As an initial part of a programme aimed at promoting safe and sound agricultural practices in Ghana, a study was made of farmers' perceptions of pesticides for use and application in vegetable production, using a small survey of 137 farmers who applied pesticides. Field surveys, interviews, questionnaires and analytical games were used to obtain information on the type, scope and extent of use of pesticides, farmers' knowledge of pesticides, and their perceptions about the chemicals' potential for harm. Data from this sample of farmers were used to describe the status of use of pesticides in vegetable cultivation in Ghana. Using chi2 tests, associations between farmers' age and possible pesticide poisoning symptoms, their farm size and method of spraying pesticides, and their perception of pesticide hazard and its perceived effectiveness against pests were also examined. The survey showed that knapsack sprayers were the most widely used type of equipment for spraying pesticides. However, on large-scale vegetable farms of 6-10 acres, motorised sprayers were also used. Various inappropriate practices in the handling and use of pesticides caused possible poisoning symptoms among those farmers who generally did not wear protective clothing. Younger farmers (<45 years of age) were the most vulnerable group, probably because they did more spraying than older farmers (>45 years of age). Farmers did not necessarily associate hazardous pesticides with better pest control. The introduction of well-targeted training programmes for farmers on the need for and safe use of pesticides is advocated.

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The measurement of chemical, physical and biological parameters is important for the characterization of streams health. Thus, cost effective and targeted water quality (WQ) monitoring programmes are required for proper assessment, restoration and protection of such streams. This research proposes a WQ monitoring network for the Limpopo River Basin (LRB) in Mozambique located in Southern Africa, a region prone to severe droughts. In this Basin both anthropogenic and natural driven processes, exacerbated by the increase water demand by the four riparian countries (Botswana, South Africa, Zimbabwe and Mozambique) are responsible for the degradation of surface waters, impairing their downstream use either for aquatic ecosystem, drinking, industrial or irrigation. Hence, physic-chemical, biological and microbiological characteristics at 23 sites within the basin were studied in November-2006 and January-2007. The assessment of the final WQ condition at sampled points was done taking into account the Mozambican guidelines for receiving waters and the environmental WQ standards for effluent discharges together with the WHO guidelines for drinking WQ. The assessed data indicated that sites located at proximities to the border with upstream countries were contaminated with heavy metals. The Elephants subcatchment was found with a relatively better WQ whereas the Changane subcatchment together with the effluent point discharges were found polluted as indicated by the low dissolved oxygen and high total dissolved solids, electric conductivity, total hardness, sodium adsorption ratio and low benthic macroinvertebrates taxa. Significant differences (p<0.05) were found for some parameters when the concentrations recorded in November and January were tested, therefore indicating possible need for monthly monitoring of WQ. From this study it was concluded that a systematic WQ monitoring network composed of 16 stations would fit the conditions of the LRB. Ambient, earl warning, operational and effluents are the main monitoring types recommended. Additional research at a Basin scale was * Corresponding author. Tel.: +258824449340; Fax: +288221492176 e-mail: mchilundo@uem.mz 2 also recommended to identify the major sources, transport and impacts to the downstream ecosystem.

The levels and distribution of trace metals (Cr, Mn, Co, Ni, Cu, Zn, Cd and Pb) at eleven water and sediment stations on the Little Akaki River (LAR) in Addis Ababa, Ethiopia, were determined. The binding forms of the metals in various geochemical fractions of the sediments were also quantified. The molar ratio of the sum of the simultaneously extractable metals (∑SEM) and acid-volatile sulphide (AVS)-as a measure for predicting metal-induced toxicity-was estimated. LAR trace levels in water for Cu, Zn, and, particularly Mn were, in most instances, higher than the recommended guidelines for healthy aquatic ecosystems. Total trace metal (TTM) contents in the LAR sediments at certain stations exceeded "threshold effect concentrations" and even "probable effect concentrations", especially in the cases of Zn, Cu, Ni, Pb, and at all stations for Mn. This became more apparent after applying "normalizations" to the relatively lower TTM adsorption capacities of coarse-grained, organic-poor sediments. Sequential extraction of the sediments showed that trace metals generally have a higher affinity for Fe-Mn oxide and organic matter/sulphidic fractions, followed by the residual fraction. Mn was relatively strongly bound to the exchangeable, carbonate bound fractions, whereas a large proportion of Cr was found in the residual fraction. The Σ[SEM]/[AVS] ratio pointed to potential metal-induced toxicity of sediments collected from seven out of the eleven stations. The results indicate that trace metal pollution pose risks to the health of ecosystems, and to human communities that use the river for a range of different purposes.