Assessment of Heavy Metals in Vegetables Grown on Irrigated Land in Butura, Bokkos LGA, Plateau State, Nigeria (Published)
Vegetables have positive antioxidative properties and are abundant in vitamins, minerals, and fiber. However, if consumed in large quantities, eating vegetables polluted with heavy metals may be harmful to human health. Therefore, this study assessed the effects of heavy metals on irrigated pepper, cabbage and Irish potatoes grown in Butura. Atomic absorption spectrophotometry (AA240FS) was used to analyze cadmium (Cd), cobalt (Co), nickel (Ni), lead (Pb), zinc (Zn), copper (Cu), chromium (Cr) and arsenic (As) levels. Three samples were selected from each of the vegetables grown on nine selected farms at distances of 0 m, 10 m, and 30 m. This forms a composite sample of vegetables at each farm. The study showed that the concentrations of cobalt, chromium, cadmium, copper, arsenic, zinc and nickel were within the standard limits set by the FAO/WHO, except for lead, which is higher than the allowable limits for vegetables. These patients may have behavioral problems, neurological complications and hematologic disorders. Thus, these findings could lead to a risk for the human population consuming these vegetables. It is recommended that irrigation water and agricultural soils be constantly monitored to determine the concentration of metals accumulated by crop plants to ensure that crop plants are safe for consumption by humans.
Keywords: Bokkos, Cabbage, Heavy Metals, Irish Potato, Irrigated, Pepper, Vegetable
Assessment of Heavy Metal Distribution in Surface Water and Groundwater in The Region of a Salt Mine (Published)
Water quality is a big concern for the humankind as it is the most important natural resource. The quality of water is affected by anthropogenic activities carried which could render it unsuitable for human consumption. The present study assessed heavy metal distribution and toxicity in surface and groundwater resources of an area characterized by salt mining from brine ponds. Samples were analyzed for pH, electrical conductivity (EC) elemental compositions of: Ba, Mn, Fe, Cu, Sr, and Zn to assess their spatial distribution, sources, variability, toxicity and possible health risks. Median concentrations of Ba, Mn, Fe, Cu, Sr, and Zn in surface water was: 0.28, 3.63, 2.23, 0.03, 0.14 and 0.05 respectively while for groundwater, median concentration was: 0.65, 0.20, 1.16, 0.03, 0.83 and 0.11 respectively. In terms of suitability, concentrations of Mn, Fe and Sr in surface water, and that of Sr, in groundwater raises some quality concerns since they are all present in concentrations above the permissible limits for drinking water. Results of Corelation and Principal Component Analyses showed that source and mobility of these metals is linked to both geogenic (host rock weathering) and anthropogenic activities mainly associated with salt mining and processing in the region of a saline pond. Spatial distribution of concentration of these metals also shows higher concentrations in the immediate region of the salt mine especially in groundwater.
Keywords: Correlation Analysis, Heavy Metals, Principal Component Analysis, Salt mining, Water Quality
Heavy Metals in Fish: Bioaccumulation and Health (Published)
Heavy metals occur during natural processes and are also obtained during anthropogenic activities. Heavy metals include chromium, cadmium, arsenic, lead, zinc, nickel, mercury, selenium and copper hence their presence in the aquatic habitat are highly toxic to fishes and shell fishes. Heavy metals are found in the aquatic environment as a result from contamination by heavy metals from industrial, agricultural waste and by-products and domestic waste and by products. The increasing level of heavy metals in fish is alarming and has spurred scientists to make researches on the dangers caused by the heavy metals resulting to heavy metal accumulation and bioaccumulation of life cells. The aim of this study was to assess the possible sources of heavy metal in the aquatic environment, impact of heavy metals in the aquatic environment, its bioaccumulation in fish and human health impact. Several reports tell of the detrimental effect of heavy metals in fish (some of which include; poisonous effect in the blood such as anemia, eosinophilia, lymphocytosis, renal lesions, convulsions and ataxia, detachment of gills, fusion of secondary gill filaments, acute inflammation in the liver, amongst several others) and in man (some of which include, skin diseases, Irritation of the gastrointestinal mucosa, nephritis, lung cancer, liver and kidney damage, necrosis, neurological and behavioral disorders and death amongst others). In conclusion, the toxic effects of heavy metals in fish and the effect of bioaccumulation and bio-magnification have been reviewed in this paper. It is therefore recommended that the treatment of all forms of wastewaters, agricultural waste, sewage, industrial effluents be carried out before their discharge in to the environment. Also, the enforcement of all laws, legislations regarding the protection of aquatic life and environment should be enforced and sanctions meted out against defaulters.
