Heavy Metal Contamination of a Dumpsite Environment as Assessed with Pollution Indices

Indiscriminate refuse dumping in and around Ado-Ekiti combined with improper management of few available dumpsites, such as Ilokun dumpsite, posed the threat of heavy metals pollution in the surrounding soils and underground water that needs assessment using pollution indices. Surface soils (0-15 cm) were taken from the centre of Ilokun dumpsite (0 m) and environs at different directions and distances during the dry and wet seasons, as well as a background sample at 1000 m away, adjacent to the dumpsite at Ilokun, Ado-Ekiti, Nigeria. The concentration of heavy metals used to calculate the pollution indices for the soils were determined using Atomic Adsorption Spectrophotometer. The soils recorded high concentrations of all the heavy metals above the background concentrations irrespective of the season with highest concentrations at the 0 m except Ni and Fe at 50 m during the dry and wet season, respectively. The heavy metals concentration were in the order of Ni > Mn > Pb > Cr > Cu > Cd > Fe during the dry season, and Fe > Cr > Cu > Pb > Ni > Cd > Mn during the wet season. Using the Contamination Factor (CF), the soils were classified to be moderately contaminated with Cd and Fe to very high contamination with other metals during the dry season and low Cd contamination (0.87), moderate contamination with Fe, Pb, Mn and Ni and very high contamination with Cr and Cu during the wet season. At both seasons, the Pollution Load Index (PLI) indicates the soils to be generally polluted with heavy metals and the Geoaccumulation Index (Igeo) calculated shown the soils to be in unpolluted to moderately polluted levels. Enrichment Factor (EF) implied the soils to be deficiently enriched with all the heavy metals except Cr (7.90) and Cu (6.42) that were at significantly enrichment levels during the wet season. Modified Degree of Contamination (mCd) recorded, indicated the soils to be of very high to extremely high degree of contamination during the dry season and moderate degree of contamination during the wet season except 0 m with high degree of contamination. The concentration of heavy metals in the soils combined with some of the pollution indices indicated the soils in and around the Ilokun Dumpsite are being polluted with heavy metals from anthropogenic sources constituted by the indiscriminate refuse dumping.




References:
[1] O. S. Adefemi and E. E. Awokunmi, “The impact of municipal solid waste disposal in Ado Ekiti metropolis, Ekiti State, Nigeria,” African Journal of Environmental Science and Technology, vol. 3(8), pp. 186-191, 2009.
[2] I. A. Ololade, “An assessment of heavy metal contamination in soils within auto-mechanic workshops using enrichment and contamination factors with geoaccumulation indexes,” Journal of Environmental Protection, vol. 5, pp. 970-982, 2014. http://dx.doi.org/10.4236/jep.2014.511098
[3] I. G. J. Zwolsman, W. G. Berger and M. T. G. Vaneck, “Sediment accumulation rates. Historical input, post depositional mobility and retention of major elements and trace metals in salt marsh sediments of the Scheldt Estuary, SW Netherlands,” Marine Chemistry, vol. 44, pp. 73-94, 1993. http://dx.doi.org/10.1016/0304-4203(93)90007-B.
[4] H. D. Loring and, R. Rantala “Manual for geochemical analyses of marine sediments and suspended particulate matter,” Earth-Science Review, vol. 32, pp. 235-283, 1992. http://dx.doi.org/10.1016/0012-8252(92)90001-A
[5] L. F. H. Niencheskil, L. H. Windom and R. Smith, “Distribution of particulate trace metal in Patos Lagoon Estuary (Brazil),” Marine Pollution Bulletin, vol. 28, pp. 96-102, 1994. http://dx.doi.org/10.1016/0025-326X(94)90545-2.
[6] P. Razos and A. Christides, “An investigation on heavy metals in an industrial area in Greece,” International Journal of Environmental Resources, vol. 4, no. 4, pp. 785-794, 2010.
[7] J. R. Okalebo, K. W. Gathua and, P. L. Woomer, “Laboratory methods of soil and plant analysis: A working manual,” 1993.
[8] A. S. Likuku, K. B. Mmolawa, G. K Gaboutloeloe, “Assessment of heavy metal enrichment and degree of contamination around the copper-nickel mine in the Selebi Phikwe Region, Eastern Botswana,” Environment and Ecology Research, vol. 1(2), pp. 32-40, 2013.
[9] L. Håkanson, “Ecological risk index for aquatic pollution control. A sedimentological approach,” Water Research, vol. 14, pp. 975–1001, 1980.
[10] D. L. Tomlinson, J. G. Wilson, C. R. Harris and D. W. Jeffrey, “Problem in the assessment of heavy metals levels in estuaries and the formation of a pollution index,” Helgoländer Meeresuntersuchungen, vol. 33, pp. 566–575, 1980.
