World Health Organization Permissible Limits Research Articles

Effects of landfill leachate on groundwater and its suitability for use

Landfill leachate is a noxious liquid with the potential to pollute groundwater resources following its horizontal and vertical mobilization from unsaturated to saturated zones. In this study, the characteristics of leachate from Roundhill landfill of South Africa were assayed using physicochemical analysis. Areal groundwater was sampled to assess the pollution capacity of leachate to the resource and the possibility of using it. Results showed that leachate had elevated levels of electrical conductivity, dissolved solids, cations and anions compared to the predefined standards by World Health Organization (WHO) and South African National Standards (SANS) for drinking water and its pH was 4.7. It was therefore not suitable for drinking and domestic use. In BH1, Ca2+, Mg2+, Fe and F− surpassed WHO permissible limits while Fe, F− and NO3− were above SANS standards for drinking and domestic water uses. In BH2, Fe levels were beyond both the SANS and WHO permissible levels. In BH3, Na+ and Fe were beyond both reference standards while Cl− surpassed SANS permissible limits. Pollution of groundwater was associated with the characteristics of disposed solid waste at the facility, which decomposed to generate leachate that infiltrated into the resource. Sodium adsorption ratio showed a mild sodicity problem while elevated levels of Ca2+ in BH1 and Mg2+ in BH1 and BH3 pointed to hardness of the water, which impedes irrigation suitability. Frequent and extensive monitoring of areal groundwater was recommended as the movement of leachate was established to be slow and inconsistent over time.

Variation of rain water quality with storage time for different coloured storage containers

It is very important to evaluate the quality of rain water collected and stored in cisterns and storage tanks. In this study, rainwater quality analysis was carried out on samples collected from an experimental set -up at the School of Engineering and Engineering Technology of the Federal University of Technology, Akure, Nigeria. The physio-chemical and bacteriological characteristics of rainwater collected and stored using four different coloured containers under outdoor and indoor conditions were analyzed and the results compared with World Health Organization (WHO) standard for potable water. The results of the physio-chemical analysis revealed that the colour, turbidity, total dissolved solids (TDS), phosphate, sulphate, iron and copper of all the rainwater samples fell within WHO acceptable standards for potable water. The pH of the harvested rainwater of the samples ranged from 5.34 – 6.73 mg/l for the indoor stored rainwater samples and 5.28 – 6.59 mg/l for the outdoor stored samples. The pH of the water samples did not fall with WHO permissible limit of 6.5 to 8.5. The Nitrate content of the water samples also did not fall within WHO permissible limit. Similarly, the total coliform count did not conform to WHO standard for potable water. Based on the results obtained from this study, it is recommended that harvested rainwater be treated to kill contaminating microorganisms and to reduce the health risks associated with its consumption.

Investigation of heavy metal levels of clams (Egeria radiata) sold in open markets in Port Harcourt and Yenagoa, Nigeria

Due to rapid urbanization, increase in coastal population, oil and gas exploration and other array of anthropogenic activities within the Niger Delta region of which Rivers and Bayelsa states are prominent amongst others, the region has been faced with coastal water pollution. There is need therefore, to evaluate the intensity of environmental contamination of the aquatic ecosystem in this region, thus this study was conducted to investigate the heavy metal levels of Clams (Egeria radiata) sold in open markets in Port Harcourt (Rivers State) and Yenagoa (Bayelsa State). Samples were collected from three markets in Port Harcourt (Mile 1, Rumuokoro and Mile 3), and three markets as well in Yenagoa (Opolo, Swali and Tombia) respectively. The samples were collected bi-weekly for 3 months and transported to the laboratory for analysis of heavy metals (Cr, Cd and Pb) levels using standard scientific method of analysis. The analysis was done in triplicates for each sample and data obtained were subjected to statistical analysis using excel spreadsheet and statistical package for social sciences (SPSS) version 21. The results revealed that samples collected from markets in Port Harcourt had higher concentrations of heavy metal than that of Yenagoa, though, the heavy metal levels were below World Health Organisation permissible limits, except for Cadmium (Cd) that ranged from 0.54±0.002 to 0.78±0.00 mg/kg in samples collected from Port Harcourt, against 0.5 mg/kg recommended by WHO. This could be attributed to oil and gas exploration, and discharges of industrial and domestic wastes bearing cadmium, and poses serious health risks. Therefore, routine monitoring and assessment of the aquatic ecosystem will be vital to forestall further contamination.

