Occurrence and Concentration of Heavy Metals in a Rural Spring in South-eastern Nigeria

Abstract

Water is essential for life on earth and its quality is important for health and economic development; seasons, anthropogenic influences and natural processes affect the chemical composition of water. Springs are natural outflow of water from an underground supply to the ground surface and the quality may be altered due to exposure to metallic elements. Some of these elements are essential for humans; they can be dangerous at relatively high exposure levels. The aim of this study was to assess the occurrence and concentrations of heavy metals in a rural spring and determine its suitability for human consumption. Eight (8) heavy metals (Mn, Cu, Pb, Fe, Zn, Cd, Cr and Ni) were assessed between January and June 2017 in 3 stations; using Atomic Absorption spectrometer (AAS) and compared with SON and WHO standards. pH and Electrical conductivity were also determined in association with the metals with hand-held meters. Manganese, chromium, lead, iron and cadmium exceeded acceptable limits in various percentages of the samples and could basically be attributed to geogenic source exacerbated by seasonal and anthropogenic influences. The values of lead, iron and cadmium were higher and pose serious health risk to the consumers of the spring water over time. Rural springs hitherto considered safe due to little or no anthropogenic influences have been found to be unsafe due to geogenic contamination. The spring is therefore not suitable for drinking but can used for other domestic purposes. Human health risk assessment is recommended for this spring.

Heavy metal content and health risk assessment of a South-eastern Nigeria River

“…Some of the recorded values of manganese were higher than the acceptable limits especially in Stations 1 and 2 and could be as a result of the combined effects of all the anthropogenic activities going on around Station 1 (Clark 1994) and effect of the effluent discharged upstream of Station 2. The values recorded in this study were within the range of 0.06-0.51 mg/l recorded by Anyanwu and Onyele (2018) in a rural spring in South-East, Nigeria. Manganese is an essential micronutrient in all living organisms because they act as a co-factor for many enzyme activities (Suresh .…”

“…Geological influence as well as anthropogenic activities could be responsible; especially in Stations 1 and 2. These values were lower than 0.01-0.24 mg/l recorded by Anyanwu and Onyele (2018) in a rural spring in South-East, Nigeria, and 0.01-0.65 mg/l recorded by Ekere et al (2014) in some drinking water sources also in South-East Nigeria. Cr is also an essential micronutrient for animals and plants.…”

“…In Stations 1 and 2, relatively higher values were recorded which may be due to anthropogenic activities. Lower values of 0.02-0.15 mg/l were recorded by Anyanwu and Onyele (2018) in a rural spring in South-East Nigeria, while Ekere et al (2014) recorded higher values of 0.21-2.65 mg/l in some drinking water sources also in South-East Nigeria.…”

“…Geological influence as well as anthropogenic impacts could be responsible. Anyanwu and Onyele (2018) recorded relatively higher values (0.21-0.90 mg/l) in a rural spring in South-East, Nigeria. Zn is also an essential element in the lives of animal and human beings.…”

“…The values recorded in this study were lower compared to values recorded in related studies. Ekere et al (2014) recorded values of between 0.75 and 15.01 mg/l in some drinking water sources in South-East Nigeria, while Anyanwu and Onyele (2018) recorded values of between 1.12 and 5.10 mg/l in a rural spring also in South-East Nigeria. Iron (Fe) is an indispensable metal for humans and most living organisms.…”