ABSTRACT

The current study aimed to determine the contamination level by human parasite eggs and cysts of sewage-irrigated soil, food crops and fodder crops. Field trials were conducted on spray-irrigated lettuce and flood-irrigated crops using raw wastewater and fresh water. Findings showed that irrigation by raw wastewater led to crops contamination with parasite eggs and cysts in varying levels. Lettuce samples were positive (27.7%) for one or more helminth eggs including the pathogens Ascaris and Trichuris with an average of 4.7 eggs/kg. Wastewater application caused an increase in lettuce contamination, followed by a decreasing phase. Cessation of irrigation resulted in helminth eggs disappearance within a week. Flood-irrigated crops were contaminated with helminth eggs in levels ranging from 1.5 eggs/kg in alfalfa to 4.75 eggs/kg in coriander. The pathogenic Giardia,Entamoeba histolytica/dispar and commensal amoeba cysts were highly detected reaching 9.97x10³ cysts/kg in alfalfa. Parasites highly concentrated in soil, with levels up to 159 eggs/100gdw and 1.3x10³ cysts/gdw. Ascaris and Trichuris eggs developed in soil and crops attaining the infective stage. Crops and soil irrigated with fresh water were free from parasite eggs and cysts. The occurrence of pathogens in soil and crops implies health risks for farmers, produce handlers and consumers.

摘要

目前的研究旨在确定人类寄生虫卵和污水灌溉土壤、粮食作物和饲料作物的孢囊的污染水平。使用未经处理的废水和淡水对喷灌生菜和洪水灌溉作物进行了田间试验。调查结果表明，原废水灌溉导致农作物受到不同程度的寄生虫卵和包囊污染。生菜样本中一个或多个蠕虫卵（包括病原体蛔虫和鞭虫）呈阳性（27.7%）平均4.7个鸡蛋/公斤。废水的应用导致莴苣污染增加，然后是减少阶段。停止灌溉导致蠕虫卵在一周内消失。洪水灌溉的作物受到蠕虫卵的污染，其水平从苜蓿中的 1.5 个卵/千克到香菜中的 4.75 个卵/千克不等。苜蓿中致病性贾第鞭毛虫、溶组织内阿米巴/dispar和共生阿米巴包囊的检出率很高，达到9.97x10 ³包囊/kg。寄生虫高度集中在土壤中，水平高达 159 个卵/100gdw 和 1.3x10 ³包囊/gdw。蛔虫和鞭毛虫卵在土壤和作物中发育，达到感染阶段。用淡水灌溉的作物和土壤没有寄生虫卵和孢囊。土壤和作物中病原体的出现意味着农民、农产品加工者和消费者的健康风险。