PHYSIOCHEMICAL ASSESSMENT ON BOREHOLE WATER QUALITY IN UYO METROPOLIS

This study was undertaken to assess the physiochemical variation of borehole water (groundwater) quality in Uyo metropolis, Akwa Ibom State, Southern Nigeria. The flame atomic absorption spectrophotometry was used to analyze the level of chemical concentration in the borehole water sample whereas a physical visibility survey was used to ascertain the quality of the borehole. Groundwater using the parameter in comparison with WHO permissible limits. A total of five (5) groundwater samples were collected in triplicates from public boreholes located at IBB way, Mechanic Village, Uyo Urban, Nwaniba road and Ewet Housing Estate. The data for previous analysis was gotten from the Ministry of Science and Technology, Uyo and new analysis was conducted on recent samples gotten from the five stations. The groundwater samples were analyzed in the laboratory for their physical, chemical and microbiological characteristics. On comparing the results with standard values recommended by World Health Organization (WHO), it was discovered that most of the groundwater samples were within permissible limits with slight variation across the locations. However, the pH of the groundwater samples was not within the permissible limit of 6.50mg/l – 8.50mg/l in three different locations which are Nwaniba, Uyo Urban and Mechanic Village with pH values of 5.57, 5.14 and 5.00. Total hardness of the groundwater samples with values of 43.0 mg/l, 12.0 mg/l, 15.0 mg/l, 5.0 mg/l and 59.0 mg/l respectively. Several other parameters also got slight differences. The study found out that minimal treatment is required in the study area and recommends continuous monitoring of the groundwater supply to keep the quality in check.

Evaluation of the Pollution Status of Lagos Coastal Waters and Sediments, using Physicochemical Characteristics, Contamination Factor, Nemerow Pollution Index, Ecological Risk and Potential Ecological Risk Index

The heavy metals and physicochemical properties of Lagos coastal waters and sediments, Southwestern Nigeria were investigated in 5 stations (station 1-5), to determine their levels, distributions and pollution index. The observed ranges of physicochemical characteristics from the study area are: dissolved oxygen (DO): 2.15-11.3 mg/L; pH: 6-7.7; temperature (Temp): 28.05-29.25°C; biochemical oxygen demand (BOD): 1.6-110.1 mg/L; electrical conductivity (EC): 1.8-29.8 mS/cm; salinity (SAL): 0.02-2.05ppt; total dissolved solids (TDS): 211.8-1210.2 mg/L and total suspended solids (TSS): 12.13-117.95 mg/L. The analyzed physicochemical properties from all the stations are within the desired values for healthy marine ecosystems when compared with Federal ministry of environment (FMENV) Nigeria and World Health organization permissible limits (DO:>5 mg/L; pH:6.5-9; TEMP:<40°C; BOD: 50 mg/L; EC:900 mS/cm; TDS:1000mg/L and TSS:600 mg/L), with the exception of low DO at station 1 and station 5; and high BOD at; station 2 and station 3 respectively. The concentrations of heavy metals present in the water samples followed the sequence: Fe > Pb > Cu > Cr > Zn > Cd, and showed high values for Pb, Cd and Cr, relative to the standard permissible limits according to FMENV (Pb 0.001; Zn 50 mg/L; Cd < 0.0018; Cu 2-4 mg/L and Cr 0.02-2.0 mg/L). The calculated contamination factor (CF) in the sediment samples showed low-moderate contamination for the analyzed heavy metals (Cr, Zn, Cu and Pb), except for cadmium (Cd) that showed extremely severe contamination (CF > 6) values across the sampling stations. The calculated Nemerow pollution index (NPI) and ecological risk index (RI) showed heavily polluted (NPI > 10) values and very high ecological risk (RI > 380) values at Apapa (location 1), Iddo (location 2) and Makoko (location 3). The potential ecological risk factor (Eir) confirmed Cd as the highest polluted heavy metals (Eir >320), with the greatest potential threat to the marine ecosystems in the Lagos coastal waters. The study highlights the impacts of anthropogenic pollutions on the coastal ecosystems and human health.

