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.

The objective of the study was to determine and compare the current level of exposure of the Ghanaian urban population to hazardous pesticide and fecal coliform contamination through the consumption of fresh vegetables produced in intensive urban and periurban smallholder agriculture with informal wastewater irrigation. A total of 180 vegetable samples (lettuce, cabbage, and spring onion) were randomly collected under normal purchase conditions from 9 major markets and 12 specialized selling points in 3 major Ghanaian cities: Accra, Kumasi and Tamale. The samples were analyzed for pesticide residue on lettuce leaves, total and fecal coliforms, and helminth egg counts on all three vegetables. Chlopyrifos (Dursban) was detected on 78% of the lettuce, lindane (Gamalin 20) on 31%, endosulfan (Thiodan) on 36%, lambda-cyhalothrin (Karate) on 11%, and dichloro-diphenyl-trichloroethane on 33%. Most of the residues recorded exceeded the maximum residue limit for consumption. Vegetables from all 3 cities were fecally contaminated and carried fecal coliform populations with geometric mean values ranging from 4.0 x 10(3) to 9.3 x 10(8) g(-1) wet weight and exceeded recommended standards. Lettuce, cabbage, and spring onion also carried an average of 1.1, 0.4, and 2.7 helminth eggs g(-1), respectively. The eggs were identified as those of Ascaris lumbricoides, Ancylostoma duodenale, Schistosoma heamatobium, and Trichuris trichiura. Because many vegetables are consumed fresh or only slightly cooked, the study shows that intensive vegetable production, common in Ghana and its neighboring countries, threatens public health from the microbiologic and pesticide dimensions. Standard recommendations to address this situation (better legislations, law enforcement, or integrated pest management) often do not match the capabilities of farmers and authorities. The most appropriate entry point for risk decrease that also addresses postharvest contamination is washing vegetables before food preparation at the household or "chop" bar (street restaurant).

A total of 208 samples of water, sediment, tomato crops, blood, and mothers' breast milk were collected from the environs of Akumadan, a prominent vegetable-farming community in Ghana. The samples were analyzed for organochlorine (OC) pesticide residues. Lindane and endosulfan were found in water and sediment, while other OC pesticide residues, such as hexachlorobenzene (HCB), p,p'-DDE, and heptachlor epoxide, were additionally found in sediment. Heptachlor epoxide was the only OC residue detected in appreciable quantity in crops. Significantly higher HCB and p,p'-DDE residues were found in blood and milk samples. The mean values of HCB and p,p'-DDE in blood were 30 microg/kg and 380 microg/kg, respectively. The mean values of HCB and p,p'-DDE in milk were 40 microg/kg fat (1.75 microg/kg whole milk) and 490 microg/kg fat (17.15 microg/kg whole milk), respectively. The presence of OC pesticide residues in breast milk requires further monitoring and epidemiological studies to clarify possible detrimental health effects in breast-fed infants.

The Volta River basin comprises ≈ 70% of mainland Ghana, being inhabited by a majority of the country's population. The purpose of this study was to analyse water and sediment samples at six locations in Volta Lake for residues of persistent organochlorine pesticides. Residues were extracted by use of two types of extractions, including a standardized solid phase extraction procedure for water samples and a Soxhlet extraction procedure for sediment samples. All samples were analysed by gas chromatography. Lindane and endosulfan were identified in concentrations ≤ 0.008 p.p.b. and 0.036 p.p.b., respectively, in water, and ≤ 2.3 p.p.b. and 0.36 p.p.b., respectively, in sediments. Dichlorodiphenyltrichloroethane and dichlorodiphenyldichloroethylene were also found in sediment samples (in concentrations ≤ 9.0 p.p.b. and 52.3 p.p.b., respectively). No significant contamination was noted in the lake. The distribution of pesticide residues in water and neighbouring sediment are briefly discussed. Different bioconcentration factors obtained in this study allowed the confirmation of the complex processes already reported in the literature regarding the partitioning of chemicals between sediment and water.

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