Environmental health impacts and controlling measures of anthropogenic activities on groundwater quality in Southwestern Nigeria.

Groundwater is the major source of drinking water in virtually all the regions of Nigeria, including the southwestern region. It is an indispensable source of drinking water that many individuals are dependent upon for daily activities in Nigeria. However, the spontaneous rise in various forms of industrialization and other anthropogenic activities of man within the southwestern region has immensely polluted these water sources. This calls for tremendous and actionable concern because of the health implications associated with the intake of contaminated water. This study aims to thoroughly disentangle the major impacts of anthropogenic activities on the quality of groundwater in the southwestern region of Nigeria through extensive reviews of literature and conceptualization of scientific and research data on the field. Unlike previous reviews, the major sources of groundwater pollution in the region were discussed extensively to set the tone for the x-raying of the subject. The study also showed major long-standing pollution cases in the region with graphical, tabular, and pictorial illustrations of some of the groundwater parameters and at the same time proposed controlling measures to enable eidetic understanding of the concepts and contribution to knowledge. In the last part of the work, we recommend improving the existing groundwater assessment techniques in Southwestern Nigeria. Regular monitoring of groundwater in Nigeria should also be encouraged to establish its quality status.

Evaluating quality of soils formed on basement complex rocks in Kaduna State, northern Guinea savanna of Nigeria.

A few investigations have been done regarding the soil quality index (SQI) for various locations, soil types, and states. Still, little has been reported regarding SQI for both surface and control sections, especially for the Northern Guinea Savanna of Nigeria. Due to the subsurface property pedogenic influence on soil function, it is crucial to assess SQI using surface and subsurface properties as both properties influence soil productivity. We investigated the potentials of choosing a minimum data set for soil quality indicators and assess soil quality (SQ), using both surface and entire soil pedon data for the soils on the basement complexes. Both additive and weighted soil quality indices and different scoring methods (linear and non-linear) were used in evaluating SQ. Out of the twenty-three soil properties subjected to PCA, eight indicators (TEB, clay, silt, K, EA, EC, BD, and Fe) were selected as the minimum data set (MDS). There was not much difference in the calculated soil quality using the non-linear additive (SQI-NLA), linear additive (SQI-LA), linear weighted (SQI-LW), and non-linear weighted (SQI-NLW) for the soils as they were all rated low (SQI < 0.55). The estimated SQI for the control section had relatively higher values than the surface soil, thus suggesting the need to incorporate both surface and entire soil profile properties in assessing SQ as both are important in integrating the relationship between soil properties and management goals which eventually provides complete information that affects the production of crops.

Variation of soil properties under different landscape positions and land use in Hunkuyi, Northern Guinea savanna of Nigeria.

The food insecurity problem in developing countries has been linked to rapid rates of soil loss and decline in fertility in tropical environments which are characterized by insidious topography. This study was conducted to assess the relationship between topographic positions, land use, and soil characteristics. Three slope classes were considered with six pedons; two on each slope position were opened, described, sampled, and analysed for morphological and physicochemical properties. The results showed that the soils were deep to very deep with drainage improving from HK1 soils (very poorly drained) to HK3 (well-drained). The mean sand fraction ranged between 320 and 740 g kg-1, while bulk density had values between 1.20 and 1.80 M gm-3. The cation exchange capacity (CEC) of the soils with values from 5.6 to 10.4 cmol (+) kg-1 was generally lower on the surface than the subsurface soils. The different landscape positions alongside variation in land use substantially influence variations in soil properties of the study area. The influence of topography was noticed for sand values and soil reaction (pH) along the slope, as mean pH values were significantly (P ≤ 0.05) higher for HK1 compared with HK2 and HK3. Intensive cultivation of soils due to rainfed and irrigated land use on middle slope position (HK2) alongside its strong slope gradient resulted in significant variation in total exchangeable bases (TEB) ((P ≤ 0.05), base saturation (P ≤ 0.05), available P ((P ≤ 0.01), and exchangeable Ca and Mg (P ≤ 0.05).

Effects of industrialization on groundwater quality in Shagamu and Ota industrial areas of Ogun state, Nigeria.

In recent years, there has been an increasing ecological and global public health concern associated with environmental contamination by heavy metals on groundwater resources especially in the developing countries. Hence, this study assessed the impacts of industrialization on the quality of groundwater in Shagamu and Ota industrial areas of Ogun State, Nigeria between the period of July and December 2018, covering both wet and dry season. A total of 80 samples was collected from the industrial areas while a total of four control samples was also collected from the residential areas of the study locations across both wet and dry season using a random sampling technique. The water samples were then analyzed in the laboratory for their physico-chemical parameters (using standard procedures) and heavy metals using the Atomic Absorption Spectrophotometer (AAS). The results were evaluated for descriptive and inferential statistics using SPSS for Windows version 20.0. The mean range of values for the measured parameters was: pH (4.35-9.42), EC (18.50-684.0 µScm-1), hardness (3.83-396.06 mg/L), Ca2+ (0.18-138.75 mg/L) and that of heavy metals concentrations in the water sample were: Pb (0.003-0.199 mg/L), Cd (0.002-0.013 mg/L), Ni (0.004-0.259 mg/L), Cr (0.002-0.54 mg/L), Mn (0.015-1.940 mg/L), Fe (0.02-2.01 mg/L), Cu (0.012-0.72 mg/L), Zn (0.004-0.500 mg/L). A comparison of the obtained results with the World Health Organization standards (for drinking water) revealed that the levels of pH, Ca, Pb, Ni, Mn, Fe, Cd, and Cr were higher than the prescribed values. It was observed that groundwater sources for the dry season in both Ota and Shagamu have higher heavy metal concentrations that are above the permissible limits than the wet season, implying that more industrial activities were probably conducted during the dry season under the sampling period. The result of the heavy metals was in the magnitude according to the trend Fe > Mn > Cu > Cr > Zn > Ni > Pb > Cd. This study revealed that these industrialized areas contained high concentrations of heavy metals which can cause health disorders and behavioral defects. Thus, the water in the study locations is not suitable for consumption without prior treatment. It is therefore, recommends that the water in the study locations should be treated before were used for various domestic purposes, and the construction of the boreholes and dug wells are proposed here to follow proper siting regulations.