Assessment of Microbial Load in Water and Sediments of Rivers Otamiri and Nworie in Owerri, South Eastern Nigeria

Water pollution is a global problem. The study was carried out to assess the microbial constituents in water and sediment of Rivers Otamiri and Nworie during dry and rainy seasons (March and September, 2020) with comparison to WHO benchmark for drinking water .Samples were randomly collected at six (6) sampling points and analyzed using routine microbiological protocols. The results revealed detectable amount of microbial activates in surface water of both rivers during the dry and rainy season. During the rainy season, a THB bioload average of 2.02x104 and 5.1x104CFU/mL for Nworie and Otamiri river respectively were measured. For the TCC, the average was 9.8x103 and 2.5x104 CFU/mL, while in the dry period there was corresponding reduction in the bioload value for both rivers. THB average value for Nworie river was 1.34x104 CFU/mL, with corresponding 3.5x104 values for Otamiri river, while in same inclination, TCC measured 6.1x103 and 1.8x104 CFU/mL. There were noteworthy variations in the values for the two rivers as well as in the two seasons. TBC value for Otamiri measured about 1.5 folds than the value for Nworie. In same trend, TCC value for Nworie measured about 39%. All values measured were above WHO permissible limit for drinking water. The biochemical and cultural features of the isolated microorganism in water showed the presence of E. coli identified in the entire stations (100%), Salmonella and faecal coliform occurred 83.3% each, while Vibrio and Shigella were detected in 4 of the 6 stations. The mean total bacterial count, total coliform count and total E. coli, were not in conformity with World Health Organization (WHO) Standard for drinking water and thus constitute a threat to the River; these were attributed to indiscriminate waste dumps around the rivers. The study underscores the need for adequate waste management system to forestall outbreak of pathogenic diseases in the area.

Water Quality of Selected Sachet Water Brands Sold in Sango-Ota, Nigeria

Clean and safe water drinking is essential for the attainment of the United Nations sustainable development goals. The study assessed the physical and chemical parameters of ten (10) brands of sachet water sold at Sango-Ota in Ogun State, Nigeria. The physical parameters (temperature, electrical conductivity (EC), total dissolved solids (TDS), total suspended solids (TSS), power of hydrogen (pH) and turbidity) and chemical parameters ((calcium (Ca), potassium (K), copper (Cu), manganese (Mn), zinc (Zn), magnesium (Mg), iron (Fe) and chloride (Cl)) of the sachet water samples were determined. The physical parameter tests were analysed using Hanna Instruments (Model HI 98130). The compliance of the physico-chemical parameters of the samples with the drinking water standard requirements of the World Health Organisation (WHO) and Nigeria Standard Drinking Water Quality (NSDWQ) was analysed. The pH values of the samples were within the range 6.5-8.5, in conformity with the WHO and NSDWQ standard for drinking water. The electrical conductivity ranged from 0.02 - 0.06 µS/cm, falling within the permissible limit (1000 µS/cm) of WHO standard. The TDS of 0.01 - 0.03 mg/l were within the recommended permissible limit (1000mg/l) recommended by WHO. Similarly, the TDS, TSS and Turbidity were within the recommended permissible limits of the WHO. For the chemical parameters, the concentrations of K, Cu, Mn, Zn, Mg, Fe and Cl in the sachet water samples were within the WHO permissible limits of drinking water. However, some brands had their Ca concentrations above the WHO drinking water permissible limit. Generally, all the brands of sachet water samples studied were considered safe for drinking.

Noise Exposure Levels in Basic School Environments in a City in Ghana

Basic schools that are located in heavily populated residential and commercial areas in Ghana are exposed to environmental noise that can have detrimental effects on the academic attainments of children. Limited studies have been conducted on noise level in basic schools to date in Ghana. The objective of the study was to assess noise levels in and around learning spaces in basic schools in Ghana with a focus on Kumasi. A survey employing the use of interviews and an empirical monitoring of noise levels in and around learning spaces in four selected basic schools were adopted. The study revealed that mean outdoor and indoor noise levels exceed the World Health Organisation permissible limits by 30 - 40 percent and 90 - 107 percent respectively for schools in the commercial zones and schools that are located near highways. The school that is sited in an educational environment with a setback from the highway attained mean noise levels ranging from 1.2 percent below to 3.7 percent above the permissible limits for outdoor and between 64 - 105 percent for indoor. The outcome of the study is expected to engender the design of environmental noise resilient buildings to facilitate teaching and learning in basic schools in Ghana.

