Chemical and microbiological safety of vegetables grown in the upper Litani basin

Abstract

The use of heavily polluted water for irrigation poses an important health hazard relating to the safety (chemical and microbiological) of grown crops. In Lebanon, the degradation in the Litani river water quality is of major concern to the agricultural production in the Bekaa region. Hence, the study objectives were to (a) identify the microbiological and chemical hazards in soils and main vegetables grown and irrigated with the Litani river water, (b) compare the levels of chemical and microbiological contaminants in irrigation water, soils and vegetables to determine the levels of contaminants and identify factors impacting the translocation and accumulation of these contaminants in grown products, (c) evaluate the magnitude of the health hazards by comparing levels of chemical and microbiological contaminants to national and international standards, and (d) determine the antibiotic resistance patterns of detected pathogenic bacteria for proper foodborne disease management. The study methodology consisted of collecting 48 composite samples of soils and vegetables (lettuce, parsley and potato) from three different experimental sites (Bar Elias, Dalhamieh and Zahle) and a control site. The microbiological and chemical quality of the vegetables and soil was determined and evaluated. Further, the antibiotic resistant pattern was determined for the four commonly prescribed antibiotics (Ciprofloxacin, Cefotaxime, Gentamicin, and Erythromycin). The results indicate that the irrigation with Litani River water is leading to the accumulation of microbiological (E. coli, E. cloacae, E. aerogenes, K. pneumonia, K. oxytoca, S. marcescens, C. freundii, Sh. sonnei, C. diversus, Listeria spp and P. aeruginosa) and chemical contaminants (barium, arsenic, lead, cadmium, chromium, zinc, iron, nickel, copper, manganese and Molybdenum) in vegetables (lettuce, parsley and potato) and soils. And, the levels in leafy vegetable are higher than in tubular crops (potato). Moreover, the results of the study showed that the exposure to