The bioaccumulation factors (BAFs) of heavy metal (Fe, Zn, Pb, Cd, Cr, Cu, Mn, and As) concentrations in benthic and pelagic fish organs (muscles, gills, liver, and hearts), and concentrations of heavy metals in water and sediments of Ogbese River, Ondo State, Nigeria were investigated. From the results, the concentrations of heavy metals in the water were within the permissible limits stipulated by the World Health Organization (WHO). However, in the sediments, Cd, Cr, Fe, and Mn concentrations were higher than the limits, while Zn, As, Pb, and Cu were within limits. Heavy metals concentrations in the fish organs showed that all fish species were within the permissible limits implying no contamination. More so, the BAFs in all fish organs revealed no probability of accumulation while the geoaccumulation index and contamination factor showed no contamination to moderate contamination. The potential ecological risk index also showed moderate risk factor indicating that the water and sediments were not extremely polluted for higher organisms but may be toxic for lower ones. The study concludes that constant monitoring and study should be conducted by researchers and the Ministry of Water Resource and that the community should be aware of the danger human pollution can cause to the river.

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Aims: To investigate the heavy metal concentrations in soil samples collected from an open dumpsite in a rural community (Aba Idi-Mangoro) in Owo, Ondo State and to compare the observed values with the regulatory limits. This study also aimed to determine the pollution levels using tools like contamination factor, pollution load index and geoaccumulation index. Study Design: Field study design was use in this study. Place and Duration of Study: Soil samples were collected from Aba Idi-Mangoro in Owo, Ondo State, Nigeria between July 2015 and February 2016 to represent the wet and dry seasons. Methodology: A total of 96 soil samples were collected (6 samples on each visit and the site was visited twice a month). The samples were taken to the Prof. Julius Okojie Central Research Laboratory at the Federal University of Technology, Akure, Ondo State, Nigeria. In the laboratory, samples were air dried to remove the moisture. 2 g of the sampes were digested into HNO3, HCl, HF and HClO4, and AA Spectrophotometer was used to analyse the concentrations of the heavy metals. Results: Out of the 8 heavy metals assessed, 6 were above the regulatory limits. The order of heavy metal concentrations for the wet season is: Fe>Mn>Zn>Cu>Pb>Ni>Cr>Co>Cd and the dry season is as follows: Fe>Zn>Mn>Pb>Cu>Ni>Co>Cr>Cd. When the mean concentrations of the samples for the wet season were compared to the dry season, Mn (0.009), Cd (0.035), Cr (0.044) and Co (0.014) differ significantly (p<0.05). No significant difference was found in Fe, Co, Ni and Zn. It was observed from the overall results that the concentrations of heavy metals were higher during the dry season than in the wet season. The contamination factor (CF), pollution load index and geo-accumulation index values of Fe was extremely high in the two seasons while it varies at different collection times for the other metals. Conclusion: Due to the high presence of some of the heavy metals found in the soil, the study suggests that water and sediment samples from nearby river(s) within the community should also be examined.

The efficacy of pulverized and extracts of Dennettia tripetala and Piper gunieense indigenous to

Aim: Resistance of mosquito vectors and harmful effects of chemicals on human and its environment have been major problems encountered in vector control through the use of synthetic insecticides, thus there is a need for alternative insecticides of plant derivatives. This research is aimed at using extracts of Tithonia diversifolia and Momordica charantia against the developmental stages of Anopheles gambiae. Place and Duration of Study: The research was conducted at the Federal University of Technology, Akure, Nigeria between the months of March to June, 2017. Methodology: Larvae and pupae of Anopheles gambiae were reared in the laboratory at ambient temperature of 28±2°C and relative humidity of 75±5%. The leave extracts of T. diversifolia and M. charantia were extracted with methanol and were prepared at concentrations, 0.1%, 0.2%, 0.3%, 0.4% and 0.5%. The larvae and pupae of A. gambiae were exposed to these concentrations of the plant extract for 24 hours. Mortality of the larvae and pupae was monitored and recorded. Probit analysis was used to determine the LC50. Results: Date of this research revealed that at all levels of concentrations, mortality of both the larvae and pupae of this insect increased with increase in the concentrations regardless the type of plant extract used.  The leave extract of T. diversifolia having a lower value of LC50 (larvae: 0.20%; Pupae: 0.27%) was more potent than extract from M. charantia having a higher value of LC50 (larvae: 0.31%; Pupae: 0.44%) after 24 hours Post Treatment of larvae and pupae of A. gambiae. T. diversifolia had significant effect on the larvae of A. gambiae with percentage mortality ranges from 23.33-100% within 24 hrs of exposure when compared with M. charantia that had 16.67-100% of mortality larvae of A. gambiae. Conclusion: The obtained results from this research revealed that extracts from the two plants exhibited great insecticidal properties against larvae and pupae of A. gambiae. Therefore, more exploration on the use of these plants for the development of insecticides at commercial level should be done.