Health risk assessment of heavy metals in irrigated fruits and vegetables cultivated in selected farms around Kaduna metropolis, Nigeria

ABSTRACT This study assessed heavy metals levels in water, soil, fruits (banana, pawpaw) and vegetables (cucumber, cabbage and garden egg) from Bashama, Danmani and Danbushiya farms within Kaduna metropolis, Nigeria. A total of 63 samples (water (9), soil (9), fruits and vegetables (45)) were randomly collected, processed and analyzed for heavy metals using a microwave plasma atomic emission spectrometer. The heavy metal concentration in soil was found to be highest for Fe (57.30–63.51) mg/kg and the least was observed for Cu (0.45–1.45) mg/kg. High levels of Pb (0.02–0.03) mg/l, Cd (0.07–0.1) mg/l and Fe (3.23–3.42) mg/l were determined in the irrigation water exceeding the World Health Organization (WHO) standard. Some of the heavy metals (Fe, Zn and Cu) found in the various fruits and vegetables were essentials metals. Toxic metals like Pb and Cd were also present with concentrations above the World Health Organization permissible limit of 0.2 and 0.1, respectively. In the fruits and vegetables examined, the average mean concentration of metals showed significant variations with Fe having highest concentration of (7.82 mg/kg) in most of the samples from the farms. Health risk assessment of heavy metals from the fruit and vegetable samples indicated that all metals are within hazard quotient limit of less than 1 except for Cd, while for the hazard index, all the metals surpass limit of 1 which showed that the samples are likely to be of health concern. For permissible maximum tolerable daily intake in the metals studied, Cd has the highest concentration. The activities around these farms play a significant role in elevating the concentration of Cd and Pb in the fruits and vegetables a little above the WHO set standard of 0.3 mg/kg and 0.2 mg/kg, respectively. Measures to reduce the concentration of heavy metals in fruits and vegetables should be carried out in further works to avoid their health risk in human.

Evaluation of Some Heavy Metals in Selected Sea Foods Directly from the Creeks in Rivers State, Nigeria

To assess and compare the levels of arsenic, cadmium, mercury and lead, in common seafoods (mudskippers, periwinkle and Shrimp) consumed in Rivers state obtained from different creeks of Rivers State Nigeria.
 Study Design: Commonly consumed seafoods in Rivers State: Periopthalmus barbarous (mudskipper), Pandalus borealis (shrimp) and Tympanotonus fucatus (periwinkle) were collected at 5 different occasions from each of the study location (creek): Eagle Island, Iwofe, Bodo and Borokiri creeks in Rivers State. Eagle Island and Iwofe creeks are in Obio/Apkor and Degema LGA respectively, Borokiri Creek is in Port Harcourt LGA while Bodo creek is located in Gokana LGA.
 Study Area: The study was carried out in the Department of Medical Laboratory Science, Rivers State University between the periods of June, 2018 – March, 2019. Samples of seafoods were collected from Bodo, Eagle Island, Borokiri and Iwofe creeks of Rivers State for 5 times at interval of 30 days between the periods of June, 2018 – October, 2018 during the wet season.
 Methodology: Periopthalmus barbarous, Pandalus borealis, and Tympanotonus fucatus were collected from Eagle Island, Iwofe, Bodo and Borokiri creeks. The samples were correctly labeled, dried in an oven at 80°C, ground to powdered form then sieved to attain homogenous particles. Each sample was weighed, recorded and the concentrations of metals in the samples were determined. Two (2) grams each of the ground samples were weighed and put into a beaker with 6mls of nitric acid (HNO3) which was added as oxidizing acid to break the sample matrix and 2ml of perchloric acid as a reagent with 2 mls of de-ionized water was added to blend it. The sample was place on a heating mantle at 105°C until the sample volume reduced to two third of its original volume, the sample color clear and turns yellowish and its entire component was digested. The concentration of HMs: lead, arsenic, cadmium and mercury in the digested seafood samples were analysed using Atomic absorption spectrophotometer (AAS). The concentration of HMs from the sample were determined from the absorbance calibration in parts per million (ppm) or mg/kg dw.
 Results: The bio-concentration mercury and arsenic in the selected seafoods from the creeks were below the World Health Organization permissible limits while levels of cadmium and lead in the seafoods in the order of periwinkle>mudskipper>shrimp collected from these creeks were above the FAO/WHO permissible limits of 0.5 1.0 mg/kg dw and 2.0 mg/kg dw respectively.
 Conclusion: Mudskipper, periwinkle and shrimp were observed to bio-accumulate HMs beyond FAO/WHO permissible limits. Toxicities of these HMs in humans could induce several clinical derangements and eventually death if drastic measures are not put in place to stop or limit these anthropogenic activities.

