Possible Abstraction Sites along Osun River Lower Course in Ogun and Lagos State, Nigeria For Sustainable Supply Of Potable Water

Water scarcity remains a major challenge in all the developing nations of the world; not because of paucity of surface water (rivers and streams) that could be abstracted for treatment, but, finding a suitable and sustainable abstraction site. The main objective of this research is to identify good locations, where water treatment plant could be sited along Osun River in Ogun and Lagos State for sustainable production of potable water. To achieve this, water quality of Osun River upstream Lekki lagoon was investigated at three sampling stations; Ogbere, Igbonla and Lekki. Water parameters such as physical (temperature, solids, turbidity) chemicals (pH, electrical conductivity (EC), dissolved oxygen (DO), chemical oxygen demand (COD), nitrate, phosphate, chloride and sulphate, alkalinity, potassium, lead, chromium, iron) and bacteriological (feacal coliform) were determined using standard procedures. The results revealed that Ogbere and Igbonla stations are better locations where water could be abstracted from Osun River than Lekki stations due to low measured parameters (indicators of water pollution), which were within World Health Organization (WHO) acceptable limits. The findings also showed that while raw water abstraction from Osun River at Ogbere and Igbonla stations would require a conventional treatment, raw water from the Lekki lagoon (station) would require special treatment especially desalination due to high chloride and EC contents with expected cost implication

Population dynamics of indoor sampled mosquitoes and their implication in disease transmission in Abeokuta, south-western Nigeria

Background & objectives: A longitudinal study was carried out to investigate the speciescomposition, seasonal abundance, parity and feeding preference of indoor sampled mosquitoes inAbeokuta, south-western Nigeria.Methods: The mosquitoes were sampled weekly from five stratified locations using Center forDisease Control (CDC) light-traps between August 2005 and July 2006. The mosquitoes wereexamined for abdominal condition and dissected for age composition. Microscopic and precipitintechniques were also employed for the determination of host blood source.Results: A total of 2969 mosquitoes which belong to 10 species of mosquitoes were collectedduring the study period. Mansonia africana (35.65%) constituted the most abundant species followedby Culex quinquefasciatus (32.23%) and Anopheles gambiae complex (13.52%). Other species indecreasing order of abundance were Coquilletidia maculipennis (8.2%), Aedes albopictus (5.9%),Ae. aegypti (1.93%), M. uniformis (1.81%), Cx. duttoni (0.25%), Cx. tigripes (0.25%) and An.funestus (0.25%). Seasonal abundance revealed a significant difference (p <0.05) in the populationof mosquito vectors collected during the wet season as compared to the dry season and theirabundance was positively correlated with rainfall. The results showed that the majority of thevector species collected were unfed and nulliparous. Moreover, the blood meal test was positive forhuman blood.Conclusion: The preponderance of mosquitoes observed in the study is of public health concernsince they serve as vectors of most tropical diseases including malari