Ecological Risk Assessment and Pollution Models of Trace Metal Concentrations in Road Dust in parts of Enugu, Southeastern Nigeria

Document Type : Original Article


1 Materials and Energy Technology Department, Projects Development Institute (PRODA), P.M.B.01609, Enugu, Nigeria

2 Faculty of Natural and Applied Sciences, Coal City University, Enugu, Enugu State Nigeria

3 Department of Geology, Federal University of Technology P.M.B.1526, Owerri, Imo State Nigeria

4 Department of Chemistry, Imo State University, P.M.B 2000 Owerri, Imo State Nigeria


Trace metal levels in road deposited sediments (RDS) from paved roads in Enugu metropolis, southeastern Nigeria were evaluated. The study aimed at determining the level of heavy metals in the RDS, with the objectives of identifying the sources of these pollutants in the environment.  Thirty-two (32) RDS samples from 10 selected major roads in Enugu were collected for this study. The concentration of Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb was analyzed using a flame atomic absorption spectrophotometer. The levels of physicochemical properties; pH, electrical conductivity (EC), total organic matter (TOM), and total organic carbon (TOC) was also established using standard procedures. The metal concentrations (mg/kg) were in the range; Cr (0.67 - 3.67), Mn (2.33 - 7.67), Fe (408.33 - 512.33), Co (3.00 - 61.75), Ni (39.67 - 193.67), Cu (11.50 - 90.00), Zn (1.00 - 31.67), Cd (0.00 - 1.33), and Pb (0.00 - 46.67). The pH, EC, TOC and TOM of the RDS samples range between 6.75-8.39, 556 - 578.67 μS/cm, 0.43 % - 3.49 % and 1.27 % - 10.35 % respectively. The relationships between the parameters were ascertained with correlation analysis. The likely source of these metals was recognized with principal component analysis and hierarchical cluster analysis, deployed to identify the potential source of these metals in the RDS. The results suggested that Mn concentrations did not exceed the crustal level. However, elevated Pb and Cd levels were recorded in the RDS samples. The models showed good consistency, indicating average to considerable levels of contamination of most parts of the studied major roads. PCA result revealed that metals in the RDS originated from three main sources which include the crustal, vehicular, and industrial sources.