The Influence of Non-Engineered Municipal Landfills on Groundwater Chemistry and Quality in Bloemfontein, South Africa.

This study assessed the groundwater quality around two municipal solid waste landfill sites, in the city of Bloemfontein, Free State Province, South Africa. The two landfill sites are located in two contrasting geological terrains, with both lacking some basic facilities found in a well-designed landfill. A total of eight groundwater samples were collected from pollution monitoring boreholes near the two landfill sites, with five samples representing the northern landfill site and three samples representing the southern landfill site. The samples were collected in the autumn and winter seasons to assess any possible seasonal variations. They were analysed for physicochemical (pH, electrical conductivity (EC), total dissolve solids (TDS), chemical oxygen demand (COD) and total organic carbon (TOC)) and microbiological parameters (Escherichia coli, total coliform). The results of the analysis showed that the waters from both landfills were generally dominated by Ca, Mg, SO4, and HCO3 ions. Some of the major anions and cations in the water samples were above the South African National Standard (SANS241:2015) and World Health Organisation (WHO) permissible limits for drinking water. Majority of the boreholes had total dissolved solids and electrical conductivity values exceeding the SANS 241:2015 and WHO permissible limits. Piper trilinear plots for the two landfill sites showed that Ca(Mg)HCO3 water type predominates, but Ca(Mg)SO4 and Ca(Mg)Cl were also found. These water types were further confirmed with expanded Durov diagrams, indicating that that the boreholes represented a water type that is seldom found which is undergoing ion exchange, typical of sulphate contamination. From the SAR diagrams, boreholes in the northern landfill site had a high salinity hazard with only one borehole in the southern landfill site having a high salinity hazard. The geology was found to play a significant role in the distribution of contaminants into the groundwater systems in the study area. The study concluded that the northern landfill site had a poorer water quality in comparison to the southern landfill site based on the analysed physicochemical parameters. However, the southern landfill site showed significant microbial contamination, due to the elevated amount of E. coli and total coliform concentrations. The high permeability of the weathered dolerites in the northern landfill site might have enabled the percolation of contaminants into the groundwater resulting in the poorer water quality.

Evaluation of long-term dermal exposure to soil contaminated with spent engine oil in male Wistar rats: An experimental approach.

Continuous occupational exposure to spent engine oil (SEO) poses physiological risks to humans, especially to automobile mechanics. This study investigated the physiological effects of SEO-contaminated soil in a male Wistar rat model. Animals were dermally exposed to soil contaminated with SEO for 120 consecutive days and compared with rats exposed to uncontaminated soil (negative control). Heavy metal (lead (Pb), nickel (Ni), zinc, and cadmium (Cd)) accumulations, hematology, biochemical (aspartate aminotransferase (AST), alanine aminotransferase, alkaline phosphatase (ALP), urea, and creatinine) parameters, sperm morphology, and histopathology (liver, kidney, lungs, brain, skin, and testis) were evaluated as end points. Results revealed that the heavy metals in SEO-contaminated soil are far greater than the World Health Organisation permissible limits, with significant (p < 0.05) increases of Pb and Ni present in the brain, and Pb and Cd in the serum compared with the uncontaminated soil for the negative control. Only significant (p < 0.05) values were observed in the lymphocytes, activities of AST and ALP, and sperm abnormalities of the exposed rats compared with those used for the negative control. Histopathological changes were not evident in the brain but lesions were observed in the liver, kidney, lungs, skin, and testis of the exposed rats. Results herein suggest that the constituents of SEO may elicit harmful physiological changes to humans who are directly exposed to them.

Implications of carbonates and chlorides contamination in groundwater: Examples from textile tie and dye markets in some parts of Southwestern Nigeria

