Abdu N, Abdulkadir A, Agbenin JO, Buerkert A (2011). Vertical distribution of heavy metals in waste water irrigated vegetable garden soils of three West African cities. Nutr. Cycl. Agroecosyst. 89:387-397.
Crossref

Abdu N (2010). Availability, transfer and balances of heavy metals in urban agriculture of West Africa. (Unpublished doctoral dissertation). Faculty of Organic Agricultural Sciences, University of Kassel, Germany.

Abdulkareem JH, Abdulahi AA, Audu M (2012). An assessment of physico-chemical properties of soils in selected vegetable farms around Sokoto metropolis. Niger. J. Soil Environ. Sci. 10:84-88.

Abdullahi AS (1997). The fertility status of soils along the microtopography of the river Galma fadama at Zaria. (Masters Thesis Department of Soil Science, Ahmadu Bello University, Zaria.

Agbenin JO (2002). Lead in Nigerian savanna soils under long-term cultivation. Sci. Total Environ. 286:1-14.
Crossref

Agbenin JO, Latifatu AO (2004). Competitive adsorption of copper and zinc by a Bt horizon of a savanna Alfisol as influenced by pH and selective removal of hydrous oxides and organic matter. Geoderma 119:85-95.
Crossref

Anderson JM, Ingram JS (1993). Tropical soils biology fertility. A handbook of methods (2nd ed.), Information Press, UK. P 221.

Alloway BJ (1995). The origin of heavy metals in soils. In: Alloway, B. J. (ed.), Heavy Metals in Soils (2nd edn). Blackie Academic and Professional, London, UK. pp. 29-39.
Crossref

Devis J, Freitas F (1970). Physical and Chemical Methods of Soil and Water Analysis. Soil Bulletin No. 10 Food and Agricultural Orgnization (FAO) Rome.

Dooyema C, Neri A, Lo Y-C, Durant J, Dargan PI, Swarthout T (2012). Outbreak of fatal childhood lead poisoning related to artisanal gold mining in northwestern Nigeria, 2010. Environ. Health Perspect. 120(4):601-607.
Crossref

Esu IE (1987). A pedological characterization of soils of the Hadejia alluvial complex in semi-arid region of Nigeria. Pedologie 39:171-190.

Gee GW, Bouder JW (1986). Particle Size Analysis in Aklate (ed.) Methods of Soil Analysis 2nd ed. No. 9 ASA Inc SSA Madison, Washington D. C. pp. 383-409.

Gimmler H, Carandang J, Boots A, Reisberg E, Woitke M (2002): Heavy metal content and distribution within a woody plant during and after seven years continuous growth on municipal solid waste (MSW) bottom slag rich in heavy metals. Appl. Bot. 76:203-217.

Gothberg A, Greger M, Holm K, Bengtsson B (2004). Influence of nutrients on uptake and effects of Hg, Cd and Pb in Ipo-moea aquatica. J. Environ. Qual. 33:1247-1255.
Pubmed

Jones MJ, Wild A (1975). Soils of the West African savanna. Commonwealth Bureau of Soils, Harpenden Technical Committee 55:246.

Kabata-Pendias A, Pendias H (1992). Trace Elements in Soils and Plants (2nd edn) Boca Raton, FL: CRC Press.

Kparmwang T (1993). Characterization and classification of basaltic soils in the northern guinea savanna zone of Nigeria. Doctoral Dissertation, Department of Soil Science, Ahmadu Bello University, Zaria.

Lal R, Shukla LK (2004). Principles of soil physics. Print edition. Marcel Dekker Inc, New York pp. 434-499.

Li Z, Shuman LM (1996). Heavy Metals movement in metal contaminated soil profiles. Soil Sci. 161:656-666.
Crossref

Lim CH, Jackson ML (1986). Expandable phyllosilicate reactions with lithium on heating. Clay. Clay Mineral. 34:346-352.
Crossref

Lo YC, Carrie AD, Antonio N, James D, Taran J, Andrew M-M, Lori de R, Douglas T, Lora D, Raymond SD, Matthias YS, Luka MI, Ossai O, Nasir TU, Alhassan HD, Mary JB (2012). Childhood lead poisoning associated with gold ore processing: a village-level investigation-Zamfara State, Nigeria, October-November 2010. Environ. Health Perspect. 120:1450-1455
Crossref

Malgwi WB (2001). Characterization of salt affected soils in some selected location in the North Western zone of Nigeria. Doctoral Dissertation, Department of Soil Science, Ahmadu Bello University, Zaria.

Maniyunda LM (1999). Pedogenesis on loess and basement complex rocks in a subhumid environment of Nigeria and the suitability of the lands for rainfed cultivation. Doctoral dissertation, Department of Soil Science, Ahmadu Bello University, Zaria.

