Heavy metals in soils along unpaved roads in south west Cameroon: Contamination levels and health risks
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Soils enriched with heavy metals from vehicular emission present a significant exposure route of heavy metals to individuals using unpaved roads. This study assessed the extent of Cd, Cr, Co, Cu, Ni, Pb and Zn contamination of soils along unpaved roads in Cameroon, and the health risks presented by incidental ingestion and dermal contact with the soils using metal contamination factor (CF) pollution load index, hazard quotients (HQ) and chronic hazard index (CHI). CF values obtained (0.9–12.2) indicate moderate to high contamination levels. HQ values for Cr, Cd and Pb exceeded the reference doses. Moderate health hazard exists for road users in the areas with intense anthropogenic activities and high average daily traffic (ADT) volume according to CHI values (1–4) obtained. The economy and quality of life in cities with unpaved roads could be threatened by health challenges resulting from long-term exposure to heavy metal derived from high ADT volumes.
KeywordsIncidental soil ingestion Vehicular emission Hazard quotients Chronic hazard index Contamination factor
The author acknowledges the assistance of Dr. L Motsei of the mineral laboratory in Animal Health Department, and Mr. L Kgosieng, Mr. KP Mogale, and Mr. OD Rapetsana of the Crop Science Department all in North West University (Mafikeng Campus) for assistance with analyses of samples and Mr. J Sakwe and Mr. Ngole EE for assistance with collection of soil samples.
- ATSDR, 2015. Toxic substances portal. Toxicological profiles. http://www.atsdr.cdc.gov/toxprofiles/index.asp. Assessed January 19 2015.
- Burningham, S., and N. Stankevich. 2005. Why road maintenance is important and how to get it done The World Bank, Washington DC Transport Note No. TRN-4 June 2005.Google Scholar
- Jaradat, Q.M., and K.A. Momani. 1999. Contamination of roadside soil, plants and air with Heavy metals in Jordan, a comparative study. Turkish Journal of Chemistry 23: 209–220.Google Scholar
- Leduc, G. 2008. Road traffic data: Collection methods and applications Guillaume Leduc working papers on energy, transport and climate change N.1 European Commission Joint Research Centre Institute for Prospective Technological Studies: 55Google Scholar
- MINEPAT, 2012. Transport Characteristics. The National Railway Master Plan Study in Cameroon 79–124.Google Scholar
- Nelson, S.C., A.T. Chen, and I.A. Dyer. 1973. Effect of chelating agents on chromium absorption in rats1. Journal of Nutrition 103: 1182–1186.Google Scholar
- Nouri, J., and K.D. Naghipour. 2002. Qualitative and quantitative study of heavy metals in runoff of highways of Tehran. Iranian Journal of Public Heallth 31: 1–8.Google Scholar
- Ogunkunle, C.O., P.O. Fatoba, O.M. Ogunkunla, and A.A. Oyedeji. 2013. Potential health risk assessment for soil heavy metal contamination of Sagamu South-West Nigeria due to cement production. International Journal of Applied Science and Technology 3: 89–96.Google Scholar
- Qu, C.-S., Z.-W. Ma, J. Yang, Y. Liu, J. Bi, and L. Huang. 2012. Human exposure pathways of heavy metals in a lead-zinc mining area, Jiangsu Province, China. PlosOne 7: 1–11.Google Scholar
- Raj, S.P., and P.A. Ram. 2013. Determination and contamination assessment of Pb, Cd, and Hg in roadside dust along Kathmandu-Bhaktapur road section of Arniko Highway, Nepal. Research Journal of the Chemical Sciences 3: 18–25.Google Scholar
- Sialelli, J., G.J. Urquhart, C.M. Davidson, and A.S. Hursthouse. 2010. Use of a physiologically based extraction test to estimate the human bioaccessibility of potentially toxic elements in urban soils from the city of Glasgow, UK. Environmental Geochemistry and Health 32: 517–527.CrossRefGoogle Scholar
- USEPA. 1989. Exposure factors handbook. Washington, D. C.: Environmental Protection Agency.Google Scholar
- USEPA, 2010. Risk assessment guidance for superfund Volume I. Human health evaluation manual (Part A). EPA 540-1-89-002, Office of Emergency and Remedial Response, United States Environmental Protection Agency, Washington, DC.Google Scholar
- USEPA, 2011. Exposure factors handbook: 2011 Edition. National Center for Environmental Assessment, Washington, DC; EPA/600/R-09/052F. National Technical Information Service, Springfield, VA, and online at http://www.epa.gov/ncea/efh.
- Van Reeuwijk, L. P. 2002. Procedures for soil analysis. International soil reference and information centre. ISRIC Technical paper, No. 9: 19Google Scholar
- Walsh, M. P. 2004. Motor vehicle pollution control—Lessons learned over the past 50 years. Motor vehicle emission control workshop December 11–14, 2004, Hong Kong.Google Scholar
- World Bank Rural Transport Thematic Group. 2003. Rural transport in multi sectoral and community driven projects. Washington, DC: World Bank.Google Scholar