Objectives: To evaluate the impact of common mineral dyes in effluents from dyeing processes on the quality of groundwater at Itoku and Asero, Abeokuta in Nigeria. Methods: Thirty-two (32) samples were examined by determining the In-situ parameters: Total Dissolved Solids (TDS), Electrical Conductivity (Ec) and pH with the aid of a multi-parameter portable meter(model Testr-35); Chemical parameters were determined with Atomic Absorption Spectrometry (AAS)and Titration methods for both cations and anions. Collected samples were analyzed for heterotrophic bacteria load using standard method. Findings: Elevated Ec-1830 µS/cm and TDS-1020mg/l values at Odutola-8 exceeded the WHO permissible limit with bicarbonate, carbonate and chlorides presence, in the water sample. DO at Ifote-6.0, Asero-6.8, Ifote-7.1, Asero carwash-7.9 was greater than WHO standard, specifying water that can support aquatic life and micro-organisms. However, other areas had low dissolved oxygen below the specified permissible limit. The results of the physicochemical parameters including; Chloride and Carbonate levels in effluent and groundwater in most of the studied sites were higher than the World Health Organization (WHO) permissible limits. Dye effluents and well water samples displayed high microbial loads. Predominant bacteria isolated from the effluent and groundwater included Aspergillus spp. Pseudomonas aeruginosa and Bacillus subtilis. Polycyclic aromatic hydrocarbon (PAHs) observed indicated probable human carcinogens found where dye fabrication processes were high and effective. Novelty: Dye effluents have high bacterial and fungal loads. Similarity in the predominant bacteria isolated from effluent and groundwater from the hand-dug wells indicated that the effluent from the dyeing processes is negatively impacting the groundwater and this may pose a risk to public health. High levels of Carbonates, bicarbonates and chlorides in groundwater indicate contamination; making the water unfit for human and animal consumption. Keywords: Minerals; dyes; contamination; groundwater; carbonates; chlorides

Hydrochemical Characterization and Suitability Assessment of Groundwater Quality in the Saboba and Chereponi Districts, Ghana

Hydrochemical data of groundwater samples obtained from the mudstones, sandstones, and siltstones aquifer units that underlie the study area have been characterized. The aim of this study was to assess the suitability of groundwater for drinking, domestic, and agricultural purposes. The physico-chemical parameters were initially compared with the World Health Organization (WHO) standards for potable water. They were further subjected to various hydrochemical techniques to assess the overall water quality for drinking purposes. Conventional methods of assessing irrigation water suitability were also adopted. The results indicate that, with the exception of HCO3− characterized as unsuitable for drinking water, most of the parameters are within the WHO permissible limits and are thus characterized as suitable for drinking water. A few samples however show slight deviation. The results also show that the abundance of major cations in groundwater is in the order: Na+ &gt; Ca2+ &gt; Mg2+ &gt; K+. However, the abundance of the major anions is in the order: HCO3− &gt; Cl− &gt; SO42−. Na-HCO3 is thus inferred as the dominant water type in the area. Analyses of the overall Water Quality Index (WQI) and irrigation water assessment indices suggest that groundwater in the area is generally suitable for drinking, domestic, and irrigation purposes.

Genotoxic Effect of Lead and Cadmium on Workers at Wastewater Plant in Iraq.

Heavy metal poisoning is a worldwide problem that is caused by different human industrial activities such as battery and painting manufacturing and occupational exposure of those working at petrol stations. Wastewater is known to contain higher amounts of heavy metals such as lead (Pd) and cadmium (Cd) and might be sources of exposure for workers at the wastewater treatment plant. However, to our best knowledge, no studies were done to evaluate the level of cadmium and lead in blood of workers at wastewater treatment plants and evaluate the subsequent effect of lead and cadmium on delta-aminolevulinic acid dehydratase (δ-ALAD), urinary delta-aminolevulinic acid (Uδ-ALA), and 8-hydroxy-2′-deoxyguanosine (8-OHdG) as markers of lead and cadmium toxicity. In this case-control study, 79 workers at the Al-Rustumiya wastewater plant in Baghdad, Iraq, and 40 control subjects were included. The levels of lead and cadmium were measured in blood of the study subjects using the atomic absorption spectroscopy (AAS) method. 8-OHdG was analysed using enzyme-linked immunosorbent assay (ELISA) technique. δ-ALAD and Uδ-ALA were estimated using spectrophotometry-based methods. Our work showed that workers had a significantly higher level of lead and cadmium when compared with the control group (P < 0.05), yet, still within the World Health Organization permissible limit. The level of both metals was positively associated with duration of work at the plant (P < 0.01). The activity of δ-ALAD was inversely associated with the lead level, while both Uδ-ALA and 8-OHdG were positively correlated with the lead level (P < 0.05). These three markers lacked any statistically significant association with the cadmium level (P > 0.05). To sum up, working at the wastewater treatment plant was associated with a higher blood level of lead and cadmium and their possible health hazard. Health and occupational safety authorities are required to set up tighter regulations and protocols to minimize these hazards and ensure a safe working environment.

