Amahmid O, Asmama S, Bouhoum K
Laboratory of Parasitology, Department of Biology, Faculty of Sciences Semlalia, Morocco.
Int J Food Microbiol. 1999 Aug 1;49(1-2):19-26. doi: 10.1016/s0168-1605(99)00058-6.
In Marrakech, raw sewage has been used for farming purposes for several decades for many types of crops. This study aimed to determine the contamination level of Giardia cysts and Ascaris eggs for crops designated for human consumption. Collected crops in irrigated fields were turnip, marrow, squash, potatoes, pepper and eggplant. Field trials were also carried out on four crops, coriander, carrots, mint and radish, using three water types for irrigation, i.e. raw waste water, treated waste water (sedimentation and 16 days retention) and fresh water. Giardia cysts were detected at a level of 5.1 cysts/kg in potatoes, while Ascaris eggs were observed in numbers varying between 0.18 eggs/kg in potatoes and 0.27 eggs/kg in turnip. Field trials confirmed that irrigation of crops by raw waste water leads to contamination. Giardia and Ascaris were isolated in coriander at concentrations of 254 cysts/kg and 2.7 eggs/kg, respectively; mint was also highly contaminated with numbers reaching 96 cysts/kg and 4.63 eggs/kg. Carrots and radish were contaminated and respective numbers observed for Giardia were 155 and 59.1 cysts/kg; Ascaris was discovered in numbers of 0.7 and 1.64 eggs/kg, respectively. However, cultures irrigated with treated waste water and fresh water were free from contamination. Cysts and eggs on coriander persisted for a maximum of 8 days.
在马拉喀什，几十年来未经处理的污水一直被用于多种农作物的灌溉。本研究旨在确定供人类食用的农作物中贾第虫囊肿和蛔虫卵的污染水平。在灌溉农田中采集的作物有芜菁、西葫芦、南瓜、土豆、辣椒和茄子。还对四种作物——香菜、胡萝卜、薄荷和萝卜进行了田间试验，使用了三种灌溉水，即未经处理的废水、处理后的废水（沉淀并留存16天）和淡水。在土豆中检测到贾第虫囊肿的含量为5.1个囊肿/千克，而观察到蛔虫卵的数量在土豆中为0.18个卵/千克至芜菁中为0.27个卵/千克之间变化。田间试验证实，用未经处理的废水灌溉作物会导致污染。在香菜中分离出的贾第虫和蛔虫浓度分别为254个囊肿/千克和2.7个卵/千克；薄荷也受到高度污染，数量分别达到96个囊肿/千克和4.63个卵/千克。胡萝卜和萝卜受到污染，观察到的贾第虫数量分别为155个囊肿/千克和59.1个囊肿/千克；发现蛔虫数量分别为0.7个卵/千克和1.64个卵/千克。然而，用处理后的废水和淡水灌溉的作物没有受到污染。香菜上的囊肿和虫卵最多能存活8天。