1. Hopke P.K., Lamb R.E., Natusch F.S., 1980. Multi-elemental characterization of urban roadway
dust. Environmental Science and Technology. 14, 164-172.
2. Beckwith P.R., Ellis J.B., Revitt D.M., 1986. Heavy metal and magnetic relationships for urban source sediments. Physics of the Earth and Planetary Interiors. 42, 67-75.
3. Xie S., Dearing J., Bloemendal J., Boyle J., 1999. Association between the organic matter content and magnetic properties in street dust. Liverpool, UK. The Science of the Total Environment. 241, 205-214.
4. Lecoanet H., Leveque F., Ambrosi J.P., 2003. Combination of magnetic parameters: an efficient way to discriminate soil-contamination sources (south France). Environmental Pollution. 122, 229-234.
5. Robertson D.J., Taylor K.G., Hoon S.R., 2003. Geochemical and mineral magnetic characterization of urban sediment particulates. Manchester, UK. Applied Geochemistry. 18, 269-282.
6. Li X., Zhang S., Yang M., 2014. Accumulation and risk assessment of heavy metals in dust in main living areas of Guiyang City, Southwest China. China. J Geochem. 33, 272–276.
7. Ibe F.C., Opara A.I., Ibe B.O., Adindu B.C., Ichu B.C., 2018. Environmental and health implications of trace metal concentrations in street dusts around some electronic repair workshops in Owerri, Southeastern Nigeria, Environ Monit Assess. 190(696), 1 – 12.
8. Yisa J., 2010. Heavy metal contamination of road-deposited sediments. American Journal of Applied Sciences. 7(9), 1231 – 1236.
9. Sezife T., Senol K., Gokhan B., 2013. Comparison of three sequential extraction procedures for portioning of heavy metals in car park dust. Journal of Environmental Monitoring. 5, 468 – 476.
10. Ibe F.C., Ibe B.O.,  Enyoh C.E., 2019. Trace metal, FTIR and phytochemical analysis of Viscum album leaves harvested from Pentaclethra macrophylla, World News of Natural Sciences. 25, 61-71.
11. De Miguel E., Llamas J.F., Chacon E., Berg T., Larssen S., Royset O., Vadset  M.,1997. Origin and patterns of distribution of trace elements in street dust: Unleaded petrol and urban lead. Atmospheric Environment. 31(17), 2733–2740.
12. Li X.D., Poon C.S., Liu P.S., 2001. Heavy metal contamination of urban soils and street dust in Hong Kong. Applied Geochemistry. 16, 1361–1368.
13. Charlesworth S., Everett M., McCarthy R., Ordonez A., De Miguel E., 2003. A comparative study of heavy metal concentration and distribution in deposited street dust in a large and a small urban area: Birmingham and Coventry, West Midlands, UK. Environment International. 29, 563–573.
14. Imperator M., Adamo P., Naimo D., Arienzo M., Stanzione D., Violante P., 2003. Spatial distribution of heavy metals in urban soil of Naples city (Italy). Environmental Pollution. 124, 247–256.
15. Sezgin N., Ozcan H.K., Demir G., Nemlioglu S., Bayat C., 2003. Determination of heavy metal concentrations in street dust in Istanbul E-5 highway. Environment International. 29, 979–985.
16. Leung A.O.W., Nduzgoren - Aydin N., Cheung K.C., Wong M.H., 2008. Heavy metals concentrations of surface dust from e-waste recycling and its human health implications in Southeast China. Environmental Science and Technology. 42(7), 2674–2680.
17. Herngren L., Goonetilleke A., Ayoko G.A., 2006. Analysis of heavy metals in road-deposited sediments. Analytica Chimica Acta. 571, 270–278.
18. Manno E., Varrica D., Dongarra G., 2006. Metal distribution in road dust samples collected in an urban area close to a petrochemical plant at Gela, Sicily. Atmospheric Environment. 40, 5929–5941.
19. Odewande A.O., Abimbola A.F., 2008. Concentration indices and heavy metal concentrations in Urban soil of Ibadan metropolis, Southwestern Nigeria. Environ Geochem Health. 30, 243–254.
20. Jonathan Y., John O.J., Onoyima C.C., 2012. Assessment of toxic levels of some heavy metals in road deposited sediments in Suleja, Nigeria. American Journal of Chemistry. 2(2), 34-37.
21. Asowata I.T., Abimbola A.F., Olatunji A.S., 2014. Geochemical evaluation of soils and road deposited sediments of Benin City using GIS and multi-variance approaches.British Journal of Applied Science and Technology. 4(18), 2590-2606.
22. Adaramodu A.A., Osuntogun A.O.,  Ehi-Eromosele C.O., 2012. Heavy metal concentration of surface dust present in e-waste components: The Westminister electronic market, Lagos case study. Resources and Environment. 2(2), 9–13.
23. Akhionbare S.M.O., 2011. Multivariate statistical analysis of heavy metals in street dust of Owerri metropolis, Nigeria. Int’l J Sci and Nat. 2(3), 844-849.               
24. Barminas J.T., Shinggu D.Y. Ogugbuaja V.O., Toma I., 2007. Analysis of street dust for heavy metal in Mubi, Adamawa State, Nigeria. International Journal of Physical Sciences. 2(11), 290-293.
25. Ekere N.R., Ukoha O.P., 2013. Heavy metals in street soil dust of the industrial market in Enugu, South East, Nigeria. International Journal of Physical Sciences. 8(4), 175-178.