[11] U. Usero, A. Garcia and J. Fraidias, “Calidad de lasaguasysedimentos del LitoralAndalaz,” In: Sevilla, Ed. Jun ta de Andalicia, Consejeria del Medio Ambiente, 164, 2000.
[12] F. Cabrera, L. Clemente, E. Diaz Barrientos, R. Lopez and J. M. Murrilo, “Heavy metal pollution of soils affected by the Guadiamar toxic flood,” Science of the Total Environment, vol. 242, pp. 117-129, 1999.
[13] W. H. Liu, J. Z. Zhao, Z. Y. Ouyang, L. Soderlund and G. H. Liu, “Impacts of sewage irrigation on heavy metal distribution and contamination in Beijing, China,” Environmental International, vol. 31, pp. 805-812, 2005.
[14] G. M. S. Abrahim, “Holocene sediments of Tamaki Estuary: Characterization and impact of recent human activity on an urban estuary in Auckland, New Zealand,” PhD Thesis, University of Auckland, Auckland (New Zealand), 2005, p. 361.
[15] P. Adamo, M. Arienzo, M. Imperato, D. Naimo, G. Nardi and D. Stanzione, “Distribution and partition of heavy metals in surface and subsurface sediments of Naples City Port,” Chemosphere, vol. 61, pp. 800-809, 2005.
[16] J. Valdes, G. Vargas, A. Sifeddine, L. Ortlieb and M. Guinez, “Distribution and enrichment of heavy metals in Mejillones bay (23 S), Northern Chile: Geochemical and statistical approach,” Marine Pollution Bulletin, vol. 50, pp. 1558-1568, 2005.
[17] G. A. Birth, “A scheme for assessing human impacts on coastal aquatic environments using sediments,” C. D. Woodcoffe and R. A., Furness, Eds., Coastal GIS 2003, Wollongong University Papers in Centre for Maritime Policy, 14, 2003, Wollongong.
[18] R. A. Sutherland, C. A. Tolosa, F. M. G. Tack and M. G. Verloo, “Characterization of selected element concentration and enrichment ratios in background and anthropogenically impacted roadside areas,” Archives of Environmental Contamination and Toxicology, 38: 428–438, 2000.
[19] P. Buat-Menard and R. Chesselet, “Variable influence of atmospheric flux on the trace metal chemistry of oceanic suspended matter,” Earth and Planetary Science Letters, No.42, pp. 398–411, 1979.
[20] K. Loska, D. Wiechula, B. Barska, E. Cebula and A. Chojnecka, “Assessment of arsenic enrichment of cultivated soils in Southern Poland,” Polish Journal of Environmental Studies, vol. 12, pp. 187-192, 2003.
[21] M. Kargar, N. A. Khorasani, M. Karami, G. H. Rafiee and R. Naseh, “An investigation on As, Cd, Mo and Cu contents of soils surrounding the Meyduk tailing dam,” International Journal of Environmental Research, vol. 6, no. 1, pp. 173-184, 2012.
[22] G. Muller “Index of geoaccumulation in the sediments of the Rhine River,” Geojournal, vol. 2, pp. 108-118, 1969.
[23] K. Loska, J. Cebula, J. Pelezar, D. Wiechula and J. Kwapulinski, “Use of enrichment and contamination factors together with geoaccumulation indexes to evaluate the content of Cd, Cu, and Ni in the Rybnik Water Reservoir in Poland,” Water, Air and Soil Pollution, vol. 93, pp. 347-365, 1997.
[24] G. Muller, “Die Schwermetallbelstung der sediment des Neckars und seiner Nebenflusse: EineBestandsaufnahme,” ChemikerZeitung, vol. 105, pp. 156-164.
[25] Department of Petroleum Resources, “Environmental guidelines and standards for the petroleum industry in Nigeria (revised edition),” Department of Petroleum Resources, Ministry of Petroleum and National Resources, Abuja, Nigeria, 2002.
[26] E. U. Etim and G. U. Adie, “Assessment of toxic heavy metal loading in topsoil samples within the vicinity of a limestone quarry in South Western Nigeria,” African Journal of Environmental Science and Technology, vol. 6, no. 8, pp. 322-330, 2012.
[27] R. Charlatchka and P. Cambier, “Influence of reducing conditions on solubility of trace metals in contaminated soil,” Journal of Water, Air and Soil Pollution, vol. 118, pp. 43-168, 2002.
[28] E. O. Adaikpoh, “Distribution and enrichment of heavy metals in soils from waste dump sites within Imoru and environs, Southwest, Nigeria,” Journal of Environment and Earth Science, vol. 3, pp. 45-54, 2013.
[29] S. Yufang, C. Ying, P. Wu and Y. Yibin, “Health risk assessment of heavy metals in vegetables grown around battery production area,” Scientia Agricola, vol. 71, no. 2, pp. 126-132, 2014.