Bioaccumulation of Heavy Metals Concentration in Some Selected Cereals Grown Near Illegal Mine Sites at Poyentanga in Wa of the Upper West Region, Ghana

The contamination of cereals by heavy metals due to illegal mining activities in most farming communities has been a major challenge to food production in Ghana. The research is thus to examine bio-accumulation of heavy metals (Cadmium (Cd), Arsenic (As), Iron (Fe), Lead (Pd) and Zinc (Zn)) concentration in Maize and Millet grown near illegal mining sites at Poyentanga. The study area was divided into five farming zones (farm 1, 2, 3, 4 and 5) and soil and crop samples were taken from each of the zones to the laboratory for analysis using the Atomic Absorption Spectrometer and the results compared to World Health Organization (WHO) permissible limits. The results indicated presence of the selected heavy metals in the cereals and soils sampled from the community. Cd, Pb and Fe concentrations in the cereals were found to be above the WHO permissible limits whereas As and Zn concentrations were below. The soil concentrations of all the five heavy metals were extremely below the WHO permissible limits. It was also observed that farms near the mining sites have higher concentrations with the concentration in the maize being lower than that of Millet. The contamination levels in both cereals are as follows: Zn &lt; As &lt; Fe &lt; Pb &lt; Cd. The bioaccumulation ratio indicated that Cd, As and Pb levels were higher in Millet whereas Fe and Zn were highest in the Maize. These results therefore show that the consumption of these cereals for a very long time could have adverse health effect on the community and an indication that activities of illegal mining could thus affect the quality and safety of food produced in many farming communities. The research was concluded with recommendations to improve agricultural activities in such communities.

Assessment of some heavy metals concentrations in soil and groundwater around refuse dumpsite in Ibadan Metropolis, Nigeria

This study reports the determination of some heavy metals’ concentration in soil and groundwater around refuse dumpsites in five locations in Ibadan Metropolis, Nigeria. Five samples were collected from each soil and ground water locations and analysed for heavy metals(Cd, Co, Pb, Cr, Zn, Mn and Ni)using Atomic Absorption Spectrophotometry. The soil samples were obtained in triplicates at 25cm depth intervals whereas the water samples were obtained from hand dug wells less than 10 m deep. The range of the values of heavy metal concentrations obtained in water is Co (0.01-0.04), Pb (0.01-0.02), Cr (0.02-0.05), Zn (0.40-0.70), Mn (0.02-0.05) and Ni (0.02-0.05), but Cadmium was not detected. The concentrations of Pb and Ni in ground water obtained from Arapaja, Aleshinloye and Alafara were higher than the World Health Organization (WHO) and Standard Organisation of Nigeria (SON) limits. The results obtained showed that the concentrations of Cd, Co, Pb, Ni and Cr in soil exceeded the WHO and SON permissible limits. However, Zn and Mn were below the limit.&#x0D; Keywords: Heavy metals, Dumpsite, Groundwater, Soil samples, Concentrations.

The assessment of water quality in river Molo water basin, Kenya

The monitoring of water quality for both domestic and commercial use is absolutely essential for policy formulation that affects both public and environmental health. This study investigates the quality of water of river Molo system which lies in the Kenyan Rift Valley. The river is considered a vital source of water for the residents and industrial activities in Nakuru and Baringo Counties. Six water samples were collected during the dry season of December 2017. Various physicochemical parameters were determined in situ by use of a portable pH meter. These parameters included pH, temperature, electrical conductivity and total dissolved solids (TDS). Anions such as fluorides, sulfates, phosphates, nitrates, chlorides, carbonates and bicarbonates were determined using conventional methods such as titrimetry and (ultra-violet visible) UV–Vis techniques. The cations including sodium, potassium, calcium and magnesium were determined using flame photometry. The results showed that the water had pH values ranging from 7.90 to 9.66 units, temperature ranged from 14.02 to 31.5 °C, while electrical conductivity ranged from 181 to 1637 μS/cm, TDS (69–823 mg/L), F (2.76–3.28 mg/L), sulfates (4.97–85.66 mg/L), phosphates (0.13–11.06 mg/L), nitrates (1.73–6.16 mg/L), chlorides (38.5–69.4 mg/L), carbonates (18–148 mg/L), bicarbonates (54–384 mg/L), sodium (19–1800 mg/L), potassium (8.9–121 mg/L), magnesium (4.8–106.8 mg/L) and calcium (13.4–77.4 mg/L). The pH, temperature, fluorides and sodium were above the World Health Organization permissible limits for drinking water in S4 and S5. All the water samples fall under bicarbonate or freshwater zone. The sampling points can be classified into five water types: Na–Mg–Ca–HCO3, Na–HCO3, Na–Ca–Mg–HCO3–CO3, Na and Na–Ca–HCO3–CO3. Chemical indices such as sodium adsorption ratio, magnesium hazard, percent sodium and permeability index are reported. Accordingly, the findings from this work indicate that the river Molo water in general is good for irrigation.

