Pesticide Residues in Fresh Fruit and Vegetables from Farm to Fork in the Kampala Metropolitan Area, Uganda

Abstract

This study assessed concentrations of pesticide residues in fruits and vegetables from farm-to-fork in Kampala Metropolitan Area, Uganda. A total of 160 samples of fruit and vegetables collected from farms, markets, streets, restaurants and homes were analysed using liquid chromatography–tandem mass spectrometry; and Gas Chromatograph–Mass Spectrometer for dithiocarbamates. Multiple pesticide residues were detected in majority of the samples (95.6%). The proportions of the most frequently detected pesticides residue classes were organophosphates (91.3%), carbamates (67.5%), pyrethroids (60.0%) dithiocarbamates (48.1%) and neonicotinoids (42.5%). Among organophosphates, propotamophos, acephate, fonofos, monocrotophos and dichlorvos were the most detected active ingredients; aminocarb, methomyl and pirimicarb were the commonly detected carbamates; while imidacloprid, a neonicotinoid and lambda-cyhalothrin, pyrethroid were also highly detected. Twenty-seven pesticide were tested at all stages, of which the concentrations either decreased or increased along the chain. Multiple pesticide residues occurred in commonly consumed fruit and vegetables with decreasing or increasing concentrations from farm-to-fork.

Consumer Awareness and Health Risk Perceptions of Pesticide Residues in Fruits and Vegetables in Kampala Metropolitan Area in Uganda

“…Consumers perceptions in our study also align well with laboratory studies carried out within the study area which found that fruits and vegetables contain pesticide residues. [20][21][22] Consumers also reported that fruits and vegetables contain multiple pesticides. This could be explained by the fact that farmers use cocktails of pesticides or application of different chemicals over different stages of development of the fruits and vegetables.…”

An assessment of health risks posed by consumption of pesticide residues in fruits and vegetables among residents in the Kampala Metropolitan Area in Uganda

“…Fruits and vegetables samples were collected from key stages along the supply chain including farms (50), markets (50), street vendors (20), restaurants (20) and homes (20), totaling 160 samples. The detailed methodology used to collect the fruits and vegetable samples has been previously described [33]. Brie y, fresh fruit and vegetable samples were purchased and collected in sterile polythene bags or PET (polyethylene terephthalate) plastic containers from selected farms, markets, and street vendors.…”

“…We ltered the crude extract using a 0.2-micron PTFE syringe lter. The nal supernatant layer (0.50 g /mL) was transferred into the vials and injected into the LC-MS/MS for analysis of pesticide residues [33].…”

“…The method developed by Keppel et al at the United States Food and Drug Administration (U.S. FDA) [32,33] was used to measure dithiocarbamates (mancozeb, maneb, dithane, thiram, metam sodium and propineb. Frozen sub-samples of 10g were placed into a Duran bottle (250ml) and mixed with isooctane (20ml) followed by stannous chloride (reducing solution) in hydrochloric acid (100ml), and sealed immediately with a septum and cap.…”

“…Fruit and vegetable consumption is a protective factor for noncommunicable diseases such as diabetes [30], and consumption is rising in among Ugandans, which consume an average 260 grams of fruits and vegetables each day [31]. Fruit and vegetable consumption has grown among residents of the Kampala Metropolitan Area (KMA) [32], and organophosphate, carbamate, pyrethroid and neonicotinoid pesticides have been previously detected in the tomatoes, watermelon, cabbages among others in this market [28,33,34].…”