Mohammed I, Abdu N (2013). Horizontal and vertical distribution of Pb, Cd, and Zn in farmlands around a Pb contaminated goldmine. Arch. Environ. Contam. Toxicol. 66(2):295-302.
Crossref

Mosugu ME (1989). A bio-climosequence study of upland soils developed on older granites in Nigeria. Masters dissertation, Department of Soil Science, Ahmadu Bello University, Zaria.

Médecins sans Frontières (MSF) (2012). Lead poisoning crisis in Zamfara State, Northern Nigeria. Available at: http://www.doctorswithoutborders.org/news-stories/briefing-document/lead-poisoning-crisis-zamfara-state-northern-niger

Nabulo G (2006). Assessment of heavy metal contamination of food crops and vegetables grown in and around Kampala city, Uganda. Ph.D. Dissertation, Makerere University.

Nelson DW, Sommers LE (1982). Total carbon, organic carbon and organic matter. pp. 530-577. In: A. L. Page et al., (ed.) Methods of Soil Analysis. Part 2. 2nd ed. Monograph 9 ASA and SSSA Madison, W.

National Population Commission (NPC) (2006). National population and housing census. Available at: View

Ogunwole JO, Ogunleye PO (2005). Influence of long term application of organic and mineral fertilizers on quality of savanna Alfisols. J. Sustain. Agric. 26(3):5-14.
Crossref

Plumlee GS, James TD, Suzette AM, Antonio N, Ruth EW, Carrie AD, Philip LH, Heather AL, Gregory LF, Gregory PM, William MB, Rhonda LD, Cyrus JB, James GC, Harland LG, Monique A, Casey LB, Simba T, Behrooz B, Ian von L, Mary JB (2013). Linking Geological and Health Sciences to Assess Childhood Lead Poisoning from Artisanal Gold Mining in Nigeria. Environ. Health Persp. 121(6):744-750.
Crossref

Sai KR, Satish KYS, Srinivas P (2013). Characterization, classification and evaluation of Chilli growing soils of Khammam District, Andhra Pradesh. Int. J. Innov. Res. Dev. 2(9):26-33.

Shobayo AB (2010). A lithoseqeuence of soils developed on basement complex rocks of Zaria, the Northern guinea savanna, Nigeria. Masters dissertation, Department of Soil Science, Ahmadu Bello University, Zaria.

Šimůnek J, Sejna M, van Genuchten,MT, Sejena M (2006). The HYDRUS software package for simulating the two and three-dimensional movement of water, heat and multiple solutes in variably-saturated media. Version 1.0. Technical manual PC progress, Prague, Czech Republic.

Soil Survey Staff (1993). Soil Survey Manual. Soil Conservation Service. United State Department of Agriculture (USDA). Handbook No. 18. 2nd ed. United State Government printing office, Washington, DC.

Tisdale S, Nelson W (1975). Soil fertility and fertilizers (3rd ed.). Macmillan publishing company Inc. New York. P. 265.

UNEP/OCHA (United Nations Environment Programme/Office for the Coordination of Humanitarian Affairs) (2010). Lead Pollution and Poisoning Crisis, Environmental Emergency Response Mission, Zamfara State, Nigeria, September/October 2010. Available at: View.

United States Environmental Protection Agency (USEPA) (2004). Estimation of relative bioavailabity of lead in soil and soil-like materials using in vivo and in vitro methods. OSWER-9285.7-77, Washington, DC.

United Nation Children Fund (UNICEF) (2011). Environmental Remediation-Lead Poisoning in Zamfara. Final Report. Available at: View

von Lindern IH, von Braun MC, Tirima S, Bartrem C (2011). Zamfara, Nigeria Lead Poisoning Epidemic Emergency Environmental Response, May 2010–March 2011, Final Report to the United Nations Childrens Fund (UNICEF). Available at: View

World Health Organization (WHO) (2010). Global Alert and Response (GAR). Nigeria: mass lead poisoning from mining activities, Zamfara state. Available at: View

Wuddivira HN (1998). Variability of infiltration in a savanna Alfisol. Masters Thesis, Department of Soil Science, Ahmadu Bello University, Zaria.

Yaro DT, Kparmwang T, Aliyu SM, Wudivira HN, Tarfa BD (2002). Status of Diethylene triamine penta acetic (DTPA) and hydrochloric (HCl) extractable cationic micronutrients in soils of the long term DNPK plot at Samaru Zaria. Niger. J. Soil Res. 3:27-32.

Zarafi GS (1993). Morphological, physicochemical and mineralogical properties of hydromorphic soils in the Zaria region. Masters Dissertation, Department of Soil Science, Ahmadu Bello University, Zaria.