Physicochemical characteristics of harvested rainwater under different rooftops in Ikole Local Government Area, Ekiti State, Nigeria

Due to scarcity of potable water in most rural and urban settings in Ekiti State, rainwater harvesting from rooftop has been favoured as an alternative source of water supply. This study investigated the physicochemical characteristics of rainwater harvested from four different rooftop sheets in Ikole-Ekiti and its environs. Samples were collected three times from the month of June to August, 2018. Parameters investigated include pH, Total Dissolved Solid (TDS), Turbidity, Electrical Conductivity (EC), Alkalinity, Total Hardness, Ca2+, Mg2+, Na+, K+, Fe, Pb, Zn, Al, and Cu. Data obtained were subjected to descriptive statistics to determine the mean and standard deviation and water quality index measured. The result shows that the physicochemical parameters ranges from 8.03-9.17 (pH), 0.47-3.17 NTU (Turbidity), 56.20 -170.43 μs/cm (EC), 30.2-50.53 mg/L (TDS), 18.56-27.58 mg/L (Alkalinity), 19.94-24.08 mg/L (Total Hardness), 8.67-14.93mg/L (SO4 2+), 4.11-11.67mg/L (Cl-), 0 - 4.62 mg/L (Zn2+), 7.11-11.13 mg/L (Calcium), 0.07-1.56 mg/L (Al2+), 0.01-0.02 mg/L (Cu2+), 9.41-21.33 mg/L (Mg2+), 29.04-40.35 mg/L (Na2+) and (Fe2+) 0.1-0.29 mg/L . Most of the measured parameters were all within permissible water quality standard as recommended by World Health Organizations (WHO) except for the slightly basic character of the rainwater. All measured parameters were high in aluminum sheets and coated rooftops but did not exceed the World Health Organization permissible limit followed by Galvanized zinc rooftop and Panted rooftop. Water Quality Index (WQI) for painted rooftop, aluminum rooftop, galvanized zinc rooftop, and coated rooftop were 3.296, 1.335, 6.078 and 2.629 respectively indicating excellent water quality. The study found that harvested rainwater in the area could be used for domestic purpose with minimum treatment to enhance drinkability.Keywords: Rainwater, Rooftop, Quality, Health and Permissible limit

Heavy Metals in Keana Salt Lake and Some Sources of Drinking Water Within the Keana Salt Lake Community, Nasarawa State, Nigeria

Utilization of Salt Lake may portend risk in terms of environmental and human health. The study aimed at analyzing for selected metallic ions in Keana Salt Lake and sources of drinking water in Keana Salt Lake Community, so as to identify and determine the amount of heavy metals in comparison with WHO (World Health Organization) permissible limits. Heavy metals analyzed in the study includes Lead (mg/L), Cadmium (mg/L), Copper (mg/L), Iron (mg/L), Nickel (mg/L), Manganese (mg/L), Aluminum (mg/L), Zinc (mg/L), Cobalt (mg/L), Arsenic (mg/L) and Chromium (mg/L). Atomic absorption spectroscopy (AAS) was used to analyze five samples collected in triplicates from well water (WW), Salt Lake water (SLW) Filtrate from salt lake water (FSLW), non-motorized borehole (BH1) and motorized borehole (BH2) located within Keana community, Nasarawa state, Nigeria. Study findings indicate that while Cobalt was not detected in any of the water samples, mean concentration values for Zinc, Copper and Alumunium were within permissible limits set by WHO. Furthermore, mean concentration values for Manganese, Chromium, Iron, Nickel, Cadmium, Lead and Arsenic exceeded WHO permissible limits. Mean concentration levels of some heavy metals analyzed in the study shows that utilizing water in the study area may be hazardous to environmental health. The study recommends regular treatment of water from the study area before utilization by the populace.