An assessment of the public health hazard potential of wastewater use in salad crop production at umguza irrigation lots

Abstract

Farmers at Umguza Irrigation Lots practise unrestricted crop production using undertreated wastewater. This presents potential public health risk to producers, vendors and consumers of the produce. The aim of the study was to establish the level of public health risk of wastewater use in unrestricted crop production at Umguza Irrigation Lots. Water samples from the dam, canal and overnight reservoir and vegetables: Lactuca sativa, Brassica oleracea, and Solanum lycopersicum were obtained and analysed for physiochemical and microbial characteristics. The results of the study revealed that the farmers grew salad crops using wastewater. The mean pH, EC, DO of the water was 8.9, 866.9µS/cm and 607.6 ppm. The EC value was far less than the 2000µS/cmFAO guidelines. Escherichiacoli O157, Shigella, Salmonella and Staphylococcus aureus were isolated in the wastewater with a steady decrease in pathogen concentration as the rain season progressed. The same trend of decreasenwas also observed on vegetable samples. The level of contamination by pathogen was noted to be ranging from significantly low to nil, where drip irrigation system was used. Future research is recommended to determine the extent of contamination and conduct confirmatory test like Biochemical tests or Quantitative Real- Time Polymerase Chain Reaction.