Background: Medicinal plants are a potent source of therapeutic molecules that heal various diseases in the world.Aim: The aim of this study was to evaluate heavy metal concentrations in the leaves of some selected medicinal plants in selected locations.Setting: The leaves of Azadirachta indica, Magnifera indica and Newbouldia laevis were collected from the botanical garden, roadside and residential area in the University of Ibadan and were authenticated at the Forest Herbarium Ibadan. The samples were thoroughly washed with deionised water and air-dried at room temperature for about three weeks, then ground into powder with a mechanical grinder. The samples were subsequently stored in air-tight bottles for further work.Methods: The milled samples were subjected to wet digestion, and then lead (Pb), chromium (Cr), cadmium (Cd) and nickel (Ni) were analysed using standard methods.Results: The results obtained show that the highest concentrations of Pb, Cr and Cd in the medicinal plants studied were found in N. laevis (23.93 ppm; road side), N. laevis (4.79 ppm; road side) and M. indica (0.36 ppm; road side), respectively, while the lowest concentrations of Pb, Cr and Cd were found in A. indica (7.10 ppm; botanical garden), N. laevis (0.73 ppm; residential) and N. laevis (0.05 ppm; residential), respectively. Ni was totally undetected in all three medicinal plants studied in all the locations.Conclusion: The concentrations of heavy metals at the roadside and residential area were higher than permissible limits set for medicinal plants, but the botanical garden was the lowest and safest in terms of heavy metals accumulation in the medicinal plants studied in the three locations.

Leea guineensis G. Don is an evergreen shrub that has been reported to be important in Nigeria due to its medicinal and nutritional uses. However, there is paucity of documented information on the anti-nutritional composition, heavy metal content and mineral bioavailability of L. guineensis whole fruits. Hence, this study investigated the essential minerals, heavy metals and anti-nutritional compositions of L. guineensis whole fruits with a view to assess the quantity, bioavailability of the mineral elements and ultimately the safety of the fruits using standard analytical procedures. The results of phytochemical screening confirmed presence of secondary metabolites in varying quantities. The anti-nutrient contents (mg/100g) were phytates (29530); oxalates (510); saponins (10333); alkaloids (30533) and tannins (53.3). The results of mineral analysis revealed that L. guineensis fruits were rich in essential minerals (mg/100g) like, potassium (493); calcium (200); magnesium (103.3); phosphorus (9.9); zinc (8.5); manganese (5.5) and iron (5.0). The heavy metals concentrations were in the order lead>chromium>nickel>cobalt>cadmium. The values obtained were within the WHO permissible limits for heavy metals in medicinal plants. Meanwhile, the results of molar ratio phytates: Ca (8.97); oxalates: Ca (0.7978) and Ca.phytates:Zn (0.64) were below the suggested critical values indicating the bioavailability of calcium to be high. While phytates: Fe (501.06) and phytates: Zn (348.22) were higher than the critical values indicating poor bioavailability of Fe and Zn. The study therefore suggests that L. guineensis fruits are a good source of phyto-minerals which can be harnessed for nutritional purpose. Also, the anti-nutrient contents in L. guineensis whole fruits should be reduced to a safe level through processing methods (soaking, de-pulping or fermentation) in order to achieve its optimum nutritional or medicinal use.

The communities surrounding the forest reserve get their daily income from the sales of some of the non-timber forest products (NTFPs) as a means of survival for them and their house hold without proper documentation. The study described the socio-economic characteristics of the rural dwellers in the study area and determined the income made from some of these NTFPs. Data was generated through the use of structured questionnaires administered to 120 randomly selected rural household heads. Data obtained were described using frequency counts, percentages and mean scores; the relationship between dependent variables and independent variables of the study was tested using binomial test and logistic regression. Finding reveal that, non-timber forest products gathering in Onigambari was male dominated (72.3%), 78.1% were married and 38.1% had formal education. Contribution of income from non-timberforest products to total income of respondents in the State was 59.46%. It was concluded that the non-timber forest products  contribute significantly to rural household income at Onigambari forest Reserve Area of Oyo State, Nigeria

Problems of kidney, liver, hypertension and cancer diseases are common this day in some parts of Nigeria among adults which could be due to prolong drinking of water containing high concentrations of heavy metals such as Arsenic, Barium, Cadmium, Chromium, Copper, Lead, and Manganese. There is a need for creating awareness in the country about the health implications of prolong drinking of water with high concentrations of heavy metals which could cause some severe diseases to man. This study was conducted to determine the concentrations of some selected heavy metals in the borehole water of Shao in Moro Local Government Area, Kwara State, Nigeria. Water samples were collected in March, 2020 from 6 borehole locations at Shao and physic-chemical properties were analyzed using standard methods. The samples were collected in March during dry season to get the actual contribution of the geological nature of the area for the heavy metals. In March, there is little or no underground water pollution from agricultural wastes, pesticides, industrial wastes and percolation of contaminated runoff. The concentrations of Cadmium, Chromium, Copper, Lead, Manganese and Zinc in the samples were 0.003-0.016 (Standard Organisation of Nigeria – SON limit: 0.003), 0.012-0.012 (SON: 0.050), 0.005-0.030 (SON: 1.000), 0.058-0.058 (SON: 0.010), 0.002-0.024 (SON: 0.200), 0.013-0.098 mg/L (SON: 3.000mg/L), respectively. Concentrations of Arsenic and Mercury were not detected in all the 6 boreholes. The concentrations of Cadmium which is toxic to kidney were above the permissible limits of SON in 5 boreholes and Lead that could cause cancer and mental disorder among children were above the permissible limits of SON in one borehole. Borehole water with high concentration of heavy metals should be treated before consumption to prevent some deadly diseases that could affect man.