHANIC WORKSHOPS IN AKURE (unpublished), 2002.
 Christoph M, Theopisti L, Volker JD. DETERMINATION OF HEAVY METALS IN SOILS, SEDIMENTS AND GEOLOGICAL MATERIALS BY ICP-AES AND ICP-MS, Mikrochimica Acta Springer-Verlag, 2001, 136; 123-128.
 Huaihui L, Xu C, Jianguo Yi, Mingzhu Z. THE RESEARCH OF HEAVY METALS POLLUTION OF SURFACE SOIL IN CITY, International conference on artificial intelligence and soft computing, 2012, Volume 12, 201-206.
 BouldingJR. DESCRIPTION AND SAMPLING OF CONTAMINATED SOILS, Lewis publishers, New York, 2nd Edition, 1994, A10.
 Tel DA. SOIL AND PLANT ANALYSIS, IITA, Department of Land Resources, Science University of Guelph, Guelph, Ontario, Canada, 1984, 117-190.
 Vitosh ML, Johnson JW. Mengel B. TRI-STATE FERTILIZER RECOMMENDATION FOR CORN, SOYBEAN AND WHEAT. Extension bulletin E, New York, 1995, 252, 28.
 Department of petroleum resources (DPR) ENVIRONMENTAL GUIDELINES AND STANDARDS FOR PETROLEUM INDUSTRY IN NIGERIA. Revised edition, 2002, 278-281.