Indiscriminate use of fertilizers by vegetable growers and poor water quality of irrigational water characterize vegetable production in most parts of Cameroon. The concentrations of As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in the soil, cabbage and carrot cultivated in Santa, North West Region, Cameroon were assessed to determine potential ecological and human health risk associated with the consumption of these two vegetables. Heavy metal concentrations were determined using a ContrAA 300 Atomic Absorption Spectrophotometer after microwave digestion. The concentrations of As (0.51 mg/kg and 0.38 mg/kg), Co (1.41 mg/kg and 1.39 mg/kg) and Pb (1.36 mg/kg and 1.31 mg/ kg) in the cabbage and carrot, respectively, were above the WHO/FAO, permissible limits for human consumption. Health risk index values for Co in cabbage (2.31 mg/kg) and carrot (2.26 mg/kg) indicated significant risks from Co exposure. Geo-accumulation Index indicated that soils from most sites were contaminated. The populations consuming these vegetables are at risk of As, Co and Pb toxicity. Monitoring and sensitization of farmers on the effects of indiscriminate use of agrochemicals is very necessary to protect the health of consumers and preserve the soil quality.

Tree species composition and diversity were investigated in the riparian forest around Lake Barombi Kotto, Cameroon. This study aimed at determining the tree species composition, population structure, and providing evidence of anthropogenic disturbances in the riparian forest of Lake Barombi Kotto. The objectives were to determine the tree species composition and diversity in the riparian forest around Lake Barombi Kotto, to elucidate the forest structure and to document the anthropogenic disturbances in this forest. Five plots were laid within which the tree enumeration and measurement of dbh were carried out. Trees were identified using scientific identification keys in the Flora of West Africa. Disturbance scores were given to each site by qualitatively assessing various disturbances. A total of 340 trees belonging to 70 plant species, 63 genera and 28 plant families were enumerated. Shannon-Wiener diversity varied across sites, with the highest value (H = 3.45) recorded in Tung and the lowest (H = 2.21) in Malenda. Population structure differed across sites, the largest stand basal area of 43.78 m 2 /ha was recorded in Bondokombo while the smallest (2.15 m 2 /ha) was recorded in the Sacred Island. Cecropia peltata L., Pseudospondias macrocarpa Oliv. Pierre and Ceiba pentandra (L.) Gaertn had the largest basal areas across the different sites. Species rich families were Malvaceae (9 species), Fabaceae (9 species), Annonaceae (4 species), and Anacardiaceae (4). This study shows that, there is a high tree species diversity in the protected forest (Tung) but the other unprotected sites are highly disturbed by anthropogenic activities. There is need to develop and enhance existing management policies for this riparian forest, especially by replanting the cut trees and creating a protected riparian buffer to conserve its floristic diversity and ecological functions.

Salacia reticulata which is a well known plant for antidiabetic properties were subject to elicitor application. The field grown plants were sprayed with aqueous extracts of 2% Aspergillus niger mycelium as biotic elicitor and 0.2mM salicylic acid as abiotic elicitor. Elicitation of phenolics and flavonoids were marginal in both the treatments. Formation of seven new compounds in biotic elicitor treatment and eight new compounds in abiotic elicitor treatment was evident from GCMS studies. Significantly Ala-Gly, Trimethylsilyl Ester; Cyclotrisiloxane, Hexamethyl and Eicosanoic Acid, 2,3-Bis[(Trimethylsilyl) Oxy] Propyl Ester were the new compounds found in both the elicitor treatments. Cyclotrisiloxane, Hexamethyl-is a known molecule with Antioxidant, Antiasthmatics and Antogonositic effects. Interestingly, Benzene acetonitrile, Alpha.-(.Beta.-D-Glucopyranosyloxy)-,(R)-, which is a potent anticancer agent and Antioxidant ,was found only upon biotic elicitor treatment. Thus this study has led to the finding of new molecules in Salacia with potent novel medicinal properties.

Lacustrine ecosystems have not been widely assessed for heavy metal contamination and associated health risks; yet, they could be accumulating these contaminants to the detriment of aquatic organisms and communities relying on them for various aspects. The water quality index (WQI) and concentrations of heavy metals including As, Cd, Co, Cu, Cr, Fe, Mn, Ni, Pb, and Zn in water, sediment, Oreochromis niloticus, and in the endemic and endangered Coptodon kottae in Lake Barombi Kotto in Cameroon were determined to evaluate fish heavy metal bioaccumulation, and heavy metal exposure risk posed to communities consuming these fish species. The WQI of the lake was found to be excellent with heavy metal concentrations that were lower than what was obtained in the sediments and fish samples. Mean heavy metal concentrations in sediment ranged from 0.86 ± 0.03 mg/kg for Cd to 560.1 ± 11.15 mg/kg for Fe. In both fish species, Fe, Mn, and Cu had the highest concentrations. Though the heavy metal concentrations in the lake water were low, heavy metal bioconcentration factors for both fish species were very high ranging from 1.6 for Fe to 1568 for Mn. The concentration patterns of heavy metals in the organs of both fish species followed the order bones > gut > muscle. Consumption of these two fish species contributes less than 1.0% of the permissible tolerable daily intake (PTDI) and provisional tolerable weekly intake (PTWI) of these metals with lead (Pb) having the potential to exceed permissible exposure levels when high amounts of these fish are consumed by adults.

This study carried out in BarombiKotto was aimed at assessing ecosystem services provided by Lake BarombiKotto and its riparian vegetation and to determine the level of awareness of this community to threats to degradation of water quality and riparian vegetation. Two hundred semi-structured questionnaires were administered to the inhabitants of BarombiKotto village using the purposive sampling method. The Likert rating method was used to derive quantitative data that was further analysed using SPSS version 17. Results revealed that, respondents depended on the lake and vegetation for the provision of water for drinking, domestic purposes, irrigation, transport, recreational and cultural activities and also on forest benefits like wood for fuel, construction and medicinal plants. Significant associations were found between age group, level of education and respondents'awareness about the threats to water quality and sustainable practices. Agriculture, harvest of wood for construction, high fishing rates, increasing abundance of aquatic weeds were identified as major threats to Lake BarombiKotto and its surrounding vegetation. Water quality attributes like reduced transparency, lake depth, and other parameters such as aquatic weeds and fish stocks have changed in Lake BarombiKotto. The absence of conventional waste management facilities in BarombiKotto community and poor sanitary conditions of toilets could be responsible for the contamination of this lake and hence the high prevalence of typhoid, dysentery and other gastrointestinal infections among respondents.