Assessment of Physical-Chemical Drinking Water Quality in the Logone Valley (Chad-Cameroon)

Unsafe drinking water is one of the main concerns in developing countries. In order to deal with this problem, a cooperation project was set up by the ACRA Foundation in the Logone valley (Chad-Cameroon). Water supplies were sampled throughout the villages of this area mostly from boreholes, open wells, rivers and lakes as well as some piped waters. The samples were analysed for their physical-chemical and microbiological quality in order to identify the contamination problems and suggest appropriate solutions. Results of the assessment confirmed that in the studied area there are several parameters of health and aesthetic concern. Elevated lead levels were detected both in aquifers and in surface waters, confirming that further investigations of the occurrence of lead contamination in the Logone valley are warranted. In addition, many groundwater sources are negatively impacted by parameters of aesthetic concern, such as turbidity, iron and manganese. Even though they do not affect human health, elevated levels of these parameters cause consumers to abandon improved water supplies, often in favour of surface water sources that are microbiologically contaminated. The use of alternative sources, improvement of water supply structures and water treatment are possible solutions to improve the quality of drinking water in the Logone valley

Chronic Toxicity Of Essential Oils Of 3 Local Aromatic Plants Towards Sitophilus Zeamais Motsch (Coleoptera : Curculionidae)

peer reviewe

Chemical composition and antibacterial activities of the essential oils of Plectranthus glandulosus and Cinnumomum zeylrrnicum from Cameroon

Two aromatic plants have been selected for chemical investigation on account of their antibacterial activities, Plectranthus glandulosus (fresh leaves) and Cinnamomum zeylunicum (dried leaves). P. glandulosus is used as a medicinal plant, while Cinnamomum zeylunicum is used as a common spice in many recipes in Cameroon. The essential oils of the plants have been obtained by hydrodistillation using a Clevenger type apparatus, the yields of oils are about 0.3% and 2.0% respectively.The essential oil of P. glandulosus contains mainly β-thujone (about 31%), p-cymen-8-01 (about 25%) and neral (about 10%) and the essential oil of C. zcylcinicum is characterised by a high percentage of eugenol (85%).These essential oils have been tested against three strains of bacteria, namely Pseudornonas fluorescens. Escherichiu coli and Staphylococcus aureus; qualitative tests (diffusion through solid medium) and quantitative tests (dilution method) have been carried out. P. fluorescens shows a higher resistance to the two oils (MIC values not less than 5000 ppm). E. coli is more sensitive to these oils, while against S uureus the essential oil of C. zcylcinicum still shows a high activity (3500 ppm).The antibacterial activities of the essential oils could be attributed to the components eugenol as the active component of C. zcylcinicum and β-thujone and p-cymen-4-01 of the essential oil of P. glandulosus

Chemical Composition, Insecticidal Effect and Repellent Activity of Essential Oils of Three Aromatic Plants, Alone and in Combination, towards Sitophilus Oryzae L. (Coleoptera : Curculionidae)

Essential oils of aromatic plants with insecticidal properties are nowadays considered as alternative insecticides to protect stored products from attack by insect pests. A combination of some of these plants in the granaries is a current practice in certain localities of northern Cameroon. The aim of the present work was to analyze the impact of the combinations of the essential oils of Vepris heterophylla (Rutaceae), Ocimum canum, and Hyptis spicigera (both Lamiaceae), the three most used local aromatic plants because of their insecticidal activity and their repellent effect on Sitophilus oryzae. The present work revealed that these plants are rich in monoterpenoids. The GC/MS analyses have shown that monoterpenoids represented 65.5% for H. spicigera, 92.1% for O. canum and 47.0% for V. heterophylla. The crude essential oil of O. canum was the most insecticidal with a LD50 of 42.9 ppm. The most repellent effect was obtained by a combination of the essential oils of H. spicigera and O. canum, with a repellent percentage at 77.5%. These results suggest a suitable strategy for pest management of stored products

Investigations on Both Chemical Composition and Insecticidal Activities on Essential Oils of Vepris heterophylla (Rutaceae) from Two Localities of Northern Cameroon Towards Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)

peer reviewe