Effect of Irrigation Water Quality on the Microbial Contamination of Fresh Vegetables in the Bekaa Valley, Lebanon

Irrigation water is probably the leading source of contamination of fresh vegetables in the world. In agricultural intensive areas, surface and groundwater resources are more likely to be exposed to be contaminated with zoonotic bacteria, given their close proximity to sources of faeces from livestock, dairy farms and wildlife. The aim of this study was to determine the role of irrigation water as a vehicle for the transmission of zoonotic bacteria of faecal origin and its contribution to the bacterial contamination of fresh vegetables to conclude with a need of risk management in rural areas. First, to determine the magnitude and the frequency of faecal contamination and the pathogens in the water source, the microbiological quality of the water resources used in irrigation in the studied area, including the upper Litani and the private wells located near its basin was investigated. In a second step, an assessment of the microbiological quality of the fresh vegetables irrigated from these water resources was done. A total of twelve different vegetables comprising spinach, parsley, cabbage and lettuce and 38 water samples were collected from both the well waters and the Litani River from the 5 studied sites and analyzed for a period of 5 months, to assess the microbial contamination level. Samples were analyzed for aerobic bacteria, total coliforms, faecal coliforms, E.coli and S.aureus. All vegetables sampled during the study period recorded high level of coliforms, E.coli and S.aureus. The microbial load recorded in the water samples was generally higher than that recorded in the vegetables. Since most of these vegetables are eaten fresh or slightly cooked, there is a concern on the public health that will be affected. Education of farmers and consumers on food safety has to be intensified to avert a possible outbreak