26. FRN, 2006. Federal Republic of Nigeria Official Gazette, Legal Notice on publication of the details of the Breakdown of the National and State Provisional total, 2006 Census. Federal Republic of Nigeria Official Gazette, Government Notice No. 21, Lagos, 15th May 2007, Vol. 94, pp 1-26
27. Uma K.O., Oteze G.E., 1999. Urban growth and pollution of shallow laterized clay aquifers: A case study from Enugu city, Nigeria. Proceedings of xxix IAH Congress, Bratislava. 545-552.
28. Enete I.C., Alabi M.O., 2012. Observed urban heat Island Characteristics in Enugu urban during the dry season. Global Journal of Human Social Science Geography and Environmental Geosciences. 12(10), Version 1.0, 73 – 80.
29. Walkley A.,  Black I.A., 1934. An examination of the Degtjareff method for determining soil organic matter and a proposed modification of the chromic acid titration method. Soil Sci. 37, 29-37.
30. Kaiser H.F., 1960. The application of electronic computers to factor analysis. Educ Psychol Meas. 20, 141-151.
31. Lu X., Wang L., Lei K., Huang J.,  Zhai Y., 2009. Contamination assessment of copper, lead, zinc, manganese, and nickel in street dust of Baoji, NW China. J Hazardous Mat. 161, 1058-1062.
32. Lu X., Wanga L., Li L.Y., Lei K., Huang L., Kang D., 2010. Multivariate statistical analysis of heavy metals in street dust of Baoji, NW China. J. Hazardous Mat. 173, 744-749.
33. Gowd S.S., Reddy M.R., Govil P.K., 2010. Assessment of heavy metal contamination in soils at Jajmau (Kanpur) and Unnao industrial areas of the Ganga Plain, Uttar Pradesh, India. J Hazardous Mat. 174, 113-121.
34. Taylor S.R., 1964. Abundance of chemical elements in the continental crust: a new table. Geochimica et Cosmochimica Acta. 28, 1273 - 1285
35. Muller G., 1969. Index of geo-accumulation in sediments of Rhine River. Geochemical Journal. 2, 108 – 118.
36. Kartal S., Aydin Z., Tokalioglu S., 2006. Fractionation of metals in street sediment samples by using the BCR sequential extraction procedure and multivariate statistical elucidation of the data. J Hazard Mater. 132, 80-89.
37. Rastmanesh F., Moore F., Kopaei M.K., Keshavarzi B., Behrouz M., 2010. Heavy metal enrichment of soil in Sarcheshmeh Copper Complex, Kerman Iran. Environ. Earth Sci. 62, 329-336.
38. Hakanson L.L., 1980. An ecological risk index for aquatic pollution control. A sedimentological approach. Water Research. 14(8), 975–1001.
39. NESREA 2013. National Environmental Standards and Regulations Enforcement Agency, Soil Guideline Values,  p 25.
40. Evans  L.J., Spiers G.A., Zhao G., 1995. Chemical aspects of heavy metal solubility with reference to sewage sludge-amended soils,” International Journal of Environmental and Analytical Chemistry. 59(2-4), 291-302.
41. Appleyard S., Wong S., Willis-Jones B., Angeloni J., Watkins R., 2004. Groundwater acidification caused by urban development in Pert, Western Austria: Source, distribution, and implications for management. Australian Journal of Soil Research. 42, 579 – 585.
42. Fuente D., Chico B.,  Morcillo E., 2006. The effects of soluble salts at the metal/paint interface: advances in knowledge. Port Electrochim Acta. 24, 191–206.
43. Smith S.R., Giller K.E., 1992. Effective Rhizombium leguminosarum biovar Trifolii Present in Five Soils Contaminated with Heavy Metals from Long-Term Applications of Sewage Sludge or Metal Mine Spoil. Soil Biology and Biochemistry. 24(8), 1992, 781-788.
44. Fotovat A. Naidu R., Oades J.M., 1996. The effect of major cations and ionic strength on desorption of native heavy metals in acidic and sodic soils. The 1st International Conference on Contaminants in the Soil Environment, Adelaide, pp. 193-194.
45. Ibe F.C., Ibe B.O., Ikpa C.B.C.,  Eneldoh M.C. 2016. Remediation of mild crude oil polluted freshwater wetland with organic and inorganic fertilizer. International Letters of Natural Sciences. 54, 75 – 84.
46. Eze V.C., Onwukeme V.I., Enyoh C.E., 2020. Pollution status, ecological and human health risks of heavy metals in soil from some selected active dumpsites in Southeastern, Nigeria using energy dispersive X-ray spectrometer. International Journal of Environmental Analytical Chemistry.
47. Han Y.M., Du P.X., Cao J.J.,  Posmentier E.S., 2006. Multivariate analysis of heavy metal contamination in urban dust of Xi'an, Central China. The Science of the Total Environment. 355, 176–186.
48. Meza-Figueroa D., O-Villanueva M.D.,  Parra M.L.D., 2007. Heavy metal distribution in dust from elementary schools in Hermosillo, Sonora, Mexico. Atmospheric Environment. 41, 276–288.
49. Ibe F.C., Njoku P.C., Alinnor J.I., Opara A.I., 2016. Evaluation of ambient air quality in parts of Imo state, Nigeria. Research Journal of Chemical Sciences. 6(1), 41-52.
Volume 11, Issue 2
May 2021
Pages 135-151
  • Receive Date: 29 March 2020
  • Revise Date: 29 December 2020
  • Accept Date: 03 January 2021
  • First Publish Date: 04 January 2021