Keywords: Bioaccumulation, Death, Growth, Health, Heavy Metals, Pollution
Sequential Analysis, Mobility Factor and Geochemistry of Heavy Metals in Ayetoro Coastal Sediments, Southwestern Nigeria (Published)
Previous geochemical investigation of Ayetoro area discovered that its coastal sediments are enriched with sulphide mineralization. However, in order to determine the geochemical phases of the heavy metals in the coastal sediments, random sampling method was utilized across 10 locations, at a depth of 40cm using Van grab sampler at a sampling density of 200m interval. Atomic Absorption Spectrophotometer (AAS) Buck Scientific Model 205A was used to analyze nine (9) heavy metal concentrations namely Ni, Zn, Co, Mn, Fe, Pb, Cr, Cd and Cu in the coastal sediments, followed by sequential extraction of the metals, using five fractional phases. The results revealed that the geochemical concentration of the heavy metals as follows: Ni (5.89ppm – 16.82ppm), Zn (2.59ppm – 115.65ppm.), Co (1.22ppm – 22.77ppm), Mn (30.95ppm – 186.49ppm), Fe (6.632ppm – 1925.96ppm), Pb (5.17ppm – 55.96ppm), Cr (0.26ppm – 28.06ppm), Cd (0.13ppm -22.23ppm), and Cu (2.26ppm – 41.94ppm) and showed the concentration order as Residual>Reducible>Organic>Exchangeable>Carbonate. Most of the heavy metals in carbonate and exchangeable phase have low concentration except for Cd. This implied that Cd is of low mobility and bioavailability which is very dangerous as its intake by man leads to kidney diseases and causes bones to become weaker. Also, Mobility factor of Cd stood out because of its high concentration in the exchangeable phase compared to other four non-residual phases. The mobility and bioavailability of the heavy metals are in this order: Cd>Co>Ni>Pb>Cr>Mn>Cu>Zn>Fe respectively. The analysis of variance (ANOVA) revealed that the heavy metals are significantly different in all the phases based on their accumulation index in the sediments while majority of the heavy metals lacked the ability to remobilize but can be released into the environment under reducing and oxidizing conditions
Keywords: Heavy Metals, ayetoro. coastal sediments, mobility factor, sequential extraction
Human Activities and Heavy Metal Concentrations in Aba River, Abia State, Nigeria (Published)
Water samples were collected from seven different locations along the Aba River close to various human, industrial, commercial and domestic activities. The heavy metals were analyzed using the Atomic Absorption Spectrometer (AAS). The result revealed that the concentration of some heavy metals like Iron, Copper, Manganese and Chromium are above the WHO and FMEnv Standard limits for surface water. These high values could be attributed to indiscriminate disposal of wastes into the river. The various parameters of the water samples from the control site (Okpu-Umuobu) were significantly different from those of locations close to the major industrial/commercial activities. This confirms the impact of human activities on the quality of the Aba River. The impacts of dredging and sand mining in and along the river bank were obvious. These activities have an adverse effect on the environment and ecology, speeding up flow and potentially increasing the risk of flooding downstream. This also has the potential to damage ecology by directly affecting its physical habitat, disrupting riverine processes and reduced connectivity with the floodplain. It is therefore recommended that effluent treatment plants be installed to treat waste generated before they are discharged into the stream as well as regular monitoring of the River should be encouraged by the regulatory bodies.
Keywords: Aba River, Anthropogenic Activities, Dredging, Effluents, Heavy Metals, Pollution