ELSEVIER The Science of the Total Environment 208 (1997) l-8 Trace elements in drinking and groundwater samples in Southern Nigeria 0.1. Asubiojo”>*, N.A. Nkonoa, A.O. Ogunsuab, A.F. Oluwole”, N.I. Wardd, O.A. Akanlee, N.M. Spyrou” ‘Depar?ment of Chemistry, Obafemi Awolowo University, Ile-Ife, Nigeria, Africa bDepartment of Food Science and Technology Obafemi Awolowo University, Ile-Ife, Nigeria, Africa ‘Deprtment of Physics, Obafemi Awolowo University Ile-Ife, Nigeria, Africa Depatiment of Chemistry, University of Surrey, Guildford, Surrey, UK eDepartment of Physics, University of Surrey, Guildford, Surrey, UK 12 February 1997; accepted 11 June 1997 Abstract The levels of Al, Sn, Cs, Rb, Sr, Br, Cr, MO, Co, Ba, Cu, Zn, Cd, Pb, Mn, Se,As, V and Ni were determinedin drinking water supplies (public taps, domestic taps and treated water from public water sources) and groundwater supplies (boreholes and shallow wells) in someparts of Southern Nigeria. The water samples were analysed using inductively coupled plasma mass-spectrometry (ICP-MS). The mean levels( pg/ll of all the elements ranged between 0.35 pg/l for Cs and 87.3 pg/l for Zn in the drinking watersand between 0.54pg/l for Co and 420.3pg/l for Ba in the groundwaters.A comparison of the elemental concentrations with WHO guidelinesshowed that with the exception of violations of Cd, Cr and Se limits in some of the drinking water samples, the levels of all the other elements investigated were below the WHO maximum allowable concentrations. 0 1997 Elsevier Science B.V. Keywords: Trace elements; Drinking water; Groundwater; WHO regulations 1. Introduction The demand for potable water is on the in- crease in most communities in Nigeria. There are over 100 major and minor municipal water supply *Corresponding author. corporations. A few of these stations rely on surface waters as their source, while the majority rely on groundwater supplies. The stations that source their water from rivers supply over 70% of domestic water needs in the country particularly in the major cities in Southern Nigeria. Surface and groundwater sources are known to contain various trace elements, some of which 004%9697/97/$17.00 0 1997 Elsevier Science B.V. All rights resewed. PII SOO48-9